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Transcript of Naturalness and the Standard Model | Of Particular Significance
Of Particular SignificanceConversations About Science with Theoretical Physicist Matt Strassler
Naturalness and the Standard Model
sler [August 27 – September 9, 2013]
ct is closely related to the hierarchy problem.]
article physicists and string theorists mean when they refer to a particular array of particles
as “natural”? They don’t mean “part of nature”. Everything in the universe is part of nature,
natural” has multiple meanings. The one that scientists are using in this context isn’t “having
nature” but rather “typical” or “or “generic” — “just what you’d have expected”, or “the usual”
aturally the baby started screaming when she bumped her head”, or “naturally it costs more
r the city center”, or “I hadn’t worn those glasses in months, so naturally they were dusty.”
tural is when the baby doesn’t scream, when the city center is cheap, and when the glasses are
sually, when something unnatural happens, there’s a good reason.
ntexts in particle physics and related subjects, surprises — big surprises, anyway — are pretty
means that if you look at a physical system, it usually behaves more or less along lines that,
experience as a scientist, you’d naturally expect. If it doesn’t, then (experience shows) there’s
really good reason… and if that reason isn’t obvious, the unnatural behavior of the system
inting you to something profound that you don’t yet know.
rposes here, the reason the notion of naturalness is so important is that there are two big
n nature that we particle physicists and our friends have to confront. The first is that the
[often referred to as “dark `energy’ ” in public settings] is amazingly small,
to what you’d naturally expect. The second is that the hierarchy between the strength of
the strengths of the other forces is amazingly big, compared to what you’d expect.
one can be restated as follows: the Standard Model (combined with Einstein’s theory of
the set of equations we use to predict the behavior of all the known elementary particles and
— is a profoundly, enormously, spectacularly unnatural theory. There’s only one
hysics — perhaps only one aspect in all of science — that is more unnatural than the Standard
that’s the cosmological constant.
n of “Natural” and “Unnatural”
concept of naturalness is best illuminated by a bit of story-telling.
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f friends of mine from college (I’ll call them Ann and Steve) got married, and now have two
ildren. Back when their kids were younger — say, 4 and 7 years old — they were pretty wild.
played rough, got mad at each other, threw things, and generally needed at lot of supervision.
nn bought some beautiful flowers and put them in her favorite glass vase. But before she put
the kitchen table, the doorbell rang. She ran to the front, carrying the vase, and as she made
the door, she absent-mindedly put the vase down on the small, rickety table that sits by the
ur later, Steve returned home with the kids, and sent them into the play room to occupy
s while he and Ann settled in from the day and prepared dinner. They heard the usual sounds:
crashes, the sounds of bouncing balls and falling blocks, yells of “no fair” and “ow! stop
oment of screaming that blissfully stopped almost as soon as it started…
y-five minutes later when Ann noticed the vase with the flowers wasn’t on the kitchen table.
ment searching the kitchen and dining room, she suddenly realized that she’d put it down and
t in the most dangerous place in the house.
t running into the play room, hoping she wasn’t too late. And what do you think she found
get three options (Figure 1). Choose the most plausible.
ase was exactly where she’d left it, comfortably placed at the center of the table.
ase was smashed, and the flowers crushed, down on the floor.
ase was hanging off the table, right at the edge, within a millimeter of disaster.
: After nearly an hour with the kids playing nearby, where is the vase? On the table?
ashed on the floor? Or right at the edge? We’d all believe the first two before we’d
believe the third — unless the third was carefully arranged.
nswer is #3. There it was, just hanging there.
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Fig. 2: Imagine a lot of different possible
universes, each one described by equations
similar to our own universe, but with small
adjustments.
I suspect you don’t believe me. Or at least, if you do believe me, you probably are assuming
be some complicated explanation that I’m about to give you as to how this happened. It can’t
that two young kids were playing wildly in the room and somehow managed to get the vase
tremely precarious position just by accident, can it? For the vase to end up just so — not
he table, not falling off the table, but just in between — that’s … that’s not natural!
t (mustn’t there?) be an explanation.
re was glue on the side of the table and the vase stuck to it before falling off? Maybe one of the
iding behind the table and holding the vase there as a practical joke on his mom? Maybe her
ad somehow tied a string around the vase and attached it to the table, or to the ceiling, so that
uldn’t fall off? Maybe the table and vase are both magnetized somehow…?
so unnatural as that can’t just end up that way on its own… especially not in a room with two
dren playing rough and throwing things around.
tural Nature of the Standard Model
let’s turn to the Standard Model, combined with Einstein’s theory of gravity.
to imagine a universe much like our
ibed by a complete set of equations —
in theoretical-physics speak — much
ndard Model (plus gravity). To keep
ple, let’s say this universe even has all
lementary particles and forces as our
nly difference is that the strengths of
and the strengths with which the
interacts with other known particles
determines how
s the known particles have) are a little
t, say by 1%, or 5%, or maybe even up
fact, let’s imagine ALL such
all universes described by Standard
equations in which the strengths with
he fields and particles interact with
are changed by up to 50%. What will
described by these slightly different
(shown in a nice big pile in Figure 2)
se imaginary worlds, we will find three general classes, with the following properties.
e class, the Higgs field’s average value will be zero; in other words, the Higgs field is OFF. In
worlds, the Higgs particle will have a mass as much as ten thousand trillion
00,000,000,000,000) times larger than it does in our world. All the other known elementary
cles will be massless (up to small caveats I’ll explain elsewhere). In particular, the electron will
assless, and there will be no atoms in these worlds.
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ig. 3: The universes in Figure 2, whose equations differ just slightly from those that
second class, the Higgs field is FULL ON. The Higgs field’s average value, and the Higgs
cle’s mass, and the mass of all known particles, will be as much as ten thousand trillion
00,000,000,000,000) times larger than they are in our universe. In such a world, there will
be nothing like the atoms or the large objects we’re used to. For instance, nothing large like a
or planet can form without collapsing and forming a black hole.
third class, the Higgs field is JUST BARELY ON. It’s average value is roughly as small as in
orld — maybe a few times larger or smaller, but comparable. The masses of the known
cles, while somewhat different from what they are in our world, at least won’t be wildly
rent. And none of the types of particles that have mass in our own world will be massless. In
of those worlds there can even be atoms and planets and other types of structure. In others,
may be exotic things we’re not used to. But at least a few basic features of such worlds will be
fraction of these worlds are in class 3? Among all the Standard Model-like theories that we’re
g, what fraction will resemble ours at least a little bit?
r? A ridiculously, absurdly tiny fraction of them (Figure 3). If you chose a universe at random
g our set of Standard Model-like worlds, the chance that it would look vaguely like our
ould be spectacularly smaller than the chance that you would put a vase down carelessly on a
nd up putting it right on the edge of disaster, just by accident.
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govern our own, may be divided into three classes. Of these, the first two are very
mmon — natural — but the third class is, relative to the other two, extremely sparsely
ulated. Surprisingly, our own universe — if the Standard Model actually describes all
of its particle physics — is found among this tiny set of unnatural universes.
(and it’s a big “if”) the Standard Model (plus gravity) describes everything that exists
ld, then among all possible worlds, we live in an extraordinarily unusual one — one that is as
as a vase nudged to within an atom’s breadth of falling off the table. Classes 1 and 2 of
are natural — generic — typical; most Standard Model-like theories would give universes in
e classes. Class 3, of which our universe is an example, includes the possible worlds that are
non-generic, non-typical, unnatural. That we should live in such an unusual universe —
since we live, quite naturally, on a rather ordinary planet orbiting a rather ordinary star in a
inary galaxy — is unexpected, shocking, bizarre. And it is deserving, just like the weirdly
e, of an explanation. One certainly has to suspect there might be a subtle mechanism,
about the universe that we don’t yet know, that permits our universe to naturally be one that
is the analogy to the playing children who endanger the vase, and make its balanced condition
implausible? It is quantum mechanics itself — the very basic operating principles of our world.
effects do not coexist well with accidental, unstable balance.
o discuss those quantum effects, and how they make the Standard Model unnatural, in a
But first, although I hope you liked my story, I should point out there’s one important
between the vase on the table and the universe. If somebody bumps the table or the vase, it
ly fall off, or perhaps, if we’re lucky, slide toward the center of the table. In other words, it can
e away from its precarious position if it is disturbed. Our universe, by contrast, is not in
of smoothly shifting its properties, and becoming a universe in Class 1 or Class 2.
s possible that someday it could shift suddenly to become a very different universe, through
nown as tunneling or vacuum decay, this event is likely to be unimaginably far off; this is a
another day, but it’s not something to worry about.] The real issue for the universe is in the
among the vast number of possible universes, did we end up in such an apparently unnatural
re something about our universe that we don’t yet know which makes it not as unnatural as it
perhaps the fact that many (most?) natural universes don’t seem hospitable for life has
to do with it? Or maybe we humans haven’t been clever enough yet, and there some other
ntific explanation? Whatever the reason, either it is due to a timeless fact or due to something
ned very long ago; the universe (or at least the large region we can see with our eyes and
) has been unchangingly unnatural [if the Standard Model fully describes it] for billions of
won’t be changing anytime in the near future.
e, let’s move on now, to understand the quantum physics that makes a universe described by
rd Model (and gravity) so incredibly unusual.
Physics and (un)Naturalness
please read about quantum fluctuations of quantum fields, and the energy carried in those
if you haven’t already done so. Along the way you’ll find out a little about another
s problem: the cosmological constant. After you’ve read that article, you can continue with
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he Higgs (and Other Similar Particles)
fluctuations of fields, and their contribution to the energy density of empty space (the
vacuum energy”) play a big part in our story. But our goal here requires we set the
cal constant problem aside, and focus on the Higgs particle and on why the Standard Model is
This is not because the cosmological constant problem isn’t important, and not because we’re
ain the two problems are completely unrelated. But since the cosmological constant has
to do with gravity, while the problem of the Higgs particle and the naturalness of the
odel doesn’t have anything to do with gravity directly, it’s quite possible they’re solved in
ays. And each of the two problems is enormous on its own; if in fact we need to solve them
usly, then the situation just gets worse. So let’s just send the cosmological constant to a far
ake a little nap. We do need to remember that it’s the elephant in the room that we can’t
t the Higgs field. There are three really important questions about the Higgs field and particle
nt to answer. [I’ll phrase all these questions assuming the Standard Model is right, or close to
f it isn’t, don’t worry: the ideas I’ll explore remain essentially the same, even though slightly
iggs field is “ON” — its average value, everywhere and at all times, at least since the very
Why is it on?
GeV. What sets its value?
iggs particle has a mass of about 125 GeV/c!. What sets this mass?
o explain to you how and why these questions are related to the issue of how the energy of
ce (part of which comes from quantum fluctuations of fields) depends on the Higgs field’s
s Field’s Value and the Energy of Empty Space
ld — not just the Higgs field — how is it determined what the average value of the field is in
se? Answer: a field’s average value must have the following property: if you change the value
it, larger or smaller, then the energy in empty space must increase. In short, the field must
e for which the energy of empty space is at a minimum — not necessarily the minimum, but
(If there is more than one minimum, than which one is selected may depend on the
the universe, or on other more subtle considerations I won’t go into now.)
f illustrative examples of how the energy of empty space in our universe, or in some imaginary
ight depend on the Higgs field, or on some other similar field, are shown in Figure 4. In each
cases I’ve drawn, there happen to be two minima where the Higgs field could sit — but that’s
e. In other cases there could be several minima, or just one. The fact that the Higgs field is
world implies there’s a minimum in the universe’s vacuum energy when the Higgs field has a
6 GeV. While it’s not obvious from what’s I’ve said so far, we are confident, from what we
t nature and about our equations, that there is no minimum when the Higgs field is zero, and
our universe’s Higgs field isn’t OFF. So in our universe, the dependence of the vacuum energy
gs field probably looks more like the left-hand figure than the right-hand one, but, as we’ll see,
look much like either of them. If the Standard Model describes physics at energies much
at distances much shorter than the ones we’re studying now at the Large Hadron Collider
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ig. 4: How the energy density of empty space might depend on a Higgs-like field’s
rage value, in two different possible universes. The Higgs field’s average value must
t a minimum — not necessarily the lowest minimum — of the energy of empty space.
ere is more than one minimum, the one the Higgs field `chooses’ may depend on the
tory of the universe. The Higgs field may be ON (left) or OFF (right); but it can only be
F if the energy has a minimum when the field’s value is zero (as in the right-hand plot).
he mass of the Higgs particle is determined by how sharply curved the minimum is
ere the field’s value lies — if the energy rises slowly away from the minimum (left) the
s particle will have a small mass, while if it rises more rapidly away from the minimum
(right) the Higgs particle will have a larger mass.
n the form of the corresponding curve is much more peculiar — as we’ll see later.
s Particle’s Mass and the Energy of Empty Space
t the Higgs particle’s mass? It is determined (Figure 4) by how quickly the energy of empty
ges as you vary the Higgs field’s value away from where it prefers to be. Why?
rticle is a little ripple in the Higgs field — i.e., as a Higgs particle passes by, the Higgs field has
a little bit, becoming in turn a bit larger and smaller. Well, since we know the Higgs field’s
lue sits at a minimum of the energy of empty space, any small change in that value slightly
hat overall energy a little bit. This extra bit of energy is [actually half of] what gives the Higgs
mass-energy (i.e., it’s E=mc! energy.) If the shape of the curve is very flat near the minimum
4), the energy required to make a Higgs particle is rather small, because the extra energy in
g Higgs field (i.e., in the Higgs particle) is small. But if the shape of the curve is very sharp
inimum, then the Higgs particle has a big mass.
he flatness or sharpness in the curve in the plot, at the point where the Higgs field’s value is
he “curvature at the minimum” — that determines the Higgs particle’s mass.
n’t Easy to Have The Higgs Particle’s Mass Be Small
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is measured to be about 125-126 GeV/c!, about 134 times the proton‘s mass.
an’t we just put that mass into our equations, and be done with this question about where it
m is that the Higgs field’s value, and the Higgs particle’s mass, aren’t things you put directly
quations that we use; instead, you extract them, by a complex calculation, from the equations
d here we run into some difficulty…
se two quantities — the average value and the mass of the field and particle — by looking at
ergy of empty space depends on the Higgs field. And that energy, as in any quantum field
the Standard Model, is a sum of many different things:
gy from the fluctuations of the Higgs field itself
gy from the fluctuations of the top quark field
gy from the fluctuations of the W field
gy from the fluctuations of the Z field
gy from the fluctuations of the bottom quark field
gy from the fluctuations of the tau lepton field
for all the fields of nature that interact directly with the Higgs field… I’ve indicated these —
ally! these are not the actual energies — as blue curves in Figure 5. Each plot indicates one
n to the energy of empty space, and how it varies as the Higgs field’s average value changes
to the maximum value that I dare consider, which I’ve called v .
e of you may have read that these calculations of the energy of empty space give infinite
is is true and yet irrelevant; it is a technicality, true only if you assume v is infinitely
hich it patently is not. I have found that many people, non-scientists and scientists alike,
anks to books by non-experts and by the previous generations of experts — even Feynman
hat these infinities are important and relevant to the discussion of naturalness. This is false.
n to this widespread misunderstanding, which involves mistaking mathematical
ies for physically important effects, at the end of this section.]
? It’s as far as one could can push up the Higgs field’s value and still believe our calculations
Standard Model. What I mean by v is that if the Higgs field’s value were larger than this
uld make the top quark’s mass larger than about v /c ) then the Standard Model would no
urately describe everything that happens in particle physics. In other words, v is the
between where the Standard Model is applicable and where it isn’t.
is… and that ignorance is going to play a role in the discussion. From
appears to be something like 500 GeV or larger. However, for all we
could be as much as 10,000,000,000,000,000 times larger than that. We can’t go beyond
because that’s the (maximum possible) scale at which gravity becomes important; if v
arge, top quarks would be so heavy they’d be tiny black holes! and we know that the Standard
’t describe that kind of phenomenon. A quantum mechanics version of gravity has to be
that point… if not before!
is somewhere between 500 GeV and 1,000,000,000,000,000,000
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Fig. 5: Summing up the energy from the quantum fluctuations of known fields
schematically shown, upper row) up to the maximum energy scale v (down to the
inimum distance scale) where the Standard Model still applies, and adding to this
contributions from unknown effects from still higher energies and shorter distances
chematically shown, middle row), we must somehow find what experiment tells us is
: that the Higgs field’s average value is 246 GeV and the Higgs particle’s mass is 125
is much larger than 500 GeV, this requires a very precise cancellation
between the known and unknown sources of energy, one that is highly atypical of
quantum theories.
In Figure 5, I’ve assumed it’s quite a bit bigger than 500 GeV; we’ll look in Figure 6 at the case
f the contributions in the upper row of Figure 5 is something we can (in principle, and to a
t in practice) calculate, for any Higgs field value between zero and v , and for all quantum
s with energy less than about v . [I’m oversimplifying somewhat here; really this energy
not be quite the same as v , but let’s not get more complicated than necessary.] If v is
ach one of these contributions is really big — and more importantly, the variation as we
Higgs field’s value from zero to v is big too — something like v /(hc) … where h is
uantum constant and c is the universal speed limit, often called “the speed of light”.
not all. To this we have to add other contributions, shown in the second row of Figure 5, which
physical phenomena that we don’t yet know anything or much about, physics that does not
pear in the Standard Model at all. [Technically, we absorb these effects from unknown
to parameters that define the Standard Model’s equations, as inputs to those equations; but
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puts, rather than something we calculate, precisely because they’re from unknown
In addition to effects from quantum fluctuations of known fields with even higher energies,
uantum mechanics of gravity,
y particles we’ve not yet discovered,
s that are only important at distances far shorter than we can currently measure,
r more exotic contributions from, say, strings or D-branes in string theory or some other
ich may depend, directly or indirectly, on the Higgs field’s value. I’ve drawn these unknown
ed; note that these curves are pure guesswork. We don’t know anything about these effects
exist (and the gravity effects definitely exist), and that some or all of them could
… as big as or bigger than the ones we know about in the upper row. In principle, all these
be zero — but that wouldn’t resolve the naturalness problem, as we’ll see, so
there’s no obvious reason to expect these unknown effects in red
y way connected with the known contributions in blue. After all, why should
ravity effects, or some new force that has nothing to do with the weak nuclear force, have
o do with the energy density of quantum fluctuations of the top quark field or of the W field?
like conceptually separate sources of the energy density of empty space.
the puzzle. When we add up all of these contributions to the energy of empty space [Unsure
d curves like these together? Click here for an explanation…] — each of which is big and many
ary a lot as the Higgs field’s value changes from zero to the maximum that we can consider —
incredibly flat curve, the one shown in green. It’s almost perfectly flat near the vertical
not quite at zero Higgs field; it’s slightly away from zero, at a Higgs field
All of those different contributions in blue and red, which curve up and down in
grees, have almost (but not quite) perfectly canceled each other when added together. It’s as
piled a few mountains from Montana into a deep valley in California and ended up with a
How did that happen?
bad is this problem? How surprising is this cancellation? The answer is that it depends on
is only 500 GeV, then there’s no real cancellation needed at all — see Figure 6. But if v is
ancellation is incredibly precise, as in Figure 5. The larger is v , the more remarkable it is
contributions cancelled.
rkable? The cancellation has to be perfect to something like one part in (v /500 GeV) , give
is close to 500 GeV, that’s no big deal; but if v = 5000 GeV, we need a
n to one part in 100. If it’s 500,000 GeV, we need cancellation to one part in a million.
as high as possible — if the Standard Model describes all non-gravitational particle
we need cancellation of all these different effects to one part in about
0,000,000,000,000,000,000,000,000.
case, the incredible delicacy of the cancellation is particularly disturbing. It means that if you
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is not much much larger than 246 GeV, then no special cancellation is really
uired; the sum of the blue and red curves could easily look something like the green
is much larger do we get the surprising effect seen in Figure 5, where,
mpared to the scale at which the blue and red curves wiggle, the green curve is very
flat.
the W particle’s mass, or the strength of the electromagnetic force, by a tiny amount — say,
a million million — the cancellation would completely fail, and you’d find the theory would
1 or Class 2, with a ultra-heavy Higgs particle and either a large or absent Higgs field value
3). This incredible sensitivity means that the properties of our world have to be, very
— like a radio that is set exactly to the frequency of a desired radio station, finely
ch extreme “fine-tuning” of the properties of a physical system has no precedent in science.
another way: what’s unnatural about the Standard Model — specifically, about the Standard
g valid up to the scale v , if v is much larger than 500 GeV or so — is the cancellation
igure 5. It’s not generic or typical… and the larger is v , the more unnatural it is. If you take
generic curves like those in Figure 5, each of which has minima and maxima at Higgs field
t are either at zero or somewhere around v , and you add those curves together, you will find
m of those curves is a curve that also has its minima and maxima at
[Class 2 theories — see Figure 3],
theories],
ot somewhere non-zero that is much much smaller than v [Class 3 theories].
if the curves are substantially curved near their minima and maxima, their sum will also
ave substantial curvature near their minima and maxima [i.e. the Higgs particle’s mass will be
, as in Class 1 and Class 2 theories], and won’t be extremely flat near any of its minimum
r the Higgs particle to be much lighter than v /c , as occurs in Class 3 theories.] This is
for the addition of just two curves, in Figure 7, where we see the two curves have to have a
l relationship if their sum is to end up very flat.
naturalness problem. It’s not just that the green curve in Figure 5 is remarkably flat, with a
at a small Higgs field value. It’s that this curve is an output, a sum of many large and
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Fig. 7: (Top) If you add together two generic curves, the result will be a
curve that is also generic. (Bottom) Only if the two curves have equal
and opposite curvature in the region near the blue arrows will the
result of adding them together be nearly flat. While this could happen
by pure accident, it is perhaps more likely that there was a hidden
relation between the two curves which assured they were nearly equal
and opposite.
ities seem to be somehow swept under the rug, leading to finite predictions. These infinities,
emoval via renormalization, sometimes lead people — even scientists — to claim that particle
don’t know what they are doing, and that this causes them to see a naturalness problem where
s are badly misguided. These technical issues (which are well understood nowadays, in any
ompletely irrelevant in the present context.
ies that arise in certain calculations of the Higgs particle’s mass, and of the Higgs field’s value,
of the naturalness problem, a mathematical symptom that shows up if you insist on
to infinity, which, though often convenient, is an unphysical thing to do. The infinities are
aturalness problem, nor are they at its heart, nor are they its cause.
any ways to see this, one very easy way is to study the wide variety of finite quantum field
discovered in the 1980s (a list of references can be found in an old paper of mine with Rob
w a professor at the University of Illinois].) These theories have minimal amounts of
, as well as being finite. If you take such a theory (see Figure 8), and you ruin the
, while assuring the theory that remains at lower energies still has
fields like the Higgs field, you do not introduce any infinities. Moreover, there is no need
ially cut the theory off at energies below v (as I have done in Figure 5, separating known
nown) since in this example we know the equations to use at energies above as well as
. The energy of empty space, and its dependence on the various fields, can be calculated
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8: Infinities have nothing to do with naturalness.
amples of finite theories abound; if they have
symmetry, there is no naturalness problem, but if
ymmetry is only applicable above an energy scale
, then the naturalness problem immediately
pears, and no spin-zero Higgs-like particles are
ically found with mass-energy (i.e. E=mc energy)
far below E .
without any ambiguity, infinities, or
infinite renormalization. So — is
there a naturalness problem here
too? Do the spin-zero particles
generically get masses as big as
v /c ? Do the spin-zero fields have
values that are either zero or roughly
as big as v ? You Bet! No
infinities, no sweeping anything
under a rug, no artificial-looking
cutoffs — and a naturalness problem
that’s just as bad as ever.
By the way, there’s an interesting
loophole to this argument, using a
lesson learned from string theory
about quantum field theory. But
though it gives examples of theories
that evade the naturalness problem,
neither I nor anyone else was able (so
far) to use it to really solve the
naturalness problem of the
Standard Model in a concrete way.
Perhaps the best attempt was this
lso repeat this type of calculation within string theory (a technical exercise, which does not
assume string theory really describes nature). String theory calculations have no infinities.
, the energy scale where the Standard Model fails to work, is much larger than 500 GeV, the
s problem is just as bad as before.
etting rid of the infinities that arise in certain Higgs-related calculations does NOT by itself
fect the naturalness problem.
to the Naturalness Problem
logical grounds, a couple of qualitatively different types of solutions to this problem come to
123 Google
2
max
max2
max
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NATURALNESS AND THE STANDARD MODEL”
First Stab at Explaining “Naturalness” | Of Particular Significance
August 27, 2013 at 9:23 AM | Reply
le Matt. More please…
ugust 27, 2013 at 9:34 AM | Reply
xplanation. Is there a calculation as to exactly how unnatural our universe is or do
know that it is a small probability and the exact number is dependent on the
f various theoretical frameworks one may use? I want to know whether the
is something on the order of one in one to the googol or something even much
August 27, 2013 at 9:48 AM | Reply
do a precise (or rough) calculation if you make definite (or rough) assumptions.
l problem is that you don’t know the probability “measure”. One way to say this is
roll two dice and I *assume* they are fair dice, then I can calculate the probability
ice showing 9 dots. But if I don’t *know* they are fair dice, I can’t calculate it. If I
ey are roughly fair, I can roughly calculate.
n the situation of having at best an extremely rough guess at the probabilities, so
, at best, an extremely rough estimate. But when you’re dealing with numbers that
small, getting them wrong by a huge amount doesn’t change the qualitative
ion: our universe, no matter how you calculate it, is very unusual, on the face of it.
August 28, 2013 at 10:22 PM | Reply
ught the idea of random physical constants was still speculative. The basic theory,
nderstand it, is that we began as a fluctuation within a multiverse from which
y other universes may also have been born; is that right? But what if our universe
s out to be — as most physicists seemed to believe when I was at Berkeley — the
one? In that case, maybe you will have to wait for more experimental data, or
e mathematical revolution, before you can say anything definite about the values of
ugust 27, 2013 at 9:41 AM | Reply
: sorry meant to write is the probability one in a googol, not one in one to the
August 27, 2013 at 10:30 AM | Reply
ve values for the fractions?
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a hard time estimating the number of balls in the other two figures
August 27, 2013 at 12:00 PM | Reply
remark by the mathematician below, and my (upcoming) reply. We cannot
te the fraction without defining a probability measure. Nevertheless, when you are
with numbers this gigantic, you can see you have a serious problem even if you
ow if the problem is one in a million trillion or one in a trillion trillion or one in a
trillion trillion. The point is that it’s certainly not one in a thousand.
st 27, 2013 at 10:47 AM | Reply
e that this is heading in the same direction as the anthropic principle. Do you
wo ideas, ie anthropic P and Naturalness, are the same, linked, or totally different.
August 27, 2013 at 11:58 AM | Reply
important, before you start talking about solutions to a problem, to make sure
erstand the problem. I cannot answer your question without having gone further
rticle; please be patient.
ugust 27, 2013 at 11:16 AM | Reply
matician (not a physicist) I find this argument rather unconvincing. It depends
tally on the existence of some meaningful measure on the parameter space which is
removed from the scale in which we choose to express the model. After all, if you
nough times, any numbers become the same order of magnitude. Are we certain
ole problem isn’t just caused by a misrepresentation of the parameters? It’s not as
xamine the parameter space experimentally.
there is something important to explain, but the same is true for all the other
s of the model: why do they take precisely the values we measure in experiments?
e is a deeper theory which explains them all (presumably including the very large
e are part of a multiverse, and anthropics explains away anything.
ole problem be reduced to “big numbers are more important than small ones”?
August 27, 2013 at 12:11 PM | Reply
ument is NOT entirely convincing. But it is a strong argument nevertheless,
the numbers involved are so huge — typically something like 10^{-32} or so —
’d have to have a hugely convoluted measure on the parameter space to make it
short: if it is a problem of “a misrepresentation of the parameters”, then it’s a huge
whose solution will likely earn someone a professorship at a major university,
bably a Nobel Prize if it can be shown to be true experimentally. Certainly no one
r proposed a re-representation of the parameters which, without adding new
s accessible at scales fairly close to the Higgs particle’s mass, would bring us even
solving the problem. It’s easy to say it’s just a problem of the measure — but give
example where this would solve a naturalness problem in quantum field
and I’ll be extremely impressed.
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akes the argument much more convincing is that there are solids and fluids to
imilar arguments apply. The equations are of the same type (Quantum Field
) and there are higgs-like scalars (which are massless at phase transitions.) If you
andom solid or fluid system away from a phase transition, and ask if it has scalar
s that are vastly lighter than other massive degrees of freedom in the system, the
is “no”, unless they are Nambu-Goldstone bosons (which the Higgs in the
rd Model is not). The same is true for the few examples in particle physics. The
rd Model (if indeed it is the complete theory of nature) is unique in this regard. I’ll
this more later in the article, I think.
se a selection bias (i.e. anthropic principle or something similar) is one possible
tion… but an incomplete one within the Standard Model, because appealing to a
n bias ***also*** requires you to know a probability measure within the
rse… perhaps the dynamics which causes one set of parameters to be realized more
an another… so it doesn’t resolve the problem you mentioned for the naturalness
our last question (if I understand it correctly) — this kind of thing is under active
ion, of course. The answer may be yes. How will we verify this, however? That is
stion that has to be addressed… otherwise, it will remain speculation.
August 27, 2013 at 12:43 PM | Reply
nks! To expand on my last question, my training is in logic, and to me, any number
ept perhaps 0, 1, e & pi) begs for an explanation. I’m uncomfortable with the idea
small numbers might just be facts of life, but large numbers can’t be. Information
ent is not dependent on magnitude.
August 27, 2013 at 9:27 PM | Reply
ut logic and math is different from physics. For example, you may be 1.24534
imes taller than your wife. Does that require explanation? No. Why not? Because
his ratio is determined by a combination of a dynamical equation, on the one
initial conditions which are not given by pure numbers, on the other.
n general, in physics, dynamical equations (i.e. equations that describe how things
hange) assure that most pure numbers that we measure are of the order that we
ould (with experience) guess, up to factors between, say, 0.1 and 10. Sometimes
ou’ll see something as small as 0.01 and 100, just by accident, or even a bit greater.
o I would claim you’re profoundly misled by thinking about physics as similar to
gic or number theory. It’s not… it’s dynamical evolution, and most results of
hysics problems are not nice numbers like 1 or pi or even e^pi.
he notion that extremely large (and extremely small) numbers require explanation
as a history going back nearly a century and has been extremely profitable for
cientists. No explanation is needed for numbers like 3.2435 or 0.543662 — it’s not
matter of “information content”, it’s a matter of whether the dynamical equations
e know are likely or not to spit out such a number.
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August 28, 2013 at 6:41 AM |
OK, but doesn’t that mean you’re assuming that there is some kind of dynamics
in the parameter space? That it is governed by laws of the same character as the
laws of physics, even though we can never test those laws in any way?
August 28, 2013 at 9:07 AM |
Going back to your vase/table analogy, aren’t you also assuming that we are at a
stable point in the dynamics of parameter space? I.e. that the vase isn’t still
falling (with respect to parameter space dynamics)?
This would make sense if you assume that the dynamic parameter is our own
familiar time, and all this happened before we could measure any of the
parameters of the model, but given the local nature of time in GR, this seems
quite a strong assumption.
August 28, 2013 at 10:39 PM |
That point — about dynamical equations — helps me understand better what you
August 29, 2013 at 7:31 PM | Reply
hen the number represents the odds against an event that has demonstrably
ccurred, then of course bigger numbers demand more of an explanation than small
nes. If you disagree, I’d be interested in hearing your reasoning why over a game of
100 minimum-bet craps. I’ll bring the dice. ;)
August 30, 2013 at 8:42 AM |
This is precisely my point: when you play dice, you know that, however biased
the dice may be, there is still some probability measure governing their fall. Even
if you don’t know what the odds are, you still know that the dice behave
randomly, so you can use both your experience of games and statistical theory to
reason about what’s happening, and to judge when the game is fixed.
When you consider the basic parameters of your model of physics, you don’t
have that. If Einstein was right, and time is part of the universe, then the
question “When were the parameters determined?” doesn’t make sense, because
there wasn’t any such “when”. Even the question “How were the parameters
determined?” assumes that there is some mechanism that operates beyond our
physics to determine them. Saying that large numbers require more explanation
than small ones is making assumptions about this mechanism.
I simply want to know what the assumptions behind the naturality argument are.
I don’t think it follows from just assuming that GR + SM is all there is.
Torbjörn Larsson, OM | September 1, 2013 at 5:11 PM |
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If physics is dynamic, the parameters can be determined anytime. As I
understand it, in some models the particles “freeze out” as the temperature of
the universe dropped. And that could happen differently in different places. (So
called landscapes of, say, string theory with many possibilities for physics.)
September 3, 2013 at 7:03 PM |
It’s actually about whether or not you need any such parameter-forcing
mechanism exists at all. GR+SM allow the parameters to be anything, with no
preferences. The values are arbitrary.
If the numbers were small, as in the ratio of the size of the total parameter space
to the subset that created a recognizable (i.e. has atoms in it) universe was
reasonable, then you could continue to say that the values are arbitrary, i.e. no
mechanism behind them needed, the Null Hypothesis, Occam’s Razor, and
getting a universe like ours is still no surprise.
When the numbers are this ridiculously huge, then you do need some
mechanism to explain how the parameters ended up this way. You either have to
figure out some “mechanism that operates beyond our physics” to force these
parameters to end up in this particular state, or you have to rely on the
Anthropic Principle to beat the long odds.
So the assumption is to *not* assume a bias in the parameter space, *not* to
assume some meta-physics mechanism for forcing parameters or merely biasing
them. That’s why it follows from assuming GR+SM is all there is. But then we
run into the problem which suggests that can’t be true.
September 4, 2013 at 12:15 PM |
I realized might be saying “Well you’re assuming a uniform distribution, and
why’s that assumption any better than any else”, so I wanted to make the point
more clear: The less fine-tuned the parameters need to be, the less need there is
to make any assumption at all. As in: Pick whatever distribution or rule for the
parameters you want. Does it result in a universe vaguely like ours? With the big
numbers we have, you need a very finely specified rule to get the parameters we
have and figuring out which one would be a big problem. With small numbers,
just about any rule would work, so you ultimately don’t need to assume any rule
Torbjörn Larsson, OM | September 1, 2013 at 5:06 PM | Reply
appealing to a selection bias ***also*** requires you to know a probability
measure within the multiverse…
n’t understand this point. Is the claim that despite Weinberg was able to predict
alue of today’s vacuum energy (cosmological constant) it isn’t relevant to selection
? And why would a full measure (as I assume the text is describing) be necessary?
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rect comparison would be biology and its selection bias. The full fitness space is
r known, nor its underlying mapping to physics. To look for ecological niches in
oastal zone you don’t need to know the exact waves, the exact dynamics of waves,
e exact probability distribution function of waves. You need to know the extremes
the optimum of the “niche construction”, what the population deems fit and
uld have assumed a gaussian centered on the average between the habitable limits
nnatural parameters (cc, Higgs mass-squared parameter), a gaussian because of
ribution of many other factors in the SM, would be the expected and needed
ability measure for selection bias. Why wouldn’t that work?
claimer: astrobiological interest, hence cosmological interest.]
rbjörn Larsson, OM | September 1, 2013 at 4:46 PM | Reply
think we can claim that we can’t examine the parameter space of universes
entally. People have suggested that in some cases of multiverses we could observe
collision “trace fossils”. So there are experimental constraints on this parameter
hether the answer would be positive or negative.
| Reply
derstanding that one of the assumptions that goes into predicting classes 1 &2
h more probable than class 3, is that there is no new physics between the Higgs
lanck scale. If this is correct it seems like a non-conservatively radical assumption.
August 27, 2013 at 11:56 AM | Reply
se it is. I made very clear what my assumption was: that there is the Standard
lus gravity, and nothing else. The whole point is that the unnaturalness of the
gives us reasons to think the assumption is wrong. But we have a long way to go
e understand the crucial subtleties.
August 27, 2013 at 11:52 AM | Reply
, unless someone finds reason for unnaturalness (extremely small probability
are stuck with anthropic argument. I am not an atheist. So I do not mind!!! But
le are shocked by this and try to get out of this by multiverse argument. Question:
r opinion on idea of multiverse which has practically zero chance of verification?
August 27, 2013 at 12:15 PM | Reply
-anthropic-principle arguments (which are statistical and do not
any discussion about where the universe [or if you prefer, “multiverse”] came
ith arguments abut the existence of a non-scientific (for example, divine) origin of
verse. There’s no conflict between atheism and the weak anthropic principle. Only
form of the anthropic principle — “the universe was designed
ally for humans” — requires any discussion of who did the designing. This is not
of the anthropic principle discussed today by scientists.
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ur being “stuck with an anthropic argument”, you’re jumping the gun a bit.
ber the LHC hasn’t run at its highest energies yet and has collected only 10% of its
ta set (in fact it’s now 1% of the total through the planned upgrade into the year
so.) We do not know that the Standard Model is correct; I’m merely pointing out
rprising it will be (from the naturalness point of view) if it is.
| August 27, 2013 at 12:33 PM | Reply
y. I did not want to bring in religion in this discussion. But my understanding is
multiverse idea was brought in to get out of fine tuning (perhaps without any
ive to fight anthropic, weak or strong argument). String theory also points to that.
until it is verified experimentally, it remains one of the hypotheses, which is ok
me. I would still like to hear your opinion about multiverse.
August 27, 2013 at 9:22 PM | Reply
August 27, 2013 at 12:04 PM | Reply
to see the conclusions in your final text version. I think that there is no
s after all (based on my hypothesis). I’ll get back to you on this issue later.
August 27, 2013 at 1:05 PM | Reply
is no naturalness, there is no time dilation, there is no constancy of speed of light,
ence to it, we will be never aging.
is no unnaturalness, there is no “rest (invariant) mass” and there will be no matter
August 27, 2013 at 2:45 PM | Reply
is that? Could you open up your reasoning a bit?
August 27, 2013 at 11:24 PM | Reply
ime slowdown means, nearing the speed of light and ultimately the clock stop
icking – thus becoming massless.
asslessness of standard model is naturalness.
he unnatural disturbance in simple harmonic motion of quantum fields (natural)
reates the “rest mass”, due to quantum mechanics.
he mass of know particles in standard model is unnaturalness ?
August 27, 2013 at 12:44 PM | Reply
ysical reality, it is naturalness or unnaturalness ?
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ugust 27, 2013 at 1:41 PM | Reply
ly 100% sure, that the universe will not be changing any time soon? Elsewhere I’ve
t vacuum transitions etc …?
August 27, 2013 at 9:28 PM | Reply
ertainly not change smoothly, which was really the only point I was making here.
s unlikely to change soon.
t this with the vase. A breath of fresh air or a little vibration could destablize it at
Reply
ntry, but “…we live, quite naturally, on a rather ordinary planet…” is jumping the
n’t know the probability measure any more than we do for the multiverse. And I
e Moon makes the Earth distinctly unnatural, even if Earth-mass planets are
found in stellar habitable zones.
rbjörn Larsson, OM | September 1, 2013 at 5:38 PM | Reply
lanet mass and its habitability is frequent (at ~ 6 % of stars). But systems are
uals, and our sun is unusually large (at ~ 5 % of stars).
ese types of large binaries are expected because they are, well, natural outcomes
ional accretion. We have many examples already in our system, Earth-Moon,
haron and smaller binary asteroids. And they are a natural outcome of low
, equal mass accretion models, which predicts Pluto-Charon and is now a strong
er for Earth-Moon. (Meaning the ancestral Tellus and Theia planetoids were likely
massed objects, an apriori most likely situation.)
moons have little to say on short-term habitability of planets. The -90’s results
med to say they are, are now known to be faulty. Both abiogenesis and later
n of complex life are possible outcomes.
rbjörn Larsson, OM | September 1, 2013 at 5:46 PM | Reply
don’t know the probability measure”, see the Habitable Exoplanet Catalog: we do,
ell, from 3 independent sources (transits, radial veolocity and microlensing).
ptember 5, 2013 at 11:12 AM | Reply
rding to your source: zero confirmed “habitable” Earth-mass planets out of ~1000
irmed planets in the The Extrasolar Planets Encyclopaedia. Too soon to say “rather
nary planet” in my book. And, based on the evidence to date, our solar system
etty atypical, too. (Eight planets!)
:)
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ging habitability into it was a mistake, because I was only making a pedantic point
t the “naturalness” of the Earth. I’m not sure Jo[e] Public would consider a planet
an orbital period of 28 days or twice the radius of the Earth as “Earth-like”, even if
apable of supporting life! (As aside, the Habitable Exoplanet Catalog doesn’t seen
count for tidal locking, and I would bet against life on those that are tidally
nk it would be even more incredible than predicting the Higgs for our model of
etary formation to survive the exoplanet revolution.
alue references on the third point about moons and habitability. Of course, now we
w” life had to evolve on Mars and then jump ship to Earth before Mars became
habitable… so now you need two planets! (No, I don’t believe that, but it would
ainly answer the Fermi paradox!)
Torbjörn Larsson, OM | September 9, 2013 at 5:42 AM | Reply
ow you have gone beyond habitability into inhabitation.
Add Earth to HEC and you have that 10 % of habitables are inhabited. This
stimate will slowly decrease until we find another inhabited planet, but it won’t
It is really finetuning if you expect just one planet out of a galaxy worth to be
habited. About 10^-13 (since we have many planets and ice moons per star),
hich is nearly as serious as what we discuss here.
The short period of time before life evolved on Earth shows that it is an easy
rocess, so a frequent outcome.
o get back to habitability:
As I said, the systems are individuals, planets not so much re traits like being
laced in the habitable zone.
“Tidal lock” is a tedious claim of “show stopper”, while we already know it isn’t.
limate models, as well as the example of nearly locked Venus, shows that dense
tmospheres will nicely distribute heat without too much surface wind. So the
requency of habitables isn’t as large as it could be, but still large. (Especially since
ost habitables will be locked around M stars.)
Large moons not necessary ref: http://phys.org/news/2011-11-life-alien-planets-
It seems that the 1993 study did not take into account how fast the changes in tilt
ould occur; … According to Darren Williams of Pennsylvania State University,
Large moons are not required for a stable tilt and climate. In some circumstances,
rge moons can even be detrimental, depending on the arrangement of planets in a
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iven system. Every system is going to be different.””
o, the argument isn’t that you need transpermia. (But we know it could happen
rom estimates of hypervelocity impact escape masses and bacterial survival rate.
e also know that many systems will have 2-3 planets within the habitable zone as
he argument is that you can evolve life robustly as it takes much less than 0.5
illion years, then evolve land life and intelligence in a similar calm period. Again,
wered outcome, no show stopper.
lso, I think the discovery of Earth global oxygenation and global “slush ball” glacial
how that orbital stability is overrated. Life survives much worse changes.
Torbjörn Larsson, OM | September 9, 2013 at 5:53 AM |
I’ll add on your last point that the Fermi question is insufficiently constrained to
be tested by negative outcomes. (A positive outcome would do.)
There will always be the problem of silent pathways, false negatives. E.g. if there
is no generic interest to communicate. It is anthropocentric to assume there is.
So it isn’t a fully testable question, a well defined hypothesis, with a definite
answer. We can only constrain (or hopefully verify) frequency of positives.
August 27, 2013 at 3:12 PM | Reply
it. Why limit ourselves to variations of the Standard Model? Why not imagine all
odels? Our imagination is limitless, after all. Of course, then all the variations of
odel will feel utterly unnatural compared compared to the enormous pile of
en if we assume the Standard Model is the correct description of the universe, than
odel, even those that are quite similar, are still as fictional as the Genesis.
August 27, 2013 at 9:34 PM | Reply
ber, the article isn’t finished yet.
try to imagine all possible worlds that are described by quantum field theory. [I
idea how other worlds would work, so there’s no point in discussing them; the
rd Model is a set of equations for which quantum field theory works.] Then my
nt would have to be generalized to the following: divide the set of quantum field
) those that have spin-zero particles like the Higgs particle, but no supersymmetry
e other technical caveat that I’ll explain later in the article), that are “lonely” (i.e.
t other particles around that specifically have to do with why they are light)
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nd the vastly overwhelming majority of the theories are in Class B. But the
rd Model is in Class A. So the mystery, now stated more thoroughly but more
ngly (which is why I chose, for pedagogical reason, not to jump that far in one
emains just as serious as before.
August 27, 2013 at 5:26 PM | Reply
nd trivial, but what if the universe is actually passing through cycyles 3-2-1 etc due
ge of higgs field value over time? If so, it would be perfectly “natural” to pass
seemingly “unnatural” transitory phase such as the one we are in, sometime during
August 27, 2013 at 6:49 PM | Reply
know much physics yet, but I feel like there’s something in this proposal that
at the fundamental truth of the Universe hidden till now to the scientists.
August 27, 2013 at 9:43 PM | Reply
impossible, logically speaking. Our scientific problem is this: how would we verify,
entally, that this is the case?
August 29, 2013 at 12:55 PM | Reply
’t we at least put forward some imposibility of implausibility arguments against my
estion? If, as I suggest, the universe has been cycling between these three
ses”, could one say that, than, we should by now have observed some tell-tale signs
ast of the “debris” of the previous phase, which, presumably we have not? Or
aps one could “prove” by logical reasoning based on proven observations and
ysis, that, once a universal phase change occurs due to change over time of the
s field, the new “state-space” of universe would now provide such a strong
actor” for the new status quo that, no further phase changes (new criticality events
rds other attractors) would be possible theoretically, thus “extinguishing” the
y above reasoning, this suggestion is proved to be false that that is the end of the
y. However, if this is indeed possible, than why would one bother with naturalness
nnaturalness arguments, perhaps inevitably(?) leading to multi-universe theories,
h philosophically put the burden of “explanation” to the 3 Space(distance)
ensions, whereas, this apparent “unnaturalness” may be explianed by just
rence to 1 D time dimesion? I do realize that I may be edging unduly towards self
nized criticality theories (which I don’t belive is a holy grail of explanatory power
verthing anyway), but still, I believe this line of reasoning deserves some further
August 27, 2013 at 6:23 PM | Reply
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m repeating Donald’s question.But I did not understand your answer to his
n SM range of values of constants is probably known (am I right?) So what is it
es it unfair dice rolling? I suppose, once you get into small numbers exact value
atter!! But if you have large no of systems (multiuniverses or whatever) the net
may become reasonable. I have seen Penrose’s estimate of big bang starting with
y as 1 in 10^10^123. Other people who consider probability of origin of life as 1 in
in 10^150. Leaving aside question of life, is there any believable range of
for SM parameters (even rough!) ? Thanks.
August 27, 2013 at 9:46 PM | Reply
lk a little bit about how we can put some precise numbers into the discussion; but
nd, there is no unique way to do this. And that could, perhaps, be the Achilles’ heel
rgument. [However, I remind you that the argument has always worked before in
rbjörn Larsson, OM | September 1, 2013 at 6:02 PM | Reply
lihood for chemical evolution proceeding to biological evolution is of order 1*,
ow fast life was established here and consonant with the known homologies
n ocean water and cells (frequency of commonest elements, i.e. CHNOPS) and
n pH modulated alkaline hydrothermal vents and early chemoautotroph
lism (Lane & Martin 2012). If abiogenesis was hard either of those would not be
stead it was fast and used the common elements and redox sources at hand on
an make that formal and testable with stochastic processes. Or at least as testable
astic processes are verifiable in industry from single samples…
ust 27, 2013 at 9:52 PM | Reply
ne hand the standard model ist a profoundly unnatural theory, on the other hand
t our scientists got? That reminds me a bit of the ptolemaic world view, where the
d the sun had to carry out weird movements in order for the earth to be in the
the phlogiston theory, where “phlogiston” with negative mass was postulated, in
plain the weight loss when burning substances. Both “correct” and useful within
s, transitional theories, but something profound was missing and it was back then
not be surprised if someday in a far future the standard model will be replaced by
quite, but not completely different. Like a reformulation from an different
But I dont believe I will witness that, it seems too far out.
ent note, to state the limitations of the current scientific world view so clearly
dibility to me. Best defense against all kind of conspiracy theories wich typically are
gnorance of “mainstream” science.
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August 28, 2013 at 1:34 PM | Reply
zing how, on the interweb, you find people who’ve had exactly the same thought!
ked at the SM for years and thought “epicycles” and “phlogiston,” that there has to
e key piece of understanding that’s just not right. The fundamental conflict
n GR and SM feed into that feeling; one of them has to be, at the least, incomplete,
Emotionally, I want Einstein to have been exactly right and SM in need of an
derstand the naturalness conundrum, either there must be a lot of universes
ng we’re not special; just another member of the pack) or we need a reasonable
tion for why the dice came up with a very rare number that allows us to be here to
zed that we’re here. If we’re not special, no problem, but if we are special… then…
n reading about the Rare Earth Hypothesis and the idea that multicellular life may
en incredibly unlikely, let alone intelligent life. Some feel the famous Drake
n factors should be such that the probability of intelligent life per galaxy is
may be hugely special, and that does seem to beg for an
others me is that The Blind Watchmaker logic seems sound. The eye was a poor
e, as there is a clear evolutionary explanation. But more and more it seems that life
erhaps even physics itself, is a kind of weirdly complex, inexplicable watch. It’s
t to think it was made or directed in some fashion (as preposterous as that
olin’s idea about the evolution of universes is interesting, but if universes evolve to
e physics laws they do, what is the physics context in which this evolution takes
s there a meta-physics universe where universes evolve? (Isn’t that the Turtles
?) I wonder the same thing about the BB. Under what laws of physics was the BB
ime reader, first time commenter, retired software designer with a lifelong interest
Torbjörn Larsson, OM | September 1, 2013 at 6:07 PM | Reply
d the REH daft, since it is an open-ended bayesian model. Just find the posterior
want between 0 and 1 by adding factors.
the REH original factors have all already been shown to be erroneous. (For
ple, the need for a large moon, se my previous comments on that.)
August 27, 2013 at 11:44 PM | Reply
e dilation doesn’t mean that particles come massless. There is two factors in time
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e strength of gravitational interaction and the velocity in it. If we take a
3 atom near a huge gravitational source where it “ticks” much slower than here
s the mechanism that makes its mass smaller?
near c velocities, again what mechanism would make it have smaller mass? Ticks
for sure, but it has nothing to do with subatomic masses (nuclei, nucleus,
gust 28, 2013 at 1:38 AM | Reply
is the cosmological constant “unnatural”? After all, its value is quite exactly the
are of the horizon distance (“radius of the universe”). This is a quite natural value
August 28, 2013 at 5:35 AM | Reply
ut you missed one state of vase in your analysis: the vase is in its fall down. Maybe
se “is falling down” between two “natural” states and maybe the notion of time
any meaning only for this “period” (and this is why we believe that the falling state
lling vase is rare when you compare it with the other two cases of natural states
le or on the floor) but it is a natural state too.
naturalness problem of our Universe is a false problem only because we just don’t
d yet what it is really happening.
ust 28, 2013 at 7:24 AM | Reply
t the most fundamental criteria for any universe is ,, meaning ,,……so no universe
ithout a sapien creature to grasp it and give meaning to it , no mathematical or
of can prove that statement as false.
as true is direct logical result from existence of homo sapien himself.
ust 28, 2013 at 7:29 AM | Reply
er view why it is not the case that our universe is the natural , normal ,expected
ll other ones are the weird non existent cases?
ust 28, 2013 at 11:37 AM | Reply
nore the obvious , the universe is un-natural since it was generated by conscious
August 28, 2013 at 11:43 AM | Reply
at would you say in the case where universe (forces, particles) emerge, without any
ust 28, 2013 at 11:48 AM | Reply
ow me one single case or equation where physical output is generated without Any
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ny input of fields , particles or forces …….
August 28, 2013 at 11:57 AM | Reply
ant an example then do some googling or follow the link. Of course there is
ing behind the big bang but after that everything emerge without any outside
ust 28, 2013 at 12:10 PM | Reply
eist response…….I SAY : NO input whatsoever ….no physical before the physical ,
ONLY way to prove ex-nihilio physical generation.
ost or paper ever started from real fundamental absolute NOTHING to generate
enomena , it is logical absurdity to state it , ….
rong , give me just one equation without any physical factors generating physical
O IT if you are so sure .
August 28, 2013 at 12:36 PM | Reply
read my previous response? Apparently not. Or at least missed my point.
ust 28, 2013 at 12:25 PM | Reply
logical ,simple , scientific explanation is to admit Divinity of creation then study it
you can , I think we must admit that any pure scientific justification for actual ,
nothingness to generate any thing is just squaring the circle…….. Grave , false
ust 28, 2013 at 12:32 PM | Reply
.. All scientific papers started from something…….no single paper would start from
it will end after The first line.
ust 28, 2013 at 12:42 PM | Reply
ou , it have been a long time since our last conversation…..
example proves Divinity case as only omnipotent effector can adjust line of center
ith line of support and KEEP it that way…………thanks Matt. You proved that our
eds extra-cosmic effector by just comparing it to the vase case……….Great
ust 28, 2013 at 12:45 PM | Reply
u agree Kimmo, that generating our cosmos needs something behind it ?
August 28, 2013 at 1:58 PM | Reply
agree. But it doesn’t have to be any “higher power” type of thing.
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ust 29, 2013 at 6:27 AM | Reply
? There are none that you can find …….it is an infinite regression with no real
st 30, 2013 at 4:11 AM | Reply
nd that many theorists are upset (not merely puzzled, but upset) at the elusiveness
/principles like “naturalness” in evidence from experiments. What puzzles me is
upsetting, when we _know_ that the SM and GR are both incompatible and
e, with something like 95% of the contents of the universe not even hinted at by
ry. (In fact, we have no idea how a Lambda-CDM universe could EVER have come
y it did — e.g., how an “inflaton” field’s potential got set, or why it evolved and
d converted its energy into particles the way it did. We don’t know ANY of that.)
n’t understand that reaction of being “upset” after reading your post so far.
t’s something else I don’t understand: You seem to imply that we can make
s with both QFT and GR/gravity somehow combined that give us an idea of what
expect as happening “naturally”, when the basic fundamentals of space and time
in the two theories are contradictory, both in their concepts and in the way they
plied mathematically. I thought that the only way to even start to make the
ion” of GR work is to restrict it to 2 dimensions; otherwise, the math falls apart —
hy all the effort has been expended over decades trying to figure out how to
correlate or map a 2D universe to a 3D + 1 universe in some homeomorphic way, as
in other posts. I wasn’t aware that such a combination of theories was required to
sons for expecting “naturalness” in a QFT.)
rstand the hierarchy enigma. I can understand “Oh damn! Guess I was just wrong”
s Nature follows some other pattern, not this one” and “So, Where do we go from
other than the standard (and insulting) ploy of blaming people (like Arkani-
d perhaps even you) for just being miffed, after years of careful work, that their
aven’t turned out to be applicable to the real world, I’m still not sure why there are
rms of actual contradictions or conundrums within the theory, are there if some
ersymmetry isn’t still an option? That is, other than “that’s just the way things
hat’s strange…”, what is it that is being impllied by the lack of (detectable)
etric particles that is so “shocking”?
is the absence of such fields any more shocking than their presence if we were to
fully agree with (and hope everyone supports) the idea of pursuing an idea
, working out its ramifications, seeing where that leads and coming up with
ys to corroborate or invalidate that idea (or parts of it) — even (perhaps
if that process is hard and/or subtle. Whether you think supersymmetry is a
tal principle or not, of course we should explore every avenue to investigate it as a
. But as mentioned elsewhere, I am reminded of 19th century thermodynamics and
of caloric: prominent scientists (and many not-so-prominent ones) spent their
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g up with the mathematics of heat as a fluid. Scientific papers on caloric were still
ten and printed in the first decade of the 20th century, 50 years after the
l theory of heat as kinetic energy of molecules and atoms had been shown to be
rate. Some of that work carried over; some of it didn’t. I also understand the
n “threading the needle” (as you have put it) with new theories that might replace
d GR, while meeting all the constraints that we now know about. I just hope that as
hasis is being applied (and funding allocated) to finding the next “particulate
atter and heat” as in exploring the older ideas that don’t seem to be working out,
ill need to be replaced/modified anyway.
August 30, 2013 at 9:42 AM | Reply
you’re wrong to use the word “upset”. “Troubled” is a much better word. It disturbs
p — it seems that we’re missing something. But “upset” is the wrong word. Yes,
e some people who engage in polemics and call each other names. I bear no
ibility for such idiocy.
the upset that you are perhaps referring to seems to have to do with whether or
ersymmetry is right — and indeed you seem to assume this too in the way you
his comment. But supersymmetry is only one possible solution to the naturalness
perhaps it was once the most plausible, but after the LHC’s 2011-2012 results I’d
now no longer the obvious front-runner. I also bear no responsibility for the people
e and who hate supersymmetry. Those people, perhaps, are “upset”. [Though not
t as the people who love technicolor, which predicts no observable Higgs particle.]
such emotional debates are silly and demeaning to the scientific process. I’m
ed in nature, not my pet theory or someone else’s pet theory. I neither love nor
ividual theories; I just want to know if any of the ones we know actually matches
ack to the issue at hand. I haven’t finished the article, so you’re running way ahead
ame. It takes time and careful thought to appreciate this problem; the typical
te student (for example, me, back in the day) has to think about it and about the
possible solutions to it for a few months before really appreciating just how hard it
lve within a quantum theory. There are only a handful of solutions (all of which I’ll
) and all of them — except a “selection bias” (also sometimes called a “weak
ic principle”, though the use of “anthro-” is misleading) — predict new particles
le at the LHC sometime in its current or future runs.
t me for a moment when I tell you that it’s really hard to solve, and that any
within theories of the class we know would predict new particles at the LHC. If we
’s a selection bias (which is a statement about the whole universe, and therefore
e naturalness criterion derived from decades of study of quantum field theory —
as not failed before, mind you — does not apply, at least not in its strongest form,
ere is a solution to the naturalness problem which violates the known principles of
m field theory (i.e., we must go beyond quantum field theory not just for quantum
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but even for the physics of the Higgs)
ding that at least one of these is the case — which will take a long time — would be
ig deal, conceptually. It would change the questions that scientists ask, and could
major shift in the history of the field — much like the Michelson-Morley
ent was a watershed event (not so widely recognized, though, at the time) whose
on our understanding of nature was immeasurable.
there’s a great deal at stake. I don’t see the point in getting upset about it, but
d? Sure. Maybe the solution is right under our noses and we’re looking right past it
ome young Einstein-II will deliver the solution one day. Or maybe we’re doing the
ets of experiments, and the solution will be revealed accidentally in an experiment
sn’t intended to address the question at all.
September 1, 2013 at 3:55 AM | Reply
average Higgs field value implies small Higgs boson mass, and a huge average
value implies huge Higgs boson mass, which is why of course the LHC thought it
the Higgs. I’m sure you must have explained theoretical reason behind this in one
dding to the Naturalness Article | Of Particular Significance
tember 4, 2013 at 12:49 PM | Reply
ar that deciding what is expected and what is un-natural is 100percent subjective ,
le , for me the most (natural) universe is like ours since in my criteria a universe
pien being is not selected , as you see ….even selection force is subjective.
: there are no solutions to naturalness assumed problem as in fact there is no
tember 4, 2013 at 12:57 PM | Reply
subjective your decision that such and such properties are not expected biased by
decision that ANY kind of universe is possible which no theory can prove.
tember 4, 2013 at 1:27 PM | Reply
this: what about the QF fluctuations that are extremely tuned to result in the UP ?
say it is extremely un-natural . But what if there exist a selection force that
at relation very very natural ? Our physics cannot tell……
tember 4, 2013 at 4:17 PM | Reply
s to solve this problem it must prove the impossibility of a meta-selector
that selects for life/mind friendly cosmos only , rendering all other ones
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( extremely un-natural with zero sigma).
ber 4, 2013 at 11:00 PM | Reply
t Fig. 4: How do you measure the Higgs field’s average value? For electric field,
easure the force on a charge placed in the electric field and calculate the value of
field at the point. Is Higgs field’s value also calculated by measuring the force on a
eptember 5, 2013 at 3:59 PM | Reply
part of this article is very interesting and helped me understand some important
really looking forward to the next part.
eptember 6, 2013 at 12:16 AM | Reply
PE I am not a proverbial pain in the neck for you. That would be the last thing I
rying to comprehend what the vacuum is, why it is black, and why it appears to be
ss when obviously it is something very unique in our physical world. For example;
ds such a physical abuse from supernovae explosions, constant radiation of the
, torquing by the gravity and the mad speeds and spin of celestial objects. Could
write something about the vacuum. It is the BIGGEST body known to us, at least
r universe. I know that quantum fluctuations are happening on a quantum scale,
veryday cup of space that we can see and observe. The virtual particles are said to
in and out of existence so much that this phenomenon is viewed as a constant of a
osmological constant). I deduct from what little I know, that vacuum is a medium,
r or water are here on earth, that can absorb things, store the radiation and make it
self. When physicists observe the virtual particles, they must do that test in some
sed cylinder. Could that be the reason for the appearance of the virtual particles,
ized vacuum is actually experiencing the pressure created by the walls of the
he energies build-up, could be resulting in a creation of fake particles because
space has to move/ flow/ breathe. Is there any evidence that vacuum in space also
hese virtual particles? Has this been proven? Hope you can answer this one,
rbjörn Larsson, OM | September 9, 2013 at 6:23 AM | Reply
uestions, and it has been some days. So short answers:
acuum here, for particle physicists, is the sum of all particle fields. Other fields
her definitions (e.g. low pressure vacuums, astronomical vacuums, cosmological
ot black but can be seen locally as a relativistic black body emitter in some cases.
ruh radiation for accelerated objects; Hawking radiation around black holes; static
acuum is not a body, it is a system of fields. Magnetic _field lines_ snap and
if stressed enough, see Wikipedia – such field lines track existing particle behavior.
particle fields are pervasive, they don’t disappear.
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al particles (a misnomer) is observed through the behavior of the electric field close
ges. See Matt’s articles. You don’t need vacuum for that – I suspect you are
g of particle accelerators which innards are pumped to low pressures for technical
ysics speculations in the rest of the comment are not contacting any of what we
and know about the actual physics. I recommend Wikipedia’s articles on low
e systems and hope they help for the basics.
September 10, 2013 at 9:23 AM | Reply
l, that doesn’t answer my question; Is there any evidence that vacuum in space also
uces these virtual particles? Otherwise we humans/ you physicists are trying to
the nature into your theory. Most of it fits, I hear with exception to cosmological
tant. If it doesn’t fit, discard it. Problem solved To say that quantum fluctuations
eate all space from far, far away galaxies to spaces between the atom and it’s
tron and even further down into the spaces or rather fields of quarks and gluons,
nd any space you can imagine is fine with me. I won’t lose any sleep over it, but
t I see wrong is you people trying to calculate the spaces of the universe you have
eans of verifying. What is the principle here, that energies of the universe have to
nce out? All the positive energy of the fermions (which are just another state of
gy) has to cancel out all the negative energy of the universe, which is the energy of
orces (their fields and bosons). WHY? If these two cancel each other out, don’t you
static universe? This universe is on the go. What’s driving it, forces or fermions?
rmions are energies in another state then everything there is is energy. There is no
to balance anything out. The problem is not in unnaturalness of nature but in
aturalness of an approach. You are trying to solve a problem that doesn’t exist in
re but is created by your way of looking at things that make up the nature of this
erse. First solve the problem of gravity. Is gravity truly the fourth force or is it an
t caused by other factors. In that case universe will have only three forces
ating upon it. Yes, that would make your problem even worse because without the
itons you’d have less negative energy. The ratio could be as low as one to two.
? Due to all the cancellations that different forces have on each other. I think that
re of the nature is not to be precise, but it’s precise enough to hold it’s shape and
hat it’s suppose to do. In your theory though, nature is precise. It’s rigid. That’s
t’s unnatural. If I weigh two ounces or pounds less in a highrise building then when
ch the ground floor, I’m none-the-wiser. Nature has imposed some strange effect
e without me even know it. I’m still me, holding my general shape. Same principle
ies to the universe, I should think. So, the problem of naturalness is man-made.
| September 11, 2013 at 11:57 PM | Reply
n its simplest form there is only one phenomenon which causes all the forces, it’s
he spinning of objects. If you think about it, what other phenomenon it could be?
unniest part comes when you derive a model based on spinning, everything comes
rystal clear. Try it for a fun :)
September 11, 2013 at 11:43 PM | Reply
vacuum here, for particle physicists, is the sum of all particle fields.” Yes, I realize
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, but by a wikipedia’ definition, vacuum is a space free of any matter. It mentions
ect vacuum and partial vacuum. Regardless of that, vacuum suppose to have
uation of energy that can be measured and observed. I don’t question that. If you
physicist, tell me where I’m wrong. If we say that universe can’t have more
tive energy than negative energy, that is assuming that we had a Big Bang. We have
art to visualize another picture of how universe started, the possibility that mater
ped out out of the vacuum itself and that vacuum existed before the matter. The
ent quantum fluctuations could be the end state of the vacuum that could have
a lot denser before. SM is ‘as if’ designed to eliminate the concept of our universe
g created out of the empty space vacuum that might have existed forever. You say;
reated space vacuum. give me some proofs of that. CMBR means nothing of the
. You are looking at magnetosphere of either this galaxy, cluster of galaxies or
erse itself but how can you know for sure which one. The weak radio energies
e nothing unusual, least that BB occurred. Tell me first where all the photons go
don’t get absorbed by matter? Tell me if universe has a magnetosphere or that
e is no difference between the space of our universe and hyperspace or whatever
wish to call it, if multiverse is reality. If BB never happened, then it changes the
re of what reality is. Unless anyone of you physicist is willing to forget for the
ent all you have learned and accepted to be the truth of reality and take a fresh
approach to this universe and nature of it, you may never solve this problem of
ing, (emphasis on seaming) unnaturalness of our universe. Yes, and please don’t
imize the importance of anthropic principle. That’s where your answers are. If you
ost in the detail of the picture, you may miss the whole meaning of it. (Too close to
rees to see the forest?)
September 7, 2013 at 1:06 PM | Reply
it. We don’t know the probabilities for any of this, so where is the problem? It’s
g a melted 20-sided die with the number 20 showing, and exclaiming “huh, there’s
percent chance that this would exist!”.
rbjörn Larsson, OM | September 9, 2013 at 6:04 AM | Reply
Matt’s comments above shows that you _can_ estimate the problem:
in the situation of having at best an extremely rough guess at the probabilities, so
, at best, an extremely rough estimate. But when you’re dealing with numbers that
small, getting them wrong by a huge amount doesn’t change the qualitative
ion: our universe, no matter how you calculate it, is very unusual, on the face of it.”
rbjörn Larsson, OM | September 9, 2013 at 6:05 AM | Reply
when you make an appeal to frequencies of events (die throws), you would here
n appeal to multiverses.
September 13, 2013 at 9:05 AM | Reply
t’s just the thing, though. You assume that the die was thrown before it melted, or
that it’s a fair die and not one with “20” written on all sides.
what Matt is saying, if I understand him correctly, is that that we don’t know
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ther there were ten thousand sides or ten nonillion sides on the die, but either way
hance of rolling a 20 is pretty low. Again, this is based on the potentially false
mption that it’s a fair die.
Torbjörn Larsson, OM | September 15, 2013 at 5:47 PM | Reply
h, so you put some significance in the “melted” part. You are speaking of “fair”.
ell, Matt was considering a fair dice, he could calculate rough probabilities within
ur universe. It seems to me it is you that has to demonstrate first if a multiverse
xist (die throws), and then if unfairness exists, and then if it applies to Matt’s
roblem, and then if it is better than Matt’s estimate. Lots of.”if’s” you take upon
n)Naturalness, Explained | Of Particular Significance
ember 9, 2013 at 1:06 PM | Reply
xplanation as usual, Professor Strassler. You really do have a gift for coming up
it of helping you polish this article, I have noted some typos in the most recent
he text adjacent to Figure 5, “It’s as far as one could can push the Higgs field’s
he text adjacent to Figure 8, where you describe someone as being “now a
t the University of Illinois Professor”
an observation – throughout the most recent section, you claim that if vmax is
eV, there is no problem, and that we do not know what vmax is. So isn’t the
lution that vmax is near 500 GeV?
recent section of your article does a good job of convincing me that the naturalness
creases as vmax increases above 500 GeV, but you have provided no evidence that
deed greater than 500 GeV. Is there some reason we have to think that vmax is so
ere really is a problem?
September 9, 2013 at 8:47 PM | Reply
indeed that vmax is near 500 GeV. And if that is true, the LHC will
r as-yet unknown particles, and other predictions of the Standard Model will fail as
e strongest evidence against it — inconclusive at this time — is that the LHC has
discovered any such non-Standard-Model particles, and there are no known
ns from the Standard Model at the current time. Arguably we should have seen
eviations already by now. But I will get to this issue soon.
for catching the typos!
tember 9, 2013 at 1:26 PM | Reply
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ctly similar to my comment on the (explained)post , I guess there are some
September 9, 2013 at 3:02 PM | Reply
such thing as a vacuum, so the the real question is do we know what all the fields
w they interact? Therefore each yet to be known particle is an indication of a field
ow interacts with other known and unknown fields? Would a black hole
be in essence, matter broken down to its constituent fields and tied up, or not, or
d into a knot? As to a Creator or not, I have had my own personal experience,
is best not to argue over something that cannot be accepted by many for their own
easons. This should not be a blog about Religion.
September 9, 2013 at 8:42 PM | Reply
s such a thing as vacuum — the universe is much emptier than you think.
ber that only 1/10^15 of the volume of an atom is occupied by the nucleus. And we
ulating the effects of fluctuations whose distance scale is at least a 10^9 times
, in volume, than the nucleus. So the universe has lots of vacuum, on these distance
zen (Jeh-Tween) Gong | September 9, 2013 at 5:08 PM | Reply
andmother of 15th century comes back to see her grand … grandson, the Apple boy.
ing is the conversation about this unnaturalness issue.
G-grandmother, I just read a great article about the unnaturalness of Nature.
ment in it makes sense. But put all together, it just doesn’t make sense to me. How
be unnatural? You have sat right beside Nature for the past 500 years. Can you
other: Oh, the only thing unnatural to me during my last visit in the 17th century
a man who walked on a rope 100 feet above the ground.
It is unnatural to an average person in their ability to perform such a stunt. But, it
llowed by the laws of Nature.
other: Well, I really see some unnatural things in this visit. When I came down
irs, I saw many people in a bird-like metal box flying in the sky. Then, I saw many
ing from a hand-held plate.
Indeed, they are some kinds of unnatural as they were invented by humans. We
rtificial inventions. Yet, they are still parts of Nature as only laws of nature allow
other: Last night, I saw a video about Ptolemy model of the universe, and all stars
g in different patterns. How can a star dance like a dancer? It is truly unnatural.
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That model put the *center* of the universe at Earth, and it is an unnatural way of
deed, that model is unnatural which means *wrong* today.
other: Hi, boy, you seemingly know all answers. Then, what is your question?
Matt showed a vase/table analogy and said that our universe sits at the unnatural
the rightmost picture).
other: Why is it unnatural? For a few hundred years, I have travelled with my
di all over this universe. And, most of the time (99.9999…%), the vase are not
he natural cases as described in his analogy. His saying is true only when my
landed on Earth. There must be some unnatural force around Earth.
Okay, okay. No analogy. But, please read the entire article. The argument is very
ividually, especially about the Standard Model.
other: Hi, boy, it took me awhile to read it. No big problem, but a major confusion.
d Model is unnatural (meaning, it is wrong).
s unnatural (meaning, … nuts).
The issue is more subtle than that. The Standard Model has three parts.
zoo of particles (especially the 48 matter particles) which are verified by tests.
set equations which *fits* the test data by hand-put many parameters into the
reverse-engineering which produced Higgs mechanism.
d Model is wrong (unnatural), which part is wrong?
other: Part A is message directly from Nature. Part B is artificial but works for
ly part C is the suspect of the problem.
But, Higgs boson was *discovered* on July 4th 2012.
other: Indeed, LHC found *something* on July 4th 2012. But, 14 months later, we
en officially established evidence for the Higgs to bottom quark pair decay (which
e *golden channel*) at all.
ument is all about the *mass* of that something (he calls it Higgs boson) vs the
nergy* (he calls it Higgs field) of the empty space.
er model, the mass of that-thing should be [(1/2) of the vacuum energy + some
ation barrier], as that-thing is a blob of [a vacuum state to a new vacuum state]
unsettled issue and thus no need to go into any further.
Okay, let’s put the Higgs issue aside. The unnaturalness can still arise in the case
other: *Possible universes* was a very old philosophical topic. The evolution
* for the universe is zillions (infinite to be exact), but the *history* of the universe
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only one history. That is, there is only *one set* of laws of universe.
iverse* in the article is about having many different sets of laws of nature. They got
om the concept of *fine-tuning*. If a set of laws can be tuned, it becomes many
*Fine-tuning* is definitely a part of nature. If we change the nature constants very
is universe will be dramatically different.
other: Well, this is another major confusion. Nature is very, very precise, locked by
imensionless pure *number*). That is, no *dimension* of any kind can change it.
s looks very much like fine-tuning but cannot be tuned.
Thanks G-grandmother. Now I understand the issue which has only two
ne is unnatural —- Nature or the Standard Model
enzen (Jeh-Tween) Gong | September 10, 2013 at 1:44 AM | Reply
oy: I think that you have swept three very important points off the table by
ning about the Higgs mechanism, didn’t you? G-grandmother.
Higgs (or other) field classes (on, off, on/small)
tum fluctuations of quantum fields, and the energy carried in those fluctuations
It Isn’t Easy to Have the Higgs (or Higgs-like) Particle’s Mass Be Small (the
tion of all different fields and the magic cancellation)
dmother: I was a farm lady, you know. I know everything about *fields*, the corn
e potato field, the sheep field, the dog field, the fish field, … the ocean field, etc..
oy: Come on, G-grandmother. A herd of sheep, a pack of dogs and a school of fish,
dmother: Okay, my bad. Just exclude those then. But, for all other fields (corn or
tnot), I could turn them on or off as I please, by plowing them out or seeding them
u can move this Earth into Mercury’s orbit, I can even turn the ocean field off.
oy: What is your point?
dmother: Just a bit Buddhism here. All those fields are transient phenomena. Their
ff have no importance for the eternal reality. For me, there was only *one* field, the
of the Earth, and it cannot be turned on or off (so to speak). And, this true field is a
er than all those *fields* add together. So, those summation operations of all those
t fields (top quark field, etc.) do not make any difference for the true Daddy field
annot be turned on or off. By the way, if a field can be turned on or off, it cannot be
oy: What is the true Daddy field for this universe?
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dmother: Now, you ask a right question. It is the space-time sheet (field). All
particles are protrusions from the space-time field. When an electron protrudes, it
oy: So, Higgs field is not space-time field. Is there anything wrong with the Higgs
gument in this unnaturalness issue?
dmother: This is the whole problem. The argument implies that the Higgs field is
Daddy field which affects the entire universe. You know, only the true Daddy field
ce-time-sheet) carries the *vacuum energy*. Any other fields also carry energy,
oy: Come on, everyone knows that the vacuum energy is the result of quantum
tions of quantum fields.
dmother: No, the quantum fluctuations of electric field are not vacuum energy.
a linguistic issue, you know. Vacuum is referring to lacking of matter in *space*.
uum energy is about the energy carried by space-field (space-time-sheet to be
If Higgs field carries some energy, it should not be called the *vacuum energy*,
he Higgs field is the space-time filed.
oy: Well, besides of not being turned on or off, what is the other reason that the
ield cannot be the space-time-sheet?
dmother: The space-time –sheet houses *all* fields (including the gravity field),
e as the Earth field houses all plant fields. If Higgs field does not house all fields,
g on or off does not truly make any difference to the space-time-sheet. If it does
ll fields, then it cannot be turned on or off. All those calculations are just games on
oy: Okay, let’s put this Higgs field vs vacuum energy issue aside. The point that the
energy is the result of quantum fluctuations is still important, isn’t it?
dmother: Wow, you got a key question again. We know three facts.
tum principle (fluctuations) is a fact.
um energy is not zero.
bove two facts (a and b) are related.
at kind of relation are they, the cause/effect or the fundamental/emergent? There
tum principle (fundamental) causes the nonzero vacuum energy (emergent).
ero vacuum energy (fundamental) causes the quantum principle (emergent).
oy: Come on, everyone knows that #1 is the answer. But, what is the big deal here?
dmother: This is *the* issue. By selecting #1 as the answer, we are facing the
ralness issue. By selecting #2 as the answer, the Nature cannot be unnatural. But,
e is very deep and cannot be discussed any further here.
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tember 9, 2013 at 7:12 PM | Reply
tastic – the way you explain things makes the investment of a little work on the
reader very rewarding, as I am now feeling quite close to really grokking the whole
r years of reading explanations for non-specialists that skirted around the tricky
e logical argument, leaving the reader unsatisfied even after effort. But–and I think
ut–I am finding one key thing elusive and I would enormously appreciate an
ion of this one issue. Why would the non-existence of particle physics beyond the
odel (apart from gravitation) imply that v_max is as high as possible? Tell me
’ll feel able to explain the whole thing to anyone who cares to listen.
September 9, 2013 at 8:32 PM | Reply
sure I’ve understood your confusion yet. If I do understand it: The answer is that it
ost by definition of v_max. v_max is the scale at which the Standard Model is no
a good description of all particle physics. If gravity plus the Standard Model
ed all of nature, then we know what v_max is… it is that huge number that I wrote
ext. Physically, this is the scale of energy above which precise calculations of
ng experiments require inclusion of gravity effects… where gravitational forces are
strong as the other forces. Have I answered you?
September 11, 2013 at 10:32 AM | Reply
nks for your answer. I think in composing my question I misidentified my
pprehension, because me_[today] can’t understand me_[yesterday], and now my
usion about Figure 5 is different (UPDATE: though 24 hours after beginning this
onse I think I’ve got it; perhaps you can verify). Here’s my understanding of it: the
s field has an average value throughout the universe, which, before we measured
ad a range of possible values. The Standard Model lets us work out, for different
ntial values that the average value might take (up to a maximum, v_max, beyond
h the SM ceases to be consistent with observed reality), the contribution to the
gy density of empty space for each of a number of known effects of the Standard
el. These are the blue curves in Figure 5. There might or might not be any
tional, as yet unknown, contributions–these are the red curves, and you’ve drawn
e fictional ones in the second row. Whether or not there are any red contributions,
um of blue and red contributions must correspond to what we observe. And what
bserve is that the Higgs field has an average value of 246 GeV, and the energy
ity of empty space is such-and-such.
, the blue effects are in principle–and, to a large extent in practice–calculable, you
Given that we know now from experiment what the average value of the Higgs
is–246 GeV–we should expect to be able to predict (if the SM is all there is) the
gy density of empty space by performing the calculations for the blue contributions
NE PARTICULAR SLICE OF THEIR CURVE, namely the slice corresponding to
GeV on the horizontal axis. And either that calculation gives us the observed value
he energy density of empty space, or it doesn’t–if it doesn’t, then there must be red
ts that provide additional contributions. The amazing thing is, whether or not we
to invoke as-yet unknown red effects to yield the observed value, that the
rved energy density of empty space is extremely tiny, and there’s no reason that all
e unrelated effects–whether or not there end up being any red effects–should end
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oming so close to cancelling out, given the comparably large individual
ributions both positive and negative. If they hadn’t cancelled out so closely, no
erse similar to that we observe could have existed.
here’s what I did’t get, and now perhaps I do get: once we have observed the
age value of 246 GeV, why do we need to consider what happens all the way up to
ax on your charts? Whatever is to the right of 246 GeV (and to the left of it) doesn’t
espond to our universe. So if there are no red effects, then the consequence is just
the blue effects have to combine to give the observed value, and the value of
ax doesn’t come into it at all. The reason we might care about v_max comes into it
want to answer the question of unlikely it was, with no other assumptions, that
ancellation should have occured: a very high v_max means a very wide range of
ntial Higgs energies, and at the largest of those energies it would be even more
edingly improbable that cancellation should occur. So the higher v_max is, the
ter the coincidence–if you model our universe as having had a randomly assigned
s energy (i.e. considering a multiverse model which leads to anthropic selection
absence of any new particle physics would mean that the limiting value for the
s energy occurs when the top quark gets too heavy for the rest of the Standard
el to work. This is really really really big, and so the absence of any new particle
ics at higher energies means the coincidence of cancellation, with such a wide
e of potential universes to choose from, is that much more startling. And that’s
you’d expect there to be new particle physics revealed at higher energies than we
currently probe: to mitigate the extraordinariness of this coincidence by giving us
e new reason to not have to consider those potential universes with really really
ly energetic Higgs fields.
right in all of that–it was writing the final sentence above that felt like a
kthrough in understanding–then there’s still something slippery to the argument
y mind: it seems that the probability of cancellation has been based on a
ibution of possible universes that all have the Standard Model or the “Standard
el Plus”, but that are allowed to vary by their different values for the energy of the
s field. Why isn’t the choice of this range, and only this range, seen as a little
trary? Thanks for taking your readers’ questions so seriously.
September 11, 2013 at 12:40 PM | Reply
once we have observed the average value of 246 GeV, why do we need to consider
hat happens all the way up to v_max on your charts?”
ou have the logic up-side down. If the theory is correct up to v_max, then we’re
LLOWED to consider what happens all the way up to v_max. And when we do, we
iscover there has to be very delicate cancellation between what we know and what
e don’t know if there’s to be a Higgs field sitting at 246 GeV. Don’t confuse what
e know from experiment (the field’s value is 246 GeV) from our efforts to get the
ight theory of nature (whose equations should predict 246 GeV, or AT LEAST
hould predict that 246 GeV is not extremely atypical.)
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to mitigate the extraordinariness of this coincidence by giving us some new reason
o not have to consider those potential universes with really really really energetic
ot quite. Mitigating the extraordinariness of the coincidence might not change our
bility or reason to consider how the universe would behave with a huge Higgs field
alue [NOT “energetic” Higgs fields — a very different thing]. What it would
ertainly do is make it more obvious why 246 GeV would emerge from our
quations, instead of zero or something much larger. Let me explain some of the
olutions; then it will become clearer what I mean.
it seems that the probability of cancellation has been based on a distribution of
ossible universes that all have the Standard Model or the “Standard Model Plus”,
ut that are allowed to vary by their different values for the energy of the Higgs
gain: “vary by their different values of the Higgs field”, NOT “different values for
he energy of the Higgs field”. Fields have both value (how big is the field at this
oint) and energy (how much energy is associated with the field being this big.)
e’re talking about varying the value up to v_max.
Why isn’t the choice of this range, and only this range, seen as a little arbitrary? ”
f the theory is valid up to v_max, then that more or less sets the range within which
e can do the calculation. (I can see that the fact that I’ve been a little vague about
ow we actually do these calculations is causing some confusion; the article needs
provement.) It’s not arbitrary; it’s pragmatic. Nevertheless, there *is* some
rbitrariness here. But the naturalness problem is so gigantic that other choices
on’t generally make it go away. Only if you make an enormously different choice
an you make the problem evaporate. But successfully justifying that choice would
epresent, in fact, an example of creating a new solution to the naturalness
There are only a few such solutions that have been proposed over the past
September 11, 2013 at 3:14 PM |
Okay. Thanks. One last thing–I wrote: “Why isn’t the choice of this range, and
only this range, seen as a little arbitrary? ” And you replied “If the theory is valid
up to v_max, then that more or less sets the range within which we can do the
But by range, I meant the range of hypothetical universes that we are imagining
ours being chosen from, not only the range of values of the Higgs field. If I’ve
understood correctly, to quantify the degree of improbability of our universe
being just so, you look at how wide a portion of the horizontal axis on Figure 5
results in a universe compatible with existence, and you see that only one in a
gazillion potential universes will work. The range of potential universes you
consider is precisely those that have the Standard Model or the Standard Model
Plus, and that have a Higgs field value ranging from v_min to v_max. But this
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seems (on the face of it, to one particular layperson at least i.e. me) a little
arbitrary, in that your realm of possibilities is unconstrained as to how the Higgs
field value varies within its range, but very constrained in other respect, namely
that the possible universes are all SM universes.
I can’t even begin to imagine how you could enlarge the calculations so as to
encompass every other kind of (non-SM) universes! But wouldn’t extending your
realm of possibilities of potential universes necessarily change the a priori
likelihood that a randomly chosen one is compatible with existence?
| September 11, 2013 at 7:25 PM |
Clearly the precise numerical likelihood that you compute depends on what
possibilities you consider, and we have no idea what options nature had
available, if any. But you notice that by focusing on the Standard Model itself —
not Standard-Model-Plus — I aim to identify an conceptual issue *internal to the
Standard Model* which appears to require resolution by something *outside the
Standard Model*. This is a way of arguing that the Standard Model and its Higgs
field are not likely to be the whole story for particle collisions with energy well
September 30, 2013 at 2:16 AM |
Excuse me for butting in, but SM accounts for only 4% of this universe. Wouldn’t
this unnaturalness problem disappear when new particles are discovered (2015,
CERN) that might describe the dark matter and the dark energy? Universe
appears to be unnatural or, opposite to what was expected and suggested by A.
Einstein. It’s not beautiful, calm, predictable, but wild, unpredictable, turbulent
and much, much bigger. Could this be because universe is open system and not
closed, as almost everyone thinks of it. If vacuum wasn’t created by a BB but
existed just about forever or, at least before this universe, and was much denser
than today, was not switched on but in inert state, why couldn’t particles come
out of this field? We’d need something to switch it on. Say it was a deliberate act,
planned, etc. If we could build a theory on this hypothesis, and it checked out,
wouldn’t we solve this cosmological problem?
September 9, 2013 at 9:26 PM | Reply
,red and green curves, I suppose you are assuming that there is only one Higgs
ne Higgs particle at the currently known values. Does having more Higgses at
higher energies help with the fine tuning problem or make it worse? In other
more Higges buried in high value of v (max)?
September 10, 2013 at 12:48 AM | Reply
y, if there were, say, two Higgs fields, the only thing that would change is that
of my curves (functions of one variable), I’d have to draw functions of two
s. The argument would be entirely unchanged; adding more Higgs fields does not
y natural cancellations, and the problem would now be just as bad.
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tember 10, 2013 at 10:39 AM | Reply
aturalness problem totally dependent on our assumption that the primary cosmic
tals are Fields so that if in the year 2100 it was proved wrong assumption then the
em vanish , or it is itself some kind of fundamental rank problem , in other words ,
ndamental building blocks tied to un-naturalness ?
September 10, 2013 at 10:48 AM | Reply
d to imagine that simply replacement of fields by something else would eliminate
blem, because we know field theory (and its quantum fluctuations) do a
ably good job of explaining particle physics on distance scales from macroscopic
10^(-18) meters, and the naturalness problem arises already at 10^(-18) meters.
Einstein’s new theory of gravity didn’t make it necessary to fix all predictions of
’s theory (i.e., bridges didn’t fall down just because gravity is more complicated
wton thought), a new theory of nature isn’t likely to eliminate the naturalness
— unless, of course, the new theory changes the Standard Model at the energy of
00 GeV (distance of 10^(-18) meters) or so. (Remember that there’s no naturalness
with the Standard Model if vmax is in ths range.) However, if fields were replaced
mething else in the 500-2000 GeV range, we would have expected predictions
antum field theory for physics at the Large Hadron Collider to begin to fail at the
energies. Instead, those predictions work very well.
tember 10, 2013 at 10:44 AM | Reply
aybe the un-natural is the field concept despite the correlations between the data
September 10, 2013 at 10:51 AM | Reply
ber “unnatural” means “non-generic”. What’s a “generic” concept?
tember 10, 2013 at 11:29 AM | Reply
un-natural concept of field that reality is built on other kind of primaries .
September 10, 2013 at 11:33 AM | Reply
you are mixing two definitions of natural.
ctacular cancellation between known and unknown large quantities is what is
ral. It is not concepts that are unnatural here.
nt is: even if we replace fields with something else, that can only change the
WN large quantities. The known large quantities will still be there… because we
uantum fluctuations of known fields exist and have large energy. That part isn’t
ent on the field concept.
tember 10, 2013 at 11:48 AM | Reply
ally a true scientist , honest , sincere and wonderful person Matt.
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s and regards are due to you for your most respectful science.
eptember 10, 2013 at 12:16 PM | Reply
I’m not sure I understand is how the Higgs particle gets mass. It seems logical that
he Higgs field value increases the energy of empty space and that makes it more
vibrate the field. However wouldn’t the same thing work for any other particle
up quark, etc)? For the other particles the mechanism of getting mass is through
with the Higgs field. Not because changing the electron field value would increase
of empty space. Is that correct? Because my understanding is that if the Higgs
zero, the other particles would be massless – so the zero point energy would not
point energy would give them some very small mass even without the Higgs field?
iggs boson does not need any other non-zero field to interact with, because for the
nough to use the zero point energy to get its mass?
September 10, 2013 at 8:25 PM | Reply
od question. There is a pedagogical flaw here, and you’ve identified it. I have to
bout whether I can improve this. Both your old impression *and* what I’ve said are
, but I agree the relationship between them isn’t well-explained.
fields that we know so far (and this may not be true of other fields currently
n), the mass of the particle is associated with the Higgs field in some way.
er, the story for the Higgs particle is slightly different from the others.
he Fields: The electron field’s average value is zero; this is true of any fermion. The
’s average value is zero; calculation shows that the minimum energy of empty space
hen the W field is zero on average. Indeed, the Higgs field is the only (known) field
ch there’s something complicated to calculate in order to determine whether the
of empty space prefers it to be zero or not.
he Particles: This is the same, in a sense, for the Higgs and for everything else. It is
t particles like the electron get their mass by interacting with the Higgs field. But
es that work in detail? An electron is a ripple in the electron field. That means that
tron field, which is normally zero in empty space, is non-zero as the electron goes
where the electron field is non-zero, it interacts with the Higgs field, which also
o even on average; and the interaction of the two increases the energy in that
Consequently the electron field’s ripple has more energy than it would have in the
of this interaction, and the excess energy is mass-energy, crudely speaking. This is
. The issue is: by how much does turning on a field like the electron field increase
rgy of empty space? The amount by which it increases tells you something about
s-energy of a ripple in that field.
cial thing that’s different about the Higgs field and particle is that the fact that the
ield affects so many other fields and their particles means there’s a complex
y between the Higgs field’s value, the Higgs particle’s mass, and the energy of the
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m fluctuations of the other fields and how they depend on the Higgs field’s value.
cription I gave above of how the Higgs particle’s mass comes about is not unique
iggs, but its relation to this complex curve, which comes from the quantum
tions of other fields, is special.
September 11, 2013 at 12:55 AM | Reply
nk you very much for the explanation.
September 11, 2013 at 3:47 AM | Reply
arding “the Higgs field is the only (known) field for which there’s something
plicated to calculate in order to determine whether the energy of empty space
ers it to be zero or not”:
read that in the theory of the strong interaction (QCD) the vacuum has interesting
cture, too. In particular that there are quark and gluon condensates characterizing
acuum. Wouldn’t these also be due to fields that prefer to be non-zero in empty
September 11, 2013 at 11:34 AM | Reply
ood point. I should have said: “elementary field”. Quark and gluon fields do not
ave any such issue, but composite fields made from a combination of quark and
nti-quark fields, and from pairs of gluon fields, have this issue. I will get into this
ubject when discussing “solutions”.
eptember 10, 2013 at 2:30 PM | Reply
ewhat confused. You state Vmax is how far you could push the value of higgs field
tolerance of the standard model, but that does not seem to imply the real field has
in fact unless I misunderstand it is deemed to be 246 which is low and does not
nnatural factors – so why do you need to push the foundations of the model that
September 10, 2013 at 8:27 PM | Reply
nt here is not to put the cart before the horse. We have *measured* the Higgs field
6 GeV. But to show that the theory *predicts* this, we need to show that 246 GeV
lly a minimum of the energy. To prove this we must do a general calculation that
first assume that the Higgs field is low. Otherwise we’d be in danger of assuming
e were trying to prove.
’t worry; if we *had* assumed that the Higgs field’s value was small, but that the
rd Model was valid up to vmax >> 500 GeV, then we would simply have
red, by calculation, that our assumption was wrong… and that there is indeed no
m in the low-Higgs-field region at all.
September 11, 2013 at 5:30 AM | Reply
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– but even according to your text 246 does not have to be the absolute but just the
onal minimum so why strain a good model to breaking point?
September 11, 2013 at 11:27 AM | Reply
mm. Not sure I understand you yet. We want to understand whether the good
complete model or not. If it is the complete model, then the
hought experiment of pushing up the Higgs field to large values should be
gitimate. And then we discover that if it *is* the complete model, it actually isn’t
hat good, because there won’t be a minimum in the energy anywhere near 246
eV. Which leads us to think it can only a good model up to around 500-1000 GeV,
nd then we should expect other phenomena to start showing up, or maybe
omething else weird is going on.
September 11, 2013 at 12:17 PM |
Sorry seems Im the one who does not understand but not sure where I go wrong:
There is one higgsfield at 246GeV – correct?
Because its there, there has to be minimum in the energy density at this level – ?
We dont know why but we dont need any unnatural factors to make it so?
If the field were >>500GeV we would need unnatural factors – but it is’nt – why
does the standard model have to hold for for hypothetical fields that do not/ or
may not exist – as an analogy its like designing a car that can go 500mph but
knowing you can never exceed 60mph on the highway
| September 11, 2013 at 12:50 PM |
Ah — do not confuse the Higgs field’s actual value with v_max. v_max is as large
as we *COULD* take the field and still trust our equations. The issue isn’t
whether the Higgs field’s value is >> 500 GeV ; it’s whether the equations
would correctly describe the world if the Higgs field’s value were that big.
Say it this way: Suppose you know a car can go at 500 mph, but you discover the
car is going at 60 mph. Now you want to explain: why is at 60 mph, given that it
can go 500 mph? One way to find out is: try running the car (maybe just in your
mind) at 200 mph, at 300 mph, at 400 mph, at 20 mph, at 30 mph. Maybe you
discover that the engine’s force and friction on the wheels exactly balance at 60
mph: if you try to run the car at 20 mph, it will speed up; but if you try to run it
at 300 mph, it will slow down; and right at 60, it will coast.
But now imagine, for example, that you had a car that could go 500 mph, and
had an engine that was powerful enough to go that fast in the absence of friction.
Wouldn’t you be surprised if it turned out that the engine and friction balanced
when the car was going 0.0001 mph? Our problem is vaguely akin to this.
Thanks for your questions. You and several other commenters are finding a
number of pedagogical flaws. I’m going to have to do a serious rethink of to
reword some of this article.
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September 11, 2013 at 3:49 PM |
Thanks for your patience,
Okay in the case of the car model I have to assume there is a hidden direct
correlation between the car’s speed and the friction, and I suppose this is what
you show in diagram 7, but if that correlation becomes known, would it not
From diagram 5 it would however appear you dont need absolute cancelation as
long as the curve beyond 500 does not dip lower than the point at 246, so if you
have a field that increases exponentially as the first of the blue graphs (would be
interesting to know what field that represents) and it were considerably stronger
than any other field one could postulate that no more potential lowpoints lie
beyond 500+, wouldnt that be a more “natural” assumption?
| September 11, 2013 at 7:15 PM |
It isn’t just an issue of whether the correlation is known; the issue is whether it is
a pure accident, or whether there’s a reason.
As for the second paragraph’s suggestion: if that were the case, then, if there
were no accidental cancellations, then the minimum of the curve would be at
zero, and thus the Higgs field’s average value would be zero and the particle’s
mass would be large — in short, you’d have a world in class 2. Not class 3.
September 12, 2013 at 7:14 AM |
Going through the comments I think I was asking the same as JonW in a
somewhat naiver way and thanks to your explanations to me and also to him I
think I now finally get the picture (more or less). When I say correlation I mean
with an underlying but unknown reason because random would be unnatural
and I guess thats what youre saying too – I suppose somewhat a long shot but if
particles are produced in pairs, maybe universes are also and then could we not
possibly imagine a corresponding “anti-universe” with all fields reversed – if
such two opposing universes were in the process of still separating or possibly
colliding then could this lead to an overall field cancellation and appear locally
similar to the situation that we experience now?
| September 12, 2013 at 10:24 AM |
You could imagine that, but now make equations that actually do it. That’s the
hard part. Then, having succeeded, make a prediction based on those equations.
That, too, may be difficult.
September 12, 2013 at 1:16 PM |
The maths to do that is beyond me, but I would predict that a mixture of
opposing universes would not be very stable, at least not for a sufficiently long
time to get to the present stage
September 10, 2013 at 3:10 PM | Reply
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id that there is no such thing as a vacuum, it was as a question, but in a sense
ield permeate all of space? At some time matter must have sprung from fields at
t in the creation of the universe? Right? Of course that would be the particles that
e Hydrogen and Helium, etc.. You can speak of virtual particles which spring in
existence evidently due to the peaks in waves that fields have, I would think.
looking at from the perspective of how I would visualize an ocean wave peak out
isappear, yet the ocean still fills all space, though we only see the surface. Please
less than knowledgeable questions.
September 10, 2013 at 6:05 PM | Reply
ave said no such thing as empty space, not vacuum, sorry.
September 11, 2013 at 1:16 AM | Reply
The fact that things are cancelling out and the total energy is nearly flat is another
ing that there is some unknown symmetry in nature! And what is that symmetry if
e draw you attention to a recent blog by Sean Carrol where he discusses the early
m dark matter searches which are giving hints of dark matter at 5-10 GeV energy
pointed out that if that turns out correct, then there might be roughly equal
baryons and dark matter particles which might have something to do with baryon
nservation. What kind of symmetry can give rise to equal number of heavier (but
avy) dark matter candidates. And other results point to interacting (Exciting) dark
nting to presence of dark electromagnetism like forces that do not interact with
September 11, 2013 at 11:31 AM | Reply
etry is only one possible explanation. Dynamical effects can cause this also. I will
ing dark matter: again, a symmetry is only one possible explanation. It could also
ark forces and dark particles, see: http://arxiv.org/abs/hep-ph/0604261
September 12, 2013 at 12:00 AM | Reply
have an error in your text. There is at least one theory which haven’t that
September 12, 2013 at 2:02 AM | Reply
ven’t read carefully. There are MANY theories that don’t have a naturalness
, and I am going to explain the most famous ones soon. I will not explain those
only believed in by one person, however.
September 12, 2013 at 2:25 AM | Reply
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I made the decision to take another route (in order to change the paradigm
article physics), experiments it is. My last option so to speak. But blasting small
gh amount of antimatter without high tech lab equipment is going to be
remely* difficult. So wish me luck! :)
eptember 12, 2013 at 1:44 AM | Reply
ne, for example, that you had a car that could go 500 mph, and had an engine that
ful enough to go that fast in the absence of friction. Wouldn’t you be surprised if it
that the engine and friction balanced when the car was going 0.0001 mph? Our
ust an issue of whether the correlation is known; the issue is whether it is a pure
r whether there’s a reason.”
use my bombastic replies to Larson wherein I included all physicists and launched
attack on Standard Model. I think I know what you are saying, but your article is
nical for my understanding of physics. I merely wish to understand the principles
se concepts and can not completely subscribe to SM theory because of the
problem and the BB theory. SM works by and large and is proven with tests but it
universe appear unnatural because, as you explained to “zbynek” the universe is
to include higher energies in Higgs field when it works perfectly well at the much
gies. No, there must be a reason for that. Universe must have more fields operating
aps another force or body of energy that operates on the space. I know you don’t
for other people’s ideas on what could be out there but just suppose that universe
bble floating in hyperspace, that it isn’t a brane either but just an empty space
sing a real source of unimaginable energy. Suppose that energy is seated in the
ur universe and our universe is orbiting this source. Say that we are at a safe
om the radiation of this source, a goldilocks zone but closer and further distances
could be that margin of possibilities that some physicists see as multiverse
Ok, that’s my two pennies worth of contribution to this topic and discussion. I
sics will have to readapt to new concepts, because the old one is ready to be
Tabues in physics are preventing fine scientist like you from exploring other
s. May be with the next generation of scientists, things will begin to move on. No,
e wrong, standard model could be the closest thing to reality of this universe, a
tep forward, but it must not stagnate. I’m truly mesmerized with you taking so
general audience that has no knowledge or very little knowledge of physics. Thank
September 12, 2013 at 2:01 AM | Reply
ot completely subscribe to SM theory because of the singularity problem and the
ndard Model describes all particles and forces *except* gravity. The singularity
hich we don’t even know is an issue) has nothing to do with the Standard Model.
Bang theory (which is in excellent agreement with measurements — I don’t know
u dislike it, given how fantastically well it works) involves both gravity and the
rd Model. If you don’t like the Big Bang theory, you probably dislike the gravity
it, and not the Standard Model anyway. As for the Standard Model alone, if you
ke it, you have some explaining to do: it works for hundreds of measurements. It
t be the whole story — indeed it is unlikely to be the whole story — even for
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vitational physics. But it works extremely well.
pression that physicists are wedded to the conventional wisdom and close-minded
ly wrong. When I go to conferences, there are always many talks that go beyond the
tional wisdom. The particular suggestion that you made (or something similar) has
ly been considered. But the problem is that there are dozens and dozens of such
ions, many far more radical than what you suggest. Almost all of them will turn out
rong; I could fill this blog with all the crazy false ideas that I and my colleagues
d, and it would make this blog impossibly confusing. (Other bloggers approach
e differently.) I tend to report the mainstream, and especially the best-established
the mainstream; I think that is the best way to explain what we think we know.
course, some of what is mainstream now will be discarded someday; that’s certain.
don’t know which parts will be discarded, or why… so we have no choice but to be
, work hard, and wait for experimental or theoretical insights to push us in the
September 14, 2013 at 2:59 AM | Reply
nks Matt, for giving it to me straight. I’m at great odds coming against you, for if I
why can’t SM explain gravity, you’d just say because we haven’t discovered
itons yet. (I could be wrong in my assumptions). Something is truly a puzzlement
, with the theory of particles. We have various fields. Every particle comes as a
le of that field. You say, fermions have zero energy fields. To me this means that
icle mops up the pre-existing field, if particles are ripples in a field. So, if not out of
s field then from a composite field of EM and nuclear (strong and weak) fields.
s field gives mass to some particles but not to Higgs boson which is scalar in
re and has no spin (?) How can a particle exist without a spin? Higgs boson has a
mass but Higgs field is not giving it that mass. Could we say then that Higgs
n doesn’t exist without a collision of hadrons and is a by-product of that collision
that a kinetic energy of that collision produces it.
ularity being mathematical deduction of gravitational force’ capabilities, yes
n’t belong in SM because SM cannot explain gravity with the known particles. I get
, I knew that. I just mentioned it anyways. Why can’t I accept SM? Because its
d on the philosophy that everything in nature must balance out. So we have
icles and antiparticles. This leads to an alternate realities theory, which to me is as
atural as can be. Why do the things have to balance out? That leads to a conclusion
universe came out of zero energy? If that’s not unnatural, I don’t know what is.
t: Multiverse problem: where did the first universe come from? Big Bang theory:
y start, gloomy ending; universe is on a ‘self-destruct’ course. Mankind has no
re since we cannot leave this universe. Scouting the galaxy by manipulating the
ical laws, creating wormholes is a short term solution if achievable. And then
ping out of the incinerating hug of our dying star or, getting wiped out by an
roid or a comet or, by our own means. I think that universe is a much better place
what theory suggests. Yes, Its full of deadly radiation, but something placed us in
fe place. Now, that would be unnatural if nothing else exists but a physical process
olution, (creation and destruction of matter), and we just happen to be an accident
is mindlessness. That to me would be highly unnatural. Otherwise, Standard
el doesn’t bother me at all. OH, I might have a wrong view of physicists as a whole,
you are not in that group, so I’m glad I stumbled on your blog.
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hing you all a positively peaceful, relaxing, rejuvenating weekend!
tember 12, 2013 at 5:41 AM | Reply
n with data does mean identity with ontology , plus if we take the agreed upon fact
termination of theories by data can’t we recognize that maybe ontology in its most
tal primary aspect is something totally different than field activities with virtual
o matter how many experiments match our purpose tailored data-match designed
tember 12, 2013 at 6:05 AM | Reply
deep grand secret of nature is that it is so constructed that the mind can describe
ny mathematical structures , every one of which matches data and able to predict
tions , that is fantastic interaction between Mind and Nature , it is the interaction
t be ignored anymore .
hat we see in ontological aspects of scientific theories.
tember 12, 2013 at 6:32 AM | Reply
e Matt. , I am confused ; is nature un-natural as it is or as we see it or as some of us
n-naturalness relative or absolute or in the category ( maybe , perhaps , it could
ear cut answer , isn’t that science ?
September 12, 2013 at 10:23 AM | Reply
ndard Model is unnatural as quantum field theory experts see it. That is: the
rd Model is a quantum field theory (and quantum field theory applies also to many
stems in nature, mainly those in solid-state physics.) Examination of the physical
s to which quantum field theory applies suggests that our understanding of how
m field theory works is excellent. Among all those systems, particle-like ripples are
n, and there are some that are Higgs-like. If you look at all the other systems, you
nd a light Higgs-like ripple with a mass-energy mc^2 far less than the energy scale
h you find other particles and forces associated with that ripple… or more
ly, the few cases where you do find it are very well-understood, and the principles
ply in those cases don’t apply to the Standard Model. All of this suggests strongly
r understanding of quantum field theory in general, and the naturalness issue in
, on the other hand, is not yet known to be unnatural, because we don’t know
yet. Only if we can show, using the LHC and other experiments, that v_max is
rger than 500 GeV will be able to conclude that nature itself is, in this sense,
tember 12, 2013 at 7:39 AM | Reply
y noticed , I am always looking into the global not the partial , so , is it safe -for
he mind – to say as a global absolute fact that the mighty forces of OUR cosmos
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ed in a truly unexpected razor edge equilibrium ?
s , no , we don’t know . Thanks.
September 12, 2013 at 10:25 AM | Reply
not make statements yet about our universe — only about the theory known as the
rd Model (plus gravity) which may or may not describe our universe. Remember:
’t know v_max, and we don’t know yet that it isn’t 500 GeV, with discoveries at the
ber 12, 2013 at 9:14 AM | Reply
re are your articles on the Standard Model (or =partial grand unified theory?) that
s prediction (by calculation) and experimental data? I heard you saying repeatedly
is spectacularly accurate and that sounds pretty good. but I want to see, check,
ate its accuracy one(by calculation) to one (by data/experiment/observation) for
le) concrete specific physical phenomenon. I also want to know where/how/why
aks down and where(under what conditions(range/scale/applications etc.)) it is
h specific (simple) examples. For what applications is the SM useful? Is the SM
odeling/calculating a behavior of a living cell or a molecular machinery inside a
proper simulations does the SM accurately picture/draw photon – molecule
? For example, how a single (or multiple?) photon(s) interact and alter structures
molecules inside a cell?, or how the molecule emits a photon(s)? Does the SM
pletely accurately describe every single moment of how a photon is absorbed to a
uring photosynthesis (with where the energy is localized in which fields at every
Could you point me to such simulation models (CG/video simulation etc.)? Or the
simulations(with real data) by SM which describes/depicts/draws the propagation
September 12, 2013 at 10:38 AM | Reply
find a few hundred things to check if you read
/twiki.cern.ch/twiki/bin/view/AtlasPublic
/twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResults
lhcbproject.web.cern.ch/lhcbproject/CDS/cgi-bin/index.php
cds.cern.ch/collection/ALEPH%20Papers?ln=en
l3.web.cern.ch/l3/paper/publications.html
www-zeus.desy.de/zeus_papers/zeus_papers.html
of the results from the last 20 years; there are hundreds more from
inspirehep.net/search?ln=en&ln=en&p=collaboration+jade&of=hb&
search=Search&sf=year&so=a&rm=&rg=100&sc=0
re no known and confirmed large deviations from the Standard Model, and
ly no glaring ones, within any particle physics experiment. That means: agreement
any tens of thousands, of independent measurements (and if you count each data
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s a separate measurement, you’d probably be in the millions). By contrast, if you
heory which is like the Standard Model but is missing one of the three
vitational forces or one of the types of particles that we know about, it would be
ut by hundreds, even thousands, of experiments.
y things in nature that are known not to fit within the Standard Model plus
energy (which you can put into Einstein’s gravity by hand, but presumably that’s
matter (we have ideas on what it might be, but nothing in the Standard Model can
rino masses (which require a small amount of adjustment to the theory — this may
September 12, 2013 at 10:43 AM | Reply
ere’s a separate part of your question: for what phenomena is it *useful* to use
rd Model equations, rather than some simplified version. For photons interacting
olecules, trying to use the Standard Model in its full glory would be impossibly
hoose what you want to study (molecules)
take the Standard Model and derive simpler versions of the equations that apply
study of molecules — giving up details in return for simplicity
then use those simpler equations to study complex molecules and their interaction
rick, and the subtlety, is step 2. You might fail to come up with sufficiently simple
ns, so you can’t carry out step 3; or you might oversimplify and then step 3 won’t
f course, that’s not a failure of the Standard Model; it’s a failure on scientists’ part
of a way to apply it to a complex problem.
ss to say, if you want to check the Standard Model carefully, you check it on simpler
s first! And there it has an incredible track record. And yes, you can derive atomic
, and the interaction of atoms and light, from the Standard Model, although if the
complex you have to rely on computers; and you can go on from there to derive
er techniques for studying complicated molecules, etc.
September 13, 2013 at 1:34 AM | Reply
t, yes, what you say sounds consistent (but just listing papers would not be so
ful). So, I want to see this part “Needless to say, if you want to check the Standard
el carefully, you check it on simpler problems first!” Could you demonstrate a few
le(er, st) cases (readable/understandable for freshman level physics) for 1)SM
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ks well and 2)SM fails? If you do not have time just one good demonstration
paring “calculation” and “experimental data”) for each (1 and 2) are fine. How
t, how the SM draws/simulates a propagation of a photon in vacuum? I hope it is
le enough so that it is easy to generate such animated CG movies in 3D coordinate
time change. I want to see how a photon radiates/moves/propagates (how photon
behave) in 3D CG as time ticks with all the known field values visibly fluctuating
haps with vector and color density representations etc.) in real time. Or, 3D video
esentations(=accurate simulation by SM) of quantum fluctuation in vacuum itself
ld be nice (if possible). Or, how electron field and photon field (with all the known
ulable/observable parameters like field direction, energy/wave localization/shape,
direction of the photon and the electron etc.) behave when a photon is emitted (or
rbed to) from an electron in 3D CG movie with time.
tember 12, 2013 at 1:12 PM | Reply
at , the SM does not specify any constant , does not specify any coupling strength ,
ason for three generations of particles , nor any hint for any system of force values
said before , it is only an effective theory meaning a tool for us to calculate
tember 12, 2013 at 1:53 PM | Reply
the collapse of hope to produce the above mentioned unknowns via the M-theory
o the power 500 of ensembles are possible and where all hope to find a theory
all cosmic parameters instead of inputting them by hand vanished , even
g new forces and particles via any rout cannot solve that fundamental problem of
parameters generating mechanism , and as such any hope of solving the hierarchy
ay be rendered as a mirage.
September 12, 2013 at 2:30 PM | Reply
There is no reason for this conclusion. What happened to the M theory dream —
ay have nothing to do with the real world — has no bearing on whether the
hy problem has a solution.
tember 12, 2013 at 3:41 PM | Reply
it is so , without a theory to specify the parameters of nature we can never explain
n between plank,s mass and W , Z masses , or the ratio of gravity force to other
hat is the hierarchy problem as stated by you , the death of M-theory dream killed
o solve the problem…….so it is so Matt. ……….it is so my friend.
tember 12, 2013 at 5:00 PM | Reply
it is logically impossible to construct a mathematical system in which the
of the SM are the variables which solving the system we get their values since then
f meta- constants are required to solve the equations which in turn need hyper-
ding to infinite regression.
September 12, 2013 at 5:48 PM | Reply
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there is a puzzle if you hold the following assumption to be true: “there’s no
ason to expect these unknown effects in red are in any way connected with the
he cancellation of the different terms, the blue and red ones, some kind of strong
ere is such a connection? The reason might not be obvious, but doesn´t it look
ome might say, even “obvious”) that such a reason must (or could) exist?
rought up an analogy, like: Imagine some thousand pieces of metal, all of different
t when you put them all together, you get a car instead of just a pile of metal. Isn´t
e? Well, only if you assume the pieces were created independently of each other.
my question, many thanks for your efforts to explain us this matter.
September 13, 2013 at 12:34 PM | Reply
, I had the same reaction early on in learning about these matters (in which I am
ovice, and a layman). I believe one response often given is that it is not obvious
eason (for cancellation between opposing terms) must exist, because there is an
tive: a multiverse, where each nucleating bubble has its own physics, and anthropic
n effects lead to the values in our unverse being constrained to come so close to
ng, with no further explanation necessary or even possible for things taking on the
hey do in our observed reality.
only half-serious, but I think the analogous reasoning in your example of a car
e: let’s say you are a member of a species that can only exist inside a car. And you
universe where thousands of pieces of metal, of random different shapes and
re created from nothing, thrown together randomly and spewed out into space,
d over and over again without end. You find yourself in a car, wondering just how
got put together and what caused its pieces to fit together just so. It turns out
no good reason that would satisfy you, save that you couldn’t have been there in
t place to ask the question in the Vast majority of assemblages–the fact of your
ce selects from among these assemblages only those, a Vanishing minority, that
ope it turns out there’s more of a reason that this though!
tember 13, 2013 at 9:03 AM | Reply
verse is impossible to exist without un-naturalness or hierarchy
tence is not the cause of our universe
erse is not the cause of our existence
re no laws , principles , rules….etc that dictate a similar scale to the energies and
e is the un-naturalness problem? Is it in the mind of the beholder ?
September 28, 2013 at 10:46 PM | Reply
io9.com/did-the-higgs-boson-discovery-reveal-that-the-universe-512856167
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tember 13, 2013 at 1:44 PM | Reply
f energies and forces in the universe does not follow our expectations of their
but are chosen to satisfy the attributes of a viable universe ……….. So where is
tember 14, 2013 at 11:11 AM | Reply
att. To say that the origin of naturalness problem is naturalism and the physicists
ns that the universe should follow their criteria , but for the cosmos itself it feels no
hatsoever having weak scale 16 orders of magnitude less that plank!s scale
follow the universe not the expectation .
n-Naturalness or A Miracle? | The Way
tember 15, 2013 at 1:55 PM | Reply
trassler : In my stand based on many studies and comparisons , the
lness aspect and the hierarchy problems are in reality features of the supreme
f our universe where the problemness is in our concepts not in reality.
aying this that you welcome those who agree with you and those who are not
, not with the scientific part but with the philosophical part of what you say.
tember 15, 2013 at 3:37 PM | Reply
e explanation of the most (un-natural) aspect of space , that is , existing of all
ields in a state of complete interconnection occupying same space without
n a global universal shortcircuit of all possible interactions simultaneously
the universe in a state of ultimate chaos ?
Quantum Gravity and Cosmology Conference | Of Particular Significance
tember 16, 2013 at 2:15 PM | Reply
vice : please read what any unbiased mind would reach in the pingback link @
lness or miracle , I do respect the writer very much for saying what many refuse to
id the LHC Just Rule Out String Theory?! | Of Particular Significance
an Nature be unnatural? | The Great Vindications
vitonsandagradstudent | September 23, 2013 at 12:30 PM | Reply
me of you may have read that these calculations of the energy of empty space give
ults. This is true and yet irrelevant; it is a technicality, true only if you assume
finitely large — which it patently is not. I have found that many people,
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ists and scientists alike, believe (thanks to books by non-experts and by the
enerations of experts — even Feynman himself), that these infinities are important
nt to the discussion of naturalness. This is false. We’ll return to this widespread
tanding, which involves mistaking mathematical technicalities for physically
effects, at the end of this section.]”
pression that here (and in the section it refers to) that you’re going for a slightly
udience than the rest of the piece, namely the grad-student-just-out-of-QFT
e. If that is what you’re going for, I think the section doesn’t really address the
ource of confusion. You point out that finite theories still have hierarchies, but I
reater source of confusion is why infinite theories are pathological at all. When
re first introduced to renormalization (especially via stuff from the previous
of experts) it’s often stated that the infinities are actual infinities, which are then
luded in the bare values of the relevant constants. Essentially, this is the “why not
mensional regularization?” confusion, which often makes people new to the subject
erstand why divergences are a problem in the first place. I don’t know if this would
rom your primary audience, but you might want to briefly address this particular
September 23, 2013 at 12:37 PM | Reply
still feel that way regarding the second attempt to address this issue at the end of
4gravitonsandagradstudent | September 23, 2013 at 3:32 PM | Reply
t’s the section I was referring to, actually. You mostly emphasize that the issue of
ities is a technical one, and that finite theories also have naturalness problems.
t shows the issue of infinities and the issue of naturalness are distinct, but if
eone started out the section wondering why we can’t just set vmax to infinity/use
reg, that wouldn’t dissuade them.
pose in a way, the counter to that is earlier in the article, in that even if you took
ite vmax seriously you’d just need infinite fine-tuning and thus would be infinitely
atural. While the structure buries this a little since you dismiss infinite vmax early
our current structure works better for the majority of readers. So on reflection I
’t think there’s anything you need to add, besides maybe a quick note for those who
ht take vmax=infinity seriously.
September 24, 2013 at 8:55 AM | Reply
es, in the end, if a young expert-in-training doesn’t understand this point even
fter what I’ve written, he or she is going to have to go through the exercise: take a
heory that has even the littlest bit of physics beyond the Standard Model, even just
ne heavy fermion with a large mass M and a small Higgs boson coupling y; use
im-reg or anything else to get rid of the infinities; and look at how the Higgs
ass-squared depends on M. That fermion comes in and blows everything to
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September 23, 2013 at 5:56 PM | Reply
on one minor point. In mentioning this fine-tuning of the Higgs field or Higgs
,000,000,000,000,000,000,000,000 (to use your number), you say, “Such
ine-tuning” of the properties of a physical system has no precedent in science.”
re seem to be at least two other similar cases of equally amazing “fine-tuning” :
ning of the cosmological constant (vacuum energy density) to one part in 10 to the
er (quantum field theory gives us an expected value 10 to the 120th power higher
ighest value compatible with supernova observations).
ning of the proton charge and electron charge, which match to 1 part in 10 to the
r, something unexplained by the standard model.
gs field fine tuning seems to be not at all a unique case in nature.
September 24, 2013 at 8:46 AM | Reply
ing (1) — I do discuss this, extensively, elsewhere. But the problem with the
ogical constant is that it too is unexplained. We do not have a proof, as yet, that its
alue is due to fine-tuning, so we can’t give it as an example of fine-tuning, only one
fine-tuning. Still, I perhaps should have clarified the wording.
ing (2) — interesting point, but I don’t think this is fine-tuning either. In many
ons of the Standard Model, anomaly cancellations fix this ratio to be exactly 1. If
ere only one generation of fermions, the anomalies would fix the ratio precisely.
s can’t vary; they don’t get quantum corrections. So if a symmetry or geometrical
ship (like anomaly cancellation) fixes the ratio to be 1, it will be forever 1, no
what happens. This is not true for the Higgs particle’s mass, which depends, for
e, on the values of all scalar fields in the universe and on every parameter in the
uantum Field Theory, String Theory, and Predictions (Part 7) | Of Particular Significance
legance, Not So Mysterious | 4 gravitons and a grad student
hat’s the Status of the LHC Search for Supersymmetry? | Of Particular Significance
isiting the University of Maryland | Of Particular Significance
100 TeV Proton-Proton Collider? | Of Particular Significance
hat if the Large Hadron Collider Finds Nothing Else? | Of Particular Significance
May 15, 2014 at 6:32 PM | Reply
w whether it’s just me or if perhaps everyone else encountering problems with
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59 of 62 10/21/15 10:23 AM
ite. It seems like some of the text on your content
g off the screen. Can someone else please comment and let me know if this is
ell? This might be a problem with my web browser because
is happen previously. Many thanks
June 21, 2014 at 2:11 AM | Reply
acture and export physics lab equipment / instruments for school, college and
boratory since 1954. We are based in Ambala.clic more
July 7, 2014 at 11:13 PM | Reply
every other wonderful post. Where else could anybody get that kind of
n in such an ideal approach of
have a presentation next week, and
search for such information.
July 26, 2014 at 2:40 AM | Reply
ice. I have a basic question.
fields were present in some empty space. Then quantum fluctuations occurred and
ergy. Then E=mc^2 starts to function. Inflation occurs. And the rest is history.
pty space came into existence at first place?
uantum fields came into existence at first place?
hysics 101: Just Act Natural | The Creation Club | A Place for Biblical Creationists to Share and
September 22, 2014 at 4:34 AM | Reply
e that i noticed yoou visite my web site thus i got here
he favor?.I am trying to in finding issues to enhance my web site!I assume its
ove It or Hate It, Don’t Fear the Multiverse | 4 gravitons
November 17, 2014 at 9:46 PM | Reply
this very informative article. I am eagerly awaiting your take on possible solutions
ural” problem. There is an interesting paper by Moffat that might be worth a look,
Natural SUSY may not be found.
iv.org/abs/hep-th/0610162
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he Anthropic Problem, Entropy, and AI | Random Musings
January 18, 2015 at 6:25 PM | Reply
ikipedia that “As of November 2006, the Standard Model doesn’t work”. This
ain why we have these problems. Personally, I don’t believe in quarks: protons and
re made up of electron, positrons, and neutrinos. Other particles such as the pions,
positrons, electrons, and photons which subsequently split into electron-positron
implies that protons ARE made of positrons and electrons and possibly neutrinos.
explain how radioactive nuclides can capture atomic electrons, emit beta minus
lus – these particles are already in the nuclides (except the captured electron which
e in the nucleus). Shouldn’t the unstable particles and the quarks be removed from
rd Model table and the whole shebang rewritten? This may solve hierarchy and
ess problems and maybe the cosmological constant problem.
March 30, 2015 at 2:56 PM | Reply
mething that still eludes me. Hope you may help.
uite get how do we know that all the contributions, as in Figure 5 add to the green
ay “What We Observe About the Higgs Field and Particle.”
his is not the result of a calculation within the SM, otherwise, why do we need to
ct we know from measurements? Have we observed the energy density, or the
egardless of the momentum cut-off?
April 6, 2015 at 9:40 AM | Reply
at stuff, thanks. I’m a high school teacher and convinced that I have to work this
hat’s the Matter with Dark Matter, Matt? | 4 gravitons
May 26, 2015 at 3:27 PM | Reply
to find your blog: As an Asperger (visual thinker) I find myself trying to explain to
ple” that the brain has the capability of processing information in various
and that individuals can favor using one or more. I became a geologist because I’m
irely a visual processor, despite having verbal skills. Math? Yikes! It’s a language I
erstood, but abstract thinking is difficult. Your posts do an excellent job of
distinctions between terms and concepts which I can grasp as structure and
posted a link to your blog for Aspergers like me. Thanks!
ergerhuman.wordpress.com
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