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Slide 2 More on the A-Word Credit: Anthony Aguirre, Martin Rees, Frank Wilczek Blame: Max Tegmark Slide 3 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 dse Slide 4 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Big Bang Zoom Four gradual discoveries: The Universe is much larger than once imagined The Universe can be well described mathematically In most theories, we cant observe everything that exists There are selection effects Slide 5 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Big Bang Zoom How big is our Universe? Slide 6 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Big Bang Zoom Four gradual discoveries: The Universe is much larger than once imagined The Universe can be well described mathematically In most theories, we cant observe everything that exists There are selection effects - probability that a random point in our observable universe is near the surface of a planet ~ 10 -43 Slide 7 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Big Bang Zoom If we want to test a mathematical theory predicting a larger universe than we can observe, then were forced to compute anthropic selection effects. That this is hard isnt Alex Vilenkins fault! So we shouldnt vent our frustrations on those who try to work on the problem.. Slide 8 Cmbgg OmOl The Standard Model Lagrangian (From T.D. Gutierrez) L=L= Slide 9 Cmbgg OmOl Standard model parameters: Cosmology Particle physics Required Optional C = h = G = k b = q e = 1 Slide 10 Cmbgg OmOl How measure ? Standard model parameters: Cosmology Particle physics Required Optional Why these values? Slide 11 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Cmbgg OmOl Slide 12 Slide 13 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 wmap movie Slide 14 (Graphics from Gary Hinshaw/WMAP team) Slide 15 Fluctuation generator Fluctuation amplifier (Graphics from Gary Hinshaw/WMAP team) Hot Dense Smooth Cool Rarefied Clumpy Brief History of the Universe Slide 16 MATTER BUDGET INITIAL CONDITIONS (Q) Required Optional tot Slide 17 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 OUR TOOLS Slide 18 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Smorga sbord Slide 19 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Measuring clustering Slide 20 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 History CMB Foreground-cleaned WMAP map from Tegmark, de Oliveira-Costa & Hamilton, astro-ph/0302496 Slide 21 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Boom zoom z = 1000 Slide 22 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Boom zoom z = 2.4 Mathis, Lemson, Springel, Kauffmann, White & Dekel 2001 Slide 23 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Boom zoom z = 0.8 Mathis, Lemson, Springel, Kauffmann, White & Dekel 2001 Slide 24 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Boom zoom Mathis, Lemson, Springel, Kauffmann, White & Dekel 2001 z = 0 Slide 25 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 1par movies LSS Slide 26 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 1par movies LSS Clusters Tegmark & Zaldarriaga, astro-ph/0207047 + updates Slide 27 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 1par movies LSS Clusters CMB Tegmark & Zaldarriaga, astro-ph/0207047 + updates Slide 28 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 1par movies Ly LSS Clusters Tegmark & Zaldarriaga, astro-ph/0207047 + updates CMB Slide 29 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 1par movies Ly LSS Clusters Lensing Tegmark & Zaldarriaga, astro-ph/0207047 + updates CMB Slide 30 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 1par movies Ly LSS Clusters Lensing Tegmark & Zaldarriaga, astro-ph/0207047 + updates CMB Slide 31 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 But the best is yet to come Precision, 21cm tomography, Slide 32 Cosmological data Fundamental theory ? Cosmological Parameters Nature of dark matter? Nature of dark energy? Nature of early Universe? Why these particular values? Slide 33 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 PREDICTING Slide 34 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 PREDICTING It's tough to make predictions, especially about the future. Yogi Berra Slide 35 Cmbgg OmOl Mass of Earth 5.974210 24 kg Radius of Earths orbit 149,597,870,691 m Mass of electron 9.1093818810 -31 kg Bohr Radius of Hydrogen atom 5.29177x10 -11 m Parameter status? Slide 36 Cmbgg OmOl Mass of Earth 5.974210 24 kg Semimajor axis of Earths orbit 149,597,870,691 m Mass of electron 9.1093818810 -31 kg Bohr Radius of Hydrogen atom 5.29177x10 -11 m Parameter status? Environmental Fundamental? Slide 37 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Cmbgg OmOl Slide 38 Big Bang Zoom What are the 4 multiverse levels like? 1)Same effective laws of physics, different initial conditions 2)Same fundamental laws of physics, different effective laws 3)Nothing qualitatively new 4)Different fundamental laws of physics Slide 39 Cmbgg OmOl A)What determines the constants of nature? B)What do the constants of nature determine? Most of our paper Motivates B Certified 100% philosophy free! Slide 40 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Cmbgg OmOl Three little numbers: Slide 41 Cmbgg OmOl R~ /m p M~ m p Weisskopf 1975 Carr & Rees 1979 Slide 42 Cmbgg OmOl R~ 1/ 1/2 1/2 m p 2 M~ 3/2 3/2 /m p 2 Slide 43 Cmbgg OmOl R~1/m p 2 1/2 M~ 3/2 /m p 2 Weisskopf 1975 Carr & Rees 1979 Slide 44 Cmbgg OmOl R~ /m p 3/2 3/4 M~ 3/4 /m p 1/2 Carr & Rees 1979 Slide 45 Cmbgg OmOl R~ /m p 3/2 3/4 M~ 3/4 /m p 1/2 Carr & Rees 1979 Slide 46 Cmbgg OmOl Slide 47 M~ /m p 2 Weisskopf 1975 Carr & Rees 1979 Slide 48 Cmbgg OmOl R~ 3 /m p 3 3/2 M~ 5 /m p 3 1/2 Carr & Rees 1979 Slide 49 Cmbgg OmOl R~ /m p 5 M~ /m p 5 Carr & Rees 1979 Slide 50 Cmbgg OmOl Based on Carr & Rees 1979, Barrow & Tipler 1986 Inside black hole Below quantum limit Slide 51 Cmbgg OmOl Based on Carr & Rees 1979, Barrow & Tipler 1986 Inside black hole Below quantum limit Fine-tuning? NO! Slide 52 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Big Bang Zoom MT 1998, gr-qc/9704009, Ann. Phys., 270, 1-51 Slide 53 Cmbgg OmOl Most spectacular fine tuning known outside cosmology is arguably in nuclear physics Slide 54 Cmbgg OmOl Agrawal, Barr, Donoghue & Seckel 1998, PRL, 80, 1822 v/v 0 5: neutrons (udd) unstable even in nuclei v/v 0 >10 3 : protons (uud) decay to ++ (uuu) Effect of Higgs VEV v=246 GeV: Savas will return to this! Slide 55 Cmbgg OmOl Jeltema & Sher, hep-ph/9905494 carbon oxygen 20 M sun 5 M sun 1.3 M sun + 8 Be 8 Be+ 12 C 12 C+ 16 O C & O yield given by one parameter that depends on , m u / QCD, m d / QCD : Oberhummer, Csoto & Schlattl, astro-ph/0007178, Science, 289, 88 Slide 56 Cmbgg OmOl 4 effective spatial dimensions: no stable orbits, no stable atoms (Ehrenfest 1917; Tangherlini 1963) MT 1997, gr-qc/9702052, Class. Quant. Grav., 14, L69-75 Slide 57 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Big Bang Zoom MT 1997, gr-qc/9702052, Class. Quant. Grav., 14, L69-75 Slide 58 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Cmbgg OmOl HOW TEST/RULE OUT A THEORY? A theory is tested by confronting its prediction f(p) with the observed parameter vector p obs Prediction f(p) f prior (p) f selec (p) Some fast-and-loose anthropic arguments ignore this factor Slide 59 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Cmbgg OmOl HOW TEST/RULE OUT A THEORY? A theory is tested by confronting its prediction f(p) with the observed parameter vector p obs Prediction f(p) f prior (p) f selec (p) Some fast-and-loose anthropic arguments ignore this factor Some papers ignore this factor Neither term is optional! Slide 60 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 ` V Slide 61 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Cmbgg OmOl * 2nd term: involves astrophysics, not biology, since were not made of dark matter Challenge: find an example where both terms can be computed. Case study: axion dark matter * 1st term: Prior: analytically computable Slide 62 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Boom zoom Mathis, Lemson, Springel, Kauffmann, White & Dekel 2001 z = 0 Slide 63 Cmbgg OmOl Slide 64 Slide 65 Slide 66 Slide 67 Slide 68 Slide 69 Slide 70 Slide 71 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Cmbgg OmOl Slide 72 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Cmbgg OmOl Measured value=4eV Slide 73 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Cmbgg OmOl DARK MATTER CONCLUSIONS: Axions theory appears viable If WIMPs contribute up cosmologically relevant dark matter density, then natural to have two dark matters! So any LHC SUSY hints need precision followup, perhaps with linear accelerator Work needed on both terms f prior (p) & f selec (p) Wish list 1: f prior (p) from inflation, landscape Wish list 2: f selec (p) from chemistry & nuclear physics Slide 74 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Cmbgg OmOl Debating what to choose? Theres no choice! A theory is tested by confronting its prediction f(p) with the observed parameter vector p obs Prediction f(p) f prior (p) f selec (p) Some fast-and-loose anthropic arguments ignore this factor Some papers ignore this factor No need to choose between traditional and anthropic calculations - neither is optional! Slide 75 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Q: Are theories like inflation, which predict the existence of other unobservable Hubble volumes (parallel universes), untestable? A: No, as long as they also make predictions for things we can observe. Indeed, many inflation models were so testable that theyre already ruled out, like V( ) 4. PHYSICS OR PHILOSOPHY? ? Slide 76 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Big Bang Zoom Bottom line: Taking anthropic selection effects is not optional when confronting a theory with observation Parallel universes are not a theory but a prediction of certain falsifiable theories (cf. black hole interiors) Critique of anthropic reasoning has largely shifted from It makes no sense and I dont like it to I dont like it I think its good that many people disagree with my views! Slide 77 Max Tegmark Dept. of Physics, MIT tegmark@mit.edu St Thomas March 8, 2006 Big Bang Zoom Beware anthropic principle taken to the Epicurean extreme: The Universe must be such that we like it Slide 78 Big Bang Zoom Even if we cant predict everything, the universe still isnt so bad!