Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of...

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Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors Ken Dickey Boise State University Philosophy Nyssa High School Chemistry

Transcript of Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of...

Page 1: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Why Water isn’t H2O(short answer: cuz it’s a mixture!):

A case study in how the history of science and science itself loosens the

grip of Realist metaphors

Ken DickeyBoise State University Philosophy

Nyssa High School Chemistry

Page 2: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

The Miracle of Semantic Realism

“Suppose I point to a glass of water and say ‘this is called “water”’…[T]he body of liquid I am pointing to bears a certain sameness relation (say, x is the same liquid as y…) to most of the stuff I and other speakers…have on other occasions called ‘water’.”

-- Hillary Putnam, “Meaning and Reference”

Page 3: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

The Miracle of Semantic Realism

“Suppose I now discover the microstructure of water – that it is H2O.”

“…the extension of the term ‘water’ was just as much H2O on Earth in 1750 as in 1950…”

-- Hillary Putnam, “Meaning and Reference

Page 4: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

The Miracle of Semantic Realism

In sum, I can point to one thing or one sample and utter a word. By the miracle of semantic realism, that word picks out all other parts of the world that have the same ?!? as my sample. Of course, this only works for natural kinds terms like ‘water’.

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Page 6: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Characteristics of natural kinds terms

• “Carve nature at its joints”• Reveal fundamental patterns of the world• Pick out the final categories that scientists

ultimately strive for• Identify things by their “real essence”

(usually microstructural features), not their “nominal essence”

• Once dubbed, their extension does NOT depend on human decision-making

Page 7: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Characteristics of natural kinds terms

• Once dubbed, their extension does NOT depend on human decision-making

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Putative Examplesof Natural vs. non-natural kinds terms

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Natural vs. Non-natural

• Temperature (average kinetic energy of tiny particles)

• ‘x has a temperature of __ oC’

• Warmth (a judgement that varies from individual to individual)

• ‘x is warm’

Page 10: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Natural vs. Non-natural

• Plant (multi-cellular organism with cells containing chloroplasts and cell walls)

• ‘x is a plant’

• Mountain (vague rise in topography)

• ‘x is a mountain’• Mountain vs. hill

Page 11: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Natural vs. Non-natural

• Globular Cluster (group of stars formed from the same nebula and bound locally by gravity to form a spherical shape)

• Constellation (recognizable pattern of stars in the sky)

• Pattern varies with location in the galaxy

• Pattern identification reflects human interests

Page 12: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Natural vs. Non-natural

• Ant Colony (grouping of ants with inter-dependent roles and directed by a single queen ant)

• Penal Colony (a human institution created to fulfill human needs/goals)

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It is the appeal to microstructure, I believe, which legitimates (in the minds of some) what I am terming the “miracle of semantic realism”.

Most people will agree that the extension (or “meaning”) of ordinary English predicates depends on human decision-making. For example, there is an active debate now over whether the term ‘marriage’ applies only to male-female unions, or could also apply to same-sex unions. Again, there was a recent debate within the scientific community over whether the term ‘planet’ should apply to bodies as small as Pluto.

But it is believed that some English predicates escape this reliance on on-going human decision-making (that’s the “miracle”). These are the so-called ‘natural kinds’ terms. What allows these terms to stand on their own, it is believed, is that, once dubbed, their extension is determined by a pure microstructure, one which could very well escape the notice of language users. Once this microstructure takes over the meaning of a word, connecting it to the fundamental patterns of nature, no amount of human decision-making can circumvent that (or so it is believed).

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Natural vs. Non-natural

• Bird (warm-blooded, feathered creature with wxyz DNA characteristics)

• ‘x is a bird’

• Plane (a human invention)

• ‘x is a plane’

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Natural vs. Non-natural

• Oxygen (element with atomic number 8)

• Phlogiston (substance with sometimes-negative weight, posited by scientists to explain experimental results but later rejected)

Page 16: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Natural vs. Non-natural

• Water (H20)

• ‘x is a bit of water’

• Mud (a mixture containing water and “dirt” in unspecified proportions)

• ‘x is a bit of mud’

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A Lesson in the History of Science

Yawn…

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How it was discovered that water is H2O

Page 19: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Joseph Louis Proust

                                                                           

French chemist

Born September 26, 1754)Angers, France

Died July 5, 1826 (aged 71)Paris,France

Law of Definite Proportions

Water sample A = 18 grams

16 g oxygen and 2 g hydrogen

16 g O / 2 g H = 8 O :1 H

Water sample B = 27 grams

24 g oxygen and 3 g hydrogen

24 g O / 3 g H = 8 O :1 H

Sample C = 32 g O / 4 g H = 8 O :1 H

LDP: In a chemical compound, the ratio of elements is always the same, regardless of sample.

* Note, this is NOT true of mixtures!

Discovering Water is H2O

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John Dalton

                                                                           

Born September 6, 1766)

Died July 27, 1844 (aged 77)

Law of Multiple Proportions

40 g of Lye (Draino)

23 g Na, 16 g O, 1 g H

16 g O / 1 g H = 16 0 : 1 H

27 g of Water

24 g O / 3 g H = 8 O : 1 H

62 g of Ethylene glycol (antifreeze)

24 g C, 32 g O, 6 g H

32 g O / 6 g H = 5 1/3 O : 1 H

32 g of Methanol (wood alcohol)

12 g C, 16 g O, 4 g H

16 g O / 4 g H = 4 O : 1 H

Discovering Water is H2O

Page 21: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

John Dalton

                                                                           

Born September 6, 1766)

Died July 27, 1844 (aged 77)

Law of Multiple Proportions

In Lye 1 g H : 16 g O, the lowest ratio, so s’pose

Lye = 1 H : 1 0

In Water 1 g H : 8 g O or 2 g H : 16 g O

Water 2 H : 1 O

In Ethylene glycol 1 g H : 51/3 g O or 3 g H : 16 g O

E. G. = 3 H : 1 O

In Methanol 1 g H : 4 g O or 4 g H : 16 g O

Methanol = 4 H : 1 O

LMP: When the same elements combine into different compounds, they do so in the ratio of small whole numbers.

Discovering Water is H2O

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John Dalton

                                                         

                 

Law of Multiple Proportions

But the ratio of masses says nothing about the MICROSTRUCTURE of water.

For that we need…………

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Dalton’s Atomic Theory(about 1803)

                      

        Various atoms and molecules as depicted in John Dalton's A New System of Chemical Philosophy (1808).

1. All elements are composed of tiny indivisible particles called atoms.

2. All atoms of the same element are identical. The atoms of any one element are different from those of any other element.

3. Atoms of different elements can combine with one another in simple whole number ratios to form compounds.

4. Chemical reactions occur when atoms are separated, joined into molecules, or rearranged. However, atoms of one element are never created nor destroyed by a chemical reaction.

Discovering Water is H2O

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Dalton’s Atomic Theory

+

2 Hydrogen atoms 1 Oxygen atom

1 molecule of water = H2O

Page 25: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Discovering water is H20

Ta da….

But this is not the end of the story…

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What Came Next

Page 27: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

What Came Next

• The Russian chemist Dmitri Mendeleev organized all of the known elements into a pattern that is today considered to be the first periodic table.

• Mendeleev’s table allowed him to predict the existence of previously unknown elements!

• Predictive power lent great credence to the emerging science of chemistry, founded on Dalton’s atomic theory. Mendeleev’s original periodic table

published in 1869 based the order of elements on their atomic mass.

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What Came Next

However…

Page 29: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

What Came Next

• Mendeleev’s table was arranged by atomic mass.

• This created puzzles where a few elements seemed to be “out of place”.

• Trusting the pattern-like character of his table, Mendeleev insisted the masses of elements simply had not been accurately determined.

• But the puzzles remained…

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Page 31: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

What Came Next

• The “fix” could not be had until the overthrow of Dalton’s atomic theory.

• It started with the discovery of the electron by J.J. Thomson in 1897.

Page 32: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

What Came Next

J.J. Thomson’s famous cathode ray experiment. The degree of deflection indicated a very high charge-to-mass ratio. These deflected particles must have been much smaller than even a hydrogen atom.

Page 33: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

What Came Next

Dalton’s Atomic Theory(about 1803)

                      

        Various atoms and molecules as depicted in John Dalton's A New System of Chemical Philosophy (1808).

1. All elements are composed of tiny indivisible particles called atoms.

Not anymore!

Comment on conceptual vs. empirical revision?

Page 34: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

What Came NextRutherford’s famous experiments involving gold foil soon followed.

Page 35: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

What Came Next

He discovered the atomic nucleus and the proton. His student Moseley introduced the concept of atomic number, which justified the correct placement of elements within the periodic table.

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What Came Next

Still later (1922), the mass spectrometer was used to isolate different atoms of the same element with different masses. In 1932, neutrons were discovered and used to explain how these atoms differ.

Isotopes = atoms of the same element with different masses (same atomic number, but different numbers of neutrons)

Page 37: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

What Came Next

Dalton’s Atomic Theory(about 1803)

                      

        Various atoms and molecules as depicted in John Dalton's A New System of Chemical Philosophy (1808).

2. All atoms of the same element are identical.

Not anymore!

Page 38: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

What Came Next

The existence of neutrons and isotopes explained WHY Mendeleev’s arrangement of elements was flawed.

The chemical properties of atoms were determined by the number of protons (and electrons). But atoms with more protons did not necessarily have (on average) more neutrons.

So, in a few exceptional cases, elements with a greater atomic number could still have a lesser atomic mass.

Mendeleev, working with Dalton’s atomic theory, could never have known this.

Page 39: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

                  

                  

       

                

Protium Deuterium Tritium

Three isotopes of hydrogen

More to the point…

Page 40: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

In any actual sample of water, all of these isotopes will be integrated within water molecules. That means, we could have:

P2O (almost all naturally occurring water)

DPO (about 1 in 3200 natual water molecules)

D2O (about 1 in 41 million water molecules)

PTO (trace)

DTO (trace)

T2O (trace)

And all are “water” molecules!

Page 41: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

A Strong Intuition of Mine

At the time of discovering isotopes of hydrogen, scientists COULD HAVE decided that only P2O is really water, and that DPO (and D2O) are impurities. Since they did not make that decision, it remains acceptable to say that water is H2O. Still, the fact that there was such a “decision point” casts doubt on whether the term ‘water’ uttered in 1750 referred to H2O once and for all, independently of all subsequent decision-making. That is, it casts doubt on whether the term ‘water’ IS a natural kind term.

Page 42: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Characteristics of natural kinds terms

• “Carve nature at its joints”• Reveal fundamental patterns of the world• Pick out the final categories that scientists

ultimately strive for• Identify things by their “real essence”

(usually microstructural features), not their “nominal essence”

• Once dubbed, their extension does NOT depend on human decision-making

Page 43: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Philosophical Upshot

• The discovery that water is H2O rests on a theory of the atom that has since been supplanted.

• A more modern theory of the atom still accepts the claim that water is H20, but would insist there is more going on than just that.

• This casts doubt on whether ‘water’ picks out a “final category that scientists ultimately strive for”.

Page 44: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

So much for the history of science…

What about the science of water itself?

Page 45: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

The Miracle of Semantic Realism

In sum, I can point to one thing or one sample and utter a word. By the miracle of semantic realism, that word picks out all other parts of the world that have the same ?!? as my sample. Of course, this only works for natural kinds terms like ‘water’.

Page 46: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Any sample of ordinary water dubbed as ‘water’ in 1750 was surely a MIXTURE of H2O with gobs of other stuff!

A new start to the debate…

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Page 48: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

So it will be difficult to isolate what the essential features of water are such that all subsequent samples of water have the same ?!? as the originally dubbed sample of water.

A new start to the debate…

Page 49: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Another way to see this point is through pH or even perhaps taste testing.

A new start to the debate…

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Page 51: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.
Page 52: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Ordinary samples of water simply do not have the same pH (or taste!) as so-called “pure” water.

A new start to the debate…

Page 53: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.
Page 54: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

But surely we can PURIFY water to remove everything except the H2O, can’t we?

(Not really, as we shall see)

Even the ancients could collect RAIN water, which is free of original contaminants.

(But not of “new” contaminants, as we shall see)

The next step…

Page 55: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

The Water Cycle

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Page 57: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Meanwhile, high up in the clouds, chemical reactions are occurring…

Nitrous Oxide (from lightning or internal combustion)NO + ½ O2 NO2

3NO2 + H2O NO + 2 HNO3 (Nitric acid)

Sulfur Dioxide (from volcanoes or coal burning)

SO2 + ½ O2 SO3

SO3 + H2O H2SO4 (Sulfuric Acid)

Carbon Dioxide (from decomposition, burning, exhaling)

CO2 + H2O H2CO3 (Carbonic Acid)

The next step…

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So regular rain water has a pH of about 5, and even lower (so-called “acid rain”), if it is subjected to very high levels of industrial pollution.

A new start to the debate…

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O.K. Appealing to rain water for “pure” water was a bad idea. Still, we can get pure water here on the ground through the process of distillation.

Another avenue for debate…

Page 62: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Distillation Apparatus

Impurities remain behind as only H2O boils and condenses

Page 63: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

You don’t have to go up high into the atmosphere to run into the problem of atmospheric gases dissolving in water. The atmosphere will “come to you”!

(Note: this is why fish can breathe underwater)

Another avenue for debate…

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Atmospheric and dissolved gases are continually exchanged through a dynamic equilibrium

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Page 66: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Henry’s Law:

“At a given temperature the solubility of a gas in a liquid is directly proportional to the (partial) pressure of the gas above the liquid.”

Dickey’s Corollary to Henry’s Law:

“If there is any gas whatsoever near the surface of a liquid, some of that gas is going to get dissolved into the liquid.”

Another avenue for debate…

Upshot: Even distilled water is impure, insofar as it has dissolved gases in it.

*At 20oC and 1 atm, water is 0.0023% dissolved air (by mass).

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All right, then. Let’s REMOVE the atmosphere entirely!

•Even if there isn’t a naturally-occurring place on Earth that is atmosphere-free, we can CREATE such a place in the lab.

•As philosophers can certainly IMAGINE water existing in the absence of any atmosphere to cause contamination.

Yet another try…

Page 69: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Interesting idea… Do you know what HAPPENS to water when you remove all of its atmosphere?

It boils! Check it out!

Then you don’t have water at all (which is a liquid), but instead a vapor.

Yet another try…

Page 70: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Not if NOT ALL of the water boils! Then you could have an equilibrium with liquid water, H20 vapor, and H20 vapor dissolved in the liquid water.

The final rejoinder…

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Then perhaps you could still say that water is a “mixture”, but it would be a mixture consisting ENTIRELY of H2O!

And this water “mixture” really DOES have a pH of 7

The final rejoinder…

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Page 74: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Is THAT supposed to be what people were talking about in 1750, when they used the term ‘water’ to describe what they were drinking, bathing in, watering plants with, etc.?

The final rejoinder…

Page 75: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

That’s the way natural kinds terms work!

You use a word, but neither you nor anyone has to know what the word refers to. That’s something to be discovered by scientists, no matter how long and complex the process is.

As it turns out, water – PURE WATER – really is nothing but H2O!

The final rejoinder…

Page 76: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

There is just one little problem…

H2O molecules are constantly in motion, crashing into one another, jostling, and even scraping parts off of one another.

Self-ionization of water shockwave animation

Page 77: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

H2O + H2O OH- + H3O+

Hydroxide Hydronium ion ion

Self-ionization of H2O

Page 78: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

At 25oC, Kw for this process is 1.0 x 10-14

(That’s why the pH scale ranges up to 14.)

This means that for “pure” water,

[H3O+] = 1.0 x 10-7 M (hence the “7” for pH);

[OH-] = 1.0 x 10-7 M

Combined, these impurities occur at a concentration of 2.0 x 10-7 M, and since water itself has a concentration of 56 M, this means…

One little problem…

Page 79: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

[Ions] / [H2O] = 2.0 x 10-7 / 56 = 3.6 x 10-9

This means that for every sample of water,

0.00000036%

of the water is NOT H20, no matter what lengths one takes to purify it!

One little problem…

Page 80: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

So water is not really just H2O, no matter how pure you try to make it.

One little problem…

Page 81: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

One little problem…

Page 82: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Conclusions

1. That water is H2O is a prime exemplar of essentialism in semantics. ‘Water’ is held to be a natural kind term that “carves nature at its joints” because of the supposed truth of this claim.

Page 83: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Conclusions

2. But the discovery that water is H2O is part of an unfolding historical process, one which has since moved beyond the claim in question, onto what are arguably even more fundamental ways to “carve up reality”.

Page 84: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Conclusions

3. Furthermore, what ordinary people for centuries have taken to be water is NOT purely H20, but is instead a mixture that at the very least contains dissolved gases from the atmosphere.

Page 85: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Conclusions

4. And finally, there is simply no possible way to purify water so that it is not a mixture (i.e., so that it contains only H2O). At the very least, it must contain trace quantities of hydronium and hydroxide ions.

Page 86: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Conclusions

In sum, the term ‘water’ does not carve nature at its fundamental joints, and the identification of water with H20 is, strictly speaking, false.

It is, no doubt, and extremely useful idealization of what’s really going on with water.

But useful idealizations are not what Semantic Realism promises.

Page 87: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Limitations

Water being only one example, this argument certainly can not disprove realism in semantics, nor can it establish that there are no natural kinds terms.

Page 88: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Benefits

But: for those of us who are suspicious about claims that scientists have arrived at a final answer about anything, or claims that certain words carve reality at its joints, pointing out that ‘water’ is NOT the clear example that many take it to be does provide some satisfaction.

Page 89: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Benefits

And for those who are watching the debate from the sidelines, this argument might help them to remain in an appropriately skeptical state of suspended judgement.

Page 90: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

Benefits

Finally, it is time to recognize that general plausibility of the view that there are natural kinds terms at all relies more on some compelling metaphors rather than a close examination of details. To learn that water is NOT H2O will, I hope, loosen the grip of those Realist metaphors.

Page 91: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.
Page 92: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.
Page 93: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

A P.S. Rejoinder?

• O.K., so water is not just H2O; it is a mixture. Still, that doesn’t prove ‘water’ is not a natural kind term.

• Water, we have learned, is really a mixture consisting mostly of H20 with 1.0 x 10-7 M of hydronium ions and 1.0 x 10-7 M of hydroxide ions.

• People who have used the term ‘water’ throughout history, without realizing it, were referring to that mixture.

Page 94: Why Water isn’t H 2 O (short answer: cuz it’s a mixture!): A case study in how the history of science and science itself loosens the grip of Realist metaphors.

A P.S. Rejoinder?

• This response is really an example of getting the point but not getting the lesson.

• Any argument of the form ‘x is too simple because of y’ can be met with the response that ‘x is now modified to take into account correction y’.

• But to go on to assert that the modified x is now the final answer, or even that there is a final answer, is to make a leap of faith.

• The lesson of the case-study for ‘water’ is that this leap of faith is not justified.