Chance Favors The Prepared Mind
Chance Favors The Prepared Mind (Louis Pasteur) What is a prepared mind? John O’Sullivan, editor of PSI, recently posted, unknown to me, an essay I had written in 2013. (https://principia-scientific.com/education-and-science-science-and-education/) This essay was from a blog-site I had begun at that time. (http://semivision.blogspot.com/)
The first paragraph of my first essay was:
While one could point to a multitude of problems, which the society of the USA face, I am most concerned with its general state of education and of science. I was a student when the general performance of USA students was competitive with those of other countries; we know that is no longer true. I was a community college chemistry instructor during the time while this sad transition was occurring. Only after I retired, did I really begin to see the truth of the quote: “It is the great arrogance of the present to forget the intelligence of the past.” (Ken Burns)
What is a prepared mind? One that is aware of history.
A not so short story about Pasteur (1822-1895):
Tartaric acid, its potassium salt known in antiquity as “tartar”, has served as the locus of several landmark events in the history of stereochemistry. In 1832 the French chemist Jean Baptiste Biot observed that tartaric acid obtained from tartar was optically active, rotating the plane of polarized light clockwise (dextrorotatory). An optically inactive, higher melting, form of tartaric acid, called racemic acid was also known.
A little more than a decade later, young Louis Pasteur conducted a careful study of the crystalline forms assumed by various salts of these acids. He noticed that under certain conditions, the sodium ammonium mixed salt of the racemic acid formed a mixture of enantiomorphic hemihedral crystals; a drawing of such a pair is shown on the right. Pasteur reasoned that the dissymmetry of the crystals might reflect the optical activity and dissymmetry of its component molecules. After picking the different crystals apart with a tweezer, he found that one group yielded the known dextrorotatory tartaric acid measured by Biot; the second led to a previously unknown levorotatory tartaric acid, having the same melting point as the dextrorotatory acid. Today we recognize that Pasteur had achieved the first resolution of a racemic mixture, and laid the foundation of what we now call stereochemistry. (https://chem.libretexts.org/LibreTexts/Winona_State_University/Klein_and_Straumanis_Guided/5{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}3A_Stereoisomerism/5.05{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}3A_Stereoisomeric_Relationships_-_Enantiomers_and_Diastereomers/001_Pasteur’s_Discovery_of_Enantiomers)
While there are more reasons than one to consider Burn’s quote, Pasteur’s quote, and the history of what chemists were doing in the 19th Century, only shortly after John Dalton had concluded that matter was composed of tiny particles which we now call atoms, I will (to keep this essay reasonably brief) only consider the one which I conclude is the more important to the mess of science and education.
It is a tale of two professors, one a chemist and one a physicist. Both Nobel Prize Laureates and both professors at the California Institute of Technology (Caltech) in the 1960s.
Linus Pauling in the preface of the 3rd Ed. of College Chemistry (1964) wrote:
The theories of greatest value in modern chemistry are the theories of atomic and molecular structure, quantum theory (quantum mechanics) and statistical mechanics. I believe that the concepts involved in these theories can be learned by the beginning student of chemistry sufficiently well for him to apply them in correlating and understanding the facts of descriptive chemistry. Moreover, the fundamental experiments upon which these theories are based can be understood by the beginning student. The theories in their detailed mathematical treatment can then be studied later.
Richard Feynman in the preface of The Feynman Lectures on Physics (1963) wrote:
..it is perfectly clear that students who will major in physics can wait until their third year for quantum mechanics. On the other hand, the argument was made that many of the students in our course study of physics as a background for their primary interests in other fields. And the usual way of dealing with quantum mechanics makes the subject almost unavailable for the great majority of students because they have to take so long to learn it. … So I tried to describe the principles of quantum mechanics in a way which wouldn’t require that one first know the mathematics of partial differential equations. … However, I think that the experiment in the quantum mechanics part was not completely successful. … I now believe the quantum mechanics should be given at a later time.
Sutcliffe (Weather and Climate (1966) wrote:
To decry schools of geography has been a commonplace reaction of the physicist, presumably because they did inadequately many things which the physicist had on his conscience and should have been doing himself.
Clearly Sutcliffe, a meteorologist considered the knowledge of the physicist to be the salvation of meteorology.
However, Sutcliffe could have read The Feynman Lectures on Physics and discovered that Feynman had question his student’s the question (32-8): Why do we ever see the clouds?
And he could have read about Feynman’s simple and brief explanation of a long known (observed) phenomenon—Tyndall (colloid) scattering (effect). Except Feynman never identified that the light (radiation) scattering that he explained was Tyndall (colloid) scattering (effect).
But he did summarize his brief explanation:
So as the water agglomerates the scattering increases. Does it increase ad infinitum? No! When does this analysis begin to fail? How many atoms can we put together before we cannot drive this argument an further? Answer: If the water drop gets so big that from one end to the other is a wavelength or so, then the atoms are no longer all in phase because they are too far apart. So as we keep increasing the size of the droplets we get more and more scattering, until such a time that a drop gets about the size of a wavelength, and the the scattering does not increase anywhere nearly as rapidly as the drop gets bigger. Furthermore, the blue disappears, because for long wavelengths the drops can be bigger, before this limit is reached, than they can be for short wavelengths. Although the short waves scatter more per atom than the long waves, there is bigger enhancement for the red end of the spectrum than for the blue end when all the drops are bigger than the wavelength, so the color is shifted from the blue toward the red.
Is what Feynman taught (wrote) so difficult to understand? Yet I have yet to read a meteorologist or a physicist who has written about that which you have just read. That I have not read such should not imply that no meteorologist or a physicist has written about what Feynman taught.
But consider what I copy at Wikipedia about Tyndall scattering (effect):
The Tyndall effect, also known as Willis–Tyndall scattering, is light scattering by particles in a colloid or else particles in a very fine suspension. It is named after the 19th-century physicist John Tyndall. It is similar to Rayleigh scattering, in that the intensity of the scattered light depends on the fourth power of the frequency, so blue light is scattered much more strongly than red light.
Now, I go back to the history of one of Pasteur’s achievements. I conclude, and believe many chemists would agree, that we embrace the quantum mechanics because of Jean Baptiste Biot’s observation of a natural phenomenon which young Pasteur, seemingly was aware of Biot’s observation.
He moved the topic forward by using a magnifying glass and a tweezer picked the different crystals apart and found that on group yielded the known known dextrorotatory tartaric acid measured by Biot.
For it was clear to Pauling and other chemists (who had participated in the Manhattan Project that produced the quantum mechanical bomb which ended WWII) that quantum mechanics explained the atom which we already knew because of observations such as Boit’s and Pasteur’s.
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