Tag Archives: Lise Meitner

The uses and abuses of molarity — III

2 dimensional gases were made years and years ago but no one talks about them any more. I found them fascinating as a neophyte chemistry student. Just take a typical fatty acid with a long hydrophobic tail (say stearic acid with 18 carbons) and place a small amount on water. The COOH groups hydrogen bond with the water, while the hydrocarbon tails lie on the surface of the water. Confine them to a small area, and the hydrophobic tails stick straight up away from the air water interface. Now constrict the area they are found in. The force on the wall forming the constriction is proportional to the number of molecules in the area and the area and the temperature — e.g. PA = nRT — the ideal gas law in two dimensions. So confined stearic acid on the surface of water is a two dimensional gas.

It would be nice if we could get a similar 2 dimensional arrangement of G Protein Coupled Receptors (GPCRs) — see the previous post — but we can’t (so far). 

Of course there is a darker side. The films are known as Langmuir Blodgett films.

Irving Langmuir won the Nobel prize in Chemistry for this (and other work). Blodgett who was instrumental in figuring out how to make the films got nothing. 

Why?  Probably because she was a woman — https://en.wikipedia.org/wiki/Katharine_Burr_Blodgett..  She was a Bryn Mawr graduate and the first woman to receive a PhD in physics from Cambridge. 

Moving along to another Bryn Mawr graduate; Candace Pert really discovered the opiate receptor at Johns Hopkins. She was screwed out of proper recognition by her PhD advisor, Solomon Snyder.  While he now has a department named after him at  Hopkins,  he will never receive the Nobel prize. 

The story of Rosalind Franklin and DNA is too well known to repeat.  So I’ll close with Lise Meitner who discovered nuclear fission and got nothing except a book from an old girl friend — https://www.amazon.com/Lise-Meitner-Ruth-Lewin-Sime/dp/0520208609.  The authoress notes in the preference that she was the female chemist that the department didn’t want.  Definitely a woman with an edge, which is why I was attracted to her. 

Now, as promised, here is the Nobelist who clearly doesn’t understand Molarity.

The chemist can be excused for not knowing what a nanodomain is. They are beloved by neuroscientists, and defined as the part of the neuron directly under an ion channel in the neuronal membrane. Ion flows in and out of ion channels are crucial to the workings of the nervous system. Tetrodotoxin, which blocks one of them, is 100 times more poisonous than cyanide. 25 milliGrams (roughly 1/3 of a baby aspirin) will kill you.

Nanodomains are quite small, and Proc. Natl. Acad. Sci. vol. 110 pp. 15794 – 15799 ’13 defines them as hemispheres having a radius of 10 nanoMeters from channel (a nanoMeter is 10^-9 meter — I want to get everyone on board for what follows, I’m not trying to insult your intelligence). The paper talks about measuring concentrations of calcium ions in such a nanodomain. Previous work by a Nobelist (Neher) came up with 100 microMolar elevations of calcium in nanodomains when one of the channels was opened. Yes, evolution has produced ion channels permeable to calcium and not much else, sodium and not much else, potassium and not much else. For details read the papers of Roderick MacKinnon (another Nobelist). The mechanisms behind this selectivity are incredibly elegant — and I can tell you that no one figured out just what they were until we had the actual structures of channels in hand. As chemists you’re sure to get a kick out of them.

The neuroscientist (including Neher the Nobelist) cannot be excused for not understanding the concept of concentration and its limits.

How many ions are in a cc. of a 1 molar solution of calcium — 6 * 10^20 (Avogadro’s #/1000).A cc. (cubic centimeter) is 1/1000th of a liter) How many ions  in a 10^-4 molar solution (100 microMolar) — 6 * 10^16. How many calcium ions in a nanoDomain at this concentration? Just (6 * 10^16)/(5 * 10^17) e.g. just over .1 ion/nanodomain. As Bishop Berkeley would say this is the ghost a departed ion.

Does any chemist out there think that speaking of a 100 microMolar concentration in a volume this small is meaningful? I’d love to be shown how my calculation is wrong, if anyone would care to post a comment.

 

Off to band camp for adults 2018

No posts for a while, as I’ll be at a chamber music camp for adult amateurs (or what a friend’s granddaughter calls — band camp for adults).  In a week or two if you see a beat up old Honda Pilot heading west on the north shore of Lake Superior, honk and wave.

I expect the usual denizens to be there — mathematicians, physicists, computer programmers, MDs, touchy-feely types who are afraid of chemicals etc. etc. We all get along but occasionally the two cultures do clash, and a polymer chemist friend is driven to distraction by a gentle soul who is quite certain that “chemicals” are a very bad thing. For the most part, everyone gets along. Despite the very different mindsets, all of us became very interested in music early on, long before any academic or life choices were made.

So, are the analytic types soulless automatons producing mechanically perfect music which is emotionally dead? Are the touchy-feely types sloppy technically and histrionic musically? A double-blind study would be possible, but I think both groups play pretty much the same (less well than we’d all like, but with the same spirit and love of music).

A few years ago I had the pleasure of playing Beethoven with Heisenberg —   along with an excellent violinist I’ve played with for years, the three of us read Beethoven’s second piano trio (Opus 1, #2) with Heisenberg’s son Jochem (who, interestingly enough, is a retired physics professor).  He is an excellent cellist who knows the literature cold.  The violinist and I later agreed that we have rarely played worse.  Oh well. Heisenberg, of course, was a gentleman throughout.

Later that evening, several of us had the pleasure of discussing quantum mechanics with him. He didn’t disagree with my idea that the node in the 2S orbital (where no electron is ever found) despite finding the electron on either side of the node, forces us to give up the idea of electron trajectory (aromatic ring currents be damned).   He pretty much seemed to agree with the Copenhagen interpretation — macroscopic concepts just don’t apply to the quantum world, and language trips us up.

One rather dark point about the Heisenberg came up in an excellent book about the various interpretations of what Quantum Mechanics actually means: “What Is Real?” by Adam Becker.  I have no idea if the following summary is actually true, but here it is.   Heisenberg was head of the German nuclear program to develop an atomic bomb.  Nuclear fission was well known in Germany, having been discovered there.  An old girl friend wrote a book about Lise Meitner, one of the discoverers and how she didn’t get the credit she was due.

At the end of the war there was an entire operation to capture German physicists who had worked on nuclear development (operation Alsos).  Those captured (Heisenberg, Hahn, von Laue and others) were taken to Farm Hall, an English manor house which had been converted into a military intelligence center.  It was supplied with chalkboards, sporting equipment, a radio, good food and secretly bugged to high heaven.  The physicists were told that they were being held “at His Majesty’s pleasure.”.  Later they told the American’s had dropped the atomic bomb.  They didn’t believe it as their own work during the war led them to think it was impossible.

All their discussions were recorded, unknown to Heisenberg.  It was clear that the Germans had no idea how to build a bomb even though they tried.  However  Heisenberg  and von Weizsacker constructed a totally false narrative, that they had never tried to build a bomb, but rather a nuclear reactor.  According to Becker, Heisenberg was never caught out on this because the Farm Hall transcripts were classified.  It isn’t clear to me from reading Becker’s book, when they were UNclassified, but apparently Heisenberg got away with it until his death in 1978.

Amazing stuff if true