To quote Sheldon from tonight’s episode, “This is a photograph of the 1911 Solvay Conference on the theory of radiation and quanta:”
Unlike Sheldon, I have not Photoshopped anything onto it. That’s not to say the above photo isn’t doctored, however. See the fellow with the gray beard sitting at the table? That’s Ernest Solvay, the Belgian Industrialist who sponsored the conference. He couldn’t be present for the photo, so his head was pasted over that of a stand-in. I heard they did it with Photoshop running on a Windows 11 laptop.
Solvay made his fortune by inventing a manufacturing process for sodium carbonate, a process used to this day. In the Solvay method, seawater was mixed with limestone to produce soda ash, the common name for sodium carbonate. Among its many uses, soda ash “softens” water; it takes up the magnesium and calcium found in “hard water” that would otherwise limit the washing action of detergent. Soda ash is used to reduce the acidity of food without using harsher chemicals, such as lye. In an important industrial process, soda ash is used to coat raw pretzels, which gives them their nice brown skin upon cooking.
Solvay dedicated much of his fortune to philanthropy, including seminal meetings among the leading luminaries of physics. Such was the origin of the first of these, the 1911 Solvay Conference.
So what happened at the Solvay Conference? I’ve consulted my go-to source on particle-physics history, the book Inward Bound, by Abraham Pais. Setting the stage for the conference, Ernest Rutherford, had just completed his famous experiments indicating that an atom has a dense central nucleus surrounded by electrons located thousands of times farther away than the radius of the nucleus. In his lab, electrically charged alpha particles scattered backwards from a gold foil target, indicating they were encountering a dense region of electric charge.
But Rutherford didn’t say a word about it at Solvay 1911. Meanwhile Marie Curie, also present, was headed down a different path to the same discovery. She realized the radioactive nature of elements had nothing to do with their chemical properties such as reactivity, thermal conductivity, etc. She was spot on:
Radioactive phenomena form a world apart, without any connection with the preceding phenomena. It seems therefore that radioactive phenomena originate from a deeper region of the atom, a region inaccessible to our means of influence and probably also to our means of observation, except at the moment of atomic explosions. -Marie Curie
Rutherford was in the audience, having already realized that his alpha particle scattering experiments showed exactly this. But he said nothing.
And yet to this day Rutherford is credited with the discovery of the atomic nucleus. As well he should be, since he designed and interpreted the experiments that proved it true. Of course Marie Curie did wonderful other experiments in her own right, elucidating the nature of radiactivity. Both won their own Nobel prizes.
Here’s a little Inside-Hollywood information. The boards Sheldon used tonight were not set dressing; they were a prop. Most weeks, I send the material for the whiteboards to the set-dressing department. They take care of furniture, various decorations on the set–and for our show–the white boards. But tonight was special. Sheldon touched a board. Anything an actor touches automatically becomes the purview of a different department–the properties department. So these particular boards were props.
If you take a closer look at these props, you will see he has Bayes’ theorem up there. Perhaps that’s because since he is studying the meaning of some genetic tests. Here’s a question about medical tests, showing you must know Bayes’ theorem to understand what yours mean. Suppose you take a blood test for a disease that only has a small chance of error: Say 99% of the time the test identifies the disease when one is present. But also rarely, say 5% of the time, it will say you have the disease when you don’t. Question: Your test comes back positive; what is the probability that you have the disease?
Answer: Not enough information.
You still need to know the probability that the disease occurs in your population and apply Bayes’ theorem, the theorem on the board. It is straightforward to see. If we test you for smallpox with such a test, a disease nobody on Earth has, then 1 time in twenty (5%) you will be positive for smallpox, even though we know you don’t have the disease. Now if only 0.5% of the population has the disease and you test positive, then there is still over a 90% chance you don’t have the disease. This is why your doctor does not give you the tests that would have found problems early…it would cost too much in all those who were identified as false positives. From your insurance company’s point of view, you aren’t worth it.
As for the family tree on the board, that is official genetic counselor notation. My sister Linda just graduated with a master’s degree in genetic counseling and she gave me all the symbols to use, including that Sheldon has a fraternal (“dizygotic”) twin, Missy. So for this episode , your consultant consulted a consultant.
(Tonight’s blog edited by my friend Karen Joyce, USAP)