Archive for April, 2008

Einstein and me

Monday, April 28th, 2008

I never met Einstein, which is not surprising, since he died over 20 years before I was born. [Update: Make that 12 years.  See Matt Trawick's comment below.]  (The most famous physicists I have ever met, I think, are Eugene Wigner and John Wheeler, who are not exactly household names to non-scientists.) But back when I was in college I did get to know an old friend of Einstein’s pretty well.

Her name was Gabrielle Oppenheim, and she was about 95 when I knew her in the summer of 1988. Because her eyesight was very poor, she hired students to read the newspaper to her. This was a great job, which was passed on from student to student. I don’t remember how much it paid; I would have done it for nothing.

Mrs. Oppenheim told me lots of stories about Einstein. She first met him at a party in Brussels in 1911. Her husband pointed Einstein out and said, “That man will be one of the greatest physicists.” Mrs. Oppenheim’s response: “So I gave him one sandwich more.” (She later told this story to F. Murray Abraham in a Nova documentary, but I heard it first.)

She also said she was with Einstein in 1919 when he got the telegram from Sir Arthur Eddington, announcing that his observations of the bending of starlight had confirmed Einstein’s theory of general relativity. This was the event that made Einstein world-famous. But according to Mrs. Oppenheim, Einstein was much less excited about the result than the other people who were there at the time, because he had never doubted what the result would be.

She knew Einstein in Europe, but she spent much more time with him later in the U.S., when she and her husband had come to Princeton. (Her husband, Paul Oppenheim, was a philosopher.) Once, she and her husband were sailing with Einstein when the boat capsized. Her husband said, “Well, at least if we die with Einstein, we’ll be famous.”

She told me lots of other good stories. Once, she said, she was at a dinner party somewhere in Europe during World War I. A German army officer asked where she was from, and she told him she was Belgian. He replied that Germany would be invading Belgium soon. Mrs. Oppenheim said, “I was so offended by that, that I turned away and didn’t speak to him for the rest of the dinner.”

Mrs. Oppenheim told me way back then that I was “the scientist type”. Given that she hobnobbed with some of the greatest physicists of the 20th century (Bohr and others as well as Einstein), I figured she must know what she was talking about.

And still more on electability

Monday, April 28th, 2008

Here’s the latest data on the electability of the Democratic presidential candidates, as determined by the political futures market Intrade.

Probability of getting nomination Probability of winning election Electability

Clinton 17.1% 13% 76%

Obama 80.1% 46% 57.4%

Remember that electability is defined to be the probability that a candidate wins the election, given that the candidate gets the nomination. Intrade lets people bet on which candidate will get the nomination and on which candidate will win the election. In both cases, the odds can be interpreted as probabilities, which are the numbers listed above. The ratio of the probabilities, by Bayes’s Theorem, is the electability.

At the bottom of this post I’ll put a graph showing electability over time. The market “thinks” that Clinton is significantly more electable than Obama, and it has thought so pretty much all the time for the past couple of months.

From conversations with various people it’s become clear that I should be more explicit about what it even means to say what the market thinks a candidate’s electability is. Here’s one way to put it: If you think that Obama’s electability is significantly different from the above value, then you can place bets on Intrade whose odds favor you, and similarly for Clinton. After the page break below, I’ll give excruciatingly explicit details about how you’d place these bets.

Lots of people are confident that the futures market has gotten this wrong — in particular, partisans of each of the two Democrats seem to think that the other one’s electability is very low. A natural question to ask these people is this: have you put your money where your mouth is?

OK. Here’s the electability graph. Data were taken from Slate’s Political Futures pages on every day when I remembered to do it.

Electability april 28

(more…)