Physics
drorzel | January 25, 2006Third in the Top Eleven is Sir Isaac Newton, who squeaks in with two nominations for two different experiments.
Who: Isaac Newton (1642-1727), famous English physicist, mathematician, alchemist, Master of the Mint, and Neal Stephenson character.
When: Newton was secretive and reluctant to publish anything, so it's sort of hard to assign dates. I'm going with "About 1700."
What: Newton pretty much kicked off modern science, so you could go on for a long time about his various accomplishments, but he was cited for two specific experiments: splitting white light with a prism, and measuring the…
drorzel | January 25, 2006The second in the Top Eleven is the first quantitative measurement of the speed of light, by Ole Christensen Roemer (whose last name ought to contain an o-with-a-slash-through-it, that I've rendered as an "oe").
Who: Ole Roemer (1644-1710), a Danish astronomer.
When: The crucial observations were made around 1675.
What: Roemer made careful observations of the orbit of Jupiter's moon Io (which circles the planet once every two days or so), and noted that the time between eclipses of Io (times when it disappeared behind Jupiter) got shorter as the Earth moved closer to Jupiter, and got longer…
drorzel | January 24, 2006The first and oldest of the experiments in the Top Eleven is actually a two-fer: Galileo Galilei is nominated both for the discovery of the moons of Jupiter, and for his experiments on the motion of falling objects.
Who: Galileo Galilei (1564-1642), the great Italian physicist, astronomer, and general Renaissance man.
When: He's known to have made the first observations of the moons of Jupiter around 1610. The dates of the experiments on accelerated objects are fuzzier, but around the same time.
What: Shortly after obtaining a telescope (after its invention by Dutch astronomers), Galileo…
drorzel | January 24, 2006Evil elves have apparently snuck into the house in the middle of the night, and stuffed my sinuses with cotton and motor oil (the dog is sitting here muttering "I told you there were evil elves out there but did you listen? 'Stop barking at nothing,' you said..." Or maybe that's the drugs.). This sort of cuts down on my ability to think Deep Thoughts and post the results here.
I can, however, carry out mechanical tasks like tallying the nominations for the Greatest Physics Experiment (to go with Clifford's Greatest Physics Paper on the theory side). The list of experiments mentioned by at…
drorzel | January 23, 2006Thursday night, I needed to work late, so rather than upset the dog by going home for dinner, and then leaving, I went for sushi at a local restaurant. I had a very pleasant meal, which I spent reading through the first few chapters of the textbook I plan to use for my Quantum Optics class next term (to make sure it will work for my purposes), and listening to the woman at the table next to me talk to her kids (ages 7 and 9, and cutely overactive).
Eventually, the kids wandered off to go pester the sushi chef (they're apparently regulars), and their mother asked me "What is it you're reading…
drorzel | January 20, 2006Over at Gene Expression, Razib spins an interesting question off my call for blog posts: why are there so many biology bloggers?
As I said in comments over there, I think there are two main reasons why you find more bio-bloggers than physics bloggers. The first is that there are simply more biologists than physicists-- we're expecting an unprecedented 13 senior physics majors next year, which is forcing some frantic re-organization to handle the load, but a class that small would be a major crisis for the Biology department. The second reason is that biology is really the main front of the "…
drorzel | January 19, 2006In the ongoing string theory comment thread (which, by the way, I'm really happy to see), "Who" steps off first to ask an interesting question:One way to give operational meaning to a theory being predictive in the sense of being empirically testable is to ask
What future experimental result would cause you to reject the theory?
I think what worries a lot of people about string thinking is that it seems so amorphous that it might be able to accomodate any future experimental measurement. In fact I am not aware of any string theorist's answer to this basic question.
It's an interesting…
drorzel | January 17, 2006There was a postdoc in my research group in grad school who had a sister in college. She called him once to ask for help with a math assignment dealing with series expansions. He checked a book to refresh his memory, and then told her how to generate the various series needed for her homework assignment.
A week or so later, he asked how she'd done. "Terrible," she said. It seems that he had just plunged ahead with generating series terms without doing the convergence tests and other proofs that a mathematician would do for the same problems. She told him, "My professor said I answered all the…
drorzel | January 16, 2006Today is the last day to vote in Cosmic Variance's Greatest Physics Paper contest. If you haven't voted yet, go over there and pick a paper.
Locally, I'm still collecting nominees for the Greatest Physics Experiment. A quick scan through the comments gives the current list as:The Michelson-Morley experiment disproving the aether.Rutherford's discovery of the nucleus.Aspect's Bell Inequality test.Galileo's inclined planes, or possibly the discovery of the moons of Jupiter.The Mossbauer Effect.If you have a favorite physics experiment, and don't see it on that list, go leave a comment…
drorzel | January 16, 2006There's a slightly snarky Review of Leonard Susskind's book on string theory (The Cosmic Landscape: String Theory and the Illusion of Intelligent Design) in the New York Times this week. Predictably, Peter Woit is all over it.
The central issue of the book, and the review, and Woit's whole blog is what's referred to as the "Landscape" problem in string theory. This is a topic that seems to consume a remarkable amount of intellectual energy for what's really a pretty abstract debate. It also leads to a remarkable amount of shouting and name-calling for something that just doesn't seem like…
drorzel | January 15, 2006I'll have something more serious to say on this subject tomorrow (I want to sleep on it, and take another look at the post in the morning), but I have one quick comment on the New York Times review of Leonard Susskind's The Cosmic Landscape:Susskind's insider perspective also lends an air of smugness to the whole affair. He falls prey to the common error of Whig history: interpreting past events as if they were inevitable stepping stones to the present. He allows remarkably little doubt about string theory considering that it has, as yet, not a whit of observational support. "As much as I…
drorzel | January 15, 2006A while back, I talked about a colloquium where Steven Boughn of Haverford argued that it's practically impossible to detect a single graviton. It was a very nice talk, relying mostly on simple dimensional analysis arguments, and very basic physics.
Today, via Wolfgang Beirl (via Mixed States), I see that Boughn and Tony Rothman have a paper on the porn server about graviton detection. It's got a bunch more math, but the conclusion is the same.
It's a clever paper, and worth a look if you're into this sort of thing.
drorzel | January 14, 2006The big news in physics yesterday was the announcement that a private donation has been made to support experiments at the Relativistic Heavy Ion Collider on Long Island. This is the accelerator that's slamming gold nuclei into each other to create a quark-gluon plasma, along with a million dippy stories about how it might make a black hole that will eat the whole New York metro area. This isn't my field (not by a long shot), but I think this is terrifically exciting work, not least because the observations that they've made confound existing theories-- the "plasma" acts more like a liquid…
drorzel | January 13, 2006Looking at the ScienceBlogs front page, I suspect that I may be well out of my league, especially when it comes to posting frequency. There's just no way I can post that many entries in one day, especially not a day like Thursday.
In addition to my lab this morning (in which half the students were using a Michelson interferometer to measure laser wavelengths and the index of refraction of air, while the other half measured the speed of light-- it was like a "Greatest Experiment Nominee" re-enactment event. Only with lasers...), we had a visit from Dave DeMille of Yale, who I had invited a…
drorzel | January 11, 2006Quite a while back, Clifford Johnson at Cosmic Variance had a post seeking nominations for "The Greatest Physics Paper Ever." Back after a long hiatus, he's now holding a vote among five finalists: Isaac Newton's Principia Mathematica, Albert Einstein's General Relativity, Emmy Noether's paper on symmetry and conservation laws, Dirac's theory of the electron, and the Einstein, Podolsky, and Rosen paper on quantum non-locality.
(Newton's Principia Mathematica had a comfortable lead when I last checked, so if you're a partisan of one of the other candidates, go over there and vote...)
Of course…
drorzel | January 2, 2006As you can tell from the date stamp, it's now 2006, so the World Year of Physics is over. The people behind Quantum Diaries are shutting their blog collection down (though several of the diarists will be continuing on their own sites), and John "End of Science" Horgan pops up in the Times book section to say that there will never be another Einstein:Einstein is far and away the most famous and beloved scientist of all time. We revere him not only as a scientific genius but also as a moral and even spiritual sage whose enduring aphorisms touch on matters from the sublime ("Science without…