We kicked off our countdown to Newton’s birthday with his second law of motion, so the obvious next step is to go to his third law of motion: This one was also originally in Latin, because that’s how Ike liked to roll: Lex III: Actioni contrariam semper et æqualem esse reactionem: sive corporum duorum actiones… Continue reading The Advent Calendar of Physics: Action and Reaction
Category: History of Science
The Advent Calendar of Physics: Force and Momentum
It’s that time of year again, when we count down the days to Isaac Newton’s birthday (according to the Julian calendar, anyway), and how better to mark this than with mathematics? Thus, I’ll post an equation a day until either Christmas Eve or I run out of ideas, and talk about what it means and… Continue reading The Advent Calendar of Physics: Force and Momentum
Neutrino Hypotheses Non Fingo
The final sentence of the neutrino paper that everybody is buzzing about: We deliberately do not attempt any theoretical or phenomenological interpretation of the results. From a somewhat older work in physics: Rationem vero harum gravitatis proprietatum ex phænomenis nondum potui deducere, et hypotheses non fingo. Quicquid enim ex phænomenis non deducitur, hypothesis vocanda est;… Continue reading Neutrino Hypotheses Non Fingo
One Person’s Golden Age Is Another Person’s Catastrophic Crash
One of the interesting things about reading David Kaiser’s How the Hippies Saved Physics was that it paints a very different picture of physics in the mid-1970’s than what you usually see. Kaiser describes it as a very dark time for young physicists, career-wise. He doesn’t go all that deeply into the facts and figures… Continue reading One Person’s Golden Age Is Another Person’s Catastrophic Crash
How the Hippies Saved Physics by David Kaiser
I heard David Kaiser talk about the history of quantum foundations work back in 2008 at the Perimeter Institute, and while I didn’t agree with everything he said, I found it fascinating. So when I heard that he had a book coming out about this stuff, How the Hippies Saved Physics, I jumped at the… Continue reading How the Hippies Saved Physics by David Kaiser
Idle Historical Question: Why p?
Today’s lecture topic was position-space and momentum-space representations of state vectors in quantum mechanics, which once again brought up one of the eternal questions in physics: Why do we use the symbol p to represent momentum? I did Google this, but none of the answers looked all that authoritative. And, anyway, I’m sure that the… Continue reading Idle Historical Question: Why p?
Why So Many Theorists?
When I was looking over the Great Discoveries series titles for writing yesterday’s Quantum Man review, I was struck again by how the Rutherford biography by Richard Reeves is an oddity. Not only is Rutherford a relatively happy fellow– the book is really lacking in the salacious gossip that is usually a staple of biography,… Continue reading Why So Many Theorists?
Quantum Man by Lawrence Krauss
While I’ve got a few more review copies backlogged around here, the next book review post is one that I actually paid for myself, Lawrence Krauss’s Quantum Man: Richard Feynman’s Life in Science, part of Norton’s Great Discoveries series of scientific biographies. I’m a fan of the series– past entries reviewed here include Richard Reeves’s… Continue reading Quantum Man by Lawrence Krauss
The Most Precisely Tested Theory in the History of Science
NASA held a big press conference yesterday to announce that the Gravity Probe B experiment had confirmed a prediction of General Relativity that spacetime near Earth should be “twisted” by the Earth’s rotation. A lot of the coverage has focused on the troubled history of the mission (as did the press conference, apparently), but scientifically… Continue reading The Most Precisely Tested Theory in the History of Science
Proving Einstein Wrong…ish: Measurement of the Instantaneous Velocity of a Brownian Particle
Last summer, there was a fair bit of hype about a paper from Mark Raizen’s group at Texas which was mostly reported with an “Einstein proven wrong” slant, probably due to this press release. While it is technically true that they measured something Einstein said would be impossible to measure, that framing is a little… Continue reading Proving Einstein Wrong…ish: Measurement of the Instantaneous Velocity of a Brownian Particle