Physics
drorzel | August 15, 2007The thirteenth edition of the physics-themed blog carnival Philosophia Naturalis has been posted at Cocktail Party Physics. There's a whole bunch of good stuff there, and also some links to the recent silliness about the term "God Particle."
If you're looking for good physics-related reading on the Internet, it's your one-stop shopping source.
drorzel | August 14, 2007A simple but high-stakes fill-in-the-blank question:
The right and proper symbol to represent the square root of negative one is _______.
The incorrect answer will brand you as an engineer, and you will be cast into the outer darkness to spend eternity converting drill sizes into sensible units.
Choose wisely.
drorzel | August 13, 2007I am sorry to report the passing of Ralph Alpher, of the famous "Alpher-Bethe-Gamow" paper. I don't know many details, but he's been in poor health for some time, so this is sad but not surprising news.
Ralph Alpher was an astrophysicist and cosmologist whose thesis work with George Gamow on the origin of the universe was a critical early step in the development of the "Big Bang" theory. Alpher predicted the existence of the cosmic microwave background, and estimated its temperature (at 5K, not far from the correct value of 2.7 K) in 1948, nearly two decades before it was detected by Penzias…
drorzel | August 10, 2007I'm working on something at the moment that involves talking a bit about the historical development of quantum theory, and specifically the demonstration of the wave nature of electrons. One of the famous proofs of this is the Davisson-Germer experiment, showing that electrons bouncing off a nickel target produce a diffraction pattern.
(As an aside, let me note that I love the fact that the Wikipedia stub on the experiment blatantly plagiarizes the text of the Hyperphysics page (which is screamingly obvious, in that it refers to a figure that they didn't cut-and-paste into Wikipedia). Way to…
drorzel | August 10, 2007This might be too abstract for a really good Dorky Poll, but I've got a bunch of stuff that I really need to do, and I've been thinking a bit about curricular issues, so this came to mind:
Which would you rather know more about, Classical Optics or Thermodynamics?
Imagine that you're being offered a choice by some sort of magical being: you can choose one of these two disciplines, and know absolutely everything there is to know about it, while you will never know more about the other than you do at the moment of the decision. Which would you pick?
drorzel | August 7, 2007In case you can't pick up his direction from the subtitle of The Theory of Almost Everything ("The Standard Model, the Unsung Triumph of Modern Physics"), Robert Oerter lays it all out for you in the second paragraph of the Introduction:
the Standard Model has a surprisingly low profile for such a fundamental and successful theory. It has deeper implications for the nature of teh universe than chaos theory, and unlike string theory, which is purely speculative in nature, it has a strong experimental basis-- but it is not as widely known as either. In physics news itesm, the Standard Model…
drorzel | August 3, 2007I'm on vacation this week, and taking this opportunity to clear out a large backlog of news items that I flagged as interesting, but never got around to commenting on. I'll group them thematically, just to spread things out over a few days, and this post lumps together some results from biophysics and astrophysics that didn't make it into the previous posts:
GZK cutoff confirmed: from Backreaction, a report on new observations of highly energetic cosmic rays. These are subatomic particles with energy roughly equaly to the kinetic energy of a tennis ball on a volley that hit the upper…
drorzel | August 2, 2007I'm on vacation this week, and taking this opportunity to clear out a large backlog of news items that I flagged as interesting, but never got around to commenting on. I'll group them thematically, just to spread things out over a few days, and this lot is a bunch of articles about fiendishly difficult experiments to make or detect something really hard to see:
This one's from email: ages ago, Geoff Koch from Michigan State sent me a pointer to an experiment in which they produced the heaviest isotope of silicon ever detected. I keep forgetting to post something about it, because I'm a bad…
drorzel | August 1, 2007I'm on vacation this week, and taking this opportunity to clear out a large backlog of news items that I flagged as interesting, but never got around to commenting on. I'll group them thematically, just to spread things out over a few days, and this lot is a bunch of articles about new developments in the study of solid state systems:
"Are Doubly Charged Particles Lurking in High-T Superconductors?": I don't know. Are they? Exactly what mechanism leads to electron pairing and superconductivity in the high-temperature ceramic superconductors remains a mystery, and this reports on a new…
drorzel | July 31, 2007I'm on vacation this week, and taking this opportunity to clear out a large backlog of news items that I flagged as interesting, but never got around to commenting on. I'll group them thematically, just to spread things out over a few days, and this lot is a bunch of articles about nifty new widgets made in various labs:
"NMR Gets Seriously Small": a French group has managed to demonstrate NMR spectroscopy on tiny solid samples. This has been a problem in the past because the small signal gets washed out by thermal noise, but they've played some tricks to allow NMR on nanoliter-scale samples…
drorzel | July 30, 2007I'm on vacation this week, and taking this opportunity to clear out a large backlog of news items that I flagged as interesting, but never got around to commenting on. I'll group them thematically, just to spread things out over a few days, and this post highlights a couple of new things in the quantum optics field:
"Single atom entangles two photons": pretty much what it sounds like. The Rempe group in Garching has used a single atom trapped in an optical cavity to produce an entangled pair of photons by sequential interaction between the atom and a couple of laser pulses. Like everything…
jstemwedel | July 27, 2007Chad and Rob have already noted this piece of news about soon-to-be-published research indicating that the order in which high school students are taught physics, chemistry, and biology makes very little difference to their performance in science classes at the college level, while a rigorous math curriculum in high school gives their college science performance a significant boost.
I have a few things to say about this.
Good math instruction is good for students.
As Chad points out, it helps you build problem solving skills and think systematically. To the extent that these skills are…
drorzel | July 24, 2007In the previous post about light polarization, I promised to post an explanation of why it is that "Polarized" is a selling point for sunglasses. Given that sunlight is unpolarized, the only obvious benefit would be that polarized sunglasses will automatically block half of the light hitting them, but it's actually much better than that. To understand why they work, though, we need to talk about how it is that light waves are produced and propagate in a medium.
Sticking with the classical picture of light as an electromagnetic wave, you can understand the production of electromagnetic waves…
drorzel | July 17, 2007The Paper of Record today features an interview with Eric Mazur of Harvard, a physicist who is probably best known for his pedagogical work. He talks aabout how typical science teaching sucks, and why we need to change it:
From what I've seen, students in science classrooms throughout the country depend on the rote memorization of facts. I want to change this. The students who score high do so because they've learned how to regurgitate information on tests. On the whole, they haven't understood the basic concepts behind the facts, which means they can't apply them in the laboratory. Or in…
drorzel | July 12, 2007Peter Steinberg is lecturing at a summer school in Florida, and has posted the slides for the three lectures he gave about recent work at the Relativistic Heavy Ion Collider on Long Island. The first lecture is linked from that post, and the other two are available (at the moment) from links on the sidebar.
These are gigantic PDF files-- the first one especially, which clocks in at 32.4 MB-- but the first lecture is a very nice introduction to the physics they're exploring at RHIC. I haven't looked at the other two yet, but if they're as good as the first, they'll be worth the long download.
drorzel | July 10, 2007Dave at the World's Fair is trying to start a "meme" based on a Science Creative Quarterly piece about physics envy among biologists and vice versa. He's asking other science bloggers whether there's another field that they wish they were working in.
While I have occasionally joked that if I had it to do over, I would become a biologist studying coral reefs, so I could justify spending my sabbaticals snorkeling in the tropics, I'm really very happy doing what I do (at least when things work). I enjoy experimental work, I like the fact that my lab is fairly self-contained, and I think AMO…
drorzel | July 6, 2007"Ahhhh... summer at last. No more classes. No more committee meetings. Do you realize what this means?"
"Ummmmm.... no. What does it mean? What are we going to do this summer, Brain?"
"The same thing we do every summer.... Try to do PUBLISHABLE RESEARCH!!!"
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"Are you pondering what I'm pondering?"
"I think so, Brain, but diffusion pump oil is all stinky and viscous, and won't the chickens get upset?"
"You are the very quantum of imbecility, Pinky."
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"The first step in our plan is to use a grating-locked diode laser to-- yes, Pinky?"
"Um, Brain?"
"Professor Brain."
"Um…
drorzel | July 5, 2007I suppose I really ought to say something about the "demonstration" of Steorn's perpetual motion machine that's supposed to start today, but, really, I don't have much to say. I mean, if they were claiming that their device extracted free energy from extra dimensions thanks to their revolutionary new theory of quantum gravity, I might need to think about it for a few seconds before dismissing it as crap, but that's not their claim:
Orbo is based upon the principle of time variant magneto-mechanical interactions. The core output from our Orbo technology is mechanical. This mechanical energy…
drorzel | July 5, 2007Looking back at the archives, I see that I never did get around to blogging about Jennifer Ouellette's Black Bodies and Quantum Cats, which I finished back in May. This is a particularly shameful oversight, as she visited campus in late May, and gave two excellent talks for us, so the least I can do is to post a measly book review.
Jennifer Ouellette (pronounced "Woah-lette," more or less, in case you were wondering) should be no stranger to regular readers of this blog, as I fairly regularly link to her blog, Cocktail Party Physics. If you're not reading it, you ought to be. And if you are…
sb admin | July 2, 2007Chad notes, in response to PZ's rather absurd assertion that biology is the only Dumped Upon science, and that physics is so well treated in movies and TV, that "Most of the SF movies I see are lucky if they can get Newton's Laws right, let alone any of the finer points of astrophysics."
Indeed, this was the topic of one of the two talks I gave at Hypericon a couple of weeks ago.
Let me try to explain one aspect of this: specifically, the motion of space fighters.
Don't get me wrong. Star Wars is a great movie, one of my all-time favorites. It's even still a pretty good movie if Han doesn't…