Experiment
drorzel | August 28, 2009The Female Science Professor is thinking about what advisors owe their students:
When I got my PhD and went out into the great big academic world, I felt that I had the respect of my adviser, but I knew not to expect anything more from him in the way of support in my career other than the standard recommendation letter.
I never minded because he was that way with all of his students. He had a sink-or-swim philosophy of advising, and this continued after students graduated.
Now that I am an adviser with former students of my own, I think his approach makes some sense because it is a very fair…
drorzel | August 25, 2009NPR last week had a story about the changing kilogram:
More than a century ago, a small metal cylinder was forged in London and sent to a leafy suburb of Paris. The cylinder was about the size of a salt shaker and made of an alloy of platinum and iridium, an advanced material at the time.
In Paris, scientists polished and weighed it carefully, until they determined that it was exactly one kilogram, around 2.2 pounds. Then, by international treaty, they declared it to be the international standard.
Since 1889, the year the Eiffel Tower opened, that cylinder has been the standard against which…
drorzel | July 31, 2009Yesterday's historical physics poll was about precision measurements. Who were those people, and why are they worth knowing about?
As usual, we'll do these in reverse order of popularity...
First up is Ole Rømer, a Danish astronomer who is no stranger to this blog, having been profiled as part of the Top Eleven series back in the early days of ScienceBlogs. Rømer's big accomplishment was the first really good measurement of the speed of light, which he did by timing the eclipses of Jupiter's moon Io. These are seen to occur slightly sooner when Earth and Jupiter are on the same side of the…
drorzel | July 30, 2009Yesterday, I posted a silly poll about optical physicists. Who are those people, and why should you care about them?
In inverse order of popularity:
Bringing up the rear in this race is John William Strutt, who, even more than Lord Kelvin in the thermodynamics poll, is hurt by the fact that people know him by his title, Lord Rayleigh. His notable achievements in optics include a formalization of the resolution limits for optical devices, and the phenomenon known as "Rayleigh Scattering," which is the short answer to the question "Why is the sky blue?" (The long answer requires a whole book.)…
drorzel | July 29, 2009The Corporate Masters have launched a "featured blogger" program, asking individual ScienceBloggers to comment on news articles from the main site, and publishing the responses with the magazine piece. I just did one on new quantum experiments, which was posted today.
The news article is Supersizing Quantum Behavior by Veronique Greenwood. My piece is Reconciling an Ordinary World, which starts out:
One of the most vexing things about studying quantum mechanics is how maddeningly classical the world is. Quantum physics features all sorts of marvelous things--particles behaving like waves,…
drorzel | July 29, 2009So, yesterday featured a silly poll about underappreciated old-timey physicists. Who are these people, and why should you know about them?
Taking them in reverse order of the voting:
Rudolf Clausius is the originator of the infamous Second Law of Thermodynamics, which states that the entropy of any closed system will tend to increase. He was one of the most important figures in terms of systematizing the study of thermodynamics, pulling a lot of other people's work together, and showing how it all fit.
James Joule was a brewer as well as a physicist, making him a really good guy to know. He's…
drorzel | July 15, 2009Yesterday's Michelson Interferometer quiz was surprisingly popular-- as of 8:30 pm Tuesday (when I'm writing this), just under 1500 people have voted in the poll, three and a half times as many as in the next most popular poll I've done. Who says there's no audience for physics?
So, what's the right answer, you ask?
The correct answer finished a distant second (as of 8:30 it has 21% of the votes, to 52% for the leading wrong answer). The answer is that the light goes back where it came from. Bob Hawkins and MattXIV have the right explanation: on the return trip, half of each beam goes to the…
drorzel | July 14, 2009Inspired by one of yesterday's easy questions, a pop quiz for you. The figure below shows a Michelson Interferometer:
A laser falls on a beamsplitter, which allows half of the light to pass straight through, and reflects the other half downward. Each of those beams then hits a mirror that reflects it directly back where it come from. The beams are recombined at the beamsplitter, and then fall on the viewing screen at the top of the figure.
When we add together the light from the two paths, we find that if the lengths of the two arms (that is, the distance from beamsplitter to mirror) are…
drorzel | July 7, 2009It's been a while since we've had any good, solid physics content here, and I feel a little guilty about that. So here's some high-quality (I hope) physics blogging, dealing with two recent(ish) papers from Chris Monroe's group at the University of Maryland. The first is titled "Bell Inequality Violation with Two Remote Atomic Qubits" (and a free version can be found on the Arxiv); the second is "Quantum Teleportation Between Distant Matter Qubits" (and isn't available on the arxiv because it's in Science, but you can get it from their web site). Both of these deal with the physics of…
drorzel | July 1, 2009I no longer recall who pointed me to this current.com post titled "Scientists Make Radio Waves Travel Faster Than Light "-- somebody on Facebook, I think. As it would be a pretty neat trick to make light move faster than light, I took a look. The opening is fairly standard semi-gibberish:
Scientist John Singleton insists that Albert Einstein wouldn't be mad at him, even though at first blush Singleton appears to have twisted the famous physicist's theories about light into a pretzel.
Most people think Einstein said that nothing can travel faster than the speed of light, but that's not really…
drorzel | June 15, 2009Martin Perl, a 1995 Nobel laureate in Physics for the discovery of the tau lepton, was awarded an honorary degree yesterday at commencement. Perl actually has a significant Union connection-- he started his career as a chemical engineer, and was working for GE making vacuum tubes when they sent him to take classes in calculus and atomic physics at Union. His physics professor, Vladimir Rojansky, convinced him that he was more interested in physics than chemical engineering, so he changed careers.
Saturday night, I had dinner with Perl, two other faculty members, and three students. He's just…
drorzel | June 8, 2009Tom at Swans On Tea comments on an article about meetings:
The most common meeting in my experience is the status meeting, where everyone gets together and reports on what they've accomplished. If it's a small group, these are usually fine because you already have familiarity with the tasks. But when you get a large group together, which has diverse tasks and goals, there is impending disaster. Bad meetings I've attended often involve people discussing details that nobody else at the table understands or possibly cares about -- the sort of thing that should happen one-on-one or in a small…
drorzel | June 5, 2009Physics World posted a somewhat puzzling story a few days back, headlined Ultra cold atoms help share quantum information:
Scientists in the US have demonstrated a novel "light-switch" in an optical fibre that could become a new tool in the communications industry. The device created by Michal Bajcsy at Harvard University and colleagues could be developed to share both classical and quantum information.
Quantum information systems could bring a revolution to global data-sharing, by encrypting, processing, and transmitting information using the properties of quantum mechanics. However, as…
drorzel | June 5, 2009Physics World reports on the awarding of a major French prize in science:
A physicist has been awarded France's top science prize for his work on atomic physics and quantum optics. Serge Haroche -- one of the founding fathers of cavity quantum electrodynamics (QED) -- was presented with this year's "gold medal" by the French national research council (CNRS) at a press conference in Paris yesterday. Haroche currently heads the electrodynamics and simple systems group at CNRS's Kastler Brossel Lab in Paris.
Previous physics recipients include the Nobel Prize winners Albert Fert and Claude Cohen…
drorzel | May 21, 2009Technically, the meeting started Tuesday, but all that happened was a welcome reception, which I missed due to travel. The real beginning of the meeting was Wednesday morning, with the traditional unscheduled half-hour welcome from local dignitaries. That was followed by the Prize Session, featuring the frighteningly smart Misha Lukin, who was awarded the I.I. Rabi Prize for being really freaking brilliant. The abstract he sent in was kind of vague, but he mostly talked about stuff related to the quantum computing in diamond stuff that I've blogged about before.
I'm fighting a bit of a cold,…
drorzel | May 14, 2009I'm a little surprised that I haven't seen bloggers commenting on Tom Hanks's appearance on The Daily Show, in which he talks about CERN:
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Everything he says is pretty much true, but garbled and exaggerated for comic effect. People at CERN have to be shaking their heads, though. Or maybe they don't bother watching the interview segments...
At any rate, it's not nearly as good as their earlier segment with John Oliver at CERN
The Daily Show…
drorzel | May 8, 2009Via Michael Nielsen, a page documenting what I really hope is the dorkiest family vacation ever: Project GREAT: General Relativity Einstein/Essen Anniversary Test Clocks, Kids, and General Relativity on Mt Rainier:
In September 2005 (for the 50th anniversary of the atomic clock and 100th anniversary of the theory of relativity) we took several cesium clocks on a road trip to Mt Rainier; a family science experiment unlike anything you've seen before.
By keeping the clocks at altitude for a weekend we were able to detect and measure the effects of relativistic time dilation compared to atomic…
drorzel | May 7, 2009You might think that Monday's discourse on thermodynamics in the Goldilocks story was the only children's story in which physics plays a role, but that's not true. Physics is everywhere in fairy tales.
Take, for example, the story of Rumpelstiltskin, in which a mysterious little man demands a terrible price for helping a miller's daughter spin straw into gold. This raises the obvious question of exactly how one would go about extracting gold from straw.
The use of the term "spin" might suggest the use of rotational motion-- if the straw were ground up very fine, and mixed with water, it might…
drorzel | May 5, 2009As I understand it, the Physics ArXiv Blog is not affiliated with the people who actually run the Arxiv (Paul Ginsparg et al.). Which is probably good, as I'm never entirely sure how seriously to take the papers they highlight.
Take yesterday's post, Diamond Challenges for Quantum-Computing Crown, which is about a paper that asks the question Could one make a diamond-based quantum computer?. It's an interesting idea, and something I wrote about last year, so it seems like a promising topic.
The preprint in question, though, is a little dodgy. It's indifferently proofread, with all sorts of…
drorzel | May 4, 2009SteelyKid is not yet at the stage where I can usefully read to her-- she likes sitting on my lap while I read just fine, but she's more interested in trying to eat the pages than listening to the story. I was reminded this morning, though, that when she gets to bedtime-story age, I'm going to face some real dilemmas. Some of the classic stories teach dangerously wrong lessons about physics.
Take, for example, the story of Goldilocks and the Three Bears (referred to at the end of the previous post). In the usual telling, Goldilocks comes upon the Bears' house and finds three bowls of porridge…