Dmitry Podolsky has got his PhD from Landau Institute for Theoretical Physics. He currently works as postdoc at Case Western Reserve University. He is also one of the editors of NEQNET.

355. Introduction into thermonuclear reactors

After a brief layman review of the theory of thermonuclear fusion let me get more practical and discuss a bit how thermonuclear reactors are supposed to work. Basically, we want the energy release of the thermonuclear reactor to be larger than the energy we pump into the reactor. Depending on a particular scenario of the [...]

354. Vortex line representation. Clebsch variables

Let us continue our brief discussion of behavior of the vorticity field in the Eulerian flow. (and that’s how vortex lines look like in reality… as if you wouldn’t know ) This time I would really like to derive some equations describing dynamics of vortex lines. For this, it is convenient to use so called [...]

353. Vortex line representation. Cauchy invariant

Several days ago I’ve promised in comments to discuss dynamics of vortex lines in turbulent flows, today is probably a good day to start. And the natural starting point of course is the Kelvin theorem and Cauchy invariant. Let us consider an ideal (inviscid, uncompressible) fluid described by the Euler equation and incompressibility condition . [...]

352. 48 years ago

Those were the days of our glory. By us I mean all intelligent people, all passionate, sensible people, all people who are able to discriminate objective reality from the bare wishful thinking. And, of course, people who are able to distort objective reality to match their wishful thinking. But those days have passed. In reality, [...]

351. Girls only

I think, it is a scientifically proved, established fact that women are so much more explicit in conversations between each other than men, isn’t it? Via uzhas_sovka.

350. V for Vendetta

Happy Easter (and Pesah), everybody! Via uzhas_sovka.

349. The question of quality

Last time we had a nice, surprisingly long discussion trying to answer the question how much should you publish in order to be considered a successful postdoc From Michal’s point of view, this is not quantity but quality of your publications that should matter. Actually, I completely agree with this point of view – that’s [...]

348. Trading olympiad

As usual, no physics today, True Geeks, only fun very distantly related to physics is allowed! Interactive Brokers has just announced that the 2009 IB Collegiate Trading Olympiad is now over. What is the idea of the olympics? Naturally, an unspecified number of guys – mostly, students of various universities – each create a piece [...]

347. Numerical simulation of vortices: video of the day

A video by New Scientist magazine featuring some really nice simulations of developed turbulence in the presence of vorticity field.

346. Thermonuclear fusion. Nuclear reaction rates – second part

Last time we have figured out that two factors determine effective rates of nuclear reactions – the probability of quantum mechanical tunnelling through the Coulomb barrier and the probability of nuclear transformation. Let us talk today about the second factor a bit. While the first factor given in the simplest case by the Gamov exponent [...]