MetaFilter posts tagged with math and Physics

Would you like to buy an fuzzy multi-instanton knot?

escabeche — Wed, 12 Nov 2008 07:56:25 -0800

"...the best place to hide bulls**t is in a refereed journal that’s not open-access!" The math-physics blog n-category cafe digs into the curious case of M.S. El Naschie. El Naschie is editor-in-chief of the journal Chaos, Solitons, and Fractals, published by the well-respected scientific publisher Elsevier and sold to academic libraries for US$4,520 a year. The problem? El Naschie has published 322 of his own papers in the journal -- papers that John Baez (of "This Week's Finds in Mathematical Physics" and "The Crackpot Index") describes as "vague, dreamlike imagery," "undisciplined numerology larded with impressive buzzwords," and "total baloney." Is El Naschie a reverse Sokal? Or a Markov process for producing random publishable papers? One thing's for sure -- he knows how to cure cancer.

Two mathematicians walk into a bar...

cthuljew — Sun, 09 Nov 2008 08:09:25 -0800

A math professor was explaining a particularly complicated calculus concept to his class when a frustrated pre-med student interrupts him. "Why do we have to learn this stuff?" the pre-med blurts out. The professor pauses, and answers matter-of-factly: "Because math saves lives." "How?" demanded the student. "How on Earth does calculus save lives?" "Because," replied the professor, "it keeps certain people out of medical school."

Symmetry. Shakespeare. Islamic medicine. Creative writing challenges.

Wolfdog — Sun, 18 Nov 2007 03:28:17 -0800

Symmetry. Shakespeare. Islamic medicine. Creative writing challenges. Four podcast series from University of Warwick.

Impossible Crystals

parudox — Sun, 18 Mar 2007 20:54:55 -0800

"This is a story of how the impossible became possible. How, for centuries, scientists were absolutely sure that solids (as well as decorative patterns like tiling and quilts) could only have certain symmetries - such as square, hexagonal and triangular - and that most symmetries, including five-fold symmetry in the plane and icosahedral symmetry in three dimensions (the symmetry of a soccer ball), were strictly forbidden. Then, about twenty years ago, a new kind of pattern, known as a "quasicrystal," was envisaged that shatters the symmetry restrictions and allows for an infinite number of new patterns and structures that had never been seen before, suggesting a whole new class of materials...."

Physicist Paul J. Steinhardt delivers a fascinating lecture (WMV) on tilings and quasicrystals. However, it turns out science was beaten to the punch: a recent paper (PDF) suggests Islamic architecture developed similar tilings centuries earlier.

Physics simulators. Lots of physics simulators.

loquacious — Sat, 03 Feb 2007 09:47:41 -0800

PhET - Physics Education Technology offers this astoundingly large library of online physics simulations. Play orbital billiards. Land on a cheesy moon. Experiment with sound. Or try more advanced quantum physics simulators. Still bored? Try the "cutting edge" catagory. Here's the complete index. (Warnings: Frames, Flash, Javascript, Java applets, graphics, sound, quantum timesuck.)

Raft to the Future

knave — Mon, 06 Nov 2006 04:32:20 -0800

Raft to the Future: An article about the weirdness of physical models of the universe, how that weirdness correlates to the inherent incompleteness of mathematical systems, and how time itself can emerge at the fringes of these incomplete models.

Show Your Work

three blind mice — Thu, 13 Apr 2006 07:43:00 -0800

Condoleezza holds a watermelon just over the edge of the roof of the 300-foot Federal Building, and tosses it up with a velocity of 20 feet per second. Using the formula provided, when the watermelon will hit the ground? Bellevue Community College President Jean Floten asked the Pluralism Steering Committee to take the lead on this, and to complete their task quickly.

This Week's Finds in Mathematical Physics

five fresh fish — Sat, 01 Apr 2006 12:58:08 -0800

This Week's Finds in Mathematical Physics. A geek's paradise. Reminiscent of Scientific American's Mathematical Games.

...almost, but not quite, entirely unlike tea.

loquacious — Tue, 28 Mar 2006 01:32:01 -0800

"...the answer to Life, the Universe, and Everything is..." "Yes? Yes!?" "...42."
via Dyson, Montgomery, Princeton, a cup of tea - as presented by Seed Magazine.

Ripple Tank Simulation

MetaMonkey — Wed, 25 Jan 2006 07:41:47 -0800

Ripple Tank Simulation is a delightful, mesmeric java applet simulation of a ripple tank. It demonstrates two dimensional wave phenomena such as interference, diffraction, refraction, resonance, phased arrays, and the Doppler effect (do try the 3D view). From Paul Falstad's fantastic collection of Math, Physics and Engineering Applets.

Nerd Porn

Gamblor — Fri, 11 Nov 2005 10:01:56 -0800

Flash Animations for Physics. Animations and interactive demos available in many varieties, such as classical mechanics, nuclear, quantum, and relativistic. There's even a nice explanation of the forces at work in Curling. And if that doesn't wet your geek whistle, then take a peek at the patterns of Visual Math.

Math You Don't Know, and Math You Didn't Know You Didn't Know.

odinsdream — Wed, 14 Sep 2005 10:39:15 -0800

Jim Loy's Mathematics Page is (among other things) a collection of interesting theorems (like Napoleon's Triangle theorem), thoughtful discussions of both simple and complex math, and geometric constructions (my personal favorite); the latter of which contains surprisingly-complex discussions on the trisection of angles, or the drawing of regular pentagons.

Similarly enthralling are the pages on Billiards (and the physics of), Astronomy (and the savants of), and Physics (and the Phlogiston Theory of), all of which are rife with illustrations and diagrams. See the homepage for much more.

If you like your geometric constructions big, try Zef Damen's Crop Circle Reconstructions.

Java applets to help visualize various concepts in math, physics, and engineering

Gyan — Fri, 09 Sep 2005 14:16:07 -0800

Java applets to help visualize various concepts in math, physics, and engineering

The Complexity of a Controversial Concept

kliuless — Mon, 20 Jun 2005 18:03:37 -0800

The Logic of Diversity "A new book, The Wisdom of Crowds [..:] by The New Yorker columnist James Surowiecki, has recently popularized the idea that groups can, in some ways, be smarter than their members, which is superficially similar to Page's results. While Surowiecki gives many examples of what one might call collective cognition, where groups out-perform isolated individuals, he really has only one explanation for this phenomenon, based on one of his examples: jelly beans [...] averaging together many independent, unbiased guesses gives a result that is probably closer to the truth than any one guess. While true — it's the central limit theorem of statistics — it's far from being the only way in which diversity can be beneficial in problem solving." (Three-Toed Sloth)

What do you call a young eigensheep?

apathy0o0 — Wed, 11 May 2005 00:10:47 -0800

The Prime Number Shitting Bear, Finite Simple Group of Order Two[video], Math Jokes, Physics Jokes

The B was easy; d/dt took a while

Wolfdog — Wed, 08 Dec 2004 13:21:32 -0800

The universe in just two symbols. The rest, as they say, is details. No wonder the "Physics Establishment" is trying to keep this quiet. The author, having conquered the universe in general, tackles poetry, as well.

What is the airspeed velocity of an unladen swallow?

riffola — Fri, 28 Nov 2003 18:36:53 -0800

Estimating the Airspeed Velocity of an Unladen Swallow. Hashing out the classic question with Strouhal numbers and simplified flight waveforms. The site also includes other very well presented number crunching articles too. [via The One]