The Nature of Computation -
Intellects Vast and Warm and Sympathetic: "I hand you a network or graph, and ask whether there is a path through the network that crosses each edge exactly once, returning to its starting point. (That is, I ask whether there is a 'Eulerian' cycle.) Then I hand you another network, and ask whether there is a path which visits each node exactly once. (That is, I ask whether there is a 'Hamiltonian' cycle.) How hard is it to answer me?" (
via)
[more inside]
posted by kliuless
on Dec 1, 2012 -
19 comments
Racetrack is a game with
very simple rules which nonetheless does a surprisingly good job of simulating the acceleration, braking, and handling of a race car. It can teach not only about inertia and kinematics, but also about optimal racing lines. Racetrack can be played with nothing more than a piece of graph paper and a pen, but there is also an online implementation called
Vector Racer.
posted by 256
on Aug 11, 2012 -
42 comments
Morton and Vicary on the Categorified Heisenberg Algebra - "In quantum mechanics, position times momentum does not equal momentum times position! This sounds weird, but it's connected to a very simple fact. Suppose you have a box with some balls in it, and you have the magical ability to create and annihilate balls. Then there's one more way to create a ball and then annihilate one, than to annihilate one and then create one. Huh? Yes: if there are, say, 3 balls in the box to start with, there are 4 balls you can choose to annihilate after you've created one but only 3 before you create one..."
[more inside]
posted by kliuless
on Jul 21, 2012 -
78 comments
Old Theories As Limits of New Ones -- Theoretical physicist, Lubos Motl, takes a brief tour through the history of physics, and explains the simple mathematical relationship of old theories to the theories that replace them.
posted by empath
on Aug 5, 2011 -
16 comments
Larry Gonick is a veteran American cartoonist best known for his delightful comic-book guides to science and history, many of which have previews online. Chief among them is his long-running
Cartoon History of the Universe (later
The Cartoon History of the Modern World), a sprawling multi-volume opus documenting everything from the Big Bang to the Bush administration. Published over the course of three decades, it takes a truly global view -- its time-traveling Professor thoroughly explores not only familiar topics like Rome and World War II but the oft-neglected stories of Asia and Africa, blending caricature and myth with careful scholarship (cited by
fun illustrated bibliographies) and tackling even the most obscure events
with intelligence and wit. This savvy satire carried over to Gonick's
Zinn-by-way-of-
Pogo chronicle
The Cartoon History of the United States, along with a bevy of
Cartoon Guides to other topics, including
Genetics, Computer Science, Chemistry, Physics, Statistics, The Environment, and (yes!)
Sex. Gonick has also maintained a few sideprojects, such as
a webcomic look at Chinese invention,
assorted math comics (
previously), the
Muse magazine mainstay
Kokopelli & Co. (featuring the shenanigans of his
"New Muses"), and
more. See also
these lengthy interview snippets, linked
previously. Want more? Amazon links to the complete oeuvre inside!
[more inside]
posted by Rhaomi
on Jun 6, 2011 -
29 comments
Horizon asks
"What is reality?" -- youtube for links for those outside the UK:
1,
2,
3,
4. It's a hard question. To help you answer it, Stanford has a set of free courses available on line by Leonard Susskind:
General Relativity,
Cosmology,
New Revolutions in Particle Physics,
Quantum Entanglement,
Special Relativity,
Classical Mechanics,
Statistical Mechanics,
The Standard Model. (Each link is to lecture 1 of a full college course of a dozen or so lectures.) If you need help with the math,
the Khan Academy should help get you up to speed.
posted by empath
on Jan 23, 2011 -
67 comments
The 300th issue of
This Week's Finds in Mathematical Physics will be the last. It is not an exaggeration to say that when
John Baez started publishing TWF in 1993, he invented the science blog, and an (academic) generation has now grown up reading his thoughts on
higher category theory,
zeta functions,
quantum gravity,
crazy pictures of roots of polynomials,
science fiction, and everything else that can loosely be called either "mathematical" or "physics."
Baez continues to blog actively at
n-category cafe and the associated
nLab (an intriguingly fermented commune of mathematicians, physicists, and philosophers.) He is now starting a new blog,
Azimuth, "centered around the theme of
what scientists can do to help save the planet."
posted by escabeche
on Aug 14, 2010 -
17 comments
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."
posted by cthuljew
on Nov 9, 2008 -
82 comments
"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.
posted by parudox
on Mar 18, 2007 -
11 comments
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.
posted by knave
on Nov 6, 2006 -
46 comments
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)
posted by kliuless
on Jun 20, 2005 -
6 comments
