Does dark matter exist?
Dark matter has been suggested as a solution to the galaxy rotation problem
where individual stars don't seem to rotate the way Newton's laws would predict. Now, some scientists are saying that observations fit with Einstein's general relativity, without any dark matter needed. I just find it amazing that no one has tried this yet.
posted by delmoi
on Oct 10, 2005 -
Americans, German win nobel prize for physics.
They won for for their contributions to the development of laser-based precision spectroscopy, including the optical frequency comb technique, which among other thing allows them to measure the speed of light to such accuracy that it is now used as the definition for the meter
, see if the laws of physics were the same at the beginning of time, and make gps satellites
work much better.
posted by stilgar
on Oct 4, 2005 -
Kung Fu Science:
The BBC News article
claims that the site "is primarily aimed at 11 to 16-year-olds," but I refuse to let temporal adolescents have a corner on 25-year-old female PhD students doing physics and then breaking wood planks with their hands.
[Flash; both the site and the videos take a while to load.]
posted by gramschmidt
on Aug 3, 2005 -
How not to clean a tank car.
Apparently someone steam cleaned a railroad tank car and then having finished the job closed all the valves and hatches tightly. Physics then took over.
posted by caddis
on Jul 28, 2005 -
Thursday non-flash fun: Pendulumania!
(Direct link here
.) Swing the ball around to hit the targets, but don't let your line break. (more inside)
posted by squidlarkin
on Jul 14, 2005 -
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 -
The Physics Evolution
- a flash based history from the Institute of Physics in London. Clickable maps with timelines and short biographies of the main figures. It's a bit superficial, but a lot of fun.
posted by thatwhichfalls
on Jun 11, 2005 -
Ever Read Hyperion,
by Simmons? In that story, the earth was accidentally destroyed by a man-made black hole. We are now one step
closer. Physicists may have created a black hole in a lab at the RHIC (Relativistic Heavy Ion Collider
). H. Nastase has posted a paper
on the possibility. Fascinating discovery, but there's no real danger of destroying the earth. This might be a good time to check up on some of the myths
surrounding black holes. (Found via that other site, /.
posted by teece
on Mar 17, 2005 -
"A theory that can't predict anything is not a scientific theory," Woit says.
That would be string theory, which was going to be the theory of everything, but apparently can't even agree how many dimensions there are. "Those who dabble in alternate-universe speculations might be just modern versions of '16th century theologians (who) speculated that spirits and angels emerge from the extra-dimensional universe,' says Krauss
, who is also an outspoken foe of creationist teaching in schools."
posted by raaka
on Mar 16, 2005 -
When an UT Austin student finds a stash of graded freshman physics homework
, he decides to pitch in and add his own comments to those of the TA. Our children is might not be learning, but at least they're getting to play with lasers!
posted by robocop is bleeding
on Feb 9, 2005 -
- follow physicists from around the world as they experience the World Year of Physics 2005.
posted by Gyan
on Feb 1, 2005 -
Does relativity have any practical significance? In fact, relativity had to be taken into account
by the designers of the Global Positioning System. The GPS satellites are affected both by special relativity
(since the satellites are moving, clocks aboard them appear to run slower as seen from the ground), and by general relativity
(since the satellites are farther away from the mass of the earth, clocks appear to run faster as seen from the ground). The net effect of both is that clocks aboard GPS satellites would gain 38 microseconds per day relative to the ground, if relativistic effects were not corrected for--a figure which can be confirmed by using Google calculator
posted by DevilsAdvocate
on Nov 30, 2004 -