A library of high-speed physics videos wmv files
Monthly Archives: December 2008
The Sad Stormtrooper
Those WERE the Droids I was looking for…
(Except it wasn’t TK421…)
Glow-in-the-Dark Trivia
Heated Prose at Futility Closet.
Marie Curie’s laboratory papers are still so radioactive that they’re kept in lead-lined boxes.
Researchers who consult them must agree to work at their own risk.
I should point out that it’s unlikely to be because the papers were irradiated, but because they were contaminated. Neutron activation can result in a radioactive nucleus, but exposure to gammas and alphas generally does not. I think that “irradiated” is often misunderstood to mean “contaminated.” Irradiated means exposed to radiation. Contaminated means radioactive materials have become attached to the object.
Energy, With a Twist
Turning a problem into a solution: aquatic clean energy from vortex-induced vibration?
Review of a paper on extracting energy from ocean currents, over at Skulls in the Stars
What is vortex induced vibration? In short, it is an effect by which little ‘whirlpools’ of fluid form in the wake of an obstructing object and regularly detach from it and are pulled downstream. These vortices carry energy and momentum (or, more accurately, the fluid which they consist of carries it) and when a vortex leaves, the obstruction itself gets a little ‘kick’ of motion from its departure. Vortices tend to leave the obstruction from opposing sides of it, and the net result is that the obstruction experiences an oscillatory force transverse to the direction of fluid flow.
Therapy
It’s supposed to be about educating people about counterfeit MINI Coopers. But don’t let that stop you.
Disney Goes to War
“Nose art” and the equivalent of heraldic icons, courtesy of Walt Disney.
According to the late WW II aviation enthusiast and author Jeffrey Ethell, “the Disney industry was pervasive in American culture and it influenced nose art in a number of different ways. Combat crews copied Disney cartoon characters because they were suitable subjects for humorous and patriotic themes. Disney’s influence also included studio artists, who joined the military and then contributed their talents to the creation of nose art. Disney Studios and the U.S. government had a history of cooperation. At the beginning of the war in 1939, Walt Disney and his artists designed and painted squadron and unit insignia. Disney raised the spirit of the troops when he transformed the ‘once staid military heraldry format created during World War I’ into inspired designs. By the end of World War II, Disney’s five-man staff assigned to insignia completed over 1,200 unit insignias, never charging a fee to the military.”
That's a Skyful
Toil and Trouble
More bubbles in microgravity
I find it interesting that, contrary to terrestrial experience with drops on a surface, the colliding drops tend to scatter rather than coelesce. In microgravity the drops are spherical, which is the minimum-energy configuration, so I expect this presents an activation barrier of sorts. The collision needs to be strong enough to perturb the shape of the drops, so that combining them doesn’t represent a configuration that requires more energy than is present.
Peer Review
Just ran across this (Thx, iNow!)
Moving Forward
Auto Bailouts and the Innovators Dilemna (sic)
By investing in an old idea, and the old guard of the U.S. auto industry, we slow the next wave of change from happening. We enable thousands of people to believe their old ways and skills are still viable, instead of motivating them to seek out new skills, products, or roles that have a chance at thriving in the decade and the next.
When you’ve been successful with an idea for years, an idea you’ve put your life into, its hard to recognize it’s time to pull the plug. Odds are high you’ll need someone else to pull the plug for you.
Related: giving retention bonuses to executives at the banks and other institutions the taxpayers are bailing out. Why? Because you’re worried you might have to hire a replacement who’s incompetent?