SMBC: The life cycle of a physicist
Remember, if we let you get a pet physicist, you have to promise to help keep the lab clean and, most importantly, you have fund him/her every year.
Please Tell Me You Know the Answer
The Ol' Switcheroo
The bit about how the speed of light being constant was established before Einstein was born refers to Maxwell’s equations, according to which electromagnetic radiation has to travel at the same speed in all frames. Physicists eventually realized the light and EM waves were the same thing. This is something that isn’t always stressed in the teaching of the development of relativity, and one might get the impression that the postulate of c being invariant was just a guess.
Good Morning, Moon
From year to year, the moon never seems to change. Craters and other formations appear to be permanent now, but the moon didn’t always look like this. Thanks to NASA’s Lunar Reconnaissance Orbiter, we now have a better look at some of the moon’s history.
Is It Hot in Here, or is it Just the Army?
US military unveils non-lethal heat ray weapon
On-demand hot-flashes. The menopausotron unveiled!
The technology has attracted safety concerns possibly because the beam is often confused with the microwaves commonly used by consumers to rapidly heat food.
“There are a lot of misperceptions out there,” lamented Taffola, saying the Pentagon was keen to make clear what the weapon is, and what it is not.
The frequency of the blast makes all the difference for actual injury as opposed to extreme discomfort, stressed Stephanie Miller, who measured the system’s radio frequency bioeffects at the Air Force Research Laboratory.
The system ray is 95 gigahertz, a frequency “absorbed very superficially,” said Miller.
The beam only goes 1/64th of an inch (0.4 millimeter), which “gives a lot more safety.”
In other words, the heating is all at the surface, not in the interior, so it cooks your skin, not your internal organs. It’s not a direct quote, but one might get the impression that the message is “it’s not microwave, it’s radio-frequency” and playing on the notion that radios are harmless. But AM and FM radio bands are at around 1 MHz and 100 MHz, respectively. However, ~ 1 GHz from microwave ovens is microwave, so 95 GHz is well into the microwave band of the spectrum.
Coordinate Transformation: People Jumping
A rope, jumping people.
You Can't Get There From Here
Q. If I find myself in a free-falling elevator, is there any position that might increase my chance of survival? (Climbing on top of other people is not an acceptable answer.)
A. The best option would be to lie on your back on the floor as flat as possible, said Eliot H. Frank, a research engineer at the Center for Biomedical Engineering at the Massachusetts Institute of Technology.
Yes, that makes sense, but how does one get to the floor and lie flat, while in free-fall?
Here Now the Neutrinews
Neutrinos not faster than photons — the lab results have come back and they were juicing, so they’ve been stripped of their title. Sean Carroll has included a graph of the results, in Superluminal Neutrinos are so 2011, which shows that the new ICARUS results are statistically well-separated from the OPERA data.
A few other summaries-
Neutrinos not faster than light
This Time, ICARUS Really DOES Refute OPERA
This is the way it works in science all the time. A first experiment makes a claim that they see a striking and surprising effect. A second experiment tries to verify the effect and instead shows no sign of it. It’s commonplace.
Cheap, Cheap
Nearly every second, a user on Twitter tweets about what time it is. It could be groaning about waking up, to telling a friend when to meet, to an automated train scheduler alerting when the next one is coming. By searching Twitter for the current time we get a tiny glimpse of how active and far reaching the social network is.
Nobody Does it Better
Sixteen Things Calvin and Hobbes Said Better Than Anyone Else
Bill Watterson’s Calvin and Hobbes ran between 1985 and 1995. His comic strip managed to infuse wondering (and wandering) on a cosmic scale into an ageless world of lazy Sunday afternoons, snow goons, and harassed babysitters. I’m not saying that you should take moral and philosophical guidance from the inventor of Calvinball (a game that runs on chaos theory), but you could do much worse.
So here, in no particular order, is a selection of quotes that nail everything from the meaning of life to special underwear. Enjoy.