Wired posts a picture of The Quiet Sun and two days later the sun farts in our general direction: Spring Fling: Sun Emits a Mid-Level Flare
Nice going.
Category Archives: Physics
Entaaangled Piiigs iiin Spaaace
Einstein’s spooky action at a distance in space.
A pair of entangled photons would be generated on the Earth. One of these would then be sent to a detector aboard the International Space Station, while the other photon would be measured locally on the ground for comparison.
Interesting. As entanglement is generally a free-space transmission experiment (going through fiber causes problems, since there are polarization effects on dispersion and loss; people are investigating if this can done), going up has its advantages — much less atmosphere, on average.
Vive la Differential
Pretty good explanation of the differential in your car works and why it’s needed
Get Your Ass to Mars?
How far is it to Mars? infographic
Momentum was Conserved, and it was Good
Should You Go For It?
Advice: Should you get your PhD?
Lots of good advice and insight. I can add this: a PhD (in physics, at least) generally allows you an opportunity to work on more interesting problems. As Ethan notes, glory and money are not usually the outcome of the degree. One should also note that you still spend 80% (or more) of the time doing mundane things. It’s the remaining 20% that has to be worthwhile to you.
Beware This on Your Fantastic Voyage
This kinda reminds me of when Donald Pleasence and the Proteus are eaten by white blood cells.
You'd Better Put Some Clothes on That Naked Singularity, Buster
In case you missed it, an Idaho biology teacher was recently under scrutiny for the unforgivable act of saying the word “vagina” in a class on human reproduction. (To add insult to idiocy, or idiocy to insult, the superintendent says “It is highly unlikely it would end with his dismissal. Maybe a letter of reprimand from the school board.” WTF?)
Anyway, Frank Noschese has a physics-related commentary, in the form of a letter about part of the physics curriculum: Dear Parents. It’s not often I file things under both physics and satire. The section on “Giggle-inducing Scientific Terminology” is absolute gold.
Goldilocks and the Laser Pointer
Most Laser Pointers Are Too Strong
This seems a little … unfinished.
Neither the story nor the referenced study mention if the lasers are all supposed to be 5 mW and thus class IIIa (or 3R), or if, as one link claims, there are higher-power lasers that aren’t limited by this threshold because they aren’t marketed as laser pointers. Or if the violation isn’t that they are claiming 5 mW and exceeding it, but rather they are incorrectly (and presumably illegally) calling the more powerful devices laser pointers and listing them as class III/3R.
Then there was this claim.
Green lasers use a shorter wavelength of light than red ones, making them brighter and more dangerous.
This was lifted from the included link, but lacking the detail found in another link. Green lasers aren’t brighter simply because they have a shorter wavelength. If that were true, a blue laser would be brighter still, and they aren’t. In fact green lasers must fire fewer photons per second at you than red lasers do, if they all have the same power. What makes the green brighter is your eye. The eye’s response to light isn’t constant across the spectrum — it’s much better at absorbing (and thus detecting) green light then either red or blue, so the green light has a better chance at doing damage.
Pew! Pew! Pew! … Splash!
Speaking of lasers, just a navy laser (not a 5 mW laser pointer) shooting down a drone. Mars rovers don’t have a monopoly on laser fun.