[C]onsider this impressive composite image of a wide region of the northern winter sky. With a total exposure time of 40 hours, the painstaking mosaic presents a nebula-rich expanse known as the Orion-Eridanus Superbubble above a house in suburban Boston, USA.
Daily Archives: April 14, 2009
Mumbo, Meet Jumbo
Skulls in the Stars: Levitation and diamagnetism, or: LEAVE EARNSHAW ALONE!!!
It’s hard to tell if the author is being snarky or really looks upon mathematical physics as a “mumbojumbo” that impedes progress. Taking the statement at face value, it highlights an important and semi-common misunderstanding of many physics theorems, and so I thought I’d take a qualitative stab at explaining Earnshaw’s theorem and its relationship to diamagnetic materials and magnetic levitation.
New Danger from Antarctica
The P-bomb
Hit or Myth
Top 10 Ridiculously Common Science Myths
The Myth: Meteors are heated by friction when entering the atmosphere
When a meteoroid enters the atmosphere of the earth (becoming a meteor), it is actually the speed compressing the air in front of the object that causes it to heat up. It is the pressure on the air that generates a heat intense enough to make the rock so hot that is glows brilliantly for our viewing pleasure (if we are lucky enough to be looking in the sky at the right time). We should also dispel the myth about meteors being hot when they hit the earth – becoming meteorites. Meteorites are almost always cold when they hit – and in fact they are often found covered in frost. This is because they are so cold from their journey through space that the entry heat is not sufficient to do more than burn off the outer layers.
Wet Shoe Problem — Check
The researchers calculated that shoes flick up about a pint of water after walking 20 kilometres on a damp day.
I wonder if the researchers really reported an imperial volume with a metric distance.