Here’s the blog for you. It’s a good guide for IDing creepy crawlies.
[Update a few minutes later]
Not related, and yet it sort of is. How did pterosaurs get into the air?
Here’s the blog for you. It’s a good guide for IDing creepy crawlies.
[Update a few minutes later]
Not related, and yet it sort of is. How did pterosaurs get into the air?
The science of attractive faces.
As Clark notes, here is a very nicely written piece on parabolic flight and weightlessness. Rare is the reporter (even science reporters) who get the physics right on this, because (as he points out) they get confused by the phrase “zero gravity,” which doesn’t really exist anywhere in the universe. Only one quibble:
Each period of ‘weightlessness’ is limited to half a minute or so; otherwise we ‘zeronauts’ would continue freefalling right into the Nevada desert at 600mph. As it is, during half-a-minute’s power- dive we drop nearly 20,000ft – although inside the plane we are completely unaware of this.
This gives the impression that weightlessness only occurs when you “drop” (i.e., descend in altitude). But it actually happens on the way up as well. In both cases, you are “falling” (in the sense that there is no force acting on you other than gravity). First you fall up, then hit the top of the trajectory, then fall down, weightless all the while, and unable to discern your direction of motion. If this seems counterintuitive, it is. But consider an elliptical orbit. As you approach perigee you’re heading down (toward the earth), and once you reach it, you start heading back up (away from the earth) to apogee, but you’re in orbit, and free fall the entire orbit. A parabola in an aircraft is an orbit that, if continued, would intersect the earth’s surface (which is why it is wise to not continue it). And of course, to be more technical yet, it is only parabolic in an approximate sense (assuming flat earth). In reality, it is a tiny section of an ellipse, because the contents of the aircraft are (briefly) in orbit, within the atmosphere.
I should also note that the phrase “power dive” is also misleading. “Power dive” implies that you are diving with engines at full thrust to get down as fast as possible, but in fact, the engines are barely running above idle throughout (until the pullout). Their only function is to overcome wind resistance so that the aircraft can approximate a cannon ball falling in vacuum.
…of evolution.
…and meditations on experts.
This is why I have no problem challenging the conventional wisdom in space policy and technology. Sometimes the experts can be completely wrong, in a groupthink sort of way.
Alan Boyle has a roundup of what happened in 2008.
…and now this:
Dr Mike Edwards, an English teacher at Meoncross School in Stubbington, Hants, first spotted the squirrel outside his classroom window.
He said: ‘I was sitting in my classroom and looked out the window and saw it sitting on the fence. I had to do a double take.
‘Since then it’s been a bit of a regular at the school – everyone’s seen it.
‘We thought it might have been paint or something but then when you look at it up close, it’s an all-over coat, not in patches like you’d expect if it had been near some paint.
‘Its fur actually looks purple all the way through. It’s an absolute mystery.’
But I can tell you any how, I’d rather see than be one.
Explained. It’s for thermal management of the brain.
Alan Boyle has a piece on what looks to be an interesting PBS series on biblical archaeology. I agree that it is not the archaeologist’s job to either prove, or disprove creation myths. His job is to, as best as can be done, utilize the scientific method to figure out what the past really was.
So, are we heading for rising sea levels, or a return of the glaciers? A roundup of the debate.