Solar ejections falling back to the sun

Solar ejections fall back to the surface, reined in by the sun's powerful gravity. Since the material is ionized (i.e., charged), it follows the sun's magnetic field lines, like iron filings in a kid's toy. Awesome. See Bad Astronomy for a more detailed explanation.

If you can will it, it is no dream

I can't tell if this is morbid or adorable. Probably both.

A new kind of astronomy

Article

In the general theory of relativity, Einstein postulated that big gravitational disturbances - like two orbiting neutron stars or the destruction of a planet - would generate gravitational waves, propagating outward like ripples on a pond. This isn't a totally crazy idea: lots of things work this way, such as light, sound, and ripples on a pond. What's intriguing about this idea is that if gravity works by warping space, it will generate waves that can be measured, and those measurements can tell us interesting things about the massive objects creating the waves. Since all of astronomy thus far has been based on electromagnetic waves (things like light, x-rays, radio waves, and gamma radiation), discovering gravitational waves and learning to interpret their physical properties will constitute a new kind of astronomy. And these guys think they can do it. Awesome.

How does it work?

Researchers use two long tunnels set at right angles to one another. They split a laser beam in two, sending one beam down each of the two tunnels where they bounce off of mirrors and return to the starting point. Since the two tunnels are exactly the same length, the two beams recombine where they started out.

But if the contraption is hit by a gravitational wave, ONE OF THE TUNNELS WILL SHRINK BY HALF AN ANGSTROM. First of all, SHRINKING TUNNELS. Second of all, half an angstrom is really really tiny. Not as tiny as the article says, but we're talking atomic level tiny here. And these guys are trying to measure it.

To give you an idea of how sensitive that is:

"The coast is more than 100km away but we can see the effect of the waves pounding on the North Sea shore on our instruments very clearly," said Lück. "Fortunately it is a highly rhythmical signal that is easy to remove from the output of our machines."

Cool.