Thursday, October 7, 2010

"Next I want to make a doorbell that sounds like a dying star," Katie Paterson.

Katie Paterson- interview


Spencer Finch

When a scientist peers into space, either through a standard telescope or with the aid of a fancy space-based observatory, the things she observes emit light energy, called electromagnetic radiation.

Galaxies, nebulae, stars, trees, microscopic bugs and anything else that can be observed glows with energy at one of these wavelengths.

But in recent decades, researchers have become increasingly convinced that there is a vast amount of material in the universe that does not glow at all. This mysterious "dark matter" is believed by most scientists to be the most common stuff in the universe, perhaps making up 90 percent or more of the total mass.

So what is dark matter made of? No one knows for sure.

Normal matter -- you, your computer and the air you breathe -- is made of atoms, which are composed of protons, neutrons and electrons. Scientists call this "baryonic" matter. They suspect some dark matter is of the normal, baryonic variety. This might include brown dwarf stars and other objects that are simply too small, or too dim, to be seen from great distances.

But most dark matter is thought to be non-baryonic -- truly strange.

A gravitational lens is formed when the light from a very distant, bright source (such as a quasar) is "bent" around a massive object (such as a cluster of galaxies) between the source object and the observer. The process is known as gravitational lensing, and is one of the predictions of Albert Einstein's general theory of relativity.

No comments: