Catching the waves

Traditionally, astronomers have observed the Universe by catching photons of electromagnetic radiation (that's light, radio waves, infrared, UV, X-rays and gamma rays) in telescopes and detectors. These methods have (and continue) to help us work out a tremedous amount about the physics and chemistry of what is out there, but it is always good to have even more ways to look at things.

A promising, and totally new way to observe the Universe would be to measure wrinkles in the very fabric of space-time; gravitational waves. These may sound like something from Back to the Future, but they are a prediction of Einstein's Theory of General Relativity. It is thought that they are created by large moving masses such as two orbiting black holes or in supernovae explosions. For several years physicists have been building instruments in an attempt to detect these ripples. So far they have been unsuccessful because the ripples are so excruciatingly tiny that the detectors have not been sensitive enough; even the strongest ripples are expected to produce an effect in the detector much smaller than the size of an atom. That is pretty tiny. The push for more and more sensitive detectors has been progressing over the last few years and it is thought that we aren't far off the sensitivity required.

There are already detectors operating in the US and Japan, but now a joint German-British team have an 18 month observation run with the GEO600 instrument. This is great news because it means that if any of the instruments makes a detection of a gravitational wave, the others should detect it too. This double and triple checking, by separate teams, will be vital to show that the first ever detection of a gravitational wave is indeed that rather than due to siesmic activity or someone knocking over a wardrobe several miles away.

The only gloomy news at the moment is that with NASA's budget cuts, the space-based gravitational wave detector Lisa may not be going ahead.

Posted in astro blog by Stuart on Wednesday 28th Jun 2006 (11:32 CEST) | Permalink
[an error occurred while processing this directive]
[an error occurred while processing this directive]