Detecting gravity
Scientists believe they are only months away from detecting gravity waves. And it's all due to a new breakthrough machine in measuring distances, the Anglo-German GEO600 interferometer - an instrument so sensitive it can detect an object moving one million billionth of a millimetre.
In his general theory of relativity set out in 1916, Albert Einstein proposed that bodies of mass such as stars cause distortions in the fabric of space - in a similar way to the effect of placing a ball on a piece of elasticated material.
In order to detect gravity waves, a laser beam is split into two branches that are sent down two identical 2000ft-long tubes to suspended mirrors and back again. The beams are recombined and, assuming the two arms remain exactly the same distance, cancel each other out.
But if the beams create an interference pattern when recombined, this means the length of the branches has been altered and a gravitational wave has been detected. A detection would only be accepted if picked up by more than one interferometer.
Read more about it at telegraph news.
posted by Unknown @ 11:34 PM
2 Comments:
"two identical 2000ft-long tubes to suspended mirrors"
Seems like the flaw would be the extreme accuracy needed in truly having identical tubes with mirrors suspended perfectly alike. When making assumptions on a scale of this size even the tiniest variance would lead to a wrong conclusion. To be meaningful, there would have to be a tremendously small margin of error.
Very true. But if they have a machine capable of interferometer capable of measuring distances in the the one million billionth of a millimetre, then I think they can build the tubes and mirrors to spec.
I bet you can't say one million billionth 3 times fast!
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