[pepsi_junkie]

Am I missing something? This article basically says "Einstein predicted these things exist, we have never actually observed them. But we probably will within two years (no real explanation of how or why we are so confident of that). And by the way, they are going to be amazing".

Basically it says something might be detected someday. I beleive the title is overstating the real situation a bit. Interesting though.

[JasonC]

True enough, it is expressing great confidence in what new detectors will be able to see, where previous less sensitive ones failed to detect anything.

I can explain the scheme of the new detector ideas, which are pretty clever. They are looking for tiny changes in space-time that propogate through the whole detector. They need a combination of a minute sensitivity with a large scale to gather a wide portion of a gradual effect. Something small would have the former, but not the latter, and thus fail. Something large would have the latter, not the former, and thus fail. They need to span as many orders of magnitude as possible between the small and the large.

Their solution is three spacecraft millions of miles apart pointing laser rangefinders at each other, able to detect changes in their distance apart down to a billioneth of a centimeter, based on changes in the interference of the laser light with split portions of itself. The scheme thus spans 24 orders of magnitude.

They need to use three in order to use a "base" pair to correct for changes in distance between each other pair due to other causes. (Otherwise put, with just two they would "drift" farther and closer due to random collisions with interstellar particles, etc, and so generate false signals).

More details on the scheme here -

http://lisa.jpl.nasa.gov/whatis.html