Gravitational wave detector in Hannover tests holographic Universe — Can GEO600 hear the quantum noise of spacetime?
Are we living in a holographic Universe? Are space and time grainy? Is there quantum noise in spacetime? American physicist Craig Hogan is convinced that he has found proof in the data of the German-British gravitational wave detector GEO600 – and that his ideas could explain mysterious noise in the detector data which has not been explained so far. New experiments in the coming months will yield more evidence about Craig Hogan’s assumptions:
To test the theory of holographic noise, the frequency of GEO600’s maximum sensitivity will be shifted towards ever higher frequencies. The frequency of maximum sensitivity is the tone that the detector can hear best. It is normally adjusted to offer the best chance for hearing exploding stars or merging black holes.
Even if it turns out that the mysterious noise is the same at high frequencies as at the lower ones, this will not constitute proof for Hogan’s hypothesis. It would, however, provide a strong motivation for further study. The sensitivity of GEO600 will then be significantly improved by using ‘squeezed vacuum’ and by the installation of a mode filter in a new vacuum chamber. The technology of ‘squeezed vacuum’ was particularly refined in Hannover and would be used in a gravitational wave detector for the first time.
“We are very eager to find out what we can learn about the possible holographic noise over the course of the coming year”, says Prof. Dr. Karsten Danzmann, director of the Hannover Albert-Einstein-Institute. “GEO600 is the only experiment in the world able to test this controversial theory at this time. Unlike the other large laser interferometers, GEO600 reacts particularly sensitively to lateral movement of the beam splitter because it is constructed using the principle of signal recycling. Normally this is inconvenient, but we need the signal recycling to compensate for the shorter arm lengths compared to other detectors. The holographic noise, however, produces exactly such a lateral signal and so the disadvantage becomes an advantage in this case. You could say that this has placed us in the very centre of a tornado in fundamental research!”
