PHYSICISTS' FLUTTER
An esoteric bet between two renowned physicists has taken another twist:
http://www.bbc.co.uk/news/science-environment-29326918
The bet between Professors Stephen Hawking and Neil Turok was about the inflation theory of the early universe and the existence of gravitational waves.
In March this year the US BICEP team said it had found a pattern on the sky left by the rapid expansion of space fractions of a second after the Big Bang at the beginning of the universe. Professor Hawking said the finding was another confirmation of inflation. He also clamed he'd won a bet with Professor Turk whose Cyclic Universe Theory predicts no gravitational waves from the early universe.
However, new data has found that the group may have underestimated the influence on the data of dust in our own galaxy. Professor Turok said 'The BICEP experiment claimed that 20% of the fluctuations from the Big Bang were due these gravitational waves, the sign of inflation. However, Planck satellite data now confirms that the limit is less than 10%.
On this evidence, Professor Turok has suggested to Professor Hawking that they should refine their bet.
Comment: Theoretical physics is an exciting field of research.
Showing posts with label gravitational waves. Show all posts
Showing posts with label gravitational waves. Show all posts
Wednesday, 1 October 2014
Monday, 15 September 2014
NEW SEARCH FOR GRAVITATIONAL WAVES
A more sensitive Ligo (Laser interferometer gravitational-wave observatory) is progressing rapidly and will start scanning the sky in summer 2015 searching for gravitational waves.
http://www.bbc.co.uk/news/science-environment-29168676
The first generation of Ligo ran between 2001 and 2010 and saw nothing. Professor AlbertoVecchio from the School of Physics and Astronomy of the University of Birmingham said: 'Advanced Ligo will be sensitive to a factor of 1,000 in the volume that we were observing with initial Ligo, and that is the sphere of volume where we expect to see a few gravitational waves'.
Ligo operates by beaming a high power laser beam into a splitter that divides the beam into two parts. Each part is then directed towards two 4 km tunnels perpendicular to each other. A mirror at the end of the tunnels reflects the rays back into a detector where they are recombined. Since both tunnels are equally long, when the two halves meet in the detector the original signal shows no pattern. But if a gravitational wave was passing through the Earth, a pattern would be observed.
Potential sources of gravitational waves are supernovae, fast spinning neutron stars, or the collision of black holes and neutron stars orbiting close to each other.
Comment: Observation of gravitational waves would be an important test for the verification of the theory of gravity in Einstein's general theory of relativity.
A more sensitive Ligo (Laser interferometer gravitational-wave observatory) is progressing rapidly and will start scanning the sky in summer 2015 searching for gravitational waves.
http://www.bbc.co.uk/news/science-environment-29168676
The first generation of Ligo ran between 2001 and 2010 and saw nothing. Professor AlbertoVecchio from the School of Physics and Astronomy of the University of Birmingham said: 'Advanced Ligo will be sensitive to a factor of 1,000 in the volume that we were observing with initial Ligo, and that is the sphere of volume where we expect to see a few gravitational waves'.
Ligo operates by beaming a high power laser beam into a splitter that divides the beam into two parts. Each part is then directed towards two 4 km tunnels perpendicular to each other. A mirror at the end of the tunnels reflects the rays back into a detector where they are recombined. Since both tunnels are equally long, when the two halves meet in the detector the original signal shows no pattern. But if a gravitational wave was passing through the Earth, a pattern would be observed.
Potential sources of gravitational waves are supernovae, fast spinning neutron stars, or the collision of black holes and neutron stars orbiting close to each other.
Comment: Observation of gravitational waves would be an important test for the verification of the theory of gravity in Einstein's general theory of relativity.
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