Posted on 08/22/2009 10:05:51 PM PDT by neverdem
Sensitive search fails to find ripples in space, but boosts hopes for future hunts.
The hunt for gravitational waves may not have found the elusive ripples in space-time predicted by Albert Einstein, but the latest results from the most sensitive survey to date are providing clear insight into the origins and fabric of the Universe.
General relativity predicts that gravitational waves are generated by accelerating masses. Violent yet rare events, such as a supernova explosion or the collision of two black holes, should make the biggest and most detectable waves.
A more pervasive yet weaker source of waves should be the stochastic gravitational wave background (SGWB) that was mostly created in the turmoil immediately after the Big Bang, and which has spread unhindered through the Universe ever since.
The Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, based in Washington state and Louisiana, look for these cosmic gravitational waves by measuring any slight disturbance to laser beams that shuttle between heavy mirrors held kilometres apart. Whereas the gravitational wave signal from a distinct event, such as a black-hole merger, would appear as a spike in the LIGO data, the SGWB is a murmur that is more difficult to detect.
“For 40 years they've been saying that gravity waves are around the corner ... I think for the first time that's actually a true statement.”
Michael Turner
University of Chicago, Illinois
Working with the Virgo Collaboration, which runs a gravitational wave detector near Pisa, Italy, the LIGO team has now analysed what their own detector saw between November 2005 and September 2007. Although LIGO did not find any waves, the teams conclude in Nature1 that the SGWB is even smaller than LIGO can currently detect. This result rules out some theoretical models of the early Universe that would generate a relatively large background of gravitational waves.
"This is the first time that an experiment directly searching for gravitational waves is essentially going and making a statement about cosmology, about the evolution of the Universe," says Vuk Mandic, an astrophysicist at the University of Minnesota in Minneapolis, and part of the LIGO team. The data also exclude certain cosmological models involving cosmic strings hypothetical cracks in the fabric of space that are thinner than an atom but have immense gravitational fields.
The LIGO results reduce the upper limit for the size of the SGWB, which had previously been set by indirect measurements. A relatively large SGWB in the very early Universe, for example, would have had a measurable effect on both the cosmic microwave background radiation left over from that time, and the relative amounts of light elements such as hydrogen, helium and lithium created within minutes of the Big Bang.
The LIGO and Virgo collaborations are in the process of merging their scientific efforts, and the teams plan to include data and collaborative work from both experiments in all of their future papers. Detector improvements should help Virgo to match LIGO's sensitivity in the next few years, and a series of upgrades to both experiments should increase their sensitivity to the SGWB by more than a thousand times by 2014 which astrophysicists say is almost certain to be enough to pin down its quarry at last.
"For some 40 years they've been saying that gravity waves are around the corner," says Michael Turner, an astrophysicist at the University of Chicago in Illinois, who was not involved in the research. "And I think for the first time in 40 years that's actually a true statement."
Thanks.
You mean gravity waves come along once in a coon’s age?
LOL.
If I said that, I mask have been mistaken. ;’)
LOL.
THX.
The aim of science is to find the universal laws of physics. Both relativity and quantum mechanics are limited in their applications. And they contradict each other. In logic in only takes one counter example to disprove a proposition. Are you proposing that science throw logic out the window?
The graviton wont show up. String theories are garbage science IMO. Even its proponents concede that to even begin getting useful results they need to fudge in an extra dimension, M-theory. 11 dimensions to describe a three dimensional, inverse square, phenomenon.
As I said, the hunt for a better theory is on. It's too early to say what that theory will be. But for about 60 years physicists worked in their respective fields and didn't talk to physicists in other fields. Those days are gone. Physicists from all fields are now talking to each other. And now physics must deal with the contradiction at the heart of its discipline.
Perhaps his theories need closer examination now that physicists are dealing honestly with the contradiction at the heart of their discipline.
Miller isn’t known for theories; what he did was to run a more accurate version of the MM experiment, and it didn’t fail. That’s fact and not theory and, to my knowledge, that eliminates the basis for relativity.
Science is about theories and measurements. The value of a theory is that it predicts measurements. Measurements are always approximate. But if measurements are close to the theoretical predictions, then it's a good theory.
As far as I can tell, Miller took measurements that seem to support theories about the existence of an ether drift to explain the constant speed of light. Today I don't think most physicists think the ether exists, but it might be worth looking into again. Whether the ether exists or not, relativity is limited in its applications, as Newtonian physics is limited in its applications.
The idea of "photons" makes about as much sense as the animal with properties of lions and elephants. When you see evidence of both waves and particles, the simplest explanation is that both waves and particles are present.
The wave/particle thing with light is probably similar to the situation for rifle fire in which waves moving at around 1100 fps are being created by bullets moving through the air much faster than that. The medium which light waves move through is probably a neutrino soup aether such as Wal Thornhill describes and the waves themselves move at a limit value which is C. The particles are probably Ralph Sansbury's sub-electron particles and the speed they move at is as Sansbury describes, around 10^22 m/sec. That would get you to one of the near galaxies in a couple of seconds.
Yes.
Your main idea: both waves and particles are present. If light is a particle, what do you call it in your theory?
The wave/particle thing with light is probably similar to the situation for rifle fire in which waves moving at around 1100 fps are being created by bullets moving through the air much faster than that. The medium which light waves move through is probably a neutrino soup aether such as Wal Thornhill describes and the waves themselves move at a limit value which is C. The particles are probably Ralph Sansbury's sub-electron particles and the speed they move at is as Sansbury describes, around 10^22 m/sec. That would get you to one of the near galaxies in a couple of seconds.
You are saying that light is a particle moving through some medium. But all we see is the effect light has on the medium which moves at speed c. OK, but why doesn't Galilean relativity apply? Well, measurements show that it doesn't. So now we have to apply ether or "wave" drift theories. And the particles themselves we know nothing about except this idea that they are moving 10^22 m/sec. I would say there is a lot more soup here than just a neutrino soup. I would call this the Minestrone Soup theory: just throw in whatever you have in the frige. When you get a consensus on that one among physicists, let me know.
This is just to suggest that maybe Amelino-Camelia’s quantized space-time and Einstein’s smoothly curving model may be in some sense “complementarities.”
Thank you again for the ping, Kevmo! Please keep me posted if you see anything more on this subject I’ll be looking, too.
13 posted on Sunday, August 16, 2009 1:01:59 PM by betty boop (Without God man neither knows which way to go, nor even understands who he is. ÂPope Benedict XVI)
***Okay, here ya go. I’m including Alamo-Girl and Swordmaker
oops, I shoulda pinged you earlier...
Thanks for the ping, dear Kevmo!
Drove by LIGO (Hanford) today. It’s still there.
Tigger: Ha ha ha, she called me “dear.” Roo, are you ready for some bouncing?
Roo: Yeah! You and me are good bouncers!
Kanga: Just a moment, dear. ...
www.lavasurfer.com/wtp/pooh-transcript.html
I just thought of a good expression for LIGO, which is what we used to say about Gallium Arsenide: The future of technology and always will be. I think gravity waves will always be “just around the corner”.
Silver Surfer
LOLOL! The gravity wave quest reminds me of the Higgs field/boson quest...
At least with Higgs-Boson one can actually put their money where their mouth is, buying or selling contracts at Intrade. I suggested a LIGO contract but they aren’t interested.
Suggested contract: Laser Interferometer Gravitational Wave Observatory detects gravity waves
http://bb.intrade.com/intradeForum/posts/list/4072.page
Observation of the Higgs Boson Particle
Contract Bid Ask Last Vol Chge
HIGGS.BOSON.DEC09
Higgs Boson Particle to be observed on/before 31 Dec 2009 M Trade - 9.9 2.0 450 0
HIGGS.BOSON.DEC10
Higgs Boson Particle to be observed on/before 31 Dec 2010 M Trade 12.1 24.9 17.0 144 0
Suggested contract: Laser Interferometer Gravitational Wave Observatory detects gravity waves
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.