Post by Andrei Tchentchik on Jan 17, 2020 18:42:59 GMT 2
(.#344).- Gravitational waves: Einstein's major hypothesis revealed ...
Gravitational waves: Einstein's major hypothesis revealed ...
February 9, 2016.
By Laurent Sacco, Futura-Sciences
The Ligo gravitational telescope would have directly detected the gravitational waves produced by the fusion of two stellar black holes. If the rumor were to be confirmed, it would be a scientific discovery more spectacular than that of the Brout-Englert-Higgs boson, which would open a new era in astrophysics.
Are we on the verge of directly detecting the gravitational waves predicted by Einstein almost a century ago ... or have we already done so? In April 2010, Futura-Sciences reported on an article published on arXiv by Chris Belczynski of Los Alamos National Laboratory and his astrophysicists, who predicted that the first waves detected would not come from binary neutron star systems but binary black holes. Optimists, the researchers did not hesitate to predict that this detection could occur in the year 2015, when the two most powerful gravity wave telescopes, Ligo and Virgo, were "upgraded" to reach a threshold of much higher sensitivity.
In January 2016, we reported a persistent rumor that actually suggested that Advanced Ligo had already observed signals from a binary black hole system shortly after it started in September 2015. Although we have predicted that one of the events astrophysics in 2016 could be the first direct evidence of the existence of the ripples of the space-time fabric, we warned against the media rush by recalling two unfortunate cases, that of the transluminic neutrinos of Cern and that of the detection of gravitational waves of the Big Bang by the collaboration Bicep2.
Presented by Hubert Reeves and Jean-Pierre Luminet, The Big Bang to the Living is a TV-Web-cinema project that covers the most recent discoveries in the field of cosmology. In this video, Jean-Pierre Luminet talks about gravitational waves. © From Big Bang to Living, YouTube
VIDÉO YOUTUBE (En français)
Jean-Pierre Luminet : Qu’est ce que les ondes gravitationnelles.
Duration : 3m11s.
Three solar masses converted to gravitational waves
It now seems reasonable to be cautious, even in the absence of an official publication by members of the Ligo collaboration who have so far refused to comment in one way or another on the rumor spread about the Canvas. The journal Science has relayed a message on Twitter from theoretical physicist Clifford Burgess. He is, like Stephen Hawking, a member of the Perimeter Institute for Theoretical Physics (PI), an independent research institute specializing in the study of theoretical physics located in Waterloo, Canada. Burgess says colleagues have had the opportunity to take a look at an article that should be published this Thursday, February 11, 2016 in the journal Nature. What does this article contain?
Nothing less than a bomb. The members of the Ligo collaboration would announce a real discovery with a signal that would reach the 5.1 sigma in the jargon of physicists, that is to say, so unlikely that it can not reasonably be explained by an effect of chance . It would then be as if radio parasites mimic Mozart's music. The symphony picked up by Ligo would be real ...
Just as the study of the electromagnetic spectrum of a star can give us information on its chemical composition, its magnetic field and the pressure prevailing in its atmosphere, the gravitational waves emitted by compact stars in binary systems can be very talkative.
In this case, the researchers deduced from the spectrum of gravitational waves that they were emitted by two stellar black holes initially orbiting one another, with masses of 36 and 29 solar masses. Losing energy in the form of gravitational waves, these black holes eventually came closer by describing spiral orbits before colliding and fusing. For a very short time, the object formed was a black hole whose event horizon was particularly "bumpy" and dynamic. However, the theory of black holes tells us that such a star can not remain long in this state because it must very quickly take the form of a stationary black hole, namely a black Kerr hole in rotation. For this, the event horizon must vibrate in the manner of a bell struck (we speak of quasi-normal modes and ringdown phase to describe this phenomenon) to lose energy in the form of waves gravitational and become perfectly spherical.
In the end, a mass equivalent to three times that of the Sun would have been converted into pure gravitational radiation in less than a second, leaving a black hole of 62 solar masses. How to represent such energy? It's really difficult. By comparison, the power radiated by the Earth around the Sun in the form of gravitational waves is only about 200 watts. Our Sun, which converts a tiny fraction of its mass into light energy, produces 1026 watts. The phenomenon of which we speak here would thus have released in a moment three times the total quantity of energy represented by its mass of 1030 kg, according to the formula E = mc2.
The era of gravitational astronomy
If Ligo did well this observation, a new era for astronomy and astrophysics has just opened. Gravitational radiation is the most penetrating of the Universe and can therefore provide information impossible to obtain otherwise on very primitive phases of the cosmos. It also allows you to explore the physics of neutron stars and black holes. If Clifford Burgess is to be believed, the observed signal is clearly what is expected if the space-time associated with a rotating black hole is that of a Kerr black hole. It is therefore a non-trivial test of the theory of general relativity and black hole theory as it was developed in the 1950s to 1970s by pioneers like John Wheeler and Stephen Hawking.
There is also a lot to bet that we already know the names of the Nobel Prize in physics for 2016 or at least 2017. The physicists Rainer Weiss, Ronald Drever were indeed teamed to co-found Ligo in 1992 with the great relativist physicist Kip Thorne, behind the science behind Interstellar's screenplay (see Jean-Pierre Luminet's comments on his blog).
www.futura-sciences.com/
www.elishean.fr/
Copyright les Hathor © Elishean/2009-2015/ Elishean mag
F I N .
Gravitational waves: Einstein's major hypothesis revealed ...
February 9, 2016.
By Laurent Sacco, Futura-Sciences
The Ligo gravitational telescope would have directly detected the gravitational waves produced by the fusion of two stellar black holes. If the rumor were to be confirmed, it would be a scientific discovery more spectacular than that of the Brout-Englert-Higgs boson, which would open a new era in astrophysics.
Are we on the verge of directly detecting the gravitational waves predicted by Einstein almost a century ago ... or have we already done so? In April 2010, Futura-Sciences reported on an article published on arXiv by Chris Belczynski of Los Alamos National Laboratory and his astrophysicists, who predicted that the first waves detected would not come from binary neutron star systems but binary black holes. Optimists, the researchers did not hesitate to predict that this detection could occur in the year 2015, when the two most powerful gravity wave telescopes, Ligo and Virgo, were "upgraded" to reach a threshold of much higher sensitivity.
In January 2016, we reported a persistent rumor that actually suggested that Advanced Ligo had already observed signals from a binary black hole system shortly after it started in September 2015. Although we have predicted that one of the events astrophysics in 2016 could be the first direct evidence of the existence of the ripples of the space-time fabric, we warned against the media rush by recalling two unfortunate cases, that of the transluminic neutrinos of Cern and that of the detection of gravitational waves of the Big Bang by the collaboration Bicep2.
Presented by Hubert Reeves and Jean-Pierre Luminet, The Big Bang to the Living is a TV-Web-cinema project that covers the most recent discoveries in the field of cosmology. In this video, Jean-Pierre Luminet talks about gravitational waves. © From Big Bang to Living, YouTube
VIDÉO YOUTUBE (En français)
Jean-Pierre Luminet : Qu’est ce que les ondes gravitationnelles.
Duration : 3m11s.
Three solar masses converted to gravitational waves
It now seems reasonable to be cautious, even in the absence of an official publication by members of the Ligo collaboration who have so far refused to comment in one way or another on the rumor spread about the Canvas. The journal Science has relayed a message on Twitter from theoretical physicist Clifford Burgess. He is, like Stephen Hawking, a member of the Perimeter Institute for Theoretical Physics (PI), an independent research institute specializing in the study of theoretical physics located in Waterloo, Canada. Burgess says colleagues have had the opportunity to take a look at an article that should be published this Thursday, February 11, 2016 in the journal Nature. What does this article contain?
Nothing less than a bomb. The members of the Ligo collaboration would announce a real discovery with a signal that would reach the 5.1 sigma in the jargon of physicists, that is to say, so unlikely that it can not reasonably be explained by an effect of chance . It would then be as if radio parasites mimic Mozart's music. The symphony picked up by Ligo would be real ...
Just as the study of the electromagnetic spectrum of a star can give us information on its chemical composition, its magnetic field and the pressure prevailing in its atmosphere, the gravitational waves emitted by compact stars in binary systems can be very talkative.
In this case, the researchers deduced from the spectrum of gravitational waves that they were emitted by two stellar black holes initially orbiting one another, with masses of 36 and 29 solar masses. Losing energy in the form of gravitational waves, these black holes eventually came closer by describing spiral orbits before colliding and fusing. For a very short time, the object formed was a black hole whose event horizon was particularly "bumpy" and dynamic. However, the theory of black holes tells us that such a star can not remain long in this state because it must very quickly take the form of a stationary black hole, namely a black Kerr hole in rotation. For this, the event horizon must vibrate in the manner of a bell struck (we speak of quasi-normal modes and ringdown phase to describe this phenomenon) to lose energy in the form of waves gravitational and become perfectly spherical.
In the end, a mass equivalent to three times that of the Sun would have been converted into pure gravitational radiation in less than a second, leaving a black hole of 62 solar masses. How to represent such energy? It's really difficult. By comparison, the power radiated by the Earth around the Sun in the form of gravitational waves is only about 200 watts. Our Sun, which converts a tiny fraction of its mass into light energy, produces 1026 watts. The phenomenon of which we speak here would thus have released in a moment three times the total quantity of energy represented by its mass of 1030 kg, according to the formula E = mc2.
The era of gravitational astronomy
If Ligo did well this observation, a new era for astronomy and astrophysics has just opened. Gravitational radiation is the most penetrating of the Universe and can therefore provide information impossible to obtain otherwise on very primitive phases of the cosmos. It also allows you to explore the physics of neutron stars and black holes. If Clifford Burgess is to be believed, the observed signal is clearly what is expected if the space-time associated with a rotating black hole is that of a Kerr black hole. It is therefore a non-trivial test of the theory of general relativity and black hole theory as it was developed in the 1950s to 1970s by pioneers like John Wheeler and Stephen Hawking.
There is also a lot to bet that we already know the names of the Nobel Prize in physics for 2016 or at least 2017. The physicists Rainer Weiss, Ronald Drever were indeed teamed to co-found Ligo in 1992 with the great relativist physicist Kip Thorne, behind the science behind Interstellar's screenplay (see Jean-Pierre Luminet's comments on his blog).
www.futura-sciences.com/
www.elishean.fr/
Copyright les Hathor © Elishean/2009-2015/ Elishean mag
F I N .
