Å·±¦ÓéÀÖ

Last year's spotlight on Nobel prize winning work of gravitational wave detection have stood as a flagship for the success of Einstein's general theory of relativity and the predicted features among the detected waves indeed behaved as per the field equations and the strain as being calculated from it.
However one of the attempts is also to gain insight in the strange prediction of a thin smeared out boundary which can lead to echoes of the gravitational waves reverberating which was theorized to be detected at specific times. This would shed light on the black hole firewall hypothesis which has a very interesting history taking us back to the Hawking radiation theory. As most of us may be aware of the stir this theory caused implying on information getting lost as a black hole completely evaporates. After several work being done on this aspect by many leading physicists, the final triumph was accepted when Juan Maldacena theorized that the information can be found encoded in the 2D boundary of 3D objects much like a hologram. Although it gave us a great theory of 2D - 3D link upon a physical object it was not well known how the information gets encoded in 2D domain as anything falls into black holes. As physicist Joseph Polchinsky set on to find out he and his team theorized something which caused a stir in the physics community once again. This time because one of the central tenets of general theory of relativity was at stake. The equivalence principle. The issue goes like this, once a cosmonaut dives into a super massive black hole (to ensure the tidal effects doesn't rip the diver off) the first idea we can have is that the cosmonaut would experience free fall much like floating in empty space. and as he or she nears the singularity the diver will be experiencing a mismaster type effect and would be ripped apart and scrambled beyond comprehension as spacetime breaks down at singularity. However event horizon wasn't such a bad place to start diving into these exotic cosmic entities. Yet Polchinsky found out that the radiation emanated from the black hole's horizon would be entangled and the other half of the virtual particle which ought to be entangled as well would be severed and creating a ring of high energy region known as firewall which would burn anything that falls into the black hole. This would be a blow to the equivalence principle which would then break down at the gravitational field near the event horizon itself.
To test this theory, physicist Niayesh Afshordi and his team is working on the prediction of detecting echoes which would be detected at 0.1 sec , 0.2 sec and 0.3 sec after the merger of the colliding black holes. Such echoes were found exactly at the specified time intervas, but the discovery is classified as 2.9 sigma. This can be very well be background noises. It remains to be seen if this result would turn out to be insignificant after much more data is received. However this is interesting on the part of a long sought after revolution in physics and the idea of John Archibald Wheeler that inspecting the boundary of the black holes can give us a glimpse of the tell tale signatures of the effects of quantum gravity, coming true.