Captain-LeChene added a photo to the album Captain-lechene.
startswithabang:
LIGO’s black holes probably did not come from one star“The best thing I can say about this idea is that it falls into the category of “not automatically impossible.” The tough thing about it is that even for the most rapid rotators, the stars themselves are still highly non-relativistic, meaning they spin at velocities well below (significantly less than 10%) the speed of light, while the inspiraling black holes were moving at speeds very close to (about 60%) the speed of light.”Ever since LIGO first announced the direct detection of gravitational waves from two merging black holes, the physics and astronomy community has been struggling to understand an unexpected phenomenon that appears to have come along with it: a short-period gamma ray burst. Arriving just 0.4 seconds after the gravitational waves did, the Fermi satellite’s detection doesn’t line up with models of black hole mergers. It’s thought that short-period GRBs originate from neutron star-neutron star mergers, and so seeing this has led to speculation of new physics, including from Avi Loeb at Harvard that perhaps LIGO’s twin black holes came from inside the same star. However, this explanation is exceedingly unlikely, and there are a number of astrophysical explanations that don’t require new physics like Loeb’s explanation would. Go get the whole — mostly critical — story of why LIGO’s black holes probably didn’t come from the same star! ... See more
LIGO’s black holes probably did not come from one star“The best thing I can say about this idea is that it falls into the category of “not automatically impossible.” The tough thing about it is that even for the most rapid rotators, the stars themselves are still highly non-relativistic, meaning they spin at velocities well below (significantly less than 10%) the speed of light, while the inspiraling black holes were moving at speeds very close to (about 60%) the speed of light.”Ever since LIGO first announced the direct detection of gravitational waves from two merging black holes, the physics and astronomy community has been struggling to understand an unexpected phenomenon that appears to have come along with it: a short-period gamma ray burst. Arriving just 0.4 seconds after the gravitational waves did, the Fermi satellite’s detection doesn’t line up with models of black hole mergers. It’s thought that short-period GRBs originate from neutron star-neutron star mergers, and so seeing this has led to speculation of new physics, including from Avi Loeb at Harvard that perhaps LIGO’s twin black holes came from inside the same star. However, this explanation is exceedingly unlikely, and there are a number of astrophysical explanations that don’t require new physics like Loeb’s explanation would. Go get the whole — mostly critical — story of why LIGO’s black holes probably didn’t come from the same star! ... See more
