![]() spacetime solution known as Minkowski space. The Universe's expansion is accelerating, and that implies that empty space itself has a positive, non-zero energy density.Ī representation of flat, empty space with no matter, energy or curvature of any type. It's the best absolute measurement of the energy density of empty space we have.Īnd, quite stunningly, that energy density, as much as we might recoil from the conclusion, isn't zero. The better we measure how the Universe is expanding, the better we constrain the properties of dark energy, which appears to equate to the energy of empty space. We can measure the energy inherent to empty space by mapping out the expansion of the Universe, though. The energy of empty space itself isn't something we can theoretically determine in an absolute sense our calculational toolkit isn't powerful enough to do it. Whether it has the same, constant value in other regions of the multiverse is something we cannot know, but there is no motivation for it to be that way. Even in empty space, this vacuum energy is non-zero. Visualization of a quantum field theory calculation showing virtual particles in the quantum vacuum. But even they won't live forever, and Jim Gerofsky wants to know what happens to cause them to die, asking: The most massive ones contain tens of billions of solar masses in a singularity surrounded by an event horizon, making them the most massive individual entities we know of. At the centers of galaxies, though, the largest single objects in the Universe form and grow even today: supermassive black holes. All the stars that will ever form will someday burn out distant galaxies and clusters of galaxies get pushed away from one another by dark energy even the stars within a galaxy, on long enough timescales, will get gravitationally ejected. ![]() Andrew Hamilton / JILA / University of Colorado What happens to that information as the black hole evaporates is still unanswered. To an outside observer watching you fall in, your information would get encoded on the event horizon. Nature Astronomy, 10 februari 2022.When you fall into a black hole or simply get very close to the event horizon, its size and scale. Wagner, Tom Oosterloo, Pierre Guillard, Dipanjan Mukherjee en Geoffrey Bicknell: Cold gas removal from the centre of a galaxy by a low-luminosity jet. Referentie: Suma Murthy, Raffaella Morganti, Alexander Y. She now works as a postdoc at JIVE, the European institute in Dwingeloo that, among other things, coordinates the cooperation of radio telescopes all over the world. Murthy defended her PhD thesis at the University of Groningen on 8 February. The observations by Murthy and her colleagues had previously been predicted by computer simulations. It is a collection of radio dishes in the French Alps at an altitude of about 2500 metres. NOEMA stands for Northern Extended Millimetre Array. The researchers made their observations in October and November 2020 with the NOEMA telescopes. From now on, we will have to take this into account in models for the evolution of galaxies." Our results show that these relatively weak radio-emitters can indeed inhibit growth. It was thought that they did not play an important role in growth inhibition. "A large part of the radio emitters are relatively quiet. "That low-power radio jets have also been found to clean a galaxy is extraordinary," says principal investigator Suma Murthy (working at ASTRON and at the Kapteyn Institute of the University of Groningen during the research).
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