11/12/2023 0 Comments Going into a black hole simulationIf you could look straight into a black hole you would see the darkest dark, you can imagine.īut, the immediate surroundings of a black hole could be bright as gasses spiral inwards –slowed down by the drag of magnetic fields they carry along.ĭue to the magnetic friction the gas will heat up to enormous temperatures of up to several tens of billion degrees and start to radiate UV-light and X-rays. So, what would a black hole actually look like? Read More: Gravitational-wave astronomy will change our understanding of the universe At least gravitational waves have let us ‘hear’ the merger of black holes, but the signature of the event horizon is still elusive and so far, we have never actually ‘seen’ a black hole – they simply tend to be too small and too far and, in most cases, yes, black. The evidence is convincing, but circumstantial. These might be supermassive versions of black holes, possibly formed through the merger of many stars and gas clouds that have sunk into the centre of a galaxy. Moreover, in the centres of galaxies we often find evidence for huge, dark concentrations of mass. In the last century strong evidence has mounted that certain binary stars with intense X-ray emissions are in fact stars collapsed into black holes. Of course, all this excitement would only be justified, if black holes really existed in this universe. Whether that is true and whether and how the theory of gravity (or of quantum physics) needs to be modified is a question of intense debate among physicists, and none of us can say which way the argument will lead in the end. It also means that suddenly basic principles of quantum information preservation are brutally violated – conserved quantum quantities can simply disappear behind a wall of silence. Hence, conventional physical wisdom will tell you that nothing can escape a black hole, once it has passed that point, which we call the “event horizon.” Of course, in a finite time the stellar core will have collapsed into something of a finite size and this would still be a huge amount of mass in an insanely small region and it still is called a black hole!īlack holes do not suck in everything around themĪt the point where you reach the speed of light while falling inwards, you would also need to fly out at the speed of light to escape that point, which seems impossible. In an infinite time, the star will have collapsed into an infinitely small point: a singularity – or to give it another name, a black hole. The matter collapses and no force in nature is known to be able to stop that collapse, ever. When a very big star explodes at the end of its lifetime, its innermost part will collapse under its own gravity, since there is no longer enough fuel to sustain the pressure working against the force of gravity (yes, gravity feels like a force after all, doesn’t it!). Falcke, Radboud university, with images from LOFAR/NRAO/MPIfR Bonn) Magnetic fields threading the supermassive black holes lead to the formation of a highly collimated jet that spits out hot plasma with speeds close to the speed of light (Image compilation: H. The left frame is roughly 250,000 light years across. Radio images of the jet in the radio galaxy M87 – observed at lower resolution. And perhaps it simply does not fit the standard model of particle physics. Einstein described it as a consequence of the deformation of spacetime. The force of gravity rules the universe, but it may not even be a force in the traditional sense. Imagine that the entire drama of the physical world unfolds in the theatre of spacetime, but gravity is the only ‘force’ that actually modifies the theatre in which it plays. Read More: Gravity: it is all in your head There’s just one issue – nobody has ever actually ‘seen’ a black hole. 15, 2016, reproduced with permission © ESO)īut there is once place in the universe where we could actually witness this problem occurring in real life and perhaps even solve it: the edge of a black hole. (Image: Moscibrodzka, Falcke, Shiokawa, Astronomy & Astrophysics, V. Simulated image as predicted for the supermassive black in the galaxy M87 at the frequencies observed with the Event Horizon Telescope (230 GHz).
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