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How can scientists detect a black hole if it does not emit light?
The black holes in the Universe do not emit any detectable type of light. However, astronomers can still find them and learn a lot about them. They do this by measuring the visible light, X-rays and radio waves emitted by material in the immediate environment of a black hole.
How does light get caught in a black hole?
Light rays that pass close to the black hole get caught and cannot escape. Therefore, the region around the black hole is a dark disk. Light rays that pass a little further away don’t get caught but do get bent by the black hole’s gravity. This makes the starfield appear distorted, as in a funhouse mirror.
How do scientists detect the presence of black holes?
Black holes are detected as surrounding material (like gas) is funnelled by the force of gravity into a disk around the black hole. The gas molecules in the disk swirl around the black hole so fast that they heat up and emit X-rays. Black holes can also be detected by watching for motions of stars near the black hole.
How does black hole suck in light?
Once a particle of light (‘photon’) passes the ‘event horizon’ of a black hole, it can no longer escape, but there’s nothing to suggest that it is destroyed. Like matter, the photon is rapidly sucked towards the ‘singularity’ at the centre of the black hole, where a huge mass is packed into an infinitely small space.
How can you prove that light has no mass?
Light is composed of photons, so we could ask if the photon has mass. The answer is then definitely “no”: the photon is a massless particle. According to theory it has energy and momentum but no mass, and this is confirmed by experiment to within strict limits.
How can we see light if it has no mass?
Light is composed of photons, which have no mass, so therefore light has no mass and can’t weigh anything. Not so fast. Because photons have energy — and, as Einstein taught us, energy is equal to the mass of a body, multiplied by the speed of light squared.
Why did Einstein say light has mass?
Light is composed of photons, so we could ask if the photon has mass. The answer is then definitely “no”: the photon is a massless particle. Energy, they say, is equivalent to mass according to Einstein’s famous formula E = mc2. They also say that a photon has momentum, and momentum p is related to mass m by p = mv.
Can we see black hole?
No, you cannot “see” a black hole, only the way that it interacts with objects or light in its vicinity. In terms of interacting with other objects, the classic observations that betray the presence of a black hole are the very rapid motions of stars and gas close to an object with a large mass, but which cannot be directly seen.
How are black holes detected?
Black holes are detected as surrounding material (like gas) is funnelled by the force of gravity into a disk around the black hole.
What is a black hole?
A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.