quot;Black hole can bend lightquot; Do they mean that AS IS? If light has no mass how does a black hole bend light by gravity? How much does it bend, at to what degree?
If the immense gravity of black holes can pull the light down from escaping from the black hole , it can be assumed that light has come mass. You know that light is found to behave like rays and particles too.Light being the lightest of particles , its mass is probably not ascertainable .That does not mean that it can have no mass.The fact that it is the fastest moving thing , itself is sufficient that it has the lightest particles. If gravity can pull light , the light rays traveling close to any massive body should also bend to some extent ..
Gravity is a universal attraction between things that have mass. However, according to Einstein's theory of Relativity, the energy in a beam of light is equivalent to a some very small amount of mass. So light too will be affected by gravity, although the effect is very small. At the surface of the Sun the effect is only half of an arcsecond, but close to a black hole it is much stronger.
It pretty much means as is. Normally light rays travel in perfect straight lines (called Light rays) but all Gravity (not just black holes gravity) bends these lines. Normally even a planet's gravity bends the light so little that we don't notice... but more massive things like suns, white dwarfs, Neutron stars and black holes have such intense gravitational fields around them that the bending of light is actually big enough for us to notice. This manifests itself in us being able to See what is behind the object... because the light hitting the back of the object is bent round the side. So in the most extreme case (a black hole) We'd see a sort of squashed ring of what's behind it around the event horizon of the black hole. Light doesn't have Mass... but it does have energy... And we all know the famous equation E = mc^2. This states that Energy IS mass. So in a twisted way... light does have mass, since it has energy... and they are the same thing elementally. And gravity acts on anything with mass. The answer below me explains roughly the same thing in a more 'general relativity' method. (a more scientifically accurate method i must admit.) While mine is more classical... This is the basis for Gravitational lensing. I'd explain more but to be honest... i don't fully understand it myself and if i tried to explain what i know fully... it would take a small essay and may not totally be right. So ill just leave it at the basics for both of our sakes lol. Hope this helps :)
A photon always travels by the shortest distance between two points. As spacetime is warped, the light appears to bend around a massive object. In reality, it is not that the object is attracting light, but it is just that the photons are traveling by the shortest distance in a curved spacetime. Around a blackhole, the distortion of spacetime is extreme. At the event horizon of a black hole, the spacetime curves into itself and as a result, light cannot escape from a black hole.
