Question

Why Black Hole attract everything towards itself?

Answer 1

Nothing can escape the gravitational pull of a block hole once past the event horizon, not even light can. Furthermore, light that passes near the black hole but does not reach the event horizon is distorted quite a bit, as seen in the gravitational lensing effect. However, how can light be attracted by the gravitational pull of a black hole if photons have no mass? Unless I'm missing something, it seems as though a massless particle cannot be affected by gravity, so what is happening here?


The first calculation of the deflection of light by mass was published by the German astronomer Johann Georg von Soldner in 1801. Soldner showed that rays from a distant star skimming the Sun's surface would be deflected through an angle of about 0.9 seconds of arc, or one quarter of a thousandth of a degree.  Soldner's calculations were based on Newton's laws of motion and gravitation, and the assumption that light behaves like very fast moving particles. Since then, one of the basic predictions of general relativity is that light is influenced by gravity. For instance, light passing a massive body is slightly deflected. This is the basis for what is called gravitational lensing.  Gravitational deflection of light 

According to  general relativity, gravity effects anything with energy. While light doesn't have rest-mass, it still has energy-- and is thus effected by gravity. When you think about how gravity affects light you really need to think in terms of general relativity, which describes gravity as the effect of a curved space-time on moving particles. 

When we apply this to light, we start with the fact that light travels in straight lines. But then, when we have a large mass in the way (say - the Sun)  curving the space around it,  our light ray will follow a straight line in this curved space-time. This path will only appearbent to us and leads to the phenomena of gravitational lensing.

Light does not get "attracted" by black holes!