Why does light not escape the gravity of a black hole?

Question

Photons have no mass and thus should not be effected by gravitational force, yet photons (light) does not escape a black hole. Is this perhaps secondary to the distortion in space-time caused by the very large mass of the black hole ?

Answer 1

Way to go, Robert! You're exactly right. Everything in the universe is embedded in spacetime, including light, and must follow whatever the local geometry of spacetime is.

Answer 2

Again, Photons have No, repeat, NO mass. 1 AMU = the mass of one PROTON, which has nothing to do with PHOTONs. Electrons are also not a constituent of light, which is simply an electromagnetic wave moving through space.

But the above answer that states that the escape velocity of the black hole exceeds the speed of light, and this is why no light escapes the black hole. This massive escape velocity is of course caused in turn by the massive gravitational warping of space-time by the extremely massive but dense black hole, so in a way, you are correct.

Answer 3

Light is not electron, light is photon. Just clear that up. But in short as a previous answerer stated, the speed needed to escape the black hole exeeds that of light thus light cannot escape it.

Light has no rest mass, but has momentum. A photon is basically the carrier for the electromagnetic force. You can find all this stuff in wikipedia or any non-crazy physics/astronomy web page or book.

Answer 4

To clarify, light is made of photons, a sub-atomic particle that is also a wave, like all sub-atomic particles; see Wave-Particle Duality for more information. The speed of light is 300 000 km/s, because that is how fast the wave propagates. According to Einstein's famous equation: E=mc^2, because a photon has energy, it also has mass and is affected by gravity. Einstein became famous because another scientist was able to observe light bending around the sun during a solar eclipse and widely published his results. The intense gravity of a black hole makes the escape velocity be in excess of the aforementioned 300 000 km/s. By contrast, the Earth has an escape velocity of only 11 km/s.

Answer 5

A black hole is a concentration of mass, the gravitational field of which is so strong that its escape velocity exceeds the speed of light. The point in space at which this occurs is known as the event horizon. This implies that nothing, including light, can escape from within the event horizon, since there is no known method to exceed light-speed.

Answer 6

Space and time are actually themselves distorted due to the black hole's gravity. The light bends because of the warped spacetime.

However, it is interesting to note that while photons have no mass, they DO have momentum!

Answer 7

***JUST FOR REFERENCE*** Electron == 1 AMU

Photons are not weightless, but they are very close to being at a state that would be unaffected by gravity. Since the inside of a blackwhole is theorized to collapse on itself at a point known as the "Event Horizon", once a photon reaches this point, it's mass is directed towards the blackhole. The mass of the device used to catylist (create) the blackhole determines the diameter of the event horizon.

Answer 8

photons actually do have mass so they are affected by gravity and since the gravity of black holes causes acceleration greater than the speed of light, photons can't escape it.

Answer 9

It has such an enormous concentration of mass in such a small radius that its escape velocity is greater than the velocity of light. Then, since nothing can go faster than light, nothing can escape the object's gravitational field.

Answer 10

because light does have mass... it is made up of electrons, and electrons have a mass of 9.1093897*10-31 kg

thusly the extreme strength of a black hole does suck in light

Answer 11

Photons do have mass but consider as negligible.