How does light get trapped in black holes?

Question

I need to know this...it has been on my mind for quite a while and I want to know the answer. I think I have an idea...but I don't understand it fully...Can you help me?

Answer 1

Black Hole:
Simply put, a black hole is a super dense object that has an intense gravitational pull. A black hole is a region of space that has so much mass concentrated in it that there is no way for a nearby object to escape its gravitational pull.

There are two parts to a black hole, a singularity and a event horizon.

The event horizon is where the force of gravity becomes so strong that even light is pulled into the black hole. Although the event horizon is part of a black hole, it is not a tangible object. If you were to fall into a black hole, it would be impossible for you to know when you hit the event horizon.

The singularity is not really a tangible object either. According to the General Theory of Relativity the Singularity is a point of infinite space time curvature. This means that the force of gravity has become infinitely strong at the center of a black hole. Everything that falls into a black hole by passing the event horizon, including light, will eventually reach the singularity of a black hole. Before something reaches the singularity it is torn apart by intense gravitational forces. Even the atoms themselves are torn apart by the gravitational forces.

Light from a Black Hole:
One of their basic properties of black holes is that they trap light. According to the special theory of relativity (and also according to the general theory since it contains the special theory) that nothing exceeds the speed of light.

The particles of light, called the photons lose energy when travelling out of a gravitational field and appear to be redder to an external observer. . The stronger the gravitational field, the more energy the photons lose because of this gravitational redshift. The extreme case is a black hole where photons from within a certain radius lose all their energy and become invisible.

Another view of the same phenomenon is that the light can not escape out of a black hole as it can not go pass the event horizon. The event horizon is the point outside the black hole where the gravitational attraction becomes so strong that the escape velocity (the velocity at which an object would have to go to escape the gravitational field) equals the speed of light. Since according to the relativity theory no object can exceed the speed of light that means nothing, not even light, could escape the black hole once it is inside this distance from the center of the black hole.

A more fundamental way of viewing this (the same phenomenon) is that in a black hole, the gravitational field is so intense that it bends space and time around itself so that inside the event horizon there are literally no paths in space and time that lead to the outside of the black hole: No matter what direction you went, you would find that your path led back to the center of the black hole, where the singularity is found.

Black Hole Radiation:
Classically, black holes are black. Quantum mechanically, black holes radiate. Recent attempts to understand black holes on a quantum level have indicated that they radiate thermally (they have a finite temperature, though one incredibly low if the black hole is of reasonable size) that is proportional to the gradient of the gravity field.

This radiation known as Hawking radiation, after the British physicist Stephen Hawking who first proposed it. Hawking radiation has a blackbody (Planck) spectrum with a temperature T given by
kT = hbar g / (2 pi c) = hbar c / (4 pi rs)
where k is Boltzmann's constant, hbar = h / (2 pi) is Planck's constant divided by 2 pi, and g = G M / rs2 is the surface gravity at the horizon, the Schwarzschild radius rs, of the black hole of mass M. Numerically, the Hawking temperature is T = 4 × 10-20 g Kelvin if the gravitational acceleration g is measured in Earth gravities (gees).

Hawking Radiation is due to the capture of virtual particles decaying from the vacuum at the horizon. These are created in pairs and one of them is caught in the black hole and the other is radiated externally.

Answer 2

The gravitational force of black holes is so high that, quite simply, they draw in light as well as other things. (Light can be said to have Mass, because it can be observed to be 'bent' around planets or stars. So it is subject, like the rest of the material cosmos, to gravity).

Stars exist in a huge variety of sizes and ages and masses. Some are more "massive" (have greater mass) than others. The more mass an object has, the more gravity it exerts on the other objects around it. Just think of a black hole as a star, which is what it is - yes, it is actually there - which has so much mass that none of its light can be emitted. Which I suppose is just another way, ultimately, of saying that it therefore doesn't have any in the first place!

Note, Der Metz: There are NO black holes at the centre of our solar system. Nor, almost without doubt, anywhere else in our system (though it is incomprehensibly big).
The Sun is at the centre of our "solar" system - or it would have been called the black hole system!

Answer 3

Black holes have so much gravity that they bend the fabric of space time so that from the perspective of the light it is travelling in a straight line but to an observer the path of the light is curved into the black hole. Once the light has entered the black hole its path is so bent that it goes in circles and can never escape even though in the lights perspective it is travelling in a straight line.

Answer 4

A black hole is a point in space where there is so much dense matter that nothing escapes not even light. Scientists believe there is a black hole at the centre of our Solar System. Look it up on wikipedia. They have a very good explanation.

Answer 5

Well I guess you could say that light is trapped in black holes. The gravitional pull of black holes are so strong that light cannot escape the pull. Light is bent on itself inside the black hole.

Answer 6

Gravitational Lensing. Light bends (lenses) around massive objects. The center of a Black Hole is said to have infinite density and therefore bends space infinitely, so in theory if there were a light source at the center of a Black Hole it would just spin in circles following the distortion of space.

Answer 7

Black holes are dimensionless points in space; the only indication of how massive a black hole is can be deduced by the size of it's event horizon - how far out from the black hole the universe stops. Inside the event horizon, escape velocity is *higher* than the speed of light, and since that speed is unobtainable, nothing - not even light - can escape.

Answer 8

Black hole is a singularity,it is defined as a single point in which mass is immense and volume is negligible hence density is approaching infinity.Its like gravity sucked the mass of a star and fit it into one point.This illustrates how great the gravity is in the black hole making light unable to escape that's why it's called black hole in the first place.

Answer 9

Light gets "bent" by strong gravitational fields. This is called gravitational lensing. The gravity of black holes is so strong that the light is bent to the extent that it cannot escape.

Answer 10

Light is affected by gravity. The gravitational attraction of a black hole is so strong that even light cannot escape.