Speed of Objects Falling to Black Hole Center

In summary: So, in summary, there is a limit to the speed at which objects can fall towards the center of a black hole and it is not possible to predict their exact speed as they pass through the event horizon. However, objects launched at different times can overtake each other if launched with a high enough initial speed.
  • #1
jBase
3
0
I was wondering what is known about the speed of objects falling to the centre of a Black Hole?
If a number of identical objects, initially located outside the event horizon, were propelled at varying speeds towards a black hole, would that variability be maintained as they pass through the horizon and all the way to the centre, or would they all approach some limiting speed?
Inside the event horizon, could an object overtake another if it's initial speed was higher, yet because they were propelled at different times, it passed through the horizon after the other?
 
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  • #2
StanEvans said:
I am no expert but I would think that the effect of gravity from the black hole would be constant acceleration, or close to constant.
Most definitely not. This isn't even true in Newtonian gravity - acceleration varies with distance.

I don't know whether it's possible to overtake inside an event horizon. Probably, since spacetime must be locally flat even inside a black hole. But I'll let more knowledgeable folk answer that one.
 
  • #3
jBase said:
If a number of identical objects, initially located outside the event horizon, were propelled at varying speeds towards a black hole, would that variability be maintained as they pass through the horizon and all the way to the centre

This question can't be answered as you ask it, because the concept of "speed" you are using no longer works inside the horizon. You are defining "speed", as far as I can tell, as "speed relative to an observer who is hovering at a constant altitude". But below the horizon, it is impossible for any observer to hover at a constant altitude. So "speed" defined this way doesn't make sense inside the horizon.

jBase said:
Inside the event horizon, could an object overtake another if it's initial speed was higher, yet because they were propelled at different times, it passed through the horizon after the other?

This question, however, can be answered, since both objects are launched from outside the horizon, where "initial speed" makes sense (we can just measure it relative to an observer hovering at the altitude from which both objects are launched). The answer is that overtaking is possible, if the second object's initial speed is fast enough compared to the first, and the time between launches (as measured by the hovering observer) is short enough. But there will be a limiting time between launches, after which, no matter how fast you launch the second object, it can't possibly overtake the first--even if the second "object" is actually a light ray (which is the fastest possible thing you could launch).
 

Related to Speed of Objects Falling to Black Hole Center

1. What is the speed of objects falling to the center of a black hole?

The speed of objects falling to the center of a black hole is always increasing as they get closer to the event horizon, the point of no return. At the event horizon, the speed of an object is equal to the speed of light, which is approximately 299,792,458 meters per second.

2. Does the speed of objects falling to the center of a black hole differ based on their mass?

Yes, the speed of objects falling to the center of a black hole depends on their mass. Objects with larger masses will have a greater gravitational pull and will fall faster towards the center of the black hole compared to objects with smaller masses.

3. Can anything escape the pull of a black hole's center?

Once an object has passed the event horizon and crossed into the black hole's center, it is impossible for anything, including light, to escape. This is due to the extreme gravitational pull of the black hole, which even light cannot overcome.

4. Is the speed of objects falling to the center of a black hole affected by the black hole's rotation?

Yes, the speed of objects falling to the center of a rotating black hole will be affected by its rotation. This is known as the frame-dragging effect, where objects falling towards the black hole will also be pulled in the direction of the black hole's rotation, increasing their speed.

5. How does the speed of objects falling to the center of a black hole compare to the speed of light?

The speed of objects falling to the center of a black hole can reach speeds close to the speed of light, but it can never exceed it. This is due to the fact that the speed of light is the maximum speed in the universe and cannot be surpassed, even by the extreme gravitational pull of a black hole.

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