Can a beam entering a black hole be used to communicate with the outside world?

In summary: The particles would have to be in a precisely-defined frame of reference, and then you could use the laws of quantum mechanics to send information.
  • #1
cragar
2,552
3
I'm not sure if this the right place to post this . But suppose I have a long steel beam entering a black hole and I am at the leading end entering the black hole and we just past the event horizon. Now I try to rotate the beam, What will happen to the beam outside the event horizon. Or suppose I strap a rocket to it and fire it towards the center of the black hole increasing the beams acceleration towards the event horizon . And could I use this to communicate with the outside world. And let's assume that the black hole is pretty big and tidal forces are minimal so it doesn't rip me apart. Electrical interactions may prevent me from interacting with the beam outside of the black hole. Any input will be much appreciated.
 
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  • #2
The beam cannot be a truly rigid object and therefore must be composed of point particles. These particles will interact via normal fundamental forces that hold the beam as a whole together. Imagine your beam is a 1 particle-wide string. The event horizon, in some frame of reference, dissects the beam. Because the particles are points and have 0 dimension, the event horizon line must be between two points in the beam; one is below the horizon, one is above. Any interaction between them will require interaction mechanics that transmit faster than light.

Extrapolate to beams with larger widths.
 
  • #3
What will basically happen is this. You'll be in apparent free fall, and the event horizion will be approaching you at the speed of light, because it's a "null surface". You can consider the event horizon to be marked by "trapped light" if that makes it easier to understand, so you can think of this trapped light as approaching you at 'c', just as any other light does.

So, you'll twist the beam, and the twist will propagate outwards at some velocity less than the speed of light - for any realistic material known, much less than the speed of light.

Because the speed of sound is less than 'c', the event horizon will outrace any such signal you try to send by twisting or pulling, or otherwise manipulating the beam.
 
  • #4
Ok thanks for your answers, What if I have two entangled particles one inside the BH and one outside, and I measure the spin on the one inside what will happen to the particle outside.
 
  • #5
Even in flat space-time you can't use entanglement to send information.
 

FAQ: Can a beam entering a black hole be used to communicate with the outside world?

What happens to an object when it enters a black hole?

When an object enters a black hole, it is pulled in by the immense gravitational force. As it gets closer to the center of the black hole, the force becomes stronger and the object is stretched and compressed until it is torn apart into its most basic particles.

Can anything escape from a black hole?

Once an object passes the event horizon of a black hole, it cannot escape. This is because the escape velocity, or the speed needed to overcome the gravitational pull, is greater than the speed of light. Since nothing can travel faster than light, nothing can escape from a black hole.

What happens to time inside a black hole?

According to Einstein's theory of relativity, time and space are intertwined. As an object gets closer to the center of a black hole, the gravitational pull becomes stronger and time slows down. At the event horizon, time stops completely, and past this point, time is meaningless.

Can we see inside a black hole?

No, we cannot see inside a black hole because the intense gravitational pull prevents light from escaping. This means that no information can be transmitted from inside a black hole, making it impossible for us to observe what is happening inside.

What is the difference between a black hole and a wormhole?

A black hole is a region of space with a gravitational force so strong that nothing, including light, can escape from it. A wormhole, on the other hand, is a theoretical tunnel through space-time that could potentially connect two distant points in the universe. While black holes are a result of collapsed stars, wormholes are purely theoretical and have not been proven to exist.

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