I think you’re all working too hard to deconstruct OP’s question, and missing the point in the process. Only **eburacum45** in Post #5 seems to have gotten it right.

All of OP’s “magical” scenarios are simply an attempt to ask one particular question, isolated from all the other effects of black holes. He wants to know if a signal from inside can get out. He didn’t specifically ask anything about “escape velocity” – maybe he doesn’t know to ask that?

So here’s the isolated answer that I think he’s looking for, to elaborate a bit on **eburacum45**’s response. **Chronos**, **Stranger On A Train**, *et al.*, is the following correct? And do you think it goes right to the question that OP is asking?

The strength of a gravitational field increases as you cram more mass into a closed region (volume) of space. The stronger a gravitational field is, the faster an object must get moving to escape from orbit there. The speed required to escape from, say, the surface of a planet is called the “escape velocity”.

It happens that, when you cram enough matter into a small enough volume, the necessary escape velocity can exceed c, the speed of light. When that happens, *nothing* can escape, since nothing can get moving fast enough. As since we now know that even light itself is subject to gravity, it follows that even light (or any other radiant energy) cannot escape if doing so would require going faster than light.

As you get farther and farther from the center of gravity, the strength of the gravitational field gets weaker, and the necessary escape velocity decreases. Thus, an object at some distance above the mass could escape. So, you have a spherical volume of space, of a certain radius, surrounding the dense mass, within which the escape velocity might be greater than c, and outside of which the escape velocity is less than c. Thus, this radius defines a sort of boundary. Anything within that distance of the mass is stuck there, and anything outside that distance can get away.

That boundary is called the “event horizon”.

Now, can the real physicists of this thread answer if the above explanation is accurate (at least as far as it goes), from a strictly technical point of view? Or even from a relatively lay point of view? Does this explanation give a good isolated answer to OP’s isolated question, free of all the other obvious physical problems with sending objects into a black hole and attempting to retrieve anything?