Do Black Holes Capture and Display Objects Indefinitely?

[Denton]

I just cannot understand the rationale behind the fact that whatever object we see 'enter' a black hole will appear to slow down to infinity next to the event horizon and never quite cross it. Would we not observe old black holes with a myriad of objects hanging around near it that it has captured over the billions of years?

Since we never observe objects enter a black hole, does that then mean the mass of the black hole does not increase in our reference frame? However the idea that mass is relative I think is incorrect. (If energy is relative, energy is not conserved?)

And hypothetically our universe collapses in 10 billion years. Would we not observe the matter finally collapsing into the singularity or will everything appear to stop still before the singularity of the big bang.

 

[off-diagonal]

I don't sure that I clearly understand your question, but I'll try my best

We never see an object cross an event horizon because when we consider time coordinate of that object in a frame far from black hole , we found that time coordinate will approach infinity when an object move nearly horizon.

and when that object reach horizon because it lie in a strong gravitational field so any EM radiation from it will be red shift until it wavelength are in the range that human eyes cannot detect. So if we look for an old black hole we cannot see an object hang around it.

others question I don't know the answer too :P

 

[Entropia]

Firstly, it is important to understand that the concept of a black hole is based on the theory of general relativity, which describes how gravity works on a large scale. According to this theory, the more massive an object is, the stronger its gravitational pull. A black hole is an object with such a strong gravitational pull that nothing, not even light, can escape from it once it crosses a certain point called the event horizon.

Now, to address your first point, it is true that from our perspective, an object approaching the event horizon of a black hole would appear to slow down and never quite cross it. This is because, as the object gets closer to the black hole, its gravitational pull becomes stronger and time slows down for the object. This effect is known as gravitational time dilation. Therefore, to an outside observer, the object would appear to take an infinite amount of time to cross the event horizon.

However, this does not necessarily mean that objects would remain hanging around near a black hole for billions of years. As an object approaches the event horizon, it would experience extreme tidal forces that would tear it apart. This is known as spaghettification. So, while we may observe objects getting closer to the black hole, they would eventually be torn apart and become part of the black hole's mass.

Regarding your second point, it is important to note that mass is not the only factor that determines the strength of gravity. In general relativity, gravity is described as the curvature of spacetime caused by the presence of mass and energy. So, even though the mass of a black hole may not increase in our reference frame, its gravitational pull would still be present and affect the surrounding space.

Finally, in the hypothetical scenario of our universe collapsing in 10 billion years, we would not be able to observe the matter collapsing into the singularity. This is because, as the universe collapses, the event horizon of the black hole would also be shrinking and eventually reach the singularity. At this point, time and space would become meaningless, so we would not be able to make any observations.

In conclusion, the behavior of black holes may seem counterintuitive, but it is based on well-established theories and observations. It is important to remember that our understanding of black holes is constantly evolving, and there is still much we have yet to discover about these mysterious objects.