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I am not a physicist but I have a question about this. If matter is being sucked into a new universe from an old one, I can understand that the mass of the new

I am not a physicist but I have a question about this. If matter is being sucked into a new universe from an old one, I can understand that the mass of the new universe would count on the old universe's balance sheet if you will, showing that the sum of matter and energy is still constant, but wouldn't the new universe be only partially logically self-contained in this regard? Wouldn't the sum of matter and energy be increasing? And if our universe is on the inside of a black hole, shouldn't the amount of energy and matter be increasing here as well? If not, why not? Why don't we get to suck in fading stars from our parent universe and get an increasing amount of m or e?

chucknelson 14y ago
I was thinking the same thing, visualizing the parent black hole still feeding on the universe "outside" of our own.
powertower 14y ago
I'm not sure that the extra matter ever "enters" the black hole in a traditional sense... As matter approaches it (pass the Schwarzschild radius) and increases in velocity, time slows down more and more for it. When velocity approaches C, time approaches zero. Though in another thought, I'd guess that due to the forces involved, the matter is ripped apart on a sub-quantum scale to the point that it literally disintegrates into its energy component and basically adds energy to the black hole (which can be interpreted as mass). But again, it never enters it.
- evanb 14y ago
  This is a well-understood problem in GR. To an outside observer, things never appear to cross the Schwarzschild radius (R_S), giving the impression that time stops for in-falling matter when it gets to R_S. This, however, is an illusion forced on a distant observer. The stuff that is actually falling into the black hole never notices R_S because the velocity they measure is not greater than c, and crossing the event horizon is a completely benign event. It's the later extreme tidal forces / spaghettification that destroys in-falling matter. So it is fair to say that stuff enters a black hole.
- einhverfr 14y ago
  But still inside, you'd expect E+mc^2 to be increasing over time, right?
gliese1337 14y ago
Inside a black hole, one dimension of space and time are transposed; this is one explanation of why you can't get out, because doing so would require going backwards in time, since the radial spatial dimension as seen from outside the black hole has been transposed with time inside the black hole. You wouldn't actually see a singularity that you're falling towards, rather the singularity exists in your future, with all matter that ever falls into the black hole collapsing together. So I would suppose that, in the timeline inside the black hole, the initial universe-creating singularity already contains all matter that ever falls into the black hole in the parent universe.
- rjsamson 14y ago
  I'm no physicist, and have no idea how technically correct this is, but I just love this answer.

chucknelson 14y ago

I was thinking the same thing, visualizing the parent black hole still feeding on the universe "outside" of our own.

powertower 14y ago

I'm not sure that the extra matter ever "enters" the black hole in a traditional sense... As matter approaches it (pass the Schwarzschild radius) and increases in velocity, time slows down more and more for it. When velocity approaches C, time approaches zero. Though in another thought, I'd guess that due to the forces involved, the matter is ripped apart on a sub-quantum scale to the point that it literally disintegrates into its energy component and basically adds energy to the black hole (which can be interpreted as mass). But again, it never enters it.

evanb 14y ago
This is a well-understood problem in GR. To an outside observer, things never appear to cross the Schwarzschild radius (R_S), giving the impression that time stops for in-falling matter when it gets to R_S. This, however, is an illusion forced on a distant observer. The stuff that is actually falling into the black hole never notices R_S because the velocity they measure is not greater than c, and crossing the event horizon is a completely benign event. It's the later extreme tidal forces / spaghettification that destroys in-falling matter. So it is fair to say that stuff enters a black hole.
einhverfr 14y ago
But still inside, you'd expect E+mc^2 to be increasing over time, right?

gliese1337 14y ago

Inside a black hole, one dimension of space and time are transposed; this is one explanation of why you can't get out, because doing so would require going backwards in time, since the radial spatial dimension as seen from outside the black hole has been transposed with time inside the black hole. You wouldn't actually see a singularity that you're falling towards, rather the singularity exists in your future, with all matter that ever falls into the black hole collapsing together. So I would suppose that, in the timeline inside the black hole, the initial universe-creating singularity already contains all matter that ever falls into the black hole in the parent universe.

rjsamson 14y ago
I'm no physicist, and have no idea how technically correct this is, but I just love this answer.