What's inside the event horizon

Photons always travel at c so there's no real argument about photons exceeding c. Is there any reason why massive particles cannot travel faster than c inside the EV?

OK, for particles of matter:

Or perhaps it is closely tied to V_escape = root(GM/R)*root(2) that can result in V_escape > c, for R < R_eh, a misconception that escape velocity > c implies anything more than a more difficult job for matter to get out.

My personal favorite is that the hypothetical structure on the other side
of the horizon is an "independent coordinate system" and obeys
the very same rules that we have here. Circular again?

Or would you prefer the concept that the Schwarzchild Metric
really represents two "independent coordinate systems" with
different rules?

Nothing that crosses the event horizon IS matter anymore, at best you're talking about radiation. Remember, a neutron star, or even a hypothetical quark star isn't dense enough to have an event horizon; by the time you reach that you've already gone beyond the limits of degenerate matter. MASS yes, but what is that in the context of an unobservable region?

Nothing that crosses the event horizon IS matter anymore, at best you're talking about radiation. Remember, a neutron star, or even a hypothetical quark star isn't dense enough to have an event horizon; by the time you reach that you've already gone beyond the limits of degenerate matter. MASS yes, but what is that in the context of an unobservable region?

Nothing that crosses the event horizon IS matter anymore, at best you're talking about radiation. Remember, a neutron star, or even a hypothetical quark star isn't dense enough to have an event horizon; by the time you reach that you've already gone beyond the limits of degenerate matter. MASS yes, but what is that in the context of an unobservable region?

Dense mass without a horizon seems to be like a brick wall to falling matter.
Dense mass with a horizon seems to be like a curtained stage with the brick
wall there or not there or both or neither. IE, if we linger long enough just
above the horizon, by the time we finally cross the horizon, the brick wall
will have evaporated.

I understand that when matter reaches the singularity it may no longer be matter but it's no longer traveling either. Between the EV and the singularity, how fast can massive particles travel and why? Is there some prohibition against exceeding c in that region?

There's no wall, especially since you have to remember that everything falling into a black hole is ripped apart by gravitational tidal forces, and blasted by radiation. The EH has no physical existence, it's just the ever-changing (as long as there is infalling matter or HR) demarcation of the point of no return. Degenerate matter is dense, yes, but even that would be "sphagettified" as it fell into a BH. In a very real sense, anything on OUR side of the EH can never be observed by us to cross the EH, so there is the theoretical notion of a wall. Keep in mind that the infalling mass will not experience any such barrier, and crosses the EH without any resistance. I believe that your understanding of Einstein's view of gravity and spacetime is incomplete, and to grasp just what a black hole is, you need to understand that first.

Nothing that crosses the event horizon IS matter anymore, at best you're talking about radiation.

I understand that when matter reaches the singularity it may no longer be matter but it's no longer traveling either. Between the EV and the singularity, how fast can massive particles travel and why? Is there some prohibition against exceeding c in that region?

There's no wall, especially since you have to remember that everything falling into a black hole is ripped apart by gravitational tidal forces, and blasted by radiation.

These consideration resolve an apparent paradox concerning the Hawking effect. The proper time for a freely-falling observer to reach the event horizon is finite, yet the free-fall time as measured at infinity is infinite. Ignoring back-reaction, the black hole will emit an infinite amount of radiation during the time that the falling observer is seen, from a distance to reach the event horizon. Hence it would appear that, in the falling frame, the observer should encounter an infinite amount of radiation in a finite time, and so be destroyed. On the other hand, the event horizon is a global construct, and has no local significance, so it is absurd to0 conclude that it acts as physical barrier to the falling observer.

The paradox is resolved when a careful distinction is made between particle number and energy density. When the observer approaches the horizon, the notion of a well-defined particle number loses its meaning at the wavelengths of interest in the Hawking radiation; the observer is 'inside' the particles. We need not, therefore, worry about the observer encountering an infinite number of particles. On the other hand, energy does have a local significance. In this case, however, although the Hawking flux does diverge as the horizon is approached, so does the static vacuum polarization, and the latter is negative. The falling observer cannot distinguish operationally between the energy flux due to oncoming Hawking radiation and that due to the fact that he is sweeping through the cloud of vacuum polarization. The net result is to cancel the divergence on the event horizon, and yield a finite result, ...

It is accepted by previous posters, that distant observers will never see a
a test mass cross the horizon. I take this to mean that when it does finally
happen(relative to the test mass), the stage and its contents will have evaporated.
Supposedly by Hawking radiation. And that a distant observer does not have a
long enough duration to observe this. But the test mass(by its own clock)
would experience nothing in particular because (after infinity by distant
observers clocks), the BH will have evaporated. A no show.

Consider two observers, observer A that falls across the the event horizon and observer B that hovers at a finite "distance" above the event horizon, and two types of (uncharged) spherical black holes, a classical black hole that doesn't emit Hawking radiation and a semi-classical black hole that does.

For the classical black hole case, B "sees" A on the event horizon at infinite future time, and B never sees the singularity.

For the semi-classical black hole case, at some *finite* time B simultaneously "sees": A on the event horizon; the singularity. In other words, the singularity becomes naked, and A winks out of existence at some finite time in the future for B.

In both cases, A crosses the event horizon, remains inside the event horizon, and hits the singularity. In both cases, B, does not see (even at infinite future time) A inside the event horizon, as this view is blocked by the singularity.

The speed of light is the local speed limit everywhere, even inside black holes.

This isn't true. If a star collapses and forms a black hole, then matter falling towards the star, but above the star, will remain matter far inside the event horizon. Matter that falls into a black hole at the centre of a galaxy won't spaghettified until far inside the event horizon.

According to the book Quantum Fields in Curved Space by Birrell and Davies, pages 268-269,


This finite amount of radiation is negligible for observers freely falling into a black hole.


Consider two observers, observer A that falls across the the event horizon and observer B that hovers at a finite "distance" above the event horizon, and two types of (uncharged) spherical black holes, a classical black hole that doesn't emit Hawking radiation and a semi-classical black hole that does.

"The first type of wormhole solution discovered was the Schwarzschild wormhole which would be present in the Schwarzschild metric describing an eternal black hole, but it was found that this type of wormhole would collapse too quickly for anything to cross from one end to the other."

Wormholes which could actually be crossed, known as traversable wormholes, would only be possible if exotic matter with negative energy density could be used to stabilize them (many physicists such as Stephen Hawking[1], Kip Thorne[2], and others[3][4][5] believe that the Casimir effect is evidence that negative energy densities are possible in nature). Physicists have also not found any natural process which would be predicted to form a wormhole naturally in the context of general relativity, although the quantum foam hypothesis is sometimes used to suggest that tiny wormholes might appear and disappear spontaneously at the Planck scale.

Do Schwarzschild wormholes really exist?
Schwarzschild wormholes certainly exist as exact solutions of Einstein's equations.
However:
# When a realistic star collapses to a black hole, it does not produce a wormhole;
# The complete Schwarzschild geometry includes a white hole, which violates the second law of thermodynamics;
# Even if a Schwarzschild wormhole were somehow formed, it would be unstable and fly apart.

Free falling observer does not observe the same Hawking radiation as observer located far from BH because for the falling observer event horizon is in different place. So the amount of hawking radiation he receives is very small. both position of the apparent Horizon and Hawking radiation are observer-dependent.

Time dilation is infinite only for the hovering observer, so true, observer hovering near the horizon would see the Universe accelerated and blue-shifted. However, falling observer would see the Universe red-shifted (surprise!)

http://en.wikipedia.org/wiki/Wormhole

So here's the wiki page on wormholes.

Now, it describes two wormholes, one which may possibly be present by a black holes:


But these cannot be traversed as it explains and as such, I don't understand how particles as the article puts it are able to 'cross between the two universes'.


This uses negative energy, enough said.

Now, you keep pointing us to the wikis and to read them, and I have done. I have also done some digging and following links provided in the wikipedia article (the articles I believe you are reading) I found this (http://casa.colorado.edu/~ajsh/schww.html):


As the type of wormhole you are referring to is the above Schwarzschild wormhole, everything I have read so far is very clear in what it is saying regarding their existence - they only exist under the 'perfect' conditions of the equations. "when a realistic star collapses to form a black hole, it does not produce a wormhole.". So unless you can cite sources which show these wormholes can exist when a star collapses, this is overly speculative and against PF guidelines. It is pointless us discussing this if it just isn't possible and so far, nothing has shown it is.

...let's forget wormholes were ever brought into this particular topic of "What's inside the event horizon?".

Consider this...a way to transport yourself into an infinitely
distant future, is to hover over the event horizon until the
BH finishes evaporating. Imagine all the cool stuff that would
just be lying around, free for the taking. And it should only
take a couple of minutes.