
What’s Inside a Black Hole? - prostoalex
http://nautil.us/issue/35/boundaries/where-nature-hides-the-darkest-mystery-of-all
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kinai
There is a misconception: Light cannot escape a black hole for gravitational
reason (not to mention that gravity does not exist, it is a not a force, read
up General Relativity). The real reason is that the space-time curvature does
simply not provide a way for the light to go back. Same reason you can't go to
the end of the universe if the universe would be a sphere.

Also if someone likes to talk about black holes it is good to remind people
that it is not a hole...as the article mentions its a region, to be more
precise it is a region in space-time that is cut off from ours. The whole
issue is not just spacial but also temporal, that is usually the point when
your brain gives up understanding the whole problem.

A good description would be: a black hole is the collection of events that do
happen outside our space-time/universe. This also explains some of the
paradoxes near the event horizon.

~~~
dschiptsov
If one consider that exactly opposite is true - gravity actually do exist as a
"function" of a matter, but space-time doesn't (especially a curved one) being
a conditioning of our "serialized", self-centered perception, everything, it
seems, falls to its places.

~~~
kinai
Gravity is not a function of matter, and proving that curved space-time is
real is trivial. So not sure where you are going with that idea...

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dschiptsov
Could you, please, give me a link for the proof of existence of time. Not some
processes in the Universe, but time itself.

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Koshkin
You can find a wealth of information at
[https://en.wikipedia.org/wiki/Time](https://en.wikipedia.org/wiki/Time)

~~~
dschiptsov
I am afraid I don't quite understand you, my friend. Are you trying to suggest
that existence of this particular page or any part of its content constitutes
the proof of existence of time as an independent from an observer phenomena?

May be it somehow related to Kantian view mentioned there about time as a mode
of perception, being, as he said, prior to all perceptions, as a condition,
but not of observable phenomena, but of sequential mode of perceptual
machinery of an observer?

But, as far as I know, in Russia "Kant - lokh".

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djaychela
Love the stat buried in there, that voyager 1 is 17 light HOURS away, and the
nearest known black hole is 8,000 light years. That will put my youngest (9)
step-son's mind at rest, he was worried about them when he heard about them
first, despite my saying there was nothing to worry about, having concrete
facts is always better!

~~~
onion2k
Just make sure you don't mention that the edge of the visible universe is
46,000,000,000 lightyears away, making 8,000 lightyears feel relatively (arf!)
close.

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arca_vorago
My theory is that it's the other side of the dual universe. (as opposed to
multiverse).

It goes something like this: membrane theory, universe a broke into our
universe, big bang, but from a single point, causing quantum entanglement on
all matter in this universe, which seeks a return of it's original state in
universe a, and therefor gravity is actually a second teir effect of matter
seeking to return via building up and entering a blackhole. Eg, quantum
mechanics and entanglement are stronger than gravity based upon the fact it
works at longer distances.

Thats my non-physicist version of the grand unifying theory, but I'm not sure
how to create a falsifiable by humankind version of it. I suspect dark matter
discoveries will be the key.

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fvargas
Could someone suggest some books or reading for someone interested in learning
about general relativity, black holes, and quantum mechanics/physics?

~~~
augustl
About Time by Paul Davies is amazing!

[http://www.amazon.com/About-Time-Einsteins-Unfinished-
Revolu...](http://www.amazon.com/About-Time-Einsteins-Unfinished-
Revolution/dp/0684818221)

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azazqadir
>>Outside the horizon, an object can escape the black hole’s gravitational
pull if it’s moving sufficiently fast; inside, it would need to move faster
than light-speed, something forbidden by the laws of nature.

Are they trying to say that if there was something that could move faster than
light then it can escape? If that's is forbidden by laws of nature, then how
did they determined that this is possible?

~~~
kqr
All things have a constant speed in spacetime: the speed of light. If you
stand completely still, you travel through time at "the speed of light". If
you start moving faster in space, you'll lose a similar amount of speed in
time. Go fast enough, and your life will pass in slow-motion. Go at the speed
of light and your time stops. Go faster than the speed of light, and your time
will start going backwards.

Since you can't get out of a black hole normally, the only way to get out is
by reversing time. I.e., going faster than light might be an option to get out
of a black hole.

Of course, doing so is nonsense, but the maths work out.

~~~
azazqadir
So how something can move faster than light. To move at the speed of light,
mass must be 0. To move faster than light, what would the mass be?

~~~
petewailes
There isn't really such a thing as faster than light. It's more that light
travels at c, than that c is the speed of light. By way of analogy, it'd be
like having a chart with an x and y axis, and having a line going straight up
the y axis, then asking "but how can we make it more along the y axis?". I
realise in terms of numbers it makes sense, but in terms of physics it
doesn't. There's no such thing as faster than light through spacetime.

Travelling at c, your perception of time would have stopped. From that point,
it can't become more stopped, any more than you can go faster.

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iofj
The weird thing is that it differs from your perspective. If you're looking in
from "infinity" (ie. where the gravity field of the black hole is negligeable)
there appears to be a region where nothing can get to : the event horizon.

After all, what does one see when looking at a light source falling into a
black hole. That light source slows down as it approaches the event horizon.
When it gets close you'll see it dim. That's because time is going slower for
that light source. Also it becomes smaller and smaller. It will never cross
the event horizon, which is the point where time would stop and it's size
would be zero. Because of the amount of time it takes to actually get there,
one can semi-accurately refer to it as the end of time. The weird thing is
that the end of time is a spherical region of actual space, not a point in the
future. Because this only happens close to the black hole it'll likely look
confusing : it would fall very quickly to the event horizon, ever
accelerating, then suddenly every 50% reduction in distance between it and the
event horizon takes 100% more time to happen.

If you're the one falling into a (large) black hole you'll see the opposite :
the rest of the universe will go faster, grow brighter, and grow bigger (since
the universe is mostly empty space and you can't really tell the physical size
of stars from a distance you'd mostly see the empty space being bigger and may
think everything else is the same size. It's not though, you just can't tell
the difference between 10e-50 degrees and 10e-48 degrees). The event horizon
is a theoretical concept, there is nothing in space that corresponds to the
event horizon. No obstacle, no marker, no force, no nothing. From up close,
it's just empty space. Think of the path between you and the rest of the
universe, that path is getting longer, and you can see and measure that.
That's all that happens, nothing more. Everything you can reach is falling in
as well, and you see the distance between you and other things falling in
increasing just the same. If you were to go anywhere, you'd notice that the
distance between you and wherever you're trying to go grows bigger with time.
If that happens fast enough you can never get there, because the distance will
never decrease.

The weird thing is that that is true for us here on earth as well. The
distance between us and everything outside of our local galactic group
(everything contained by a few galaxies who are bound by gravity. Granted,
this structure is several million lightyears across, but it is finite and very
tiny compared to the total universe) is getting bigger and further away. The
vast, vast majority of the universe is expanding, exactly like you'd expect to
see if you were falling into a (extremely huge) black hole. Furthermore the
edge of the universe is suspiciously close to where those "hallways" expand at
superluminal speeds (ie. the rate of distance increase between us and the
faraway object > c). The distance between the furthest object ever measured
and the point where distance increase speed becomes superluminal is 400
million light year. That seems suspiciously close to be coincidental.

So the answer for "big" black holes might be very simple. What's inside ? Look
around you. That's what's inside. Certainly some black holes are of a size
that you could conceivably throw a solar system inside, and nothing out of the
ordinary would happen to it at all for a very long time, essentially for the
lifetime of the black hole, which can be hundreds of billions of years.

That leaves small black holes where you'd be torn to shreds by the difference
in gravity between the closest part of you to the black hole and the parts
further away. It'd be like falling while having rockets accelerating your feet
downwards. At some point, those rockets accelerate fast enough to rip your
feet clean off. However, small black holes evaporate through Hawking
radiation. They quickly convert all their mass to energy. So there'd be a
massive explosion happening below you, which will likely vaporize you long
before the tidal forces become an issue.

