Big Bang or Big Splat?

Joseph Lazio wrote:

This statement fails to distinguish between the observable Universe,
which did indeed once fit inside a space smaller than the head of a
pin, and the entire Universe, which may very well be infinite in extent.

How long would it take such a universe to become infinite?


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

In article ,
Joseph Lazio wrote:

"p" == p6 writes:

A universe with billions and billions and billions of galaxies that
once fit inside a space smaller than the head of a pin is just
well, hmm.. a bit far out

This statement fails to distinguish between the observable Universe,
which did indeed once fit inside a space smaller than the head of a
pin, and the entire Universe, which may very well be infinite in extent.

OTOH even the observable Universe has more than a few billion
galaxies, doesn't it?

--
----------------------------------------------------------------
Paul Schlyter, Grev Turegatan 40, SE-114 38 Stockholm, SWEDEN
e-mail: pausch at stockholm dot bostream dot se
WWW: http://stjarnhimlen.se/

p6 wrote [reordered]:

[...]

We are mostly familiar with Big Bang where the
entire universe before inflation is just planck size.

The currently visible portion of the Universe, but that
need not be the entire Universe.

What's more likely. A Big Bang where everything starts from
a singularity or M-theory Big Splat (ekpyrotic scenerio)
where two higher dimensional colliding branes produced
the matter and energy in our universe??

Try a web search on "black hole", "cauchy horizon", and
especially "mass inflation".

To keep Uncle Al off my case, here is a link to what is
generally regarded as the seminal paper on mass inflation
in black holes (and a couple of other miscellaneous links):

http://prola.aps.org/abstract/PRD/v41/i6/p1796_1

"Internal structure of black holes"
by Eric Poisson and Werner Israel

http://www.cap.ca/awards/press/2005-Poisson.html

Herzberg medal awarded to Eric Poisson in 2005
for his work on black holes and the Cauchy horizon

http://www.phys.unm.edu/~finley/P570...ackCauchy.html

Interiors of Black Holes and their Cauchy Horizons (1999)

In the right circumstances (currently an active area of
research), when mass or radiation, even a modest amount,
falls into black hole which is rotating and charged
(as all physical black holes almost certainly are)
the result is a colossal amplification of the energy
inside the black hole at a region called the Cauchy
horizon.

It's hard to believe, but the resulting mass/energy can
be that of our entire universe outside the black hole.
None of this is discernable to an outside observer, as
the interior of the hole is "causally disconnected"
(i.e. no information can escape).

Currently, what goes on "beneath" the Cauchy horizon is
largely a closed book, except that I gather the radial
time-like coordinate between the event horizon and the
Cauchy horizon can, beyond the latter, flip back to
being a space-like coordinate (as it is to us outside
the event horizon).

So, getting to the point finally, it seems quite plausible
that the Big Bang, and hence our Universe, is none other
than a continuation, or dynamic evolution in some sense,
of the Cauchy horizon nearer the centre of a Black Hole,
most likely a common or garden galactic one, in some
universe just like ours (perhaps our Universe itself?!
Nah, now I'm freaking even myself out ;-)

Assuming our universe itself contains black holes, to
model this mathematically, one would presumably have
to start with a set of general relativity equations
for the outer black hole, and find some endomorphic
structure to these, i.e. express them in coordinates
which can be parametrized by other coordinates that
themselves in certain ranges satisfy the original
equations (or at least equations consistent with GR).

An obstacle to this is that at the Cauchy horizon
spacetime crumples up to a curvature comparable with
the Planck scale.

One closing thought (almost certainly not original,
and probably quite commonplace by now among the
experts, but you never know): In theory the Cauchy
horizon packs all the mass/energy that enters the
black hole from our Universe during all future times,
from a standpoint outside the hole.

(Some experts worry about this, as it seems to require
an infinite energy density there; but if the Universe
is expanding and that expansion will accelerate, this
doesn't apear to be an issue, and indeed practically
proves in itself that the expansion _will_ accelerate.)

Thus, in some sense and at some rudimentary level, the
energy at the Cauchy horizon is correlated with the
mass/energy outside the hole, and if that persists
into the interior, then by our assumption it carries
over into the new universe inside.

So who knows, if Everett's "many universes" hypothesis
has any bearing on reality, maybe Nature has chosen to
implement it not as "side by side" universes but as an
inconceivably vast labyrinth of one-way interconnected
black holes!


Cheers

John R Ramsden

"BC" == Bob Cain writes:

BC Joseph Lazio wrote:

This statement fails to distinguish between the observable
Universe, which did indeed once fit inside a space smaller than the
head of a pin, and the entire Universe, which may very well be
infinite in extent.

BC How long would it take such a universe to become infinite?

The Universe didn't "become" infinite in spatial extent (if in fact it
is).

The problem here is that many people (based in part on poor
descriptions from my learned colleagues) think that the initial
singularity in the Big Bang model was a point in space. It wasn't.
It was a point in time. If you extrapolate backward in time, we reach
a point at which our understanding breaks down, because the
temperature and density of the Universe become infinite.

In contrast, the spatial extent of the Universe could be infinite. If
so, it always has been infinite.

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Joseph Lazio wrote:

The problem here is that many people (based in part
on poor descriptions from my learned colleagues)
think that the initial singularity in the Big Bang
model was a point in space. It wasn't. It was a
point in time.

If you extrapolate backward in time, we reach a
point at which our understanding breaks down,
because the temperature and density of the
Universe become infinite.

Would it help if you could extrapolate backward in
time and, subject to the hypothesis summarized in my
other post in this thread, forward in time in some
other spacetime framework and pursue a "meet in the
middle" strategy?

wrote:

[...]

Try a web search on "black hole", "cauchy horizon", and
especially "mass inflation".

Another good link, especially suitable for amateurs:

http://sl4.org/archive/0309/7100.html

"The black hole survival guide"
New Scientist vol 179 issue 2411 - 06 September 2003, page 26

wrote:
"What's more likely. A Big Bang where everything starts from a
singularity or M-theory Big Splat (ekpyrotic scenerio) where two higher
dimensional colliding branes produced the matter and energy in our
universe?? "

There are BB theories that do not start out as 'singularities', one of
which was developed by Hawlking.

In any event, the physics we understand today is simply not capable of
describing much about the universe before around 10**-35 seconds and is
completely incapable of describing the universe before 10**-43 seconds.
A lot of strange physics occurs between t=0 and t=10**-35 seconds.

As I understand it, the ekpyrotic scenario evolves into the BB senario
around plank time (10**-43 seconds) but is based upon physics for which
not test has yet been devised to acertain whether these string theories
are a part of physics or part of philosophy.



i don't think there's any question string theories are more philosophy
than physics and why i love it so. if you broaden the definitions
and perspective, it's astounding how this dichotomy of physics
(digital) and philosophy (analog) is so pervasive, and so fundamental
to the nature of things. what's striking to me (and i'm novice at
this), is the analog nature of "strings" itself, and what they do,
vibrating at different frequencies that could almost be interpreted as
music, and yet produces particles that are so cut and dried -- so
digital. that the analog strings produce digital electrons, protons,
neutrons is the mirror opposite of how digital dna produces analog
proteins in our own bodies. there is a rough inverse symmetry there
between how the universe is made vs how our bodies are made.

what fascinates me about the bb theory is how such an infinitely
chaotic and analog event produces such a handful of digital constants
that govern the laws of our universe (i believe there are only about 20
or so constants such as the speed of light, the mass of electrons,
etc.) shouldn't infinite chaos produce an infinite number of
constants? that's why i'm inclined to any theory that is less chaotic
than the bb theory. that's why i like string theory, i suppose.

i think einstein was right: god doesn't play dice. rather, god is the
dice.



In addition, the colliding branes only release the energy that is
embodied in our universe, it took until about t=300 seconds for the
first atomic particles to condense out of the fireball. That is; matter
is simply condensed energy, and the BB (by whatever means) was pure
energy until the universed cooled to the point where mater could exist.


The only really strange part is how were the diemnsions of space and
time were released in the BB.

I suspect that when these theories are more developed and more
measurements are performed, that they will either converge or become
different mathematical tools to describe the same set of events.
Thereby, I refrain from picking a winner, but get to watch it all play
out (hopefully).

"Bob Cain" wrote in message
...


How long would it take such a universe to become infinite?


It has always been infinite. We have no frame of reference to describe time
after or before the universe or size after or before the universe.

"Nick" wrote in message
oups.com...


Neither there was an original energy bulidup at
the Big Bang.

Where did the energy come from?

When Einstein was asked about God he answered simply:
There must be something behind all that energy.


Did you ask him?

Who were God's parents?

Joseph Lazio wrote:
"BC" == Bob Cain writes:


BC Joseph Lazio wrote:


This statement fails to distinguish between the observable
Universe, which did indeed once fit inside a space smaller than the
head of a pin, and the entire Universe, which may very well be
infinite in extent.


BC How long would it take such a universe to become infinite?

The Universe didn't "become" infinite in spatial extent (if in fact it
is).

Right, nothing can "become" infinite. It was a leading
question. We are left, it seems, with the idea that if the
universe is infinite in extent, it went spatially from
nothing to infinite in the initial instant. That's really
hard to come to any kind of grips with.


The problem here is that many people (based in part on poor
descriptions from my learned colleagues) think that the initial
singularity in the Big Bang model was a point in space. It wasn't.
It was a point in time.

But what can be said about space at that time. If there was
no time before that point, was there no space either?


Thanks,

Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein