Localized Big Bang

Greetings and Salutations:

I read some articles on the Big Bang, and I am sure that this
question
has been asked before but I really didn't see an answer specific to
my
question.

My question is why is "The Universe" made up of just "our" Big Bang?
I
realize that time / the Universe really doesn't exist without matter
and
energy, and that the "Big Bang" made up our universe, but couldn't
there
be another "Big Bang" universe next door (if you will)?

The analogy is that our galaxy is not the only galaxy, that there are
other galaxies "next door" to ours.

Thank you,
Ken

---------------------------------------------------------------
Do not meddle in the affairs of wizards for they are subtle and
quick to anger.
Ken Hollis - Gandalf The White - - O- TINLC
WWW Page - http://digital.net/~gandalf/
Trace E-Mail forgery - http://digital.net/~gandalf/spamfaq.html
Trolls crossposts - http://digital.net/~gandalf/trollfaq.html
Woodworking For Geeks - http://digital.net/~gandalf/woodmain.htm

wrote in message
ups.com...
Greetings and Salutations:

I read some articles on the Big Bang, and I am sure that this
question
has been asked before but I really didn't see an answer specific to
my
question.

My question is why is "The Universe" made up of just "our" Big Bang?
I
realize that time / the Universe really doesn't exist without matter
and
energy, and that the "Big Bang" made up our universe, but couldn't
there
be another "Big Bang" universe next door (if you will)?

The analogy is that our galaxy is not the only galaxy, that there are
other galaxies "next door" to ours.

It could be that you read the answer to your question but
didn't recognize it as such.

Since the Big Bang is presumed to have been the origin of
space and time, that is, prior to the Big Bang there was
no space "outside" for anything else to happen in, the
results of the Big Bang that we see are unique; If there
are other universes with their own Big Bang events, they
are unconnected to ours, cannot be observed, and have no
influence at all on our universe.

Dear gandalf:

wrote in message
ups.com...
....
My question is why is "The Universe" made up of just
"our" Big Bang? I realize that time / the Universe really
doesn't exist without matter and energy, and that the
"Big Bang" made up our universe, but couldn't there
be another "Big Bang" universe next door (if you will)?

When we look out in space, outside our supercluster, we see
objects that are of similar age, that have very similar physics,
and are "moving" very uniformly away from us by proportion to
distance. And we do not see anything that supports the "Big
Bang" having been a central explosion from which all matter /
energy sprang forth into empty space.

This doesn't mean that there may not be other Universes fully
parallel to ours, or that they might not intermingle at some
point in the future. Just nothing like that has happened in the
~13 Gy displayed.

You might be interested in this...
http://www.astro.ucla.edu/~wright/cosmo_01.htm

David A. Smith

Greetings and Salutations:

From: "Greg Neill"
If there
are other universes with their own Big Bang events, they
are unconnected to ours, cannot be observed, and have no
influence at all on our universe.

O.K... So even if light from the "other universe" were to enter our
universe then that would constitute "connecting" the universes.
Correct?

On Apr 29, 10:06 am, "N:dlzc D:aol T:com \(dlzc\)"
wrote:
This doesn't mean that there may not be other Universes fully
parallel to ours, or that they might not intermingle at some
point in the future. Just nothing like that has happened in the
~13 Gy displayed.
David A. Smith

Since everything is moving away from a central point, another universe
colliding with ours would (by definition) have objects moving from
*that* central expansion point. Thank you.

These responses answered my question.

Thank you,
Ken

---------------------------------------------------------------
Do not meddle in the affairs of wizards for they are subtle and
quick to anger.
Ken Hollis - Gandalf The White - - O- TINLC
WWW Page - http://digital.net/~gandalf/
Trace E-Mail forgery - http://digital.net/~gandalf/spamfaq.html
Trolls crossposts - http://digital.net/~gandalf/trollfaq.html
Woodworking For Geeks - http://digital.net/~gandalf/woodmain.htm

wrote in message
ps.com...
Greetings and Salutations:

From: "Greg Neill"
If there
are other universes with their own Big Bang events, they
are unconnected to ours, cannot be observed, and have no
influence at all on our universe.

O.K... So even if light from the "other universe" were to enter our
universe then that would constitute "connecting" the universes.
Correct?

By implication, yes. Unless there was some pre-existing
connection, or in other words unless the two regions
were parts of a single universe looking perhaps like a
dumbbell, there would be no path for the light to travel
along to get from one to the other.

On Apr 29, 10:06 am, "N:dlzc D:aol T:com \(dlzc\)"
wrote:
This doesn't mean that there may not be other Universes fully
parallel to ours, or that they might not intermingle at some
point in the future. Just nothing like that has happened in the
~13 Gy displayed.
David A. Smith

Since everything is moving away from a central point, another universe
colliding with ours would (by definition) have objects moving from
*that* central expansion point.

No! There is no "central point" in current cosmological
models, our universe is probably infinite in size and by
measurement the section we can observe appears homogenous
and isotropic, the same (on average) everywhere.

Any other universe might also be infinite in size and by
definition must be totally unconnected to ours.

Thank you.

These responses answered my question.

Before thinking you understand these ideas, please look
at Ned Wight's tutorial:

http://www.astro.ucla.edu/~wright/cosmolog.htm

He was one of the team that ran the COBE mission whose
members recently received the Nobel prize.

HTH
George

Greetings and Salutations:

On May 19, 9:55 am, "George Dishman" wrote:
Since everything is moving away from a central point, another universe
colliding with ours would (by definition) have objects moving from
*that* central expansion point.

No! There is no "central point" in current cosmological
models, our universe is probably infinite in size and by
measurement the section we can observe appears homogenous
and isotropic, the same (on average) everywhere.

WRT Cosmic Microwave Background (CMB), correct? And homogeneous "in
general", as when you look at the COBE map some areas are "darker" and
some "lighter". This would be expected because there are clusters
that show up as lighter.

Before thinking you understand these ideas, please look
at Ned Wight's tutorial:
http://www.astro.ucla.edu/~wright/cosmolog.htm

I hadn't fully grasped what significance that source had.

He was one of the team that ran the COBE mission whose
members recently received the Nobel prize.
HTH
George

Yes it did. Thank you.

But from reading that paper, the "big bang" is not disputed, correct?
It is just that the universe has a homogeneous 2.725 K background
radiation.

I may have missed something in the above reference, but as far as I
understand with the "big bang" space continues to expand along with
matter. So how can the Universe be infinite if space continues to
expand? Or is Universe != Space?

Thanks,
Ken

---------------------------------------------------------------
Do not meddle in the affairs of wizards for they are subtle and
quick to anger.
Ken Hollis - Gandalf The White - - O- TINLC
WWW Page - http://digital.net/~gandalf/
Trace E-Mail forgery - http://digital.net/~gandalf/spamfaq.html
Trolls crossposts - http://digital.net/~gandalf/trollfaq.html
Woodworking For Geeks - http://digital.net/~gandalf/woodmain.htm

Dear gandalf:

wrote in message
ups.com...
Greetings and Salutations:

On May 19, 9:55 am, "George Dishman"
wrote:
Since everything is moving away from a central point,
another universe colliding with ours would (by
definition) have objects moving from *that* central
expansion point.

No! There is no "central point" in current cosmological
models, our universe is probably infinite in size and by
measurement the section we can observe appears
homogenous and isotropic, the same (on average)
everywhere.

WRT Cosmic Microwave Background (CMB), correct?

Even comparing galaxies at similar distances, yields similar
aging, and similar physics.

And homogeneous "in general", as when you look at
the COBE map some areas are "darker" and some
"lighter". This would be expected because there are
clusters that show up as lighter.

Before thinking you understand these ideas, please look
at Ned Wight's tutorial:
http://www.astro.ucla.edu/~wright/cosmolog.htm

I hadn't fully grasped what significance that source had.

He was one of the team that ran the COBE mission
whose members recently received the Nobel prize.

Yes it did. Thank you.

But from reading that paper, the "big bang" is not
disputed, correct?

Does it matter? Every scientist is supposed to test his
theories, to try and find where they fail. Unfortunately, the
Big Bang is a one-shot deal. So all we can do is look back and
see where the roads behind came from. See if they are "paved" in
ways that are consistent with a Big Bang.

If your job is to try and disprove your own theory, then how can
you tell the difference between a proponent and a "disputor"?
Which one is actually doing work?

It is just that the universe has a homogeneous 2.725 K
background radiation.

With some anisotropies, but yes.

I may have missed something in the above reference, but
as far as I understand with the "big bang" space continues
to expand along with matter.

The "Big Bang" is just a name. There was no explosion of matter
into a preexisting space. The relationship between bits of
matter and energy that we call space (or spacetime) is the thing
that is "expanding" and "accelerating".

So how can the Universe be infinite if space continues to
expand?

Because you can never make it back to your starting point at the
fastest possible speed, ever. And you never hit any walls.

Or is Universe != Space?

Correct. Universe == (matter U energy)... and space and time are
the smoke and shadows of their dance.

David A. Smith

wrote in message
ups.com...
Greetings and Salutations:

Hi Ken,

On May 19, 9:55 am, "George Dishman" wrote:
Since everything is moving away from a central point, another universe
colliding with ours would (by definition) have objects moving from
*that* central expansion point.

No! There is no "central point" in current cosmological
models, our universe is probably infinite in size and by
measurement the section we can observe appears homogenous
and isotropic, the same (on average) everywhere.

WRT Cosmic Microwave Background (CMB), correct?

Not just that, also studies like the distribution of
galaxies, quasars and so on. While there is clearly
'evolution' in that the structure of galaxies varied
with the age of the universe and quasars were more
prevalent in the first few billion years, the
distribution is uniform. In other words, an astronomer
in a galaxy like ours which is so far away that we
only see the cluster to which it now belongs as a
one of the bluer patches in the COBE and WMAP charts.

And homogeneous "in
general", as when you look at the COBE map some areas are "darker" and
some "lighter". This would be expected because there are clusters
that show up as lighter.

The areas are 'blue' or 'red' indicating hotter or
colder relative to the 2.725K average. Blue are the
areas which later turn into galactic clusters. Look
at the bottom of page 4 of the tutorial:

http://www.astro.ucla.edu/~wright/cosmo_04.htm

When I say "the same (on average) everywhere", what
I mean is that the distant astronomer could draw a
similar chart from his location and the shell whose
temperature he would map would have a blue smudge
where our local group would eventually form. His map
would be quite different in detail but a statistical
study would show the same mean temperature, the same
RMS variation and the same angular power spectrum as
we see, and another astronomer as far again in the
same direction would get the same results - repeat
ad infinitum.

It might help to look at the "conformal space-time
diagram" just below the Mercator chart he

http://www.astro.ucla.edu/~wright/cosmo_03.htm#mstd

The first astronomer above would have a past light
cone (the two red lines) that converged at the top
about quarter of the way from the left and the line
going down to his right would meet ours at the surface
where the CMBR was produced. Just below there is an
illustration of the "horizon problem" and you can
see two red lines bounding the yellow triangle on the
left:

http://www.astro.ucla.edu/~wright/cosmo_03.htm#hp

The short line on the right of those two would be the
end of his light cone.

The third astronomer I mentioned above would have a
similar relationship to the second as the second does
to us and would be off the left of all the charts.

Before thinking you understand these ideas, please look
at Ned Wight's tutorial:
http://www.astro.ucla.edu/~wright/cosmolog.htm

I hadn't fully grasped what significance that source had.

I have been using it for several years and still keep
finding more in it.

HTH

Yes it did. Thank you.

But from reading that paper, the "big bang" is not disputed, correct?

Correct, though a few cranks have some philosophical
problems with it.

It is just that the universe has a homogeneous 2.725 K background
radiation.

When the light was emitted, the temperature of the
plasma was about 3000K but the 'redshift' since then
makes it look like that lower value.

I sometimes think of it like standing in the middle of
a field on a foggy day. The fog is the same everywhere
but you can only see a sphere centered on your own
location. Another version is like a flea in the middle
of the cylinder in your car engine:

http://www.briar.demon.co.uk/CMBR/Flea/

The duller red area is transparent while the bright
yellow is opaque. The 'red' and 'blue' areas in the maps
are tiny variations of temperature in the intermediate
brown shell.

I may have missed something in the above reference, but as far as I
understand with the "big bang" space continues to expand along with
matter.

Yes, that's right, or you can say space is expanding
and carrying the matter with it, or you can say "space"
is an abstract concept we use to describe spatial
relationships of matter. YMMV ;-)

So how can the Universe be infinite if space continues to
expand?

If it had a boundary, that could run into something
and get stopped but something infinite has no edges
to get stopped.

Or is Universe != Space?

Universe is all of space and everything in it.

You have to make a mental transition from thinking
of matter expanding in a container to the container
expanding in proportion, and then do away with the
container by tiling the universe with your mental
picture of the contents. One approach is to take a
piece of paper and draw some random dots, then
photocopy it at 110% onto a transparency and overlay
it on the original. That shows the universe some time
later than the original, and then imagine both your
finite sheets have been cut from one that is infinite,
similar sheets tiled forever in every direction.

That may take a little effort :-)

Go back to the conformal diagram down from

http://www.astro.ucla.edu/~wright/cosmo_03.htm#mstd

and imagine that chart being infinitely wide. To see
how that can be compatible with multiple universe, go
to part 2 and look at the second diagram below he

http://www.astro.ucla.edu/~wright/cosmo_02.htm#dh

Note that in these coordinates, infinite distance is
measured along the parabolic lines. The boundaries
are expanding at the speed of light. Now you can
perhaps envisage two of these diagrams some distance
apart but leaned over so the gap between them is also
increasing. I would like to write "increasing with
time." but (cosmological) time and space as we know
them are the lines radiating upwards from the bottom
of the cone and the parabolic curves respectively.
Anything outside that diagram doesn't have coordinates
in our universe, hence it is "not in our universe".

George

wrote in message
ps.com...
Greetings and Salutations:

From: "Greg Neill"
If there
are other universes with their own Big Bang events, they
are unconnected to ours, cannot be observed, and have no
influence at all on our universe.

O.K... So even if light from the "other universe" were to enter our
universe then that would constitute "connecting" the universes.
Correct?

Correct, since clearly there would have to be a spacial
path between source and destination.


On Apr 29, 10:06 am, "N:dlzc D:aol T:com \(dlzc\)"
wrote:
This doesn't mean that there may not be other Universes fully
parallel to ours, or that they might not intermingle at some
point in the future. Just nothing like that has happened in the
~13 Gy displayed.
David A. Smith

Since everything is moving away from a central point, another universe
colliding with ours would (by definition) have objects moving from
*that* central expansion point. Thank you.

Except that the universe has no center in space; it's
expanding from every point in all directions equally.

Dear gandalf:

wrote in message
ps.com...
Greetings and Salutations:
....
On Apr 29, 10:06 am, "N:dlzc D:aol T:com \(dlzc\)"

wrote:
This doesn't mean that there may not be other Universes fully
parallel to ours, or that they might not intermingle at some
point in the future. Just nothing like that has happened in
the
~13 Gy displayed.
David A. Smith

Since everything is moving away from a central point,

Keep in mind that *every point* is as close to the Big Bang as
every other. There is no special "central point" visible
anywhere we look. And we can see pretty clearly in the direction
we are moving away from.

another universe colliding with ours would (by definition)
have objects moving from *that* central expansion point.

Maybe not. What "laws of physics" are there in common between
the two? Is there only matter in that Universe too? Do they
have the same value for c? There could be a real opportunity for
the presence of a "normal shock" at the interface between two
Universes.

David A. Smith