Cosmic Inflation & the speed of light

Le 28/09/10 20:19, Yousuf Khan a écrit :
Something that puzzles me is that if according to the theory of
inflation, the universe experienced a period of inflation immediately
following the Big Bang, and that Inflation produced a universe that is
at least 80% as big as the observable universe is today, and it all
happened in less than a fraction of a second. Then that means that the
universe expanded at faster than the speed of light, of course. So if
that's the case, then how is that we can see any of the galaxies in the
distant universe at all? The universe was already too big for light to
traverse across it then.

Yousuf Khan

If the universe is expanding faster than light, and nothing material can
move faster than the speed of the light all objects in the universe
can't move at all, and the cinetic energy of all particles is NEGATIVE.

But we are not going to get bothered for yet another contrdiction in all
this stuff.

Excuse me but if space is "expanding", it is "expanding" into WHAT???
Into more space obviously.

Nice. So space is expanding into more space. Was this space before
already there or it got just "created"???

On Wed, 29 Sep 2010 19:53:59 +0200, jacob navia
wrote:

Le 28/09/10 20:19, Yousuf Khan a écrit :
Something that puzzles me is that if according to the theory of
inflation, the universe experienced a period of inflation immediately
following the Big Bang, and that Inflation produced a universe that is
at least 80% as big as the observable universe is today, and it all
happened in less than a fraction of a second. Then that means that the
universe expanded at faster than the speed of light, of course. So if
that's the case, then how is that we can see any of the galaxies in the
distant universe at all? The universe was already too big for light to
traverse across it then.

Yousuf Khan

If the universe is expanding faster than light, and nothing material can
move faster than the speed of the light all objects in the universe
can't move at all, and the cinetic energy of all particles is NEGATIVE.

But we are not going to get bothered for yet another contrdiction in all
this stuff.

Excuse me but if space is "expanding", it is "expanding" into WHAT???
Into more space obviously.

Nice. So space is expanding into more space. Was this space before
already there or it got just "created"???

Jacob, you make some good points, here, but this can't be explained
and understood easily by our minds which are adapted to 4 dimensions
of space/time. To tone it down a bit and get a grasp on the concept,
think of a two dimensional space such as the surface of large sphere.
If that large sphere is being enlarged, obviously this surface is
expanding, but into what? The situation of our expanding 3-dimensional
space is similar...an unrolling of our spatial dimensions, or
something like that.

Gordon

Dear jacob navia:

On Sep 29, 10:53*am, jacob navia wrote:
Le 28/09/10 20:19, Yousuf Khan a écrit :

Something that puzzles me is that if according to the
theory of inflation, the universe experienced a period
of inflation immediately following the Big Bang, and
that Inflation produced a universe that is at least 80%
as big as the observable universe is today, and it all
happened in less than a fraction of a second. Then
that means that the universe expanded at faster than
the speed of light, of course. So if that's the case,
then how is that we can see any of the galaxies in
the distant universe at all? The universe was already
too big for light to traverse across it then.

If the universe is expanding faster than light,

It isn't now. When it was, was before the CMBR stopped glowing.

and nothing material can move faster than the speed
of the light all objects in the universe can't move at all,

Expansion is NOT proper motion.

and the cinetic energy of all particles is NEGATIVE.

But we are not going to get bothered for yet another
contrdiction in all this stuff.

Excuse me but if space is "expanding", it is
"expanding" into WHAT??? Into more space
obviously.

If the cost of a gallon of milk keeps increasing, into what is its
cost expanding (besides your wallet)? Same kind of stuff. "Value",
"cost", "distance" are just relative measures of stuff in this
Universe.

Nice. So space is expanding into more space.
Was this space before already there *or it got just
"created"???

I know I have tried to get you to read up on this before, and you
chose to ignore it. But let's try one more time:
inflation:
http://www.astro.ucla.edu/~wright/cosmo_04.htm
faster than light:
http://www.astro.ucla.edu/~wright/cosmo_02.htm
http://www.astro.ucla.edu/~wright/co...y_faq.html#FTL

David A. Smith

On 9/29/10 12:53 PM, jacob navia wrote:
If the universe is expanding faster than light, and nothing material can
move faster than the speed of the light all objects in the universe
can't move at all...

Nope... the cosmic speed limit applies to mass and energy, not space.

My dearest Antares 531,

"Antares 531" wrote...
in message ...
On Tue, 28 Sep 2010 19:32:36 +0100, "Androcles"
wrote:
"Yousuf Khan" wrote in message
...
| Something that puzzles me is that if according to the theory of
| inflation, the universe experienced a period of inflation immediately
| following the Big Bang, and that Inflation produced a universe that is
| at least 80% as big as the observable universe is today, and it all
| happened in less than a fraction of a second. Then that means that the
| universe expanded at faster than the speed of light, of course. So if
| that's the case, then how is that we can see any of the galaxies in the
| distant universe at all? The universe was already too big for light to
| traverse across it then.
|
| Yousuf Khan
|
You forgot about magical time dilation.
Time slows down when you are having fun.
--
Clock A reads 6:00 am at dawn, its a perfect clock.
Clock B reads 12:00 pm at noon, its a perfect clock.
Clock A remains in synch with Earth wherever it goes because
"In accordance with definition the two clocks synchronize if
tB-tA = t'A-tB",clock A can see the Earth and Earth can see
clock A, "the ``time'' required by light to travel from A to B
equals the ``time'' it requires to travel from B to A."-- Einstein.

Because of time dilation, "if one of two synchronous clocks
at A is moved in a closed curve with constant velocity until
it returns to A, the journey lasting t seconds, then by the clock
which has remained at rest the travelled clock on its arrival at
A will be 1/2 tv^2/c^2 second slow." -- Einstein.

Clock A meets clock B at A and is 6 hours slow. Both clocks
synchronize with Earth. Therefore clock A meets clock B at
dawn and clock B sees clock A arrive at noon.

There's another question that I've never had answered for me. How do
we know that the universe, out beyond the visible horizon, hasn't
already started collapsing back to a point such as it started from? We
won't be able to detect this until it is all over and done with.

Gordon

When you think about it, this could be happening at much
closer ranges than you mention above. All those many
galaxies we can see at, say 12 billion light years away from
us might have actually begun to blueshift (come closer), and
we wouldn't be able to detect it for another 12 billion years.

Happy days *and*...
Starry, starry nights !

--
Indelibly yours,
Paine Ellsworth

P.S.: "Frisbeetarianism is the belief that when you die, your
soul goes up on the roof and gets stuck." George Carlin

PPS. http://astro.painellsworth.net !
http://www.secretsgolden.com !
http://en.wikipedia.org/wiki/User:Paine_Ellsworth !

My dearest Greg,

"Greg Neill" wrote...
in message om...
Yousuf Khan wrote:

Something that puzzles me is that if according to the theory of
inflation, the universe experienced a period of inflation immediately
following the Big Bang, and that Inflation produced a universe that is
at least 80% as big as the observable universe is today, and it all
happened in less than a fraction of a second. Then that means that the
universe expanded at faster than the speed of light, of course. So if
that's the case, then how is that we can see any of the galaxies in the
distant universe at all? The universe was already too big for light to
traverse across it then.

That's right. We can only see as far as our own
cosmic horizon where, due to continuing expansion,
space is expanding away from us at the speed of
light. This is a very, very tiny portion of the
whole universe.

Forgive me, i must take issue with your usage of the
phrase "space is expanding", which infers that since
we see large redshifts billions of light years away,
then those galaxies must NOW be moving at great
speeds away from us. How is it that scientists can
determine this? For all we know, those galaxies we
can see that have large redshifts, might have slowed,
stopped, and are presently touring the Universe back
in the direction of the Milky Way. And we would not
be able to sense this for billions of years. For all we
know, the Universe could be in a contracting phase,
with all those faraway galaxies heading back toward
us, but since their redshifted light left them so long
ago, billions of years ago, we cannot detect this
contraction.

So i suppose my actual question is, how can we speak
with any confidence as to what those faraway galaxies
are doing right NOW, at this present moment?

Happy days *and*...
Starry, starry nights !

--
Indelibly yours,
Paine Ellsworth

P.S.: "Frisbeetarianism is the belief that when you die, your
soul goes up on the roof and gets stuck." George Carlin

PPS. http://astro.painellsworth.net !
http://www.secretsgolden.com !
http://en.wikipedia.org/wiki/User:Paine_Ellsworth !

My dearest David,

"David Staup" wrote in message
...

"Sam Wormley" wrote in message
...
On 9/28/10 1:57 PM, bert wrote:
On Sep 28, 2:19 pm, Yousuf wrote:
Something that puzzles me is that if according to the theory of
inflation, the universe experienced a period of inflation immediately
following the Big Bang, and that Inflation produced a universe that is
at least 80% as big as the observable universe is today, and it all
happened in less than a fraction of a second. Then that means that the
universe expanded at faster than the speed of light, of course. So if
that's the case, then how is that we can see any of the galaxies in the
distant universe at all? The universe was already too big for light to
traverse across it then.

Yousuf Khan

Read stuff by Guth TreBert

Brad Guth?

heh heh, no not brad, Alan

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

Pretty sure that was an excellent stab by Sam at "irony".

I once thwarted a self-proclaimed astrophysicist in
alt.astronomy with this bit of irony. We were discussing
BB theories, and i brought up "Guth's inflation theory".
The false scientist then proceeded to jump all over me for
giving credence to anything that Brad Guth, a "well-known"
kook would say.

Rather enjoyed blasting him out of the water with that one.

Happy days *and*...
Starry, starry nights !

--
Indelibly yours,
Paine Ellsworth

P.S.: "Frisbeetarianism is the belief that when you die, your
soul goes up on the roof and gets stuck." George Carlin

PPS. http://astro.painellsworth.net !
http://www.secretsgolden.com !
http://en.wikipedia.org/wiki/User:Paine_Ellsworth !

On 9/30/10 2:03 PM, Painius wrote:
My dearest David,

"David wrote in message
...

"Sam wrote in message
...
On 9/28/10 1:57 PM, bert wrote:
On Sep 28, 2:19 pm, Yousuf wrote:
Something that puzzles me is that if according to the theory of
inflation, the universe experienced a period of inflation immediately
following the Big Bang, and that Inflation produced a universe that is
at least 80% as big as the observable universe is today, and it all
happened in less than a fraction of a second. Then that means that the
universe expanded at faster than the speed of light, of course. So if
that's the case, then how is that we can see any of the galaxies in the
distant universe at all? The universe was already too big for light to
traverse across it then.

Yousuf Khan

Read stuff by Guth TreBert

Brad Guth?

heh heh, no not brad, Alan

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

Pretty sure that was an excellent stab by Sam at "irony".

I once thwarted a self-proclaimed astrophysicist in
alt.astronomy with this bit of irony. We were discussing
BB theories, and i brought up "Guth's inflation theory".
The false scientist then proceeded to jump all over me for
giving credence to anything that Brad Guth, a "well-known"
kook would say.

Rather enjoyed blasting him out of the water with that one.

Happy days *and*...
Starry, starry nights !


Right on, Painius!
-Sam

Painius wrote:
My dearest Greg,

"Greg Neill" wrote...
in message om...
Yousuf Khan wrote:

Something that puzzles me is that if according to the theory of
inflation, the universe experienced a period of inflation immediately
following the Big Bang, and that Inflation produced a universe that is
at least 80% as big as the observable universe is today, and it all
happened in less than a fraction of a second. Then that means that the
universe expanded at faster than the speed of light, of course. So if
that's the case, then how is that we can see any of the galaxies in the
distant universe at all? The universe was already too big for light to
traverse across it then.

That's right. We can only see as far as our own
cosmic horizon where, due to continuing expansion,
space is expanding away from us at the speed of
light. This is a very, very tiny portion of the
whole universe.

Forgive me, i must take issue with your usage of the
phrase "space is expanding", which infers that since

implies

we see large redshifts billions of light years away,
then those galaxies must NOW be moving at great
speeds away from us. How is it that scientists can
determine this? For all we know, those galaxies we
can see that have large redshifts, might have slowed,
stopped, and are presently touring the Universe back
in the direction of the Milky Way. And we would not
be able to sense this for billions of years. For all we
know, the Universe could be in a contracting phase,
with all those faraway galaxies heading back toward
us, but since their redshifted light left them so long
ago, billions of years ago, we cannot detect this
contraction.

So i suppose my actual question is, how can we speak
with any confidence as to what those faraway galaxies
are doing right NOW, at this present moment?


We can only presume that the laws of physics
are as observed so far, and that, barring new
information to the contrary, the extrapolation
of observed events via physical laws (such as
gravitation and inertia in universe adhering
to General Relativity as a model) predicts that
that the universe is not about to collapse but
will go on expanding.

If you ignore the physics models and just say
"what if...", then that is not science; It's
equivalent to invoking magic or believing in a
fairy tale.

My dearest Sam and Khan,

"Sam Wormley" wrote...
in message ...
On 9/28/10 1:19 PM, Yousuf Khan wrote:

Something that puzzles me is that if according to the theory of
inflation, the universe experienced a period of inflation immediately
following the Big Bang, and that Inflation produced a universe that is
at least 80% as big as the observable universe is today, and it all
happened in less than a fraction of a second. Then that means that the
universe expanded at faster than the speed of light, of course. So if
that's the case, then how is that we can see any of the galaxies in the
distant universe at all?

We can't as what is "beyond" our observable horizon is not causally
connected.

Physics News Update -- Number 685, May 12, 2004
by Phil Schewe and Ben Stein
Ref: http://www.aip.org/pnu/2004/685.html

Our Universe Has a Topology Scale of at least 24 GPC

Our universe has a topology scale of at least 24 Gpc, or
about 75 billion light years, according to a new analysis
of data from the Wilkinson Microwave Anisotropy
Probe (WMAP).

What does this mean? Well, because of conceivable
hall-of-mirrors effects of spacetime, the universe might
be finite in size but give us mortals the illusion that it is
infinite. For example, the cosmos might be tiled with
some repeating shape, around which light rays might
wrap themselves over and over ("wrap" in the sense
that, as in video games, something might disappear off
the left side of the screen and reappear on the right
side).

A new study by scientists from Princeton, Montana
State, and Case Western looks for signs of such
"wrapped " light in the form of pairs of circles, in
opposite directions in the sky, with similar patterns in
the temperature of the cosmic microwave background.
If the universe were finite and actually smaller than the
distance to the "surface of last scattering" (a distance
that essentially constitutes the edge of the "visible
universe," and the place in deep space whence comes
the cosmic microwaves), then multiple imaging should
show up in the microwave background.

But no such correspondences appeared in the analysis.
The researchers are able to turn the lack of recurring
patterns into the form of a lower limit on the scale of
cosmic topology, equal to 24 billion parsecs, a factor of
10 larger than previous observational bounds. (Cornish,
Spergel, Starkman, Komatsu, Physical Review Letters,
upcoming article; contact Neil Cornish, 406-994-7986,
.)


The universe was already too big for light to
traverse across it then.

Yousuf Khan

Doesn't all this take for granted that our position is at dead-
center of the observable Universe? Suppose we are not. If
we were "off to one side" just a bit, that would screw with
the topology just a bit, and maybe enough to blow away any
pattern. Might be interesting to play with the topology to
see if there is a position somewhere near or far where those
correspondences would emerge and show themselves?

Happy days *and*...
Starry, starry nights !

--
Indelibly yours,
Paine Ellsworth

P.S.: "Frisbeetarianism is the belief that when you die, your
soul goes up on the roof and gets stuck." George Carlin

PPS. http://astro.painellsworth.net !
http://www.secretsgolden.com !
http://en.wikipedia.org/wiki/User:Paine_Ellsworth !