The space-expansion tag has no wiki summary.
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Light coming from distant galaxies
Some of the distant galaxies appear to be receding from us faster than the speed of light due to stretch of the space between us and those galaxies.
By an analogy with the ant on a rope paradox, the ...
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4answers
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Space Expansion vs. Relative Motion
Inspired by a recent dialogue from another question:
Given 2 objects moving at some velocity $v$ relative to one another, is it possible to determine whether they are moving or whether the space ...
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1answer
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Does the large red shift value of galaxies mean they are far away?
When the red shifts of galaxies are large, why do we think that they are far away?
I know about Hubble's law, Tully-Fisher relation of spiral galaxies, Faber-Jackson relation of elliptical ...
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4answers
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As the universe expands, why do some things stretch but not others?
I got into watching a video on Olbers' Paradox a few days ago, and from there read about the origins of the universe, its expansion, and so on... it's always fascinated me, but now something about it ...
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1answer
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Cosmological constant of standard model of cosmology and observational data
I am curious whether the current Lambda-CDM model of cosmology matches well with observational data, especially expansion of the universe.
How well does Lambda-CDM defend its established status from ...
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Expansion of space [duplicate]
Possible Duplicate:
spacetime expansion and universe expansion?
So I've heard that space is expanding very quickly and that the redshift we see when we look at other galaxies is evidence of ...
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1answer
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The expansion of space time (EST)..and the one directional flow of time?
Time flows one way...cause creates effect.
Could the expansion of the universe also cause an expansion of space time in a similar fashion?...and if so, would this phenomenon explain the one way ...
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6answers
585 views
Does gravity slow the expansion of the universe?
Does gravity slow the expansion of the universe?
I read through the thread http://www.physicsforums.com/showthread.php?t=322633 and I have the same question. I know that the universe is not being ...
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1answer
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Does cosmic expansion imply the possibility of the universe splitting in half; multiple big-crunches?
There is an event horizon where cosmic expansion leads to superluminal recession speeds for sufficiently distant objects -- the Hubble Volume.
1) Does matter beyond the event horizon affect us ...
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Expansion of Universe [duplicate]
Possible Duplicate:
Why space expansion affects matter?
If the Expansion is prevalent, i.e. it is observable and true then shouldn't that result in the expansion of the Milky Way galaxy, ...
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0answers
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Expansion of Universe. Will it come to an end? [duplicate]
Possible Duplicate:
Is there a consensus on the fate of our universe?
Its been about 13.7 billion years past the Big Bang took place. According to Hubble's law, the universe is under ...
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1answer
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spacetime expansion and universe expansion?
First of all, does the expansion of spacetime solely cause the expansion of universe?
Secondly, if spacetime is the sole cause, do objects(matter with mass) themselves expand?
Thirdly, by spacetime ...
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1answer
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Is the FRW metric describing the shape of the universe or the shape of the expansion applied to the universe?
Is it (the output, i.e, spherical, flat, hyperbolic) describing the physical shape of the universe and its curvature at any given instance of time or is it describing the shape of the expansion ...
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1answer
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Curvature, Omega, the Flatness problem, and the evolving shape of the universe
I'm a little confused by this:
http://en.wikipedia.org/wiki/Flatness_problem
Which seems to imply the universe is more curved now than it was soon after the Big Bang. Look at the graph on the right ...
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2answers
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How to test whether galaxies are moving away from each other in a static background or whether space is being created beween them?
Observations show that galaxies are moving away from one another on the macroscopic scale.
Now, scientists interpret this by saying this happens not because galaxies are really moving away from each ...
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1answer
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Superluminal expansion of the early universe how is this possible?
Is this a postulate? I get the expansion of the universe, the addition of discrete bits of space time between me and a distant galaxy, until very distant parts of the universe are moving relative to ...
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1answer
336 views
How is the expansion of space itself explained in LQG?
To explain the expansion of space I have often heard people saying that space is continuously created. This picture is usually applied to cosmological scales but I`m nevertheless curious if some ...
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1answer
249 views
how many times have the first photons lapped the universe?
I'm not really interested in the actual number of times, but rather an explanation of a closed Universe. How do we still measure the background radiation of the Big Bang? Those electromagnetic waves ...
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2answers
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Elasticity of Space; How does the expansion of Space effect gravity?
Does space have an elastic quality?
What I was thinking about was if space is expanding, is it being 'stretched', like a balloon being blown up, and if so, is this causing gravity to weaken? Imagine ...
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1answer
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The range of light
It occurs to me that the empirical evidence shows that there is a point out in space where light stops coming from.
Putting aside the expansion of the universe for a second, and focusing strictly on ...
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2answers
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Value of the Hubble constant over time
There is something I don't understand about the Hubble "constant" H, as it seems to clump two concepts together that I can't quite unify in my head. On the one side, we have
V = D * H
which means ...
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3answers
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Universe is expanding at enormous speed
I'm not an expert but I've come to understand that the universe is expanding at enormous speed. That means that all of the visible galaxies are moving away from us at great speed.
I also came to ...
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2answers
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Space expansion effect on wavelengths across two points in space
Is the expansion of space taken into consideration when calculating light or any (Radio to Gamma) wave length distance and speed? I know C is a constant, but my concern is if "space expansion" is ...
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2answers
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Reformulated: Universe expansion or collapse
I reformulate the question a little bit because I feel that
I was misunderstood.
There are cosmic observations that tell us the universe seems to expand.
It also seems to expand always faster ...
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3answers
236 views
How long does it take for expanding space to double in size
I have been reading about Hubble's constant and trying to make 'sense' of the theory of the expanding Universe. Is is possible that space in the universe expands uniformly? If so, absent of other ...
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1answer
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Is the number of wavelengths of light spanning a distance invarient with respect to spacetime distortion?
I was recently asked by a friend how the expansion of spacetime effects photons. I gave him what I feel is a satisfactory general response, but it got me wondering how, exactly to calculate this ...
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1answer
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Cosmic bubble collision
I'm reading this review right now. The claim seems to be that when you have an expanding "false vacuum", finite size bubbles form due to phase transition (cause by finite action instantons) (which, in ...
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5answers
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What is the extent of the universe?
Is there any realistic, understandable, provable (even in some extent) explanation/model for the extent of the universe?
What is its shape? and Why? I mean physical explanations not philosophical ...
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1answer
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Since the universe is expanding, does anything ever occupy the same point in space?
Let's say we can observe expansion in a supercluster.
We define origin of our frame of reference at the center of the supercluster.
We observe an object/atom at point A at time T. The object is ...
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3answers
520 views
At what speed does our universe expand?
Conceivably it expands with the speed of light. I do not know, but curious, if there is an answer. At what velocity, does our universe expand?
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1answer
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Virtual particle production in space-time.
Are virtual particles created within existing space-time, or do they create new space-time for them to occupy?
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3answers
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How can a quasar be 29 billion light-years away from Earth if Big Bang happened only 13.8 billion years ago?
I was reading through the Wikipedia article on Quasars and came across the fact that the most distant Quasar is 29 Billion Light years. This is what the article exactly says
The highest redshift ...
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0answers
249 views
composition of space expansion and movement as a gauge invariance
suppose i have a space-time where we have one point-like object* which we will call movement space probe or $\mathbf{M}_{A}$ for short, and it will be moving with constant velocity $V^A_{\mu}$ in ...
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Why is the universe so big?
The Universe is approximately 13.7 billion years old. But yet it is 80 billion light years across. Isn't this a contradiction?
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2answers
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Will the night sky eventually be bright?
I have read that the night sky should have been bright because every spot should end up pointing to a star in the infinite universe but this is not the case because the universe is expanding. I am ...
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3answers
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Seeing cosmic activity now, really means it happens millions/billions of years ago?
A Recent report about a cosmic burst 3.8 billion light years away. It is written as though it is happening now. However, my question is, if the event is 3.8 billion light years away, doesn't that mean ...
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2answers
216 views
Have CMB photons “cooled” or been “stretched”?
Introductory texts and popular accounts of why we see the "once hot" CMB as microwaves nearly always say something about the photons "cooling" since the Big Bang. But isn't that misleading? Don't ...
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2answers
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Expanding universe
If we know the universe is expanding in whatever direction we look, can't we reasonably estimate where the 'center' of the Universe is?
Is the rate of expansions in all directions the same?
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2answers
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Do cosmological and Doppler redshift produce different patterns?
For a given black body radiation curve, would the changes to the spectrum resulting from cosmological expansion and those from Doppler effects be distinguishable on the basis of the shapes of the ...
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4answers
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Origins of the universe questions
If the universe is expanding, what is it expanding into?
Similarly when the big bang happened where and how did it occur? - Where did the energy come from? Energy can not be created or destroyed does ...
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4answers
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Redshifting of Light and the expansion of the universe
So I have learned in class that light can get red-shifted as it travels through space. As I understand it, space itself expands and stretches out the wavelength of the light. This results in the light ...
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3answers
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Effect of expansion of space on CMB
Is it true that the expansion of space time cause the CMB to become microwaves from a shorter wavelength. If it is has the amplitude been increased?
Seeing as the amplitude has decreased; why hasn't ...
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2answers
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Star trace in the sky
If the space of universe is expanding at fast rates..(even faster than light)
Why we do not see the trace of the stars?
A possible answer could be that the stars are only moving away but mantaining ...
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3answers
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Expansion of space and gravity
In my previous question I asked how gravity can be represented as dents in space. It seems that it's a metaphor. But I wondered with spac expanding does the effect of gravity get bigger as well, I ...
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6answers
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How Does Hubble's Expansion Affect Two Rope-Tied Galaxies?
Suppose we have two galaxies that are sufficiently far apart so that the distance between them increases due to Hubble's expansion. If I were to connect these two galaxies with a rope, would there be ...
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5answers
390 views
What experiments, other than Hubble Expansion, support the Dark Energy theory?
Dark energy is introduced as a constant inside Einstein's equations. Its primary purpose, from what I understand, is to make Einstein's equations compatible with the accelerating expansion of the ...
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6answers
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Why does space expansion not expand matter?
REFORMULATED:
I have looked at the other questions (ie "why does space expansion affect matter") but can't find the answer I am looking for.
My question:
There is always mention of space expanding ...
9
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3answers
561 views
Why space expansion affects matter?
If space itself is expanding, then why would it have any effect on matter (separates distant galaxies)?
Space is "nothing", and if "nothing" becomes bigger "nothing" it's still a "nothing" that ...
