Questions about the increase with time of distance between two distant points in the Universe.
Questions tagged [expansion]
237 questions
22
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5 answers
How do we know the expansion of the universe is not centered around our position?
It is my understanding that the red shift of galaxies in whatever direction we look shows the universe is expanding in every direction around us. That could be explained in two ways:
A (accepted): The universe is expanding in every point, like the…
armand
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21
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2 answers
Space expansion in layman terms
So far I got to understand the expansion of space is not to be understood as stars drifting further apart through space. There's something more fundamental - e.g. you can't simply measure speed of it, nor tell where the center of the universe (the…
SF.
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14
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3 answers
Does a measuring stick with a size of a billion lightyears in intergalactic space keep the same length in expanding space?
Imagine a measuring stick (a rod or ruler) made of ordinary matter which has a length of a billion lightyears. The space surrounding the ruler expands. Will the ruler keep the same length by the accumulating electromagnetic forces opposing…
Gerald
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12
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4 answers
Do all objects get larger in an "expanding universe"?
I'm envisioning an analogy of the universe as a plane with marbles in that plane to represent different planets.
Now, if this plane expands how does this work? I assume that it is not like 'nothing' becomes 'something' then but rather…
hashier
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10
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3 answers
How far apart has the sun drifted from Alpha Centari due to the expansion of the universe since its formation?
From what I read Alpha Centauri formed 250 million years before the sun which was 4.85 billion years. So how far apart were they when the sun formed vs what they are now?
The expansion of the universe must be contributing to it's 4.4 light years.…
Sedumjoy
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Does the gravity oppose to the Universe expansion?
I'm trying to understand the very basis of the current cosmology.
I searched in the old questions but I found nothing that answers my questions specifically.
As far as I understand, we have to think the "expansion" more like a "stretching" of the…
Mark
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7
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7 answers
How can an infinite universe expand?
I understand the expansion of the universe as actually an increase in the ratio of space to matter. Is this a correct understanding? Otherwise, I don't understand how an infinite structure can expand.
Justin Waters
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How did scientists come to the conclusion that it is space that is expanding?
How did scientists come to the conclusion that it is space that is expanding and not galaxies moving away from each other as in a giant explosion?
user17081
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4
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Why would all places appear to be at the center of the universe's expansion?
I just watched an iMax planetarium video that claimed that no matter where you are in the universe, it will appear that you are at the center of the universe and all things are expanding away from you.
What the heck?? Can someone please explain…
CuriousWebDeveloper
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Expansion of the Universe
Please forgive my ignorance. I dare say that these questions arise from me trying to understand the nature of the Universe using Newtonian physics. There are a few things that really bother me when topics such as red shift and expansion are…
Martin
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2
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Does the radius of your cosmic horizon decrease as velocity increases?
If I was moving at c-1 meters per second, and was observing an object moving 2 m/s away from my starting point as a result of the expansion of the universe rather than classical velocity, would I ever see the light coming from this object? Does that…
Kinorana
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2
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Why hasn't the CMB already receded away faster than the speed of light?
If there are supposedly galaxies, or whole other parts of the universe, that we can't ever see due to them receding away from us faster than the speed of light, then why isn't or hasn't this occurred with the cosmic microwave background?
yoda
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How much does a linear lightyear of space expand in a year?
Now that we know that the universe is expanding, how much does a linear lightyear of space expand currently in a year?
Zamicol
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Expansion of Space in the Very Distant Future
Given a nearly infinite timeline, would the expansion of space eventually cause individual particles to become "unobservable" from one another due to the vast distance and increasing rate of expansion with that distance.
Matt P
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2
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What exactly is meant by "expanding universe"?
What exactly is meant when we say the universe is expanding? I understand stars and galaxies are getting farther and farther away from us, but are individual particles (atoms, molecules, anything found on Earth, etc.) drifting away from each other…
creative_name
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