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wolram
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I am trying to get my head around how much the volume of the universe increases per some time scale, say 1000yrs, how would one calculate this?
The volume of the universe is unknown, so you cannot calculate what you asked. To get a feeling, it is best to just realize that all large scale distances are presently increasing by about 68 km per second per Mpc, which translates to about 1/144 % per million years. So, pick any large volume that you fancy, increase the radius by 1/144 % and calculate the volume increase.wolram said:I am trying to get my head around how much the volume of the universe increases per some time scale, say 1000yrs, how would one calculate this?
Alltimegreat1 said:I get it that the universe is (presumably) infinite. But what about the distribution of matter? Is it likely that there are stars and galaxies trillions or quadrillions of lights years away from here?
This inherently assumes you can define a universal "now" at which you sum up the matter. While this is the case in the models describing the Universe on large scales, it gets problematic if these models are not accurate, eg, if you also want to describe smaller scales.Alltimegreat1 said:But if it is, then there would also be an infinite amount of matter, right? I used to envision the universe as having a sphere of matter that is expanding outward, but beyond the edge of the furthest matter lie endless expanses of empty space.
The Universe IS space.Alltimegreat1 said:But if it is, then there would also be an infinite amount of matter, right? I used to envision the universe as having a sphere of matter that is expanding outward, but beyond the edge of the furthest matter lie endless expanses of empty space.
Yes that is one conclusion which a lot of people agree with, but it's somewhat debatable since it depends on how the rate of expansion might have changed over time.Alltimegreat1 said:According to that link, space only increases between galaxies that are sufficiently distant to each other. Apparently the Milky Way and Andromeda galaxies are too close to each other for that. Assuming spacetime continues to expand eternally, eventually after quadrillions of years we would be able to observe nothing else outside of our own galaxy?
Scientists use a variety of methods to measure the expansion of the Universe, including observing the redshift of distant galaxies and studying the cosmic microwave background radiation.
The current rate of expansion, also known as the Hubble constant, is estimated to be 67.4 kilometers per second per megaparsec. This means that for every megaparsec (3.26 million light years) of distance, the Universe is expanding by 67.4 kilometers per second.
The expansion of the Universe causes objects to move away from each other, as the space between them is expanding. This effect is known as cosmological expansion and is responsible for the observed redshift of distant galaxies.
Recent observations have shown that the expansion of the Universe is indeed accelerating. This is believed to be due to a mysterious force called dark energy, which makes up about 70% of the total energy in the Universe.
Based on current observations and theories, it is believed that the expansion of the Universe will continue indefinitely. However, the rate of expansion may change over time due to the effects of dark energy and other factors.