# Tag Info

## New answers tagged universe

0

That depends on what you mean by "made up of". Is static electric field "made up of" photons? Is the stream of water "made up of" waves? To me these are semantic games that have no connection to reality. But if you are willing to answer "yes" to the questions above, then you can safely say that those domain walls are "made up of" Higgs bosons (and also the ...

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My answer to How does the Hubble parameter change with the age of the universe? (which is itself adapted from Equation for Hubble Value as a function of time) explains how to calculate the scale factor. In fact we calculate the time as a function of the scale factor rather than the other way around. The equation we use is:  t(a) = \frac{1}{H_0}\int_0^a ...

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All of your questions have no good answer at this point in time. All of them are being researched by physicists, cosmologists, and theorists. We don't even know whether our universe is the only universe or whether what lies beyond the visible universe is just more space like the kind we can see. Our best theories of space and time (Einstein's General ...

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You are correct that the gravity of everythig in the Unuverse should have contracted the universe from everything we know, but the fact is we don't have all the answers. For example, what caused the big bang? What cause the sudden inflation? what is dark energy? String theory has some potential answers for the initial inflation but string theory has run ...

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Your question assumes that the universe started out as a point at the Big Bang and then expanded outwards, however this is not the case. Have a look at my answer to Did the Big Bang happen at a point? for more on this. However your main point remains, that is shouldn't gravity be slowing the expansion, and indeed it did until a few billion years ago. The ...

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First of all, the universe is not infinite. There is enough reason to disprove an infinite universe model. In such a case, the universe can have a beginning. Reasons to why the universe simply cannot be infinite are as old as the time of Isaac Newton. The problem is gravity. In an infinite universe, the total gravity of the mass it contains would be infinite ...

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There is another big problem with ultra-small luminosities: due to the small initial light + 1/r² decrease, it might be that only a few photons per hour sent by your target planet reach the diameter of Earth (better be in your telescope ! ). At very small luminosity you have to remind that light is not continuous and made of photons. And way before the ...

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The spatial resolution of a telescope is going to be limited in what it can resolve by something called the diffraction limit. Basically, light can only be focused so much by a lens given its initial starting size and the focal length of the lens. Its useful to think about this in terms of angular resolution for the case of telescopes, and the minimum ...

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have a read through Did the Big Bang happen at a point? as this provides important background. If, as you say, you are considering only a simply connected universe, so it isn't finite due to its topology, then the assumption we make when solving Einstein's equations is that the universe is the same everywhere - the technical terms are isotropic and ...

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The elements that make up the bulk of the Earth were part of the presolar nebula. A similar (though not identical) mixture of elements is found in meteoritic material, which is thought to more accurately represent the mean abundances of that nebula (minus the volatiles) and indeed also agrees with the abundance patterns in the Sun. There are grains of ...

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