Astronomy Stack Exchange
Astronomy Stack Exchange

Questions tagged [early-universe]

Questions regarding the universe shortly after its formation, up to the CMB or even as far as the formation of the first galaxies

64 questions
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How do we know the big bang didn't happen in an existing universe?

I understand the evidence for the big bang (expansion, background radiation, etc), but how do we know that it was the start of the universe? Why couldn't it have occurred in an existing, but very sparsely populated universe?
SArcher
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13
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Age of the universe

We know that the universe is approximately 13.7 billion years old. What methods did we use to discover this? How sure are we about its accuracy?
Rich
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Flatness of the universe?

How does inflation explain why the curvature in the early universe was flattened out and now results in a flat universe?
user1542
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4
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Can we observe the same very old object more than once?

Assuming the universe is curved and that is it possible to travel in a straight line and return to your starting point, it would make sense that at a younger age when the universe was smaller that light from an object sent in opposite directions…
Zenzizenzizenzic
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3
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Question about expansion of space time

Was the expansion of space time during big bang uniform if so how come the stars and planets be formed because and matter as well as gravity would have been same everywhere
Ginormousbeet
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2
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Time-density and time-temperature functions of the Universe since the Big Bang

I am looking for these... functions. I want to be able to say, "at a 1873. second there were around 54230000000 K temperature and 0.00435 kg/m^3 density". On the net I could find only tables or diagrams, as this: . (Here is a link to the page it…
peterh
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What is the meaning tiny bundle of energy smaller than an atom

At the beginning of a video on youtube titled "history of the world in 2 hours", it is said that "every thing begins with this tiny bundle of energy smaller than an atom". I want to know what it means. atom is matter. energy is different from…
Seetha Rama Raju Sanapala
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Expanding universe

If the first stars in the universe were formed 400 million years after the big bang, and the universe is expanding, should that stars at that time not been in our cosmic backyard? And should their light not have reached earth much sooner?
user17081
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What happened just before the Big bang?

Does the CMB contain any clues to what caused the Big Bang? Does a mathematical model theorize it?
signsgeek
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0
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Size of the Universe before the Big Bang

I can't understand how all the matter contained in the Universe, was contained in an area the size of a grapefruit before the Big Bang ? How could so much matter have been compressed in such a tiny space ?
Peter U
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What was the entity/particle/state at the time of the Big bang?

At the time of the big bang if there was an original entity, what were it's attributes(if applicable) - mass, electric charge, color charge or spin? Can the current matter and dark energy together account for the original entity or was some of the…
signsgeek
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Estimates VOLUME of the ur-Supermassive Black Hole of this universe

Assuming Prof. Poplawski's "universe in a black hole" ( and at Arxiv here ) concept is true--that our universe is the result of a nonsingular Big Bounce from a supermassive black hole (SMBH) under Einstein-Cartan gravitation--then it seems possible…
Tom Holzel
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