Questions tagged [big-bang-theory]
Questions regarding the currently prevalent cosmological model for the origin of the universe.
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How is the big bang a plausible theory? [duplicate]
In the Big Bang Theory, it is said that it started with a small speck of matter, yet we have an unimaginable mass of expanding universe which is assumed as immeasurable. If the theory of "Matter ...
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When did relatvistic effects take hold after the big bang? [duplicate]
As far as I understand it the universe did not become a black-hole at the big bang.
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Is there a place where one can see the beginning of the universe? [duplicate]
If the night sky Is dark because we’re seeing the world as it was a long time ago, when there wasn’t much to see, is there a place on the universe where we can see the universe at the beginning of ...
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Why is CMB an evidence of hotter and denser early Universe?
In his book Gravitation and cosmology, Steven Weinberg says that CMB makes it "difficult to doubt that the universe has evolved from a hotter denser early stage".
In my understanding, CMB is just a ...
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1answer
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Did Einstein supported Big Bang Theory cosmological model?
Einstein made many predictions, including gravitational waves and the possibility of black holes.
Relativity is taken into consideration for the Big Bang model, so did Einstein agree with it or did ...
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Is Olbers' Paradox Nonsense? [closed]
Ok, this is a bold question, I know. But, let me explain: After first hearing about Olbers' paradox, I found that something seemed 'off' about it, so I looked into the subject as much as my skills (...
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Must all galaxies in a galaxy cluster have the same expansion rate?
If we observe a distant galaxies cluster where all galaxies travel with the same speed away from us, except for one galaxy whose speed is significantly lower than of the neighboring galaxies. Does ...
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1answer
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What reference frame do age-of-the-universe calculations assume?
I'm thinking, in particular, about general relativity. When we speak, for example, of neutrino decoupling, what do we mean when we say this happened in the first second after the Big Bang? Do we mean ...
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Are there only a set number of atoms in the whole universe?
As per the title, are there only a set number of atoms in the universe? Or does the universe make more atoms, and if so, how does it work?
I'm a high school student that just had a question during ...
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Understanding The Fluctuations In The CMB Maps
If I'm understanding this correctly the fluctuations in CMB are a result of the "last scatter" of photons when electrons joined together with nuclei that before this formed plasma. CMB is among other ...
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How do we know so many details about Big Bang, but we do not know if Universe is finite/infinite?
I understand that this question may be too vague, but I am confused about the following:
On one hand we know a lot of "details" about Big Bang, like really precise details, evolution of universe, age ...
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If space is negative energy and matter is positive energy then does that mean the universe is finite?
I was reading a book by Stephen Hawking, it was written that universe is made up of 2 ingredients,i.e., space and energy and space was the negative energy, so they add up to 0. But since space is ...
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What does it mean for space to expand?
In this YT video Michelle Thaller says The Big Bang wasn’t an explosion but an expansion and as such there's no empty center where the explosion would've been.
To explain expansion she uses the ...
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Expansion of space or constriction of length scales?
According to wikipedia,
"Technically, neither space nor objects in space move. Instead it is
the metric governing the size and geometry of spacetime itself that
changes in scale. Although ...
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Why do galaxies collide?
If the universe is expanding outward, what is the processes for one galaxy to get off track enough to collide with another?
Say, the Andromeda Galaxy and the Milky Way.
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1answer
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Have we measured or found evidence of a detectable origin point of the big bang? [duplicate]
Based on reading the wiki page of the big bang, a simple question with a probably not a simple answer came to mind.
The statement on the wikipedia page was.
Since Georges Lemaître first noted in ...
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Is it possible for 'pre-big bang' empty space to have the property of being able to spawn matter and/or energy into existence? [closed]
.. and if so, wouldn't this also mean that during this event, time would be created as a collateral, as a canvas for this property to manifest?
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Expansion of space - how do we end up with an unobservable region?
I've just been answering a question on this issue,in physics SE,and realised that my answer conceals a point I don't myself understand.
I understand that
The expansion of metric isn't affected by ...
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1answer
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How much helium has been created since the Big Bang?
When I try to find figures for the amount of helium today and just after the Big Bang, I get similar figures. I was expecting that all of the stars since then would have created more helium. Is the ...
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How did the Big Bang occured if before that there was no time? [duplicate]
I am thinking, that if the Big Bang created time, it implies that before the Big Bang there was no time (correct me if I am wrong).
My question is that, if there was no time before the Big Bang, how ...
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1answer
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How can you verify the theories presented on TV shows like “How the Universe Works” is current and/or valid? [closed]
There are many TV shows such as "How the Universe Works" that explain theories about the origin of the universe such as the Big-Bang Theory.
What resources can I access to verify the scientific ...
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2answers
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How does science knows what is the early universe?
I've read about Hubble seeing the brightest quasar in the early universe. Question is, how does science knows what is early and what is late?
Please correct me if I'm wondering, but after the big ...
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1answer
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Why more matter still left after collision with anti-matter?
Question implies all, why is that? Why we exist even after equally creation of matter and anti-matter, any possible exception?
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Is there a theory about a collision between a shrinking universe and a new expanding universe?
I recently read a post on a discussion board about the creation of our current universe that stated, and I quote:
[T]he shrinkage activity of the old universe and the new Big Bang expansion ...
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2answers
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How could time only have started with the Big Bang?
I understand that before the Big Bang time (as well as dimensions) didn't exist. But how could this be? If there was no time then nothing could change, and so time itself couldn't come into existence.
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Is it possible that the Universe is expanding due to additional Big Bang events?
Is it theoretically possible that the Universe is expanding due to additional Big Bang events that have occurred at the same location that the original Big Bang occurred at?
Perhaps there has been an ...
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1answer
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How thick is the cosmic microwave background, including the part we cannot see within the observable universe?
What I want to know is how thick the observable universe is from the point of the cosmic microwave background and beyond.
It appears the thickness of the cosmic microwave background itself (the part ...
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3answers
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If the Higgs field only formed after the Big Bang, how was hydrogen formed?
These two statements seem to conflict, but since we're here they can't:
Electrically charged particles cannot be massless.
Hydrogen was created at the moment of the Big Bang.
However, the Higgs ...
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3answers
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How did space start?
How did this 'black fabric' that we call space start? How was it made? How was the initial singularity formed? How did the first atom come into existence?
If it all started from a tiny particle that ...
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1answer
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What created the big bang's singularity?
I have heard theories for the big bang like: of another universe existing before the Big Bang, or an unstable white hole that blew up, or our universe detaching from our mother universe, or our ...
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Fundamental axioms in LCDM
What are the axioms (if any) behind the LCDM model of cosmology?
NB: axioms, not postulates (e.g., inflation)
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1answer
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Just after the Big Bang, was the space, in its entirety, filled with Hot gas?
After the Big bang occurred, was the space filled with hot gas totally?
If there's any problem in my question please inform me. Thanks!
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1answer
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calculation of characteristic expansion time of the universe
Hubble's constant is estimated at 15km/s at a distance of million light years, without considering effects of mutual gravity, relativity, etc.
I am trying to calculate the characteristic expansion ...
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1answer
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Location of Big Bang [duplicate]
Can I point to somewhere in the sky where the Big Bang happened? A pathway so to speak on where we (and our progenitor elements) came from?
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Singularity at the time of origins
According to the big Bang Theory, the universe have started from a point and it describes how the universe expanded from a very high-density and high-temperature state.The initial singularity was a ...
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Why Helium could be produced in first minutes of big bang but not heavier elements
At what extent could be sure that no heavier elements than helium could be produced, if we know that matter in universe today is about 25% composed on helium, why could be so sure that the kind of ...
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BIg Bang Happened everywhere
According to the Friedmann equations big bang happened everywhere, but if we account for inflation theory, big bang did not happened everywhere. How ? Anyone please explain. Please see the video for ...
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1answer
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Is it fruitful to search for a correlation between rates of in-falling matter in black holes and the expansion rate of our universe? [duplicate]
To my understanding, white holes are hypothetical objects that are time-reversed black holes; black holes gravitationally "suck in" matter whereas white holes "spit" matter back out. As such, I think ...
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1answer
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How could the universe be a few light years across just 1 second after the big bang?
I was skimming through Neil deGrasse Tyson's book Astrophysics for People in a Hurry when I noticed he says something curious on page 26:
"By now, one second of time has passed [since the big bang]. ...
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Was the whole Universe close to Big Bang very small, or just very dense?
I am sorry this question is probably silly for professional astronomers, of which I am not one.
I often hear at lectures that immediately after the Big Bang, the universe was small, say, the size of ...
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How the observed deuterium abundance constrains big bang nucleosynthesis?
I know deuterium can be used as a good tracer to constrain the big bang nucleosynthesis. But can anyone tell me the in details how this is actually done?
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How does inflation justify the nonexistence of magnetic monopoles?
It is said that inflation justifies that magnetic monopoles don't exist. Can anyone explain how inflation theory explains the non existence of magnetic monopoles?
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What is beyond the observable universe? [closed]
What is beyond the edge of the observable universe? Scientists say that the Big Bang is the cause of all creation in the known universe, but it would seem the bang must have happened in the center of ...
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3answers
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How can the universe be expanding faster than speed of light? [duplicate]
So the story goes like this:
A long time ago, 13.799±0.021 billion years to be exact, something happened. It was a big bang, loud explosion and universe came to existence. It grew and grew, and now ...
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1answer
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Why do we we even exist? [closed]
It came to my mind one day that why does this universe even exist and why do we even exist and like we are enclosed in the so called atmosphere and a floating rock in space called the Earth, so is ...
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Is there a way to know how the magnetic field was at the very beginning of our universe?
I recently read that
Gamma-ray bursts are catastrophic events, related to the explosion of massive stars 50 times the size of our sun. If you ranked all the explosions in the universe based on ...
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1answer
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Was Milky Way formed after Sagittarius A Explosion?
Is it possible that most galaxies (and our galaxy) were formed from leftovers of supernova explosions?
In order to have a black hole 4,000,000 x solar mass the initial mass of the star should have ...
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Why did the big bang produce a low entropy universe?
In order for the universe to be as it is, containing stars and galaxies, it is a requirement that the early universe was at a relatively low entropy state.
Why did the big bang produce this low ...
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Does a White hole lies behind a Black hole?
While reading about a White holes, I stumbled upon a question "Where does the matter emitted by a White hole come from?" There seems to be 2 possible candidates:
It was the matter engulfed by a ...
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How does the earth not continue accelerating? [closed]
I'm not scientist at all so the answer might be obvious but I was pondering about the big bang. I started wondering how is it possible that the earth had to accelerate at some point in history to the ...
