Questions tagged [big-bang]
According to the current cosmological theories, it's the model that explains the early life of the universe, starting from a rapid expansion of hot and dense matter.
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Are any mathematical constants justified, is a universal equation defining them all even possible? [closed]
Alright. I know this is way too philosophical right off the bat. What I can't get around are the mathematical constants, where they came from, and why they are so fine tuned. In "newer" ...
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Is it possible that if the universe collapses, it reaches the same state as in its beginning? [closed]
Suppose the universe were to eventually collapse in a Big Crunch. How closely could the universe's final moments resemble those at the beginning of the universe? Could the universe return to its ...
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Why easiest path from Big Bang to Heat Death is not followed by nature? [closed]
Why after Big Bang it is not going to Heat Death in the easiest path, actually the energy can get distributed uniformly to all directions. Instead we see the energy in Big Bang is being converted to ...
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Has the age of the universe changed in 2023?
I teach high school physics and physical science. I was going through the definitions of theory and law when a couple of my students (of different periods) asked about some recent development that ...
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Are we surrounded by Big Bang? [duplicate]
Maybe the questions is too stupid to be asked or I do not know the technical words, but I could not find any answer to this question.
Here is how I started to think the title:
First I thought of if we ...
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Theoretical: what is the meaning of nothing? [duplicate]
Before the big bang, there was a point surrounded by nothing (no space or anything). Then the big bang happened and the universe expanded. so beyond the universe's limits, there is nothing? I don't ...
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In the future, can advanced telescopes be used to observe different laws of physics at the time of the big bang?
I've heard that because light takes time to travel from one place to another, we see objects in distant galaxies as they were when they released the light. new and advanced telescopes are able to see ...
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Big Crunchs and Event horizons [duplicate]
There are Two different defintions for the event horizon of a black hole.
The Absolute horizon and the Apparent horizon.
An apparent horizon is a surface that is the boundary between light rays that ...
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Does The Big Bang Require An Infinitesimal Point, Or Is Another Shape Possible? [duplicate]
Einstein's Spacetime has four dimensions. If the size of one of these dimensions is zero, then the four-dimensional 'volume' - or whatever the corollary to 3D volume is called in 4D - would be zero.
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How come mass is conserved if the universe is formed from singularity? [duplicate]
If mass is conserved then how come there happened singularity?
since singularity is a point of infinite density and gravity.
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Is the big bang an ongoing process?
Was all the energy that is the universe today, present at that femtosecond theory has pushed back to or was there an influx of energy for a period of time?
My question was: is the big bang like a pin ...
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Event after big bang that cause dark matter [closed]
When the universe was formed by the Big Bang, what was the event that made some matter visible to us, while some became dark matter?
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Cycles of the big bang related to entropy
I recently watched this video about entropy by Veritaserum, and I've been thinking about the consequences of this in relation to the big bang and the most probable final stage of the universe (the ...
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Is this the Format of the Observable Universe?
The way I have it is: the Observable Universe looks as follows. In some ball, all the galaxy clusters exist, then in a bigger concentric ball the dark ages exist (no galaxies), then on the surface of ...
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How did the big bang's low entropy (which comes from gravity) get converted to sunlight?
In many places you will read that just after the big bang, the universe was filled with very hot gas which appeared to be in thermal equilibrium. You will then read that this is actually quite a low ...
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Contradiction b/w Big bang theory and conservation of mass
As per the conservation of mass, matter cannot be created or destroyed.
Doesn't this contradict the big bang theory? Like, it states that it all started from a single point. But seeing the massive ...
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How is Big Bang as a starting point possible?
I have a man-in-the-street question that was probably "predetermined".
If everything around us is co-interacting particles whose source is some infinite small point that started their ...
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What experimental evidence shows that the "explosion" model of the Big Bang with an explosion at a single point of space is wrong?
A popular misconception in the layman public is that the Big Bang was some sort "explosion" at a single point of space, where originally all matter was concentrated and then it "...
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The Big Bang initial state
I saw the excellent answer here:
Did the Big Bang happen at a point?
but I have a hard time imagining the initial state. If the distances between all points in the universe were zero at the Big Bang, ...
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Duration of inflationary epoch
Why is it thought that the inflationary epoch of the universe lasted approximately $10^{-30}$ seconds and why did it take the inflaton (assuming its existence) to release the energy contained itself ...
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Time from big bang to here [duplicate]
New to this so apologies for my ignorance, the simpler the answer the better. Here goes.
Light took 13.5 billion years to get to us from the big bang.
On an imaginary neighboring planet that is much ...
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Analytic expression for a universe without a big bang [duplicate]
I was reading introduction to modern cosmology by Andrew Liddle. On page 56 he shows a graph of the $\Omega_{\Lambda}$, $\Omega_{0}$ plane and there's a region where no big bang is needed, later on ...
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How was the universe once small enough to be subject to quantum mechanical effects?
I have often read that our universe was once small enough to be subjected to quantum mechanical effects, potentially altering how our universe turned out. This is a large theme in Laura Mersini-...
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Do all galaxies in our observable universe have more or less the same age?
What is the current consensus about the age variation of the existing galaxies in our observable universe?
Not to be confused with the age of very distant galaxies as observed today by our telescopes ...
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How can there be a Big Bang without a singularity?
I have read to Sean Carroll that he says that the Big Bang model is correct, but the Big Bang event is incorrect, so what is the difference? And everyone knows that the Big Bang model is linked to ...
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Big Bang and where do we stand relative to it? [duplicate]
Maybe dumb question, not sure, but I would need some help here to understand.
https://theglobestalk.com/james-webb-telescope-see-back-in-time/
So according to physics we can look back in time ...
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No symmetries in the universe at the Big Bang...?
I apologize in advance if this is a stupid question but...
According to some scenarios about the beginning of the universe (namely cosmological inflation), in layman terms, everything was born out of ...
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Matter-antimatter asymmetry during hadronization
When quark gluon plasma is created during heavy ion collisions, the QGP exists extremely briefly before hadronizing--the process where the QGP cools and quarks combine to form colorless hadrons. A ...
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Can the quark-gluon plasma of the very early universe be accurately characterized as a type of quark star?
The very early universe was dense and opaque. During the quark epoch, the entirety of the universe, up to every boundary, was a filled-in ball of QGP. Much like a star is a ball of ionized nuclei that ...
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Were all particles once bosons?
For all matter to have been occupying the same point in space, this would violate the Pauli exclusion principle. Since fermions cannot occupy the same quantum state, the particles that are now ...
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Is there any remote possibility that a singularity may be real? [closed]
Usually, when physicists talk about singularities in Einstein's theory of relativity, they say that these cannot exist and that they are only mathematical artifacts that indicate that is likey that ...
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In the Steinhardt's bouncing cosmology, how would the CMB differ for patches close to pre-existing black holes
In Steinhardt's bouncing cosmology model, during the contraction phase the Hubble radius shrinks to microscopic sizes, although the overall contraction of the universe is much less significant. Each ...
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Why is it surprising that the universe was in an extraordinarily low-entropy state right after the big bang? [duplicate]
So I don't understand why it's surprising that the universe in an extraordinarily low-entropy state right after the big bang?
The way I see it the second law of thermodynamics forbids almost anything ...
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Why is the deuterium bottleneck temperature 0.1 MeV?
During big bang nucleosynthesis (BBN), deuterium has a lower binding energy per nucleon (~1.1 MeV) than the other similar nuclei, and so prevents heavy elements from forming until the temperature ...
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Solving this first-order differential equation for neutron abundance using given data
The time rate of change of neutron abundance $X_n$ is given by
$$\frac{dX_n}{dt} = \lambda - (\lambda + \hat\lambda)X_n$$
where $\lambda$ is neutron production rate per proton and $\hat\lambda$ is ...
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Was Big Bang the "START" of time? [duplicate]
I know that this question has been repeated a lot. But I still don't understand this concept.
Big bang created matter and space but how could it possibly create time?
If Big bang didn't create time ...
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Relic density and cross section
Is it possible that our annihilation cross section and relic density decreases if we add more dark matter particles having same mass the same portal couplings in the model ? if yes, what is the ...
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Is the big bang (BB) correctly summarized as a sequence of symmetry-breaking events? [closed]
Please take this as a serious question from a curious yet deeply underinformed lover of this universe. This is more of a basic question concerning the overall mechanics of the transition stages from ...
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Did time have a beginning? [duplicate]
Did time have a beginning in the current scientific consensus? Or has it existed forever?
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Why is Big Bang so misunderstood?
I was reading this answer where it's explained that the Big Bang is not a theory but a model and that it doesn't say anything about the origins of the Universe.
I was taught in school instead that ...
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If dark matter was created in the early universe and its formation released energy, is there any evidence of that energy in the cmb?
When atomic nuclei fuse, energy is released. Is there anything about the CMB energy distribution that suggests that dark matter could have formed from other particles that released energy?
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The common explanation to what happens before the Big Bang is wrong? [closed]
When you ask a physicist what happens before the big bang, they will say - the question does not make sense cause there was no time, hence no "before" etc. And that Time appeared with the ...
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Why didnt early universe collapse into black hole? [duplicate]
Given the early universe was infinitely small, why didnt it immediately collapse into a blackhole before it had time to expand?
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Why can't we run the laws of physics backwards and forwards in time infinitely?
So assuming we know all the laws of physics in differential equation form, and I have an estimate for the current large scale state of the universe (whatever standard assumptions/data cosmologists use ...
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LCDM epoch or point where it fails
Nobody denies the currently success of the LCDM of cosmology. Recently, I wondered myself if there is a point or epoch (beyond the space-time singularity) where it breaks down. Does it fail at phase ...
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Is anti-desitter cosmology internally consistent?
In the string landscape all known vacua that have been found have been anti-desitter (negative cosmological constant).
Is there any cosmological or physical principle that may rule out anti-desitter ...
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What happened to particles with less energy than their rest mass?
Today, particles like electrons can only be created if there is enough energy that exceed their corresponding rest-mass energy. As far as i understand, all particles were massless before the higgs ...
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When was the Higg's particle created after the Big Bang?
Was the Higg's particle created with the Bag Bang?
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What were the first particles, according to different models?
At what point, and in what cosmological epoch, did particles begin to exist? What particles were they?
My understanding is that things as we know them involved the Big Bang singularity, and that the ...
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Can we infer the size of the whole universe from its expansion rate? [closed]
If the universe inflated to 100 billion km in its first second, that suggests only 1/160,000 of it was observable from any point at that moment. The expansion rate slowed after that, of course, but ...
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