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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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Did inflation stop because of energy density drop or some other reason?

If I am understanding big bang correctly... During big bang Approximately $10^{−37}$ seconds into the expansion, a phase transition caused a cosmic inflation, Which was 'free lunch' of energy ...
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(Physics newbie)Expansion and the big bang [duplicate]

I recently had an answer to one of my questions where i was told that the "Expansion of space" is basically as far as light has moved to date. Does that mean that there is a possibility that multiple ...
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(Physics Newbie) Reaching the edge of the expanding universe

Say you have a space ship so fast that it was able to instantly reach the edge of the expanding universe. and you decided to try and drive straight into that edge, would you : Ram into something ...
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What did the big bang “look like”? [closed]

I've been reading here for a while now and something I always see is people saying "the big bang happened everywhere" or "the center of the universe is where you are", explaning that the big bang didn'...
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“Before” the Big Bang was the Universe really compressed into a mathematical point? [duplicate]

A couple of weeks ago a teacher of mine (I'm taking mathematics) was giving a final inspiring lecture about how fundamental Math is to every possible universe. During the lecture though, he said that ...
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Why did the big bang happen? [duplicate]

Why did the big bang burst and not collapse under its own gravity like a black hole? And also why does the singularity a the center of the black hole does not burst?
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Why not the big crunch? [duplicate]

Entropy As per the second law of thermodynamics "Order tends to disorder" And recently I watched a video series by minute physics 3:25 The Big Picture: Entropy & Time (feat. Sean Carroll)S1 • E1 ...
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Creating two universes at the event horizon of a black hole

Using the uncertainty principle involving time and energy, is it possible a universe and anti-matter universe be formed at the event horizon of a supermassive black-hole? If so, could one the anti-...
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Age of the universe $ \equiv 1/H$?

How can the age of the universe be calculated as $1/H$, with $H$ the Hubble constant, when its expansion has been far from linear? The $1/H$ comes from Hubble’s law, and implies that the universe ...
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What evidence do we have that CMB is the result of the Big bang?

I got the main picture repeated over and over again about why if there's a Big bang we indeed should see the CMB with this feature. In this question I'm asking something different: what independent ...
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How can the universe be homogeneous and isotropic while it has started with a big bang? [duplicate]

We assume the universe has been shaped by a explosion "Big Bang" but from what I understand explosions make the environment "not" homogeneous and "not" isotropic. If that's right how can we assume the ...
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Could matter and antimatter have drifted away early after Big Bang?

Early after Big Bang, could small parts of matter and antimatter have drifted away in opposite directions and thus still be able to maintain anti/matter balance, but keep local isolated pockets that ...
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Big Bang expansion [duplicate]

Did the big bang expand in all directions? If so are there galaxies 13.7 billion LY on the other side of the Big Bang? Does the universe go out beyond us on the side away from the Big Bang for ...
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What determined the amount of energy and matter in big bang

I have been somewhat of a fan of astronomy and cosmology, but I am not trained physicist. So please correct me kindly in case I have stumbled with some terminology. The causes of big bang are ...
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On the beginning of energy-dependent time

In this episode of through the wormhole with Morgan Freeman which is titled," when did time begin?", , an Italian physicist makes the following comment about time(not verbatim but it's the point he ...
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Is Einstein's theory really challenged by the recent paper in news?

A recent paper authored by Niayesh Afshordi and Joao Magueijo is in the news claiming to challenge Einstein's theory on constancy of light speed. It says light might have travelled with a faster pace ...
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What evidence is there that The Big Bang was not just a local phenomenon?

This post is the second in a series of posts that met (decreasingly) with some contention from the physics community, do to my status as a pure mathematician at the very beginning of trying to discuss ...
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Why all that mass didnt collapsed in on itself at the begining of 'big bang'(whatever it was)?

Im not a physicist,but i love physics.I cant find an answer for this questions easily as an amateur. If the big bang happened by itself in nothingness,why it doesnt happen in our space-time again and ...
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How many Planck times would there be from the Big Bang to the Big Rip?

How many Planck times would there be from the Big Bang to the Big Rip? (approx.) Does this number have any numerical significance to mathematics? If you had a CPU clock which had a timer counting ...
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1answer
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Matter and antimatter ratio

My question is about the creation of the Universe. The current theory I know is that matter is the debris left after matter/antimatter annihilation at the dawn of the Universe. The question is, wouldn'...
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Classical Inflation Theory and the pre-existence of space-time

The most accepted theory about the beginning of the universe is the classical inflationary big bang theory. It states that the universe emerged out of a vacuum fluctuation and that space-time itself ...
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In the early universe, could there have been “atoms” made of W bosons?

I'm wondering if there ever could have been a time in our universe's history during which the charged W bosons could have combined to form a kind of short-lived "atom". For example, we know that ...
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If the universe turns out to be infinite, would we have to reject the Big Bang Theory? [duplicate]

As per my understanding of the big bang theory, it stipulates that the entire universe was contained in this single point of "pure energy" and that the big bang happened when the universe rapidly ...
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Is it possible that big bang are still happening?

I was reading on this site about big bangs, and it got me wondering, about two things. There’s no exact spot that the Big Bang happened. In fact, the Big Bang happened everywhere in the Universe. ...
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Are there any counter proofs against everything being entangled before and after the Big Bang?

If particles are emitted simultaneously (or quasi-simultaneously) by the same entity then they are entangled. Also I refer to entanglement not only to maximally entangled states but more essentially ...
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What are the evidences of the big bang theory? [duplicate]

We can say about a mention is scientific if we can analyze and repeat that mentioned process. Our theory of the origin of the world is the big bang theory, which say that there was the absolutely ...
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Are White Holes the inside of Black Holes?

I read about a theory that says that The Big Bang could be actually considered a White Hole. Than I started thinking. White Hole: an unreachable region from which stuff can come out. Black Hole: a ...
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Photons at the big bang

Did photons exist at the singularity of the Big Bang? If they did not, then does that mean that it is impossible to see what happened at the big bang?
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Is BAO a standing or moving wave?

The sound horizon is the distance that a wave of plasma can move from the end of Inflation to Recombination (roughly 300,000 years). In several papers and talks, this is described as a moving wave (...
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1answer
226 views

Is it possible to say we are inside a black hole? [closed]

Why I am asking is because I read about it on the internet. But if that is true, does it imply the following? If one is inside a black hole than he could be seen as trapped in a space-time ...
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1answer
385 views

How can I monitor background radiation from the universe with a reasonable accuracy?

Physics newbie here investigating for a potential art project. As I understand, radio and TV static contain approximately 1%, is there a way or a device I can buy/build that will increase the amount ...
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Where does the matter and energy go in a black hole?

Is it possible that when matter and energy enter the singularity inside a black hole, that it all re-appears at the big bang? Some say that black holes will eventually swallow all the matter in the ...
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Where are all the Population III galaxies?

We can now see back to 400 million years after the Big Bang. Yet we still haven't seen any Population III galaxies. Why is this? How do metal-rich galaxies evolve in just 400 million years?
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Why doesn't Dark Matter participate in BBN reactions?

This is a slightly different variation on an earlier question: In the very early universe, the hot plasma consisted of fixed amount of radiation (photons and neutrinos) and matter (electrons, protons,...
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Jim Al-Khalili's comment on White Holes

In 2014, I attended a talk by broadcaster and physics professor Jim Al-Khalili. During the question time, someone asked him about white holes. He responded with something like: "A black hole sucks ...
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Time at the big-bang

At the moment of the big-bang there were no particles with positive rest mass. What is the meaning to aspeak of time then (as a clock can be created only with particles with mass).
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If the Big Bang started in a state of low entropy then shouldn't the Big Crunch be in a state of low entropy also?

I recently read that: What our current level of thermodynamics does tell us though is that if there is such a thing as a Big Crunch, the universe will look a lot different as it heads towards ...
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Question on Big bang

Why was it necessary to think of the existence of a singularity during the big bang? As per the current theory, during the big bang, the universe had an infinitesimally small radius, and just after ...
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Particle horizon with dark or phantom energy : $-1 < w < -\frac{1}{3}$, and $w < -1$

Consider a flat universe with curvature parameter $k = 0$ (for simplicity), with a dark fluid only, of state parameter $-1 < w < -\frac{1}{3}$ (lets call this "dark energy"), OR $w < -1$ ("...
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What is the hypersurface that represents the particles horizon?

I need to clarify a detail about the particles horizon (also called the causality horizon, not to be confused with the event horizon). For simplicity, consider an euclidian static universe, with a ...
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How early did primordial oxygen form?

It has been suggested liquid water could exist 10-17 million years after the Big Bang, warmed by the CMB instead of stars. Would Big Bang nucleosynthesis produce oxygen that soon? (Empirically, the ...
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How close can we get to duplicate the conditions of big bang?

The particle accelerator has attempted to smash gold nucleus together to reproduce the moment of or after big bang, how close can we go and how to verify if that result is not a fluke? Can we create a ...
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Is there any credible evidence for big bang? [duplicate]

The big bang model is first discussed when the people witnesses that almost every galaxies are speeding away from each other suggesting that at one point in time or more accurately at $t=0$ everything ...
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Have we found Absolute Time with Big Bang?

Since we found $T_0$, the origin of the line/ the absolute zero of ..Time with the Big Bang, can we consider that the absolute time, the same as we do with absolute temperature?
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Is the observable universe an absolute? [closed]

A short summary of a question difficult to easily describe: Assume objects from the begining of the universe are at a fixed distance at T equals 0 when the universe is created. These objects become ...
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How widely accepted/supported is inflation theory? [duplicate]

To the less well acquainted, inflation theory seems like a rather far fetched proposal. It makes very specific claims about the earliest moments of the universe, without being explainable in terms of ...
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question about other dimensions

The Big Bounce theory says that before the Big Bang there were other Big Bangs over and over. For example, the universe would have a Big Bang within it and then this new mini-universe would expand, ...
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How did the big bang create space and time? [duplicate]

Does the big bang theory state that space and time originated after the bang? So, was the singularity was converted into the vast space plus time?
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How can the universe expand if there is gravitation?

We live in an expanding universe - so I'm told. But how can that be possible? Everything imaginable is attracted by a bigger thing. So, why can't gravitation stop the expansion of the universe? I know ...
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Did quantum fluctuations create matter and energy out of nothing?

I found a popular science article explaining that the existence of the Higgs particle can be interpreted to mean that matter and energy are created by quantum fluctuations of nothingness (i.e. the ...