Big bang Definition and 916 Threads

Hello everyone, My question is: The big bang model proposes that the rate at which the universe is expanding is now decelerating. The inflationary theory proposes that the speed of expansion and separation started out slow and now it is accelerating. But as we know, recently it has been found...

Dear Sir, Going through the books at Cosmology written by Mr. Matt Roots, Brife History of time by Sir, S. Hawkins and first three minutes by Mr. Steven Weinbergs. The Event Place of BIG BANG ( the location of Big Bang) is not mentioned. Suppose in universe at Poit "A" the Big Bang...

Hi there. I'm having a hard time understanding the precise meaning of the so called "cosmological principle": My understanding of the general Big-Bang model is that far enough back in time the observable universe came down to something very small (compared to now), very dense, very hot... Ok, i...

Dear PF Forum, I have read a link about big bang time line. Started from time zero, then Baryogenesis, lepto genesis, Planck time then on... http://www.physicsoftheuniverse.com/topics_bigbang_timeline.html I try to make a simple calculation here with Schwarzschild calculator. The mass of the...

Hello everyone, Questions keep on rushing through my mind. If we can see light from 300,000 years after the big bang (THE OLDEST LIGHT EVER) then why can't we see beyond our cosmic horizon? We are seeing the oldest light ever... then why do we have a cosmic horizon?

I have very little understanding of the Big Bang, but it seems like it would require a finite universe even though there seems to be a scientific consensus that an infinite universe is a strong possibility. How are these ideas compatible? If space started expanding from a small point at a finite...

Following on from this thread. If the universe is infinite and was at the time of the big bang does that not mean that the size and contents was infinite? In other words at the BB there was already infinite amount of galaxies. I had understood that at, or just after, the BB the mass of the...

In this documentary they discussed some research experiments which concluded that the universe is infinite. I didn't really understand it. Can someone explain how we know that the universe is infinite? Wouldn't this also mean that the universe was infinite at the big bang?

Predicted Heat Death of the Universe In his thought provoking documentary “Wonder of the universe” ( ) Professor Brian Cox explains the thinking behind current predictions for the “Heat death of the universe”. He explains the predictions through the effect of the second law of thermodynamics...

I know that likening Black Holes to the Big Bang is common among laymen and that scientifically educated people quickly reply that they are completely different things. But I would like to understand better in which aspects are they similar and in which they are different. If we run the...

If I understand what the BB Theory proposes, all the universe was originally confined to the size of something very small, like a dot or an atom. This small dot or atom or whatever was said to explode, although some say there was no explosion in the sense of a bomb going off, but would be more...

I am trying to understand some things but I seem to be confused a little... I was watching a video and it said when you look with hubbles telescope you see the past universe but I seem to have trouble understanding this, does that mean we could see the future if we knew which direction to point...

I am by no means familiar with anything in quantum physics, so bear with me. This recent experiment that proved that future events can affect the past for an atom got me thinking, does that mean that, the timeline of atoms is the opposite of ours, and that the end of time for them is what we...

When we talk about the BB occurring 13.8Billion years ago (see time chart below) http://en.wikipedia.org/wiki/Big_Bang#/media/File:History_of_the_Universe.svg Does a 1ns of interval time at each of those points in time mean the same thing as a 1ns interval of time now, or is the measurement of...

Hi All, Is the Angular momentum conserved at the singularity ? Thanks in advance

Hi. From what I've read about the "observer effect" in the two slit experiment, the electron's wave function collapses due to photons altering its momentum. Now, in the beginning of the universe photons couldn't escape the original Big Bang fog until it cleared out, so these should have...

As the question says. Sorry if it seems like a dum question!

Can we be sure about there was nothing before big bang?

Dear forum, Can someone tell me what WAS the temperature of the Big Bang in time zero? Before Planck epoch I think. Or the question is not relevant because there were no four forces then, like asking what is the "north" of the North Pole. Thanks for your attention.

If the universe had stayed the size of a baseball, would it have taken light 13.5 billion years to travel across it?

I know that you can measure redshift from stars by looking at the shift in there balmer lines or more generally there line absorption spectra and seeing how far these lines have shifted from actual balmer lines or line absorption spectra of the same elements on earth. But how would you...

I am trying to wrap my brain around the evidence for accelerating expansion of the universe from type 1a supernovae. From what I understand, it was first realized that the universe was expanding at an increasing rate from discrepancies between the calculated distances to type 1a supernovae using...

hello guys, i just want to know if space had been there before the big bang, or is it a property of the big bang :)

Penrose wrote in the Road to Reality that gravitational clumping increases the entropy of the universe. The early universe was very low in entropy because it was very smooth, with very little clumping. So, is it accurate to say that the early universe was high in entropy except for the...

If the Big Bang created space time, what did the singularity of the Big Bang "rest" on?

Could it be possible that space-time might have existed before the big bang, but separately? And that "time" somehow collided with "space", and then merged together into space-time, and in the process created energy as a bi-product? Or how about if "time" collided with "space" like above...

Question TO: Physics Forums – March 17, 2015 Various sources I have read talk about the big bang origin as a point singularity. Here is one example:

So I was reading threads and i came across a question on what happens when a black hole collapses. As I was reading the responses, I saw some people commenting in which they asked if the mass the black hole absorbed was released when the black hole collapsed. If it did would the black hole...

I just read an article saying that scientists disproved The Big Bang Theory. Is this true? and please run me through the whole "big bang theory" in brief as I'm no expert but just a school student.

hey guys, my question about the big bang is this.. we have all this matter "out there" and "maybe" we had a " big bang". now can anyone answer.. where did the " nothingness " or the "emptiness" that the "big bang" expanded out into..or . how was emptiness made or come to be. without the...

I am not sure where to find people who may understand the following paper but I figured someone here might be interested and or educated enough to weigh in on this subject. I tried with my local astronomical society and haven't heard anything back from them. This idea is interesting to me but I...

http://www.iflscience.com/physics/quantum-equations-dispute-big-bang Should we be taking this seriously or not? Thoughts?

If the energy or matter can't be created nor destroyed but can only be converted from one form to another, does it mean everything including us, used to be stardust or chemicals or whatever that existed right after the big bang? Is everything that we use now, are made from the stuff that...

Did space time be created at the Big Bang, if it did, then theoretically, gravity would not be a fundamental force associated with the Big Bang and any events before the Big Bang would be undefined?

It seems as though that according to conservation of energy, there could never have been a point in the timeline of the universe where nothingness existed. It seems to me that the claim that there was nothingness before the big bang would violate these laws. For example if E is the total energy...

What Fundamental force is most associated with the creation of the Big Bang? I never see one mentioned. Is it considered a possibly still un-named new force? Or is the theory still undeveloped to the extent that we have an effect without cause? Wes ...

It is said, that in the beginning the universe was a singularity and then it exploded. A picoseconds or so after the explosion it was a fiery ball trillions of degrees in temperature and containing pure radiation. as it expanded it cooled down until quarks and then barons and other particles...

I was listening to Brian Cox on Intelligence Squared and he somewhat casually mentioned the general acceptance among physicists of a possibly "infinitely long" period of cold inflation predating the big bang and of the "sudden" stop to this inflation as the source of energy for the big bang...

Personally I like Cyclic model, what do you think is the most interesting, and which do you think is the most likely.Title is meant to say universe As phinds has said the 'creation' of the universe is the wrong word, therefore I would like to replace it with the word 'beginning'

As i read when the big Bang happened,it was in a hot dense state for the first million years. Then the gases started to collect together and cool down,to form stars. (Sorry if i`m being wrong). So when did and how did the first ray of visible light came into existence?

Hi, I have a simple question that will probably have a simple answer. If the Big Bang was a finite event (i.e. took place over a certain amount of time) why is it that the background radiation from it as sensed on Earth (TV static) is continuous? Will it continue to be continuous forever? How...

Just a quick question. How big was the current observable universe at the point in time where we reach 'singularity conditions' in the early universe? I'm assuming it can't be a single point, as there is no way that I know of to make a zero-dimensional point into a 3-dimensional object or space.

How massive would the neutrinos have to be so that relic neutrino from the big bang would account for all dark matter?

People say that Multiverse doesn't exist, But as per #TheGrandDesign by Stephen Hawking, Quantum Fluctuations led to the creation of tiny universes out of nothing. A few of these reached a critical size, then expand in an inflationary manner, formed galaxies, stars and, in at least one case...

I'm having some trouble understand this correctly, so I was hoping someone could enlighten me a bit :) Okay, so in the early Universe most of the hydrogen and helium was formed, and then kept in equilibrium, and ionized via photons. So we have a plasma of baryonic matter, including dark matter...

If the universe was created by the Big Bang, then how did Multiverse come into existence?

It would be most helpful and beneficial to the world of Physics if everybody would stop calling the Big Bang, the big bang. It is very misleading to the lay man (myself) and it does not do anything to promote the understanding of the universe. The very word suggests that something went "Bang"...

I was watching the news the other day and saw an article about scientist rethinking on the big bang. The article stated that some scientist believe that there had be something else that occurred for everything to evolve as far as it has in the amount of time since the so called big bang. Can...

Hi My question is about absence of equal antimatter in our universe: If charge and energy is conserved, then this means there was matter before big bang that crunched and created more particles. The charge before and after big bang is conserved; just when two protons are accelerated toward each...

Can someone explain the disappearance of 57% of dark matter since the Big Bang? Is dark energy eating dark matter?