Big bang Definition and 916 Threads

I was under the impression that originally the main impetus for inflationary Big Bang was that the original Big Bang model implied a finely tuned Universe, or highly unlikely starting conditions for the Universe. In other words, the flatness and horizon problems, etc., don't necessarily...

Hi, The theory about big ban says that there were high temp. and high pressure. But pressure=force/surface I want to ask about the the force. Force of what? Is it the force of gravity? And is the surface for the atoms? Thanks.

Can someone answer this for me please: is it possible to work out how much time has elapsed for a theoretical (and for argument's sake, mass-less) observer at the centre of the big bang whose speed of time then subsequently remained constant (rather than massively speeding up with the rest of...

Hello all . Why mater victory to anti/matter after big bang ? There is any relation to gravity ?

Homework Statement Show that by using the Friedmann-equation you can determine the scale factor for a Universe in it's early stages (starting with the Big Bang) to: Homework Equations The equation for the scale factor: Where r(t) is the distance from us to a given galaxy to the time t...

So I read everywhere that everything was packed into an infinitely small space at the big bang. But then after some thousands of years the universe condensed enough to let electromagnetic waves travel through and these waves have been traveling 13.7 billion years to get here. The problem here...

I am a bit confused about big bang. Is the big bang referred to as the expansion of universe from singularity or not. Sorry if i have posted it in wrong section

Can we measure the distance between the first particle to enter the Bang event field and the last particle to enter? What would this distance indicate?

I hope this makes sense. When the bang event occurred and pushed everything outwards, shouldn't a space/field start developing between the bang event and the matter/gases being pushed outward? What would you call this field? Could there still be something left behind in this field?

I came across this argument in the book The Nature of Space and Time, which is based on a series of lectures given by Hawking and Penrose. Although it relates to Penrose's Weyl curvature hypothesis (WCH), it does not depend on it, and that, to me, makes it a lot more interesting, since I...

How do we know how hot the big bang was, is there some way to extrapolate back from the CMB, if there is i would like to know how such accuracy was achieved. Thanks.

How long did the big bang last (initially)? How far did everything travel in that time? I was under the impression that it all happened in a fraction of a second and some things went many light years. If I'm right, how is that possible? (Traveling faster than the speed of light). If I'm wrong...

Hi, Firstly, I want to thank all those knowledgeable people here that offer their input so freely. I have found it very enlightening and educational. I apologise in advance if the following is quite long but there are a couple of cosmic rules that I can't quite grasp so I will try to articulate...

Can anyone explain to me in easy terms a couple of things? 1- five minutes prior to the big bang, what was there? 2- did matter exist before the big bang? 3- if no matter existed prior to the big bang, what was there?

I hope I'm not being redundant here. I would like to re-start discussion on how, according to quantum mechanics, the universe can exist. The question could go deeper and ask why, since the universe does in fact exist, did it become so complex, develop life on at least one planet, etc. How did...

Some time ago there was a thread which suggested that there was a logic / papers that demonstrated why the the CMBR could not be the result of ligh from background objects / galaxies. Unfortunately, I have not been able to locate the thread or associated material. Is this correct, and could...

I hope I will be welcome here. Please keep in mind that I have a very limited and novice understand of science and maths. I guess you could say I'm here to understand the big bang and how it can be plausible for our universe to exist the way it does. Several years ago I saw this production...

Because the universe started as a point of almost infinite density, wouldn't that mean that every particle in the universe interacted with one another while in that state, crammed together, thereby causing all the particles in the universe to be entangled, including those particles that created...

After the big bang ,how long did it take for atoms to be formed? how long did it take for the elementary/fundamental particles to come together and form atoms?did atoms formed instantly after the big bang? first atoms were hydrogen right?

Perhaps I misunderstand the big bang theory but doesn't it basically hold that nothing existed prior to the big bang? If there truly was no energy or mass prior to the big bang then doesn't that conflict with the law of conservation of mass and energy?

I like this idea guys: http://www.foxnews.com/scitech/2012/08/22/big-bang-was-actually-phase-change/?intcmp=features It just makes sense to me since so much of Nature involves phase-changes. What do you guys think? Is this consistent with the current work in LQG?

Is the Earth moving away from the moon (however tiny amount it may be) due to expansion of the universe? Or is Hubble's law applicable to only to gravitationally-UNbound object?

I was wondering, if the gravitational pull due to dark matter is greater and at some point the universe stops expanding and starts contracting(Big Crunch)..from galaxies to stars,from stars to planets,molecules,atoms etc.and it reaches the minimum length scale Plank (according to ST) to one...

Hi As I understand it there are several attmepts to explain the low entropy configuration of the universe at the big bang. Is seems to me the choices on the table that I am aware of are a mutliverse as in the Caroll/Chen model . A cyclic universe as in the CCC model or some hybrid of the two...

How old was the universe when the first wave function collapsed? Just wondering. I've checked all the FAQs on this, and the one hit in Google doesn't really cover it from a cosmological angle. I see there is a "Participatory Anthropic Principle" but my question is really more about, well, how...

After reading a few chapters of an astrophysics/ cosmology book, I took some time to think about the big bang and what existed before it. After thinking, I thought, "What if the big bang wasn't the beginning of existence? What if it were a just a big event that happened over the course of the...

The answer is 'everywhere and nowhere'. First of all, remember that our entire foundation is the cosmological principle, telling us that no point in the Universe is special. If there were a particular point where the 'Bang' happened, that would clearly be a special point and violate the...

Anytime I ask this question it is met with people who angrily argue that there is nothing outside our universe. What proof is there that time started at the moment of the big bang and that there is nothing that our universe is expanding into.. The universe expanding faster and faster...

I apologize if this is a "stupid" question, but I have been trying to find information on this for weeks and it has been to no avail thus far. I know that there are two theories in regards to what came "before" the singularity; the cyclic universe and the "universe came from a vacuum...

I understand what inflation is, but what are the reasons behind why scientists are near definitive that it indeed happened? Please go as in depth, complex, or over the top as you need/want.

i know that they are trying to recreate the higgs boson at CERN LHC, but talking about when the big bang happened, how was the higgs field suppose to happen?

Maybe this question is already asked, but how did the first proton came into existence? A soup of quarks cooling down?At which temperature? How late was it on the clock? What was the size was the universe? How long did this proton lived? Did this proton had an impuls,energy,entropy?

The matter/energy was not evenly distributed after the big bang is this correct? I like to think of the big bang as all matter/energy in a perfect sphere that explodes out perfect and symetrical, but the evidence proves otherwise I guess? Other branes pulling perhaps on our universe altered the...

can we calculate the orgin of the big bang based on the wmap and drift of galaxies?

Michio Kaku (see link) says that the Higgs Boson is the reason for the Big Bang. Is that true? I am not initiated enough in cosmology to know if I believe that a Higgs Boson triggered the Big Bang. Thanks...

Hello. Cosmologists leave open the possibility that the universe as a whole may be infinitely big. My question is, does that mean that the entire infinite universe was compressed into the initial singularity? And how can a universe go from a singularity to being infinitely big in a finite time?

I was watching a video on Youtube about the Big Bang, and they said something that I did not understand. They said light from the big bang can still be seen from the Earth in the form of microwaves. I understand, however, that nothing travels faster than light. So how did our Earth come to its...

I attended a theistic high school and did not receive much of an education on the big bang theory. My question is was there any sort of matter or energy at the start of the big bang, and if so where do scientist hypothesize its origin?

Do the GR tensor equations have specific solutions that post-dict the big bang? I have seen references to GR providing a theoretical basis for the big bang. Exactly what is the nature of this theoretical basis? If the mathematics for this is too complex for posting on this forum, I would...

Hi, I've bought PW recently and began reading it just yesterday. I have felt some doubts while reading it, since I haven't had any physics since I left high school and that has been a long time ago. Also, all this astrophysics always a tad mind-boggling to me. So far I have 2 sets of questions...

This is several questions crammed together because they overlap in my mind. Thanks! Is the Higgs Field something that occupies the complete void of space, or is it thought to be a property of space itself? Was the Higgs Field caught up in the mass of the pre-big bang singularity, or would...

I meant which frames distance divided by which frames time gives the velocity of frame 2 wrt frame 1..I guess the 'v' measured from rest frame is different from v measured from other frame right(concerning time dilution since time always dilutes in frame 2 only).? Btw do u think their is a...

Hi, I'm sorry if this question has been answered before, but I was wondering whether anyone had seen the '30 Problems with the Big Bang article? I'm not a physics student, but I've a keen interest in it, and the Big Bang has always been a particular point of fascination for me and this paper...

This comes from Paul Davies the Cosmic Jackpot He says that as "space expands the number of particles contained within a volume of space bounded by the horizon is therefore going up year by year as the horizon expands to encompass more and more matter." I thought that number of 10^80...

Question: as title says. I'm not a physicist at all and I do not know much about how people obtained the big bang theory from red shift. So here is what I thought from red shift: In a time period t1, a distant body emits a light wave with a certain amount of energy with n oscilations(I don't...

I am not sure if this belongs in General Relativity or Quantum Theory or just General -but here goes. First , I have to say that I do assume Space-Time to be quantized (since anything else seems too difficult!) and this is my question. I have often read that physicists have peered back...

Has anyone thought about the big bang and dark energy like this? Dark energy is simply empty space which has the opposite affect of gravity. Put simply, stuff is attractive. No stuff is repulsive. Or, gravity is to mass as repulsion is to empty space. I think that the bigbang had...

Good evening. I am wondering if energy has always been quantized. I read that the shortest time after the Big Bang (the time it took for gravity to separate first) was 10^-43 seconds. At these moments of earliest symmetry breaking, was energy already discrete, or did quantum mechanics emerge...

If the universe is finite, what would its total volume have been at t = 1 s?

Let us suppose that there is no largest space or no smallest space as it relates to the universe. If this were the case it would be impossible for you to determine which direction the universe was heading.You would always see an infinite amount of space ahead of you and the space between...