Big bang Definition and 910 Threads

Homework Statement the relative concentration by mass of helium at 3 minutes after the big bang is 2-5 parts per 100,000. If you had 1 kilogram of the normal matter from the universe at a time 3 minutes after the big bang, how much of it would be normal helium nuclei? Homework EquationsThe...

I've never been able to visualize the big bang and my hubris is now leading me to believe it must be impossible. A line in "A Universe from Nothing" talks about how if you look far enough away, since you're looking into the past, you could theoretically see the big bang. I get that; I just can't...

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 (see https://www.youtube.com/watch?v=JSqIBRbQmb0 at the 23 minute mark). The velocity of the wave...

If it is not know what happened in the first fraction of a second after the big bang, how is it know that it was really only a fraction of a second?

Hey guys, It is widely publicized that space and time originated during the Big Bang, but what exactly surrounds this lone hot and dense singularity? Space is the background of something, so I think void (which is just empty space) is already there even "before" the Big Bang event started...

The value for the red-shift of the CMB is 1090 according to the latest Plank study. How do they arrive at this number? You can look at how hydrogen lines of supernovae light are shifted, but how do you tell how far light is shifted when looking at the light from a primordial soup? Is there...

How do quantum fluctuations become gravity wells? I thought the whole idea of the fluctuation was that it had to happen so quickly that the universe didn't notice. I see how a field could have a random, but non-zero value, but I don't see how that momentary variation in the field can stick...

The theory of cosmology assumes that the universe has been created from a single point by one big bang event. This theory implies processes which exceed the speed of light. <<Mentor note: This post has been edited to remove some content.>>

We all know that the temperature of the back ground radiation is 3k, but how have we calculated the intiial temperature of the big bang.

Hi I hope this is the right place for this questions, I started to think about this several years ago but had has a hard time finding anyone that's been interested in discussing this. As far as I understand time travel is not ruled out by modern physics at least if you limit yourself to go into...

I discovered this interesting series of videos that others might appreciate. Includes interviews with Alan Guth, Roger Penrose and loads of other interesting people. Definitely not pop-sci and fairly up to date. Episode 1 is a bit low quality with unnecessary subtitles, but it gets better as it...

Hi all:smile: I have a question If now we can see objects from 13 billion years ago, what we'll see if the light will come to us more than 13 billion years, can we see what was before the Big Bang? Is that possible?

How does the universe's expansion relate to Newton's 1st law. In other words, is all the expansion due to an unknown cause at the big bang and the 4 forces now act on it? Or maybe is the expansion not really due to a force (as is gravity) so the 1st law doesn't apply?

In the big bang model the singularity is all ways quoted as being the start of the universe, but AFAIK scientists do not accept the singularity as real, the same with the black hole singularity, what is proposed to be in their place? from Wiki. The initial singularity was the gravitational...

I have these questions: 1) Why must light always move along a geodesic line? What is the principle behind that? 2) A second question about spacetime: We mostly depict or imagine spacetime as a net of flexible fiber that extends everywhere as a plane as we see it.. As we are looking it, what...

The following article is interesting to me, however particle physics is not one of my strong points, could anyone comment on it and its implications regarding the early universe? Thanks. http://www.bbc.com/news/science-environment-36776167

A light particle solution to the cosmic lithium problem Andreas Goudelis, Maxim Pospelov, Josef Pradler (Submitted on 29 Oct 2015 (v1), last revised 24 May 2016 (this version, v2)) We point out that the cosmological abundance of 7Li can be reduced down to observed values if during its formation...

Do professionals use the term universe to mean what was created in the big bang?

Hello everyone, I've come across a problem that i can't solve but which i find really interesting. I'm not here to ask where the big bang was because I've already read enough about that is was a singularity, so you could say that is was everywhere. But here my problem comes in, if the big bang...

Hi, As I know we now think that time translation is not a symmetry of spacetime because of the Big Bang, so we cannot say that our physical laws are applicable at every point in time. But then isn't the developing of the Big Bang theory against this asymmetry?

Homework Statement Two scientists detected the cosmic microwave background radiation at a frequency of 160 GHz. What is the temperature of the universe? Homework Equations peak wavelength x temperature = 2.898 x 10^-3 c = f x wavelength The Attempt at a Solution I calculated the wavelength of...

When I read that conditions were such and such 1 to .05 seconds after the big bang, is that duration somehow longer than 1/2 second is now (maybe because of the difference in density or like the twin paradox?)?

multiple_authors submitted a new PF Insights post Where Did the Big Bang Happen? Continue reading the Original PF Insights Post.

Was the beginning of the univeres's Big Bang, a one dimensional construct which then formed into a two dimensional form and later, our three dimensions with time?

Hello! I watched a video on the Youtube channel Kurzgesagt titled How far can we go? Limits of humanity The video attempts to explain why we may be limited to our local galaxy group even with science fiction technologies. During a part of the video (starting at 2:26), they try to explain how...

I have been reading that until the universe was one Planck time old (10-43 seconds) all the forces were unified into one. Do we know why would they be unified? Is it very large temperatures and pressures? Could we replicate it in the labs one day? Today Electric and Magnetic force are unified...

A recent discussion at the Expanding from and eventually to a singularity thread has been both interesting and informative, and it has shown me very clearly that I would benefit from a few good books, rather than the piecemeal approach I've been taking to understanding singularities and the Big...

Just watched the documentary 'Stephen Hawking Grand Design: Did God Create The Universe'. S.H. stated that the big bang was similar to subatomic particles that appear, disappear and reappear somewhere else following the laws of quantum mechanics. If that were so, wouldn't it also be possible for...

Big Bang versus No Beginning and No End... What is the latest chatter on this subject? See discussions under references below. Creation says... "In the beginning, God created heaven and earth"... But science points to much more pertaining to the heaven or the universe. The Earth formed...

Hi, I have a silly question, Could one, in theory make a accurate model of the life of our universe that one could look at from within. Let's say I put on my VR/AR goggles, 'there' Iam elevated from the earth, then I remain static, and the time begins to rewind. At some point I maybe hear...

nikkkom submitted a new PF Insights post A Brief on the Expansion of the Universe Continue reading the Original PF Insights Post.

This might be a stupid question due to a simplistic under standing of the Big Bang. But why is the CMB uniform across the sky. Why is it not sognificantly higher on one side from the other. Surely if the Big Bang was a point then everything would eminate from that point resulting in one side...

On just about every thread concerning the Big Bang, beginner questions are asked which other members consider to be unfounded. Hopefully this thread can serve as a central point to help beginners understand this issue correctly. 1. Where did the Big Bang happen and how far away is Earth from...

According to Einsteins Theory of relativity if an object traveled at the speed of light, it's mass would become infinite, time would seem to stop relative to others and it length would become absolute zero. The same conditions were thought of at the Big Bang, when time didn't seem to have...

The recent observed gravitational wave is claimed due to two merging black holes colliding or infusing into each other. Could it be just another local Big Bang? (Of course I am implying Big Bang occurs in various scales). So "our Big Bang" was a large scale Big Bang and was triggered by two...

I have read that the total energy of the universe is zero and that the big bang might have emerged from a quantum fluctuation. Also that there is a chance (extremely low) of another big bang occurring in the quantum vacuum energy fluctuations. As far as I understand the vacuum energy / dark...

Okay, first off let me say hello, I am new here. I am creating this thread in the hope that I can get some answers to some questions that are bugging me. Please keep in mind that I am not educated in physics so some of my questions might seem silly. Also, feel free to write responses as lenghty...

I am not a scientist, but as a hobby I am summarizing different initial condition theories, specifically, eternal inflation, LGC, cyclic, and bounce theories. I need a completion time ATB where all theories produce an identical plasma. The plasma then enters the big bang process of expansion...

I'm not talking about white holes. Indeed, the big bang as the explosion of a black hole are an explosion of singularity.

Since Edwin Hubble proposed distant galaxies move apart from each other as spectra of each galaxy is shifted towards the red end. this created the law that universe is expanding exponentially since big bang. and these galaxies spectra are due to stretching of wavelength of light incident from...

I've been thinking about the balloon surface analogy and I want to ask some questions. Perhaps I am pushing it too far. But in that case it seems important to find its limits. My understanding is that the this analogy is used to illustrate the expansion of the universe and in particular how it...

A singularity is a region in which the curvature of space-time becomes infinite. But according to standard big bang models, at the initial point (at which T = 0) the pre-expansion space - as miniscule as it was - was filled uniformly with all energy that ever existed or will exist. But if all...

I was thinking about the concept of Unification at extreme energies, and how the symmetry breaking / condensation as a result of universal expansion resolves the necessary fields for our universe. As such, it stands to reason to consider a Hot Big Bang as candidate for the arena to allow for the...

i haven't even got any idea how what to search in order to find such an answer, but whenever i watch a documentary about physics, astrophysics, astrobiology,.etc and they do thr token intro of this is how the universe began... this question always niggles... because i don't reckon it would of...

I had a thought a while ago, but it was removed because I cited a youtube video of physicists talking rather than papers, so I'll have another go. My thought was that the universe could be cyclical and infinite even if heat death is the eventual end of the universe as we know it. During the...

Just wondering if the speed of light in vacuum has always been constant since the big bang. Is there any evidence (theoretical or experimental) that the speed of light could have been faster or slower in the early universe or just after the big bang? How about at the big bang itself? Was the...

Regarding expansion, from the present to the past: Do light beams (generally) converge to a single point, in the remote past, as geometry and matter was also condensed to a single point, prior to the big bang? Thank you.

Wikipedia states that, after he heat death of the universe: "Random quantum fluctuations or quantum tunneling can produce another Big Bang in years." How would this work?

I know there is a lot of misconception amongst the general public involving the big bang theory. Most people outside the scientific community still believe that the big bang theory says that the all the universe - and not just the observable one - started from a single point, and that the...

Do we actually know if the Big Bang was an instantaneous event, that is an event not measurable in time? Or, would it be possible that the Big Bang had a duration, a length in time? In other words, was the Big Bang more like, say, an explosion or more like a volcanic eruption, and how do we know...