Before the beginning

  • Thread starter 3.14159265
  • Start date
  • #1

Main Question or Discussion Point

hi, im new to the forum, i am 18 years old and i am really interested in astrophysics and cosmology.

there is one thing i just can't understand, what existed before the big bang? please state theories or even your own so i can least have a clue.
thnx
 

Answers and Replies

  • #2
144
0
there is one thing i just can't understand, what existed before the big bang? please state theories or even your own so i can least have a clue.
thnx
Nothing existed before the Big Bang.
But how can this be so - Since nothing expresses Non-Existence.
We have a contradiction here, and you can thank yer lucky stars for it. Reality is a representation of nothing ( The Existence of nothing). The reality of nothing is an ongoing process. It is expressed as ones, and there is the potential for an infinity of them. I.E. One nothing ... then another and yet more to follow. The existence of nothing is read something like this - 101000101000010100001000010001000010010100000001. Where the contradiction I spoke of earlier is quite apparent.
 
  • #3
Nereid
Staff Emeritus
Science Advisor
Gold Member
3,367
1
Originally posted by 3.14159265
hi, im new to the forum, i am 18 years old and i am really interested in astrophysics and cosmology.

there is one thing i just can't understand, what existed before the big bang? please state theories or even your own so i can least have a clue.
thnx
Welcome to Physics Forums 3.14159265!

In a narrow sense, "what existed before the big bang?" is a meaningless question, since time itself began with the big bang.

In a broader sense, it's a question which can't really be addressed by the application of the scientific method (at least, not yet), because, AFAIK, there are no theories or hypotheses which produce predictions which could be tested through observation or experiment, even in principle.

There are a number of interesting ideas - about multi-verses, about cyclical universes, and more - which you can find discussed in several places in Physics Forums.

Then there's a huge amount of work going on to produce a "Theory of Everything" (which is a misnomer) - a theory which encompasses the best that physics has today - General Relativity, Quantum Mechanics, the Standard Model - and wraps it up into a single new theory. You can find discussion of these in Strings, Branes, and LQG
 
  • #4
marcus
Science Advisor
Gold Member
Dearly Missed
24,738
785
Originally posted by 3.14159265
...i am really interested in astrophysics and cosmology.
..., what existed before the big bang? please state theories or even your own...
If you are interested in cosmology that means you probably are or will be interested in mathematical models of the universe

and you indicate you are willing to consider different theories, you invite people to state alternatives

this is a can of worms but fun too

I disagree with Nereid in a subtle way. I would say that we cannot know there was nothing before BB, or that there was no time.
I would emphasize that the prevailing mathematical model (the cosmologists' favorite for now) breaks down and will not compute at a certain point when you push it back in time.
This gives the impression that there was no time and that nothing existed, but what it means is simply that the model starts dividing by zero, predicting infinities, and gives meaningless results.

But recently it has been found that without doing violence to that model one can fix it so it does not break down, and can be pushed back before the instant that expansion began. And then the model predicts a prior contraction phase. So the prevailing model can be fixed in such a way that the "singularity" or failure of the original model is eliminated, but it still predicts the same story of expansion----coinciding with the original model except right around that critical instant.

Several groups of researchers have done this. A recent paper is by Viqar Husain and Oliver Winkler "On singularity resolution in quantum gravity"
http://arxiv.org/gr-qc/0312094 [Broken]

An interesting feature of their article is that it belongs to an older research line from before "string theory" and "loop quantum gravity" were invented.
It uses long-established "ADM" (Arnowitt-Deser-Misner") variables
and the most widely accepted cosmology model, the "FRW" (Friedmann-Robertson-Walker) model.

So there is not much novelty in Husain/Winkler's approach. FRW has been the standard model since the 1930s and ADM has been standard since 1961. They quantize the FRW model and the singularity goes away.
It is hard to argue with because the FRW-ADM picture has been unchallenged for so long.

A similar result was obtained in 2001, but not using the ADM variables. This was by Martin Bojowald. A number of other people have
derived the same results since then, removing the BB singularity and running the quantized FRW model back through the moment when the prior contraction ended and the present expansion phase began.

There are also exotic cosmologies which are not based on quantizing the FRW model. (colliding braneworlds etc.) But pretty much all of contemporary cosmology uses the FRW model of the universe, so certainly the most obvious and direct approach to dealing with the model-failure at BB is to fix that model by quantizing it.

If you want to read more I will try to find some links. The Husain Winkler article is just one I happened to have handy because it is recent. It is short, but not the easiest to read.
 
Last edited by a moderator:
  • #5
43
0
I found that in Savov's theory of interaction [1] that the same universe existed before BB, driven by the same laws working between similar finite bodies having different scales. We do not need to fix the current knowledge here and there and thus to avoid the singularity in the universe beginning. We should model the underlying structure and then derive in its terms the current models after describing it at the scales of observations.

1. Savov, E., Theory of Interaction, Geones Books, 2002.
 
  • #6
920
0
I really like the idea of LQC about a contraction phase before Big Bang, but some subtles aspects of LQC should be modified, IMO. The main is, that I guess that would be interesting to incorporate the idea of cyclic universe to LQC. An universe expanding forever does not make sense to me. An universe that had been contracting since ever prior to the Big Bang also does not make sense to me. I prefer the dynamics of an eternal expansion-contraction-expansion and this repeteadly. So, put jointly LQC with cyclic universe in your cocktail shaker, shake it and you will obtain an splendid theory!
 
  • #7
I personly like the theory of the multiverse. Where under the condition of a certain heat, density or space ( about the plank size) the universe would almost undergo a bug bounce. So a new universe is born out of an old one!!!
Hope you like the forum!
 
  • #8
marcus
Science Advisor
Gold Member
Dearly Missed
24,738
785
George Jones provided these YouTube segments of a 60-minute BBC program that interviews a number of people working on the problem of what happened before the bang.

YouTube - BBC Horizon 2010: 1/6 What Happened Before the Big Bang
YouTube - BBC Horizon 2010: 2/6 What Happened Before the Big Bang
YouTube - BBC Horizon 2010: 3/6 What Happened Before the Big Bang
YouTube - BBC Horizon 2010: 4/6 What Happened Before the Big Bang
YouTube - BBC Horizon 2010: 5/6 What Happened Before the Big Bang
YouTube - BBC Horizon 2010: 6/6 What Happened Before the Big Bang

They are dumbed down and I don't especially like several of the models or all the personalities. But it's a resource. I don't know of any other online video program that covers the same ground.

Here is GJ's original post. It was in a thread in cosmology forum called "Before big bang"
https://www.physicsforums.com/showthread.php?p=2934877#post2934877

There is some other stuff in that thread that might be relevant here.
 
Last edited:
  • #9
I disagree with the statements, "It's irrelvant" or "Nothing existed" or "it's pointless to ask" because it's not, thats a simple way of saying, "I have no idea" without looking stupid. There WAS something before the big bang, do I know? No idea... What theory do I believe?

Multi-Universe.
 
  • #10
Chronos
Science Advisor
Gold Member
11,408
738
Good for you . . . so what is your point? We all have beliefs.
 
  • #11
Good for you... Why does one have to have a point? I never said we didn't have beliefs.
 
  • #12
2,257
7
saying that 'before the beginning' is meaningless is not a way of saying we dont know.
'before the beginning' is a contradiction of terms.

on the otherhand if you want to say that we dont know that the big bang was the beginning then you might be right.
But there certainly had to be a beginning somewhere

I think it may all have begun with a single particle that kept growing until it collapsed and caused the big bang.
 
  • #13
655
0
I think its great so many people have their own theories on the big bang, and creation. Even though I welcome all theories, the fact that someone says there was nothing before the big bang, is kinda strange. Its science, we need proof, not just a thought. We know very little about this.
 
  • #14
110
0
Good for you... Why does one have to have a point? I never said we didn't have beliefs.
You just told us that belief was wrong though. You told us there is something before the big bang and we're just too stubborn to admit we don't know. Plenty of people believe it is a useless question because before the big bang there was potentially no universe as we know it and thus no time as we know it. There is no fixed time regardless of the existence of a universe or not, much less fixed time WITHIN a universe. If the big bang was the beginning of time, then time was created by the big bang you can't look back further on the clock. That is the belief that you are saying is wrong, it very well may be wrong but you have no proof of that.

At least you never said multiverse was fact, you just said you believed it. But you did say
"There WAS something before the big bang, do I know? No idea... What theory do I believe?"
Meaning that you're accusing anyone who believes that the big bang was the beginning of our universe and time is incorrect.
 
  • #15
That's a silly assumption. I never accused anyone of anything... I don't know any Scientist who believes the Big Bang was the beginning of everything, and there was nothing before it.

Ignorance is bliss.
 
  • #16
37
0
I believe space and time are...gravity or "products" of it.
Why do i think that.

Ok,Time as we all know is directly affected by gravity,the denser the matter the slower the time,so no/or almost no time at singularity.
Space - Matter.
When Gravity is strong like singularity/black hole ,matter compresses,if matter compresses then there is LESS space.Because we perceive matter WITHIN the space.

When big crunch happens it sucks in time,matter/space,and the Explosion expands the time,matter/space.
So it seems that gravity expands universe,the edge of gravity is the edge of universe.
It sounds kinda silly i know but there is some sense in it.
Now tell me how wrong is this theory?
 
  • #17
2,257
7
correction. There is no time at the event horizon which is usually well away from the singularity.
 
  • #18
correction. There is no time at the event horizon which is usually well away from the singularity.
Time does not slow down, stop, or go backwards at a black holes event horizon.
 
  • #19
2,257
7
from the point of view of an observer far away from the black hole it stops.

its called gravitational time dilation
 
  • #20
309
0
I think the term "time" is used a lot without people having a clear concept of what time really is.
 

Related Threads on Before the beginning

  • Last Post
3
Replies
57
Views
5K
  • Last Post
Replies
12
Views
4K
Replies
1
Views
1K
Replies
1
Views
912
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
18
Views
2K
  • Last Post
Replies
5
Views
2K
  • Last Post
Replies
6
Views
3K
  • Last Post
Replies
19
Views
6K
  • Last Post
Replies
22
Views
7K
Top