Before the Big Bang

[Atrebates]

Why is there a new thread about this every week or more?

Nobody knows what there was before the big bang or if there even was time before it. Hell, no body has any theories for what happened at the instant of the big bang or in the 10^-40 seconds after is. All known physics breaks down near then so we don't even have any approximations as to what could have happened. General relativity and quantum field theory (which are both applicable during the big bang) both fail. Even if one of them could be twisted to work under those extreme conditions it wouldn't be valid as only a unified theory (which hasn't been created yet) which takes into account both the warping of spacetime and quantum effects would work.
In short not only do we not know what happens, we don't know how in which direction we need to work to know.

Best Answer.

EDIT: Although GR & QFT don't apply during the big bang surely? Afterwards yes, but the earliest part of "during the BB" needs a valid GUT? (Grand Unified Theory)

 

[Birdjaguar]

Why is there a new thread about this every week or more?

Nobody knows what there was before the big bang or if there even was time before it. Hell, no body has any theories for what happened at the instant of the big bang or in the 10^-40 seconds after is. All known physics breaks down near then so we don't even have any approximations as to what could have happened. General relativity and quantum field theory (which are both applicable during the big bang) both fail. Even if one of them could be twisted to work under those extreme conditions it wouldn't be valid as only a unified theory (which hasn't been created yet) which takes into account both the warping of spacetime and quantum effects would work.
In short not only do we not know what happens, we don't know how in which direction we need to work to know.

People talk about it because it is an interesting topic to think about.

 

[Omni314]

What?? But before the big bang spewed out everything, nothing as we know it existed in the same form as it is now. Everything was completely combined into one, completely different 'thing', whatever it may have been.

The big bang didn't create anything, the big bang is just an end of the universe just like the bottom of a bag or the roof on your house the big bang is simply a perimiter of the universe in the direction of time

 

[achilleszero]

The big bang didn't create anything, the big bang is just an end of the universe just like the bottom of a bag or the roof on your house the big bang is simply a perimiter of the universe in the direction of time

So my birth didnt create me? It was just a perimeter of my life in the direction of time? You should read some of the other posts in the thread to see that your a little off.

 

[Mise]

So my birth didnt create me? It was just a perimeter of my life in the direction of time? You should read some of the other posts in the thread to see that your a little off.

Yes, birth created you, because there was some time before it in which you didn't exist. No, the big bang didn't "create" matter/energy, because there was no time before it in which matter/energy didn't exist.

 

[MrCynical]

So my birth didnt create me? It was just a perimeter of my life in the direction of time? You should read some of the other posts in the thread to see that your a little off.

Your birth (or wherever you want to draw the line) did create you. Time extends both back before your birth and in the opposite direction, so it makes perfect sense to talk about a time when you didn't exist.

With the big bang, since time itself is a component of the universe, it doesn't extend back before its creation, and indeed the whole concept of it being created is dubious in the first place. Asking what was before the big bang is like asking what is north of the north pole. Another analogy would be asking what matter does at -1000 degrees. You're asking what happens at a point on a scale which doesn't extend that far. Absolute zero simply means all atoms are stationary - they can't go any slower than that, so the question of what happens at lower temperatures doesn't make sense. Similarly with the big bang, the question of what happened "before" it doesn't make sense. It is the starting point of time and, as in the case of the temperature scale, time cannot simply be extrapolated back past it. There was no point in time before it, so there's no reason to assume there even was the "nothingness" which is so often discussed.

 

[Olleus]

I agree with you, but it depends on what you mean by "before". If you mean "at an earlier time" then, indeed, the question is meaningless. However, I believe that earlier in the thread someone suggested that we use it to mean "the cause of". In which case the question might possible mean something. It is not self evident that at ever scale causality follows the arrow of time. Indeed, at a truly tiny scale there is no evidence for an arrow of time.

 

[uppi]

I agree with you, but it depends on what you mean by "before". If you mean "at an earlier time" then, indeed, the question is meaningless. However, I believe that earlier in the thread someone suggested that we use it to mean "the cause of". In which case the question might possible mean something. It is not self evident that at ever scale causality follows the arrow of time. Indeed, at a truly tiny scale there is no evidence for an arrow of time.

QFT.

Really, the suggestion that asking what was before the big bang is as pointless as asking what is north of the north pole is a cop out to me. While it might not make sense to refer to time prior to the big bang, the question "What caused the big bang or does it even have a cause?", is a very valid one. If such a cause was found, it would be before the big bang, even if it might not make sense to assign a time to it.

Even if science might not give an answer to that, ever, the question is valid nevertheless.

 

[Mise]

I'm not convinced that that is the question being asked...

 

[MrCynical]

Really, the suggestion that asking what was before the big bang is as pointless as asking what is north of the north pole is a cop out to me. While it might not make sense to refer to time prior to the big bang, the question "What caused the big bang or does it even have a cause?", is a very valid one. If such a cause was found, it would be before the big bang, even if it might not make sense to assign a time to it.

Hardly a cop out - if a question doesn't make sense, you can hardly complain at not getting an answer to it. The question "what was before the big bang?" is not valid. Now if you want to ask a slightly different question "what, if anything, was the cause of the big bang?" you may get a different answer.

Firstly you need to keep in mind the point that has been made about time. With causality there's a tendency to think of cause preceding effect. This is useless here - there is no before the effect. Does the big bang therefore have a cause? Certainly not in the normal sense of an event preceding it in time for the previously discussed reasons. So that seems to leave a couple of possibilities.

1)The big bang has no cause, nor does it need one. Our view of cause and effect is merely an artifact of our steady movement along the time axis, which is merely one component of the universe.

2)The big bang does have a "cause" but not in the normal sense of something preceding it on the time axis. The cause and big bang would therefore have to lie at two different points on some higher dimensional axis (5th or higher).

3)The cause of the big bang occurs after the effect on the time axis. This seems to have some problems (if time originates at the big bang), unless of course time is circular.

 

[warpus]

2)The big bang does have a "cause" but not in the normal sense of something preceding it on the time axis. The cause and big bang would therefore have to lie at two different points on some higher dimensional axis (5th or higher).

Another dimension of time, perhaps?

 

[Olleus]

I once asked that question to a string theorists and he told me that there is no reason why we can't have more dimensions of time. He said that we could because, mathematicaly, the only difference between space and time dimensions is the sign in invariance equations in general relativity. eg: x^2 + y^2 + z^2 - t^2 = constant (under lorentz transformations).
However, having an other dimension of time is almost impossible to visualise. It would mean that we have to define a second velocity as the rate of change of displacement with respect to the time. In the same way you have new accelerations, forces, energy, etc...

Iv never been able to even start at getting my head around what it would mean.

 

[Mise]

I don't think the traditional "physical interpretations" of that kind of maths make much sense. IMO those kinds of maths' only "physical interpretation" is to arrive at a result that predicts the results of various high energy experiments and cosmological phenomena.

 

[uppi]

Hardly a cop out - if a question doesn't make sense, you can hardly complain at not getting an answer to it. The question "what was before the big bang?" is not valid. Now if you want to ask a slightly different question "what, if anything, was the cause of the big bang?" you may get a different answer.

You claim that the question is not valid, but give no reason for it. You can question the validity of the question, but there is no proof, that there is no before. For some hypothesises there is a before, e.g. the big bounce hypothesis.

Firstly you need to keep in mind the point that has been made about time. With causality there's a tendency to think of cause preceding effect. This is useless here - there is no before the effect. Does the big bang therefore have a cause? Certainly not in the normal sense of an event preceding it in time for the previously discussed reasons. So that seems to leave a couple of possibilities.

What point exactly? No one has challenged my view that time is a product of causality. If there is a cause of the big bag it would then make sense to refer to it as before the big bang. It might not make sense to assign it a time inside of a coordinate system of our universe, but with a coordinate transfer one probably could find a continous timeline. This could be similar to how time behaves at the Schwarzschild radius of a black hole.

1)The big bang has no cause, nor does it need one. Our view of cause and effect is merely an artifact of our steady movement along the time axis, which is merely one component of the universe.

Granted. The answer to the topic would then be "nothing"

2)The big bang does have a "cause" but not in the normal sense of something preceding it on the time axis. The cause and big bang would therefore have to lie at two different points on some higher dimensional axis (5th or higher).

Whatever that cause was, it then was before the big bang on that higher dimensional axis. Thus that cause would be the answer to the topic.

3)The cause of the big bang occurs after the effect on the time axis. This seems to have some problems (if time originates at the big bang), unless of course time is circular.

Again here you assume that time begins with the big bang, which might or might not be true. If there is any way to continue time beyond the big bang, be it by using a different metric or by higher time dimensions or by looking at causality, or whatever, then the question what was before the big bang would indeed be valid. As there is no proof either way we should assume it is valid to not prohibit thinking in that direction.

 

[Omni314]

I think that the question is more "why does the universe exist?" and after quite a bit of searching I re-found this bit on wikipedia that exlains it quite well.

1The absurd universe
Our universe just happens to be the way it is.
2The unique universe
There is a deep underlying unity in physics which necessitates the universe being the way it is. Some Theory of Everything will explain why the various features of the Universe must have exactly the values that we see.
3The multiverse
Multiple Universes exist, having all possible combinations of characteristics, and we inevitably find ourselves within a Universe that allows us to exist.
4Creationism
A creator designed the Universe with the purpose of supporting complexity and the emergence of Intelligence.
5The life principle
There is an underlying principle that constrains the universe to evolve towards life and mind.
6The self-explaining universe
A closed explanatory or causal loop: "perhaps only universes with a capacity for consciousness can exist." This is Wheeler's Participatory Anthropic Principle (PAP).
7The fake universe
We live inside a virtual reality simulation.

Personally I quite like 6

 

[Atrebates]

As a physics student I can honestly say that the strong anthropic principle can suck my <censored>, lick clean my <censored> and chow down on <censored> <censored> <censored> in a tumble dryer <censored>.

The importance of sentient consciousness in observation is bull.

Sorry, needed to get that off my chest. Sure very clever people believe it, but I am not aware of a good reason to do so. Or even a bad reason.