Something that's bugged me about Time

Gambler

I haven't read up anything on this subject and my google searches haven't brought up anything that makes sense to me so far so I'm wondering if someone here can give me their thoughts..

People always go on about "the start of time" and occasionally about how at some point something "must have come from nothing". Both of those concepts give me trouble.

I can happily understand that there was an incredibly dense mass that gave birth to the universe (takes a bit of head wrapping but I do get it) but the idea that there was a start or beginning bugs the hell out of me.

As humans that have a finite amount of time (we are born, we live, we die) I can understand that it can be difficult for us to imagine but surely time is something that has no "start" and that will always exist, Infinite as it were :P

Or am I missing something?

r3nu4l

I'm no expert on time but from what I can gather, time is only a construct of our universe. There are theories that state that even as I type this other universes are born, grow old and die within the 'time' it takes me to tap one key on the keyboard. During that 'time' there are perhaps countless species evolving, civilisations and empires growing and disappearing and planets dying off. (That's making the assumption that these universes contain nebulas, galaxies, solar systems, planets etc., perhaps they don't).

I'd love to hear from anyone who knows anything about this. I read "A Brief History of Time" but that was many years ago and I can't remember what Hawking says about it.

kevmy

Well essentially time is another dimension like up/down, left/right, forward/backwards. There are lots of other dimensions we can't see (I think at the moment the most popular number is 11 overall dimensions).

So if you can imagine that in that infinitesimally small, incredibly dense ball of mass that you had at the start of the Big Bang up/down, left/right, forwards/backwards wouldn't have much of a meaning. So if you view time as just another dimension you could say it wouldn't have much of a meaning either.

That's not to say in a way it didn't exist it just didn't exist as time as we know it. I'm not a theoretical astrophysicist so don't ask me on exact details but that kinda how I view it.

Gambler

That's no problem, I understand the concept that we have our own "time" and the idea of it as a dimension is no problem for me, it's the idea that there was nothing else before the big bang that I am talking about.

Can anyone point me in the direction of some of the pre "big bang" theories?

r3nu4l

Gambler wrote: »

Can anyone point me in the direction of some of the pre "big bang" theories?

God is pre-big bang!

/I'm a Christian, I have to say that

There are some who say that there was another universe before ours but I'm not sure what other theories exist.

GreeBo

Where was this dense mass before it exploded? Didnt it have to explode into something? And what created the mass?

Ow, my head hurts now.

Gambler

r3nu4l wrote: »

God is pre-big bang!

/I'm a Christian, I have to say that

There are some who say that there was another universe before ours but I'm not sure what other theories exist.

Lol - When did they start letting you christian types say there might be other theories :P

Gambler

GreeBo wrote: »

Where was this dense mass before it exploded? Didnt it have to explode into something? And what created the mass?

Ow, my head hurts now.

You see that's the bit I'm trying to wrap my head around! There must be some evidence\theories out there..

I do think that the mass is probably just the compress ball of the universe that was there "before" if you get me but hey, that's a personal thought with no reason behind it

r3nu4l

Gambler wrote: »

Lol - When did they start letting you christian types say there might be other theories :P

Well I am also a scientist Besides, some of the finest scientific minds of the past were actually priests! Our own Father Nicholas Callan of St Patrick's College Maynooth invented the induction coil...

I'll have to think/read more about the time question, it's easy to state the fact of it simply being another dimension but the implication of that is interesting...are there universes where that dimension (time) doesn't impact on that dimension? Who knows?

What was there before? More reading might lead to some theories

gondorff

r3nu4l wrote: »

God is pre-big bang!

This is tripe. Let's try and keep the discussion vaguely scientific.

wireless101

Gambler wrote: »

You see that's the bit I'm trying to wrap my head around! There must be some evidence\theories out there..

I do think that the mass is probably just the compress ball of the universe that was there "before" if you get me but hey, that's a personal thought with no reason behind it

Well as regards pre-Big bang theories here's one tht might satisfy you and is currenty gaining momentum in scientific circles.

The Big Bounce contradicts the Big bang Theory. It states that, a long time ago the universe was expanding (just as it is now) and eventually it reached a point where no further expansion could take place (just as this universe will) and it all snapped back into a dense core and begun again.

That is the theory presented ridiculously simply by the way but I hope it helps!

Gambler

Yeah, that's a theory I've heard before and I can certainly get behind as it were :P

The thing that I wonder about in that situation is does it negate the idea of a "beginning" of time?

r3nu4l

gondorff wrote: »

This is tripe. Let's try and keep the discussion vaguely scientific.

The little smilie indicated a friendly joke :rolleyes:

[Mod hat on]I note you haven't contributed to the debate on Time. Unless you have anything 'on-topic' to contribute to this thread, I'll ask you to stay out of this thread.[/Mod hat on]

@wireless101, what does the Big Bounce theory state will happen to Time during the contraction?

GreeBo

to my (albeit feeble) mind the big bounce theory sounds like the universe is alternating between having a black hole and a white hole as its centre point.
Black hole sucks everything in until it reaches some tipping point where the forces (gravity?) become repulsive and we get a white hole spewing everything out, again, until it reaches a point where the forces are attractive again.

/me wondering if this is an example of perpetual motion or are we losing something each time, and if so what? Maybe time? Can you "lose" time in this way? If its truly just another dimension then I guess you can.

gondorff

OP, if there is no space, there is no time.

Hope this helps.

Incidentally, if I am located somewhere between here and there, where exactly is 'here'?:rolleyes:

Gambler

gondorff wrote: »

OP, if there is no space, there is no time.

OK, How does that work? I can understand time as being an additional dimension but how is that related to space? What's the link and surely if there is a ball of immense density does that not occupy some sort of space? Maybe not space as we understand it but surely there is something and if it's tiny isn't there something else around it?

Hellm0

My understanding of time;

Given that one accepts special relativity, time and space are linked. If one does not have space(IE the void "outside" of the currently expanding universe) one cannot have time.

Following on from this, time is relative to the observer. If one is theoretically capable of traveling close to or at the speed of light, time should (in theory) flow differently than it would for those observing you from a different point of reference.


An important addendum to this is entropy, which is essentially the direction in which time flows. Much research has been devoted to WHY exactly time flows in the direction it does however this is a very abstract field of study of which I know very little.

Bare in mind I am no Physicist and any or all of the above may or may not be wrong. In fact, I may or may not exist depending upon whether people are looking at me or not. I think I do though.

Mr. Incognito

Okay,

The first thing you must accept as a scientist or a human being in this world are the words glorious to anyone with any true curiosity.

We don't know.

How did the universe start- we don't know. We'll probably never know

some think it may be a leak from and older universe, some that it may have always been there, and some that at some point all matter was condensed into an infintesimally small point and KABOOM!

The concept of time is an interesting one. It exists and yet it's only a figment of your imagination if it were.

As you sit reading this you are hurtling through space at millions of miles an hour on the earth, through space and time. If you could stop somehow- creat a bubble that insulated you from this movement- would time stop?

Time may only be a measurement of the movement and yet we can "feel time pass", we have a constant internal chronometer.

The point you make about the start of time is that if the whole universe was a tiny dot- floating in nothingness as it were getting ready to explode time is one of the constructs that is incorported into that universe seed- without space to move through, is there no time? that's the theory.

As for something coming from nothing, once again we don't know. The theory about the universe expanding and contracting is known as the big crunch, ie it expands and collapses. In truth we have not discovered an edge to the universe so perhaps it continues to infinity or loops around- anything is possible.

What is sure is that we don't know, and there are a lot of easy answers.

God did it. The end.
We'll never know so forget it.
We're all dreaming

etc.

All of these supress the one gift that we do have- curiosity, thought, and scientific observation and evaluation. As soon as someone accepts as irrefutable one facet of the universe they are closing others, and we cannot do that.

So in short mate, we don't know.

kevmy

r3nu4l wrote: »

I'll have to think/read more about the time question, it's easy to state the fact of it simply being another dimension but the implication of that is interesting...are there universes where that dimension (time) doesn't impact on that dimension? Who knows?

Theoretically there could be a dimension where time doesn't play a part - apparently there are many dimensions we are not aware of.

If there are other dimensions then it's a possibility that they are aware of time

gondorff wrote: »

This is tripe. Let's try and keep the discussion vaguely scientific.

Einstein believed in God - "God doesn't play dice" - and so did many other eminent scientists of the past and the present.

And you could say it was God-like - a supernatural force of which we are yet unaware

wireless101 wrote: »

Well as regards pre-Big bang theories here's one tht might satisfy you and is currenty gaining momentum in scientific circles.

The Big Bounce contradicts the Big bang Theory. It states that, a long time ago the universe was expanding (just as it is now) and eventually it reached a point where no further expansion could take place (just as this universe will) and it all snapped back into a dense core and begun again.

That is the theory presented ridiculously simply by the way but I hope it helps!

I believe this one has gone out of favour in recent years - not sure why - I read it somewhere but I forget.

Essentially this is an open question and one that borders on the metaphysical. No one knows exactly what happened in the nano and micro seconds after the Big Bang - although we're now fairly sure the Big Bang happened - let alone what happened before that if anything.

Kwekubo

kevmy wrote: »

Einstein believed in God - "God doesn't play dice"

Not wishing to hijack the thread, but Einstein was probably agnostic as regards religion and certainly did not believe in a personal god. In a letter he wrote, "The word god is for me nothing more than the expression and product of human weaknesses."

Gambler

Hehe I don't care if Einstein believed in god or not (I personally think he didn't really but hey..)

If someone wants to discuss "Did god create the big bang\universe" there's many better forums (Philosophy\Atheism etc.) for that discussion!

How did the universe start

I guess that gets to the crux of my question, why do people think the universe\time had to have a start? Is there any evidence\theories that prove\require there be a Start of time? Can it not just have always been? Yes the planets etc. that occupy "the void"\universe may have come from one explosion from a super dense ball etc. etc. but why does that have to signal a "start"?

From my point of view I can't get my head around the idea of there being a "start".. Surely there just always "was"?!

kevmy

Just to say there is a BBC 'Horizon' programme on the issue of time on tonight - not exactly sure what it's about but it may be worth looking at if your interested.

It's on at 9 tonight.

gondorff

kevmy wrote: »

Einstein believed in God - "God doesn't play dice"

And Hawking signs off by saying that to achieve grand unification would be to truly know the mind of God. Or something.

Said somewhat tongue in cheek I think.

Phototoxin

Einstein believed in God - "God doesn't play dice" - and so did many other eminent scientists of the past and the present.

He didn't these guys say God for the unknown. However there are and were a lot of scientists who were religous.

to my (albeit feeble) mind the big bounce theory sounds like the universe is alternating between having a black hole and a white hole as its centre point.
Black hole sucks everything in until it reaches some tipping point where the forces (gravity?) become repulsive and we get a white hole spewing everything out, again, until it reaches a point where the forces are attractive again.

/me wondering if this is an example of perpetual motion or are we losing something each time, and if so what? Maybe time? Can you "lose" time in this way? If its truly just another dimension then I guess you can.

the universe must be a closed system if it is all that exists, but if it is all that exists then it will be heading towards a state of less energy. But if its bouncing like a balloon being blown up and then deflated evetually the guy blowing up the balloon will die and then its stuck in deflated mode. So there is something else, something that made the matter/energy to begin with, and that is what people like Einstein called God.

However, for me personally, its hard to equate a judaeo-christian God with the creator due to the madness in the Old testament and difficulty with the dea of Jesus and organised religion

kevmy

I hoped the OP watched the Horizon programme last night - very interesting. It gave different explanations on when, how or if time began.

I won't even attempt to explain them as I will undoubtedly only confuse people and won't do anywhere near as good as job explaining things.

If you missed it try and catch it again

Gambler

I recorded it, haven't watched it yet but looking forward to it

mickeydevine

kevmy wrote: »

I hoped the OP watched the Horizon programme last night - very interesting. It gave different explanations on when, how or if time began.

I won't even attempt to explain them as I will undoubtedly only confuse people and won't do anywhere near as good as job explaining things.

If you missed it try and catch it again

hat
It was great, is great, will be great arrrrrrrr........

As far as the big crunch goes it is my understanding that due to dark matter/energy the universe is expanding at increased speed and not slowing down like you would expect. In the future galaxies will be so far away that their'll be no visible stars in the sky. Bummer.

A Primal Nut

I'm certainly no expert but this is my understanding from reading A Brief History of Time, or at least one way of looking at it.

Think of time as being like a curved surface. There is no beginning and no end. It appears we are going in a straight line because we evolved to see things in the third dimension. In fact time is curved, so as we are going further and further away from the beginning we are also getting closer to the beginning. Think of it as if you are travelling around the surface of the earth. This theory states that time is just like that. It appears we are travelling in a straight line but if you keep travelling you would eventually get back to where you began. Of course no real beginning or end other than what is relative to us (birth and death).

So the cycle is that the big bang happens, and the thermodynamic arrow of time moves in the direction that makes disorder and entropy increase (2nd law of thermodynamics) and the universe expands.

Eventually, the universe reaches a point where the density of matter in the universe is less than the gravitational pull of all that mass, and so the universe begins to collapse and everything happens in reverse. Suddenly the second law of thermodynamics happens in reverse and order increases while entropy decreases Organisms living in this cycle would remember the future instead of the past, although from their point of view they would still consider it the past, if you understand! And eventually we come back to where we start - the big bang happens etc.

I'm not sure if I explained properly and I certainly don't understand it fully - its a theory with little evidence - indeed, a lot of evidence suggests the universe will keep expanding forever. Either way, think of time as a curved surface - finite but with no beginning or end, the further you travel from one point the closer you get to that point again (just like travelling around the world). Its just one way of looking at it.

Another theory is quite simply that the big bang is the beginning because at any point before the big bang there was infinite density and hence all the laws of physics would break down (there is no infinity in physics) therefore the big bang is the beginning of physics and hence, time.

Where was this dense mass before it exploded? Didnt it have to explode into something? And what created the mass?

There is an amazing explanation in A Brief History Of Time but as I don't understand it I'm not going to explain it. Basically it seems to suggest that the positive particles are cancelled out by the negative gravity of these particles therefore the law of conservation of mass and energy holds - its way more complicated than that and gets into how particles and antiparticles cancel each other out and again just a theory.

Einstein believed in God - "God doesn't play dice" - and so did many other eminent scientists of the past and the present.

Both Einstein and Hawking used God as a metaphor. Hawking states that he can't confirm whether God exists, just that if he did, there was nothing he needed to do regarding creating the universe, he had no choice in creating the universe that it had to exist.

Dan Sanchez

Before I start Im not a scientist.
Doesnt time slow down in immense gravity? For instance if you were sucked into a black hole and you were looking out through a telescope say, things would look speeded up on the outside.
In the big bang all matter in the universe was condensed in a small area so the gravity would have almost stopped time?
Arent all things in our universe linked, gravity, matter, time...
Whether time ever 'started' or if it has always been here in a loop, bang after bang after bang I dont know.