# Can Stephen Hawking really claim that there was no time at all before the Big Bang?

by cdux
Tags: bang, claim, hawking, stephen, time
 P: 1,857 Lol your secrets safe with me
 P: 26 Yes, but what is time itself? We define it as the duration between 2 events. Actually, it a measure how many specific regular/periodic events occur between the 2 events occurring that we are trying to measure. I honestly think that time is not an entity at all but something we as conscious observers would naturally invent to understand the Universe. Wikipedia described it well and it goes something like this: The moment you say something happened at time 0, you can immediately ask what happened before! like a number line where once you put down 0, you will immediately have -1, -2....in addition to 1,2.... What existed or happened before the big bang is of course not settled. Maybe nothing happened but that doesn't mean time as our construct isn't valid. I did a simple thought experiment: Measure the age of Universe and count 30 seconds before it. Call this experimental 0. Then allow 30 seconds to pass and there will be a bang because we know it happened. Then you have time before this Universe :) (BTW, the second only exists as a unit of measurement because we invented it. Aliens might have a unit which is equal to 2 seconds or .5 seconds but that it the normal discreet unit for them)
Mentor
P: 11,823
 Quote by osxraider Yes, but what is time itself? We define it as the duration between 2 events. Actually, it a measure how many specific regular/periodic events occur between the 2 events occurring that we are trying to measure.
Per wiki:

Time is a dimension in which events can be ordered from the past through the present into the future, and also the measure of durations of events and the intervals between them.

The measurement of time is based on regular cycles of some sort, such as the oscillations of a crystal or atom. But time itself is not this measurement. If you meant pretty much this same thing I apologize.

 I honestly think that time is not an entity at all but something we as conscious observers would naturally invent to understand the Universe.
Would you define any of our 3 spatial dimensions as an "entity"? What does "entity" mean in this context?

 What existed or happened before the big bang is of course not settled. Maybe nothing happened but that doesn't mean time as our construct isn't valid. I did a simple thought experiment: Measure the age of Universe and count 30 seconds before it. Call this experimental 0. Then allow 30 seconds to pass and there will be a bang because we know it happened. Then you have time before this Universe :)
You're skipping all the problems involved with that though. For example, what existed before the universe? How can time pass if there is no universe? That's the big issue with time before the big bang. We don't know what existed, if anything, before then.
 P: 26 Drakkith, I meant just that. No need to apologize :) Nothing needs to exist for time to pass. Do you need to be alive for us to reach the next day. You said "The measurement of time is based on regular cycles of some sort, such as the oscillations of a crystal or atom" of course we would need the crystal or atom to calibrate our measurement of time but time itself should exist as a dimension regardless of whether there is something to move within the dimension at all. I am biting myself in the foot because in another post , I have been asking how/why dimensions exist and whether they exist only within our universe or can exist outside it. I am not skipping anything. Time can and should pass regardless of a universe in which things happen one after another or simultaneously. It would just be really boring and disorienting since for a very long time, you would not know how much time has passed since there is no regular cycle/or periodic event of anything to measure by. In the BRANE theory, the speculated timescale for BRANE's to come together and create big bangs is perhaps a trillion years or so? This means that if this theory is correct, then something periodic happens outside our universe that enables creation of universes on a regular basis. The moment you have that regular basis, you have time. Actually, I am quite comfortable about time existing even before the Universe. My problem is whether there truly is a beginning and/or an end and if not so, if time is cyclic, how did originate as a cyclic entity. Speaking of entities, in this context, yes the dimensions of space are also entities. The difference between time and other dimensions is that one is always moving (and moving forward ) in the time dimension and cannot really help it. BTW, question: does a photon experience time? (or if you were sitting on top of a photon although you never could) would time still pass for you?
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P: 11,823
 Quote by osxraider of course we would need the crystal or atom to calibrate our measurement of time but time itself should exist as a dimension regardless of whether there is something to move within the dimension at all. I am biting myself in the foot because in another post , I have been asking how/why dimensions exist and whether they exist only within our universe or can exist outside it.
Whoa, hold on. There's a big difference between saying nothing exists within the universe and saying the universe itself doesn't exist. I take the latter to mean NOTHING exists, even dimensions.

 I am not skipping anything. Time can and should pass regardless of a universe in which things happen one after another or simultaneously. It would just be really boring and disorienting since for a very long time, you would not know how much time has passed since there is no regular cycle/or periodic event of anything to measure by.
Not quite sure what you are saying here.

 In the BRANE theory, the speculated timescale for BRANE's to come together and create big bangs is perhaps a trillion years or so? This means that if this theory is correct, then something periodic happens outside our universe that enables creation of universes on a regular basis. The moment you have that regular basis, you have time.
But here we have a different view of what a "universe" is. Some define it as EVERYTHING that exists. Others, especially if you view brane theory to be correct, define it differently where our universe is in a "bigger" universe so to speak.

 Speaking of entities, in this context, yes the dimensions of space are also entities. The difference between time and other dimensions is that one is always moving (and moving forward ) in the time dimension and cannot really help it. BTW, question: does a photon experience time? (or if you were sitting on top of a photon although you never could) would time still pass for you?
Don't know. According to the math of SR and GR a photon doesn't experience time. But that math may not mean anything for light, as I believe it was made for things with mass. As far as I know we simply cannot even assign a frame of reference to a photon, so the concept of time for a photon is meaningless.
 P: 190 Hey, what about my original question? :D I guess it turns out it's not exactly concensus to claim there was no time universally or multiversally before the Big Bang. BTW, to add something new, in a recent documentary he claimed that one of the justifications of the Universe and Big Bang 'starting there and not before' was that the concept of negative energy shows there can be energy out of nothing and most of the space of the universe is used as a repository of negative energy. It turns out that theory is not exactly consensus either. I guess I should stop watching documentaries about "God and Science". I should know what I'm getting myself into.
 Mentor P: 11,823 Yeah, watching shows like that don't really get you anywhere.
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 Quote by Drakkith Yeah, watching shows like that don't really get you anywhere.
But the pictures are so pretty !
 P: 153 Hey, what about my original question? :D I guess it turns out it's not exactly concensus to claim there was no time universally or multiversally before the Big Bang. >>>>It could be something else other than 'Space/=Time' as we know it. In an effort of postulating mathematical predictions out of what we understand on BB version of /or QP and/or GR. It led to strange outcomes (String Theory) multiverses with unique configuration and properties so on. >>>We can measure time in our universe and mathematically figure out what's beyond that 'dimension' but it is begging for verification. I guess I should stop watching documentaries about "God and Science". I should know what I'm getting myself into. >>> "Unicorn and science"? They don't go together.
P: 153
 Quote by phinds But the pictures are so pretty !
My kids asked me about the BB once and offered them the balloon/ant/bread+raisin analogy and even drew pictures (I tried)! They just stared @ my face startled .....later on . Later on. I ended up showing them a program on NOVA by Neil, TTWH by Freeman, BBC's and few other stuff. It has blinding colors (HD), CGi, cool allegoric animations and annoying explosions which they kept on repeating. Some of the part are misleading. I just can't figure out if it was done on purpose or for entertainment's sake.
 P: 9 The original query is an interesting question, that has no doubt been pondered for thousands of years, well before physics turned up. Martin Luther's response, when asked what happened before creation, was to say God was making sticks to hit people with who asked such impertinent questions. (I'm not a fan of that answer.) As for why is there something rather than nothing, or where this universe came from, the review below list two titles that shouldn't intimidate the average reader. The "there was no time before the big bang so don't ask such a silly question" line is not helpful (and I am not saying anyone is doing so here). Physicists have done the calculations and said the chances of this universe coming into existence from another universe's big crunch is very unlikely. http://physicsworld.com/cws/article/...-how-of-it-all
 P: 724 Some people don't seem to have the basic understanding of just how much speculation goes into any statement about the Big Bang. Even tentative claims by authorities on this particular topic would include no less than 90% speculation. It's just a loose model of the ordering of the events that comes at a time of great conceptual difficulties for the currently adopted worldview. In my opinion, the model should only be used as a chronological ordering of how everything seems to have unfolded. It's definitely not on par with the theory of evolution in any way or form. PS. Stephen Hawking is a popularizer of science and overdramatizations aren't exactly unheard of.
 P: 63 Isn't the general idea that perhaps there was a black hole of unimaginable density which was somehow triggered into the big bang? If that's the case, then time within the black hole to an outside observer (if there was one) would have stopped, as we believe is the case with black holes in the universe. However, as in black holes, until an observer is destroyed, time would proceed normally as perceived by that observer. Right? So maybe some version of time was going on in there.
P: 190
 Quote by CCWilson Isn't the general idea that perhaps there was a black hole of unimaginable density which was somehow triggered into the big bang? If that's the case, then time within the black hole to an outside observer (if there was one) would have stopped, as we believe is the case with black holes in the universe. However, as in black holes, until an observer is destroyed, time would proceed normally as perceived by that observer. Right? So maybe some version of time was going on in there.
Yeah the (relatively abstract I would say) theory is that since the observers would also be eventually part of the hole, then there would be nothing but the hole and no time. I understand this is very "hands on" science but I've heard some respectable minds describe it like that.
It would then, even if that was accepted, be clashed with theories involving other universes IMO.
Emeritus
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 Quote by Mordred Every article I have ever read describes it as an infitismally small point. Perhaps all those articles are wrong. here is one example http://burro.astr.cwru.edu/stu/cosmos_bigbang.html
This particular article is sloppy. Using GR as a model, an infinite universe stays infinite, and a finite universe stays finite. We don't know whether the universe is finite or infinite.

Perlmutter, 1998, http://arxiv.org/abs/astro-ph/9812133

Kowalski, 2008, http://arxiv.org/abs/0804.4142
 P: 13 ...the idea that the big bang emanated from a giant black hole appeals to me for a couple of reasons... ...firstly it dispenses with the problem of a singularity and secondly, matter either couldn't ever have existed, or previously had been reduced to pure energy by this big bang/big crunch eventuality... ...also light energy is rendered impotent due to the crushing effects of the overwhelming gravitational forces... and until a situation occurs whereby energy degrades into matter is when time can be inserted as a functioning, viable useful device to measure the effects of the transition from this one extremely pure state, to another more massive, chaotic one....
 P: 190 I don't know how they could say a lone black hole equates or tends to a big bang when they also accept it emanates radiation. edit: Unless I guess they take the effect to be diminishing as the black hole implodes and then not existing somehow (?).
 P: 8 using logic one can say that something can't just come into existance which means the energy from the big bang and time itself have always existed (I think Kalam's Law says something like this, I may have just used the law of sylogism). You could also make the argument that something can't just always have existed but time coming into existance and always being there is the same thing (irrelevant) since there wasn't anyone to observe before the big bang since all observers emerge from the big bang.

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