Time Before Big Bang: Stephen Hawking & Other Universes

In summary, the big bang is a theory that is still not fully understood and remains outside of our current models. It is unclear if time existed before the big bang and what caused it. Different ideas about the big bang and its relation to other universes exist, but the standard model of cosmology is based on observations and confirmed by Einstein's General Relativity. More research and evidence is needed to fully understand the origins of the big bang. Personal opinions and speculations are not allowed in scientific discussions.
  • #1
cdux
188
0
Can Stephen Hawking really claim that there was no time at all before the Big Bang when a black hole can have an outside observer on normal time? And what about other Universes in relation to our Universe? Don't they have a normal time at the time of our Big Bang?
 
Space news on Phys.org
  • #2


No one yet knows exactly what the BIG BANG was. It lies outside our best current models. No one knows if time existed before such a bang. No one knows exactly what caused the big bang.

And there are different ideas about what existed before such a bang, if anything. No one knows if there was a single big bang, multiple big bangs, or simply a series of repeated finite bangs. The standard model of cosmology used in these forums is the Lambda CDM model which applies observed parameters to the more general FLRW cosmological model, and these start after the big bang. They do not explain the initial bang itself.

It is believed everything we currently observe around us, all the particles and different energies, for example, like gravity, the strong force, the electromagnetic force, maybe time and space, originated from such an initial high energy and unstable beginning in what is called spontaneous symmetry breaking.

Many of the core ideas of the Big Bang, like the expansion, the early hot state, the formation of helium, and the formation of galaxies, are derived from and confirmed by observations that are independent of any cosmological model.

So we know our models fit what we observe pretty well because we made them that way; whether they are the final solution remains an open question. The cosmological models, theories of the very large, are based on Einstein's General Relativity; It may be more likely that what caused the big bang will eventually emerge as a result of the theory of the very small, related more closely to quantum theory. Stay tuned!
 
Last edited:
  • #3


Big bang is not fact just a theory, for sure not start of the universe or time.
 
  • #4


rashi said:
Big bang is not fact just a theory, for sure not start of the universe or time.

I agree completely with both of those statements, but I feel that saying the big bang is "just a theory" is overly dismissive.

It is a theory in the same sense that evolution is a theory. It fits all the facts and is the best theory we've got.

Theories in science are ALWAYS "just theories" because they are always open to being disproved.
 
  • #5


In a simple logical way for teh big bang to be happen, we need mass, energy and space.

Where they come from? obvoisly it was there before the big bang, clearly Big bang is not the start of the universe then?
Even the law of nature were existed before the big bang!
 
  • #6


rashi said:
In a simple logical way for teh big bang to be happen, we need mass, energy and space.

Where they come from? obvoisly it was there before the big bang, clearly Big bang is not the start of the universe then?
Even the law of nature were existed before the big bang!

You are just making this up. You have no evidence for any of this and it is pure speculation on your part. Personal theories are not allowed on this forum.

There ARE theories that included some of what you say, but you need to reference those theories, not just say something is true becuase you think it is true.
 
  • #7


phinds said:
You are just making this up. You have no evidence for any of this and it is pure speculation on your part. Personal theories are not allowed on this forum.

There ARE theories that included some of what you say, but you need to reference those theories, not just say something is true becuase you think it is true.

Science is the subject where opinion and speculation really matter! Where is your evidance to disprove me. Do not just say 'there are theories'! wheer are they?
 
  • #8


rashi said:
Science is the subject where opinion and speculation really matter! Where is your evidance to disprove me. Do not just say 'there are theories'! wheer are they?

You misunderstand how this forum works. When you make a statement, YOU have to back it up with references. We don't have to disprove it.

Personal speculation is not allowed on this forum.
 
  • #9


rashi said:
Science is the subject where opinion and speculation really matter! Where is your evidance to disprove me. Do not just say 'there are theories'! wheer are they?
"Opinion and speculation" matter as the basis for theories that then need to be proven by experimentation. You asserted several matters as if they were fact. It is your responsibility to support them.
 
  • #10


rashi said:
In a simple logical way for teh big bang to be happen, we need mass, energy and space.

Where they come from? obvoisly it was there before the big bang, clearly Big bang is not the start of the universe then?
Even the law of nature were existed before the big bang!

Logic? The universe cares not for our logic. It is we who must bend our logic to fit the universe. This is why pure philosophy and logic don't do squat to figure out the natural world. One MUST have empirical evidence.
 
  • #11


rashi said:
In a simple logical way for teh big bang to be happen, we need mass, energy and space.

Where they come from? obvoisly it was there before the big bang, clearly Big bang is not the start of the universe then?
Even the law of nature were existed before the big bang!

How so? Energy does not require space to exist, Energy can form into matter so mass would not have been necessary. You cannot have time without mass so Time isn't even a factor.
When we refer to the universe we are stating the visible, Observable universe. There have been plenty of theories as to what lays beyond our universe. However as we have no way to detect anything beyond our universe assuming there is other universes. Scientists will not state any definitive answer to where the energy came from for the big Bang. All current accepted theories are based on countless tests, observations etc. The CMB confirms that space did in fact start from a point and inflated. The big bang theory at one time was one of the more controversial theories. After years of arguments its born out to be the most accurate to those observations.


On a side not note of this If the Higgs field proves true and its certainly looking that it will do so, Then in order to get mass there would have to first be a Higgs field. I'd be curious at to a projected order of formation of the fundamental particles leading up to the first mass particles. However that's a different post lol. Particularly since its evident that the standard model of particles is no where near complete.
 
  • #12


Post #11 is full of more speculation.
If you guys don't stop it, this discuss will be closed.
 
  • #13


Mordred said:
The CMB confirms that space did in fact start from a point and inflated.

Nonsense ! There is not only no evidence that it started as a POINT, it would not make sense for it to have done so. It started as an incredibly hot dense "plasma" of energy of undetermined size.

If you are going to make definitive statements on this forum you need to get your facts straight.
 
  • #14


phinds said:
Nonsense ! There is not only no evidence that it started as a POINT, it would not make sense for it to have done so. It started as an incredibly hot dense "plasma" of energy of undetermined size.

If you are going to make definitive statements on this forum you need to get your facts straight.

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 [Broken]

perhaps we should look more at the intent of a post rather than the wording itself if my post was poorly worded I apoligize for that. However I do not visit a forum to get lectured but rather to learn if that is against forum policy to try and assist others, and then get lectured for simple mistakes in wording then iwill find a more flexible forum.

Naty I had no speculations in my post we do not care what is outside our universe as we cannot ever examine it other than looking for a collision in the CMB. Many papers describe that without space there is no time. You cannot have spacetime withut matter so where is the speculation?
 
Last edited by a moderator:
  • #15


Mordred said:
Every article I have ever read describes it as an infitismally small point. Perhaps all those articles are wrong.

Don't let Phinds upset you. He is notoriously grumpy in the mornings, afternoons, and nights. In fact, I recently went to dinner with him and his teeth leaped out of his mouth and nearly bit my finger off! I had to leap from table to table using a makeshift rapier to defend myself! It as quite a spectacle!

What he means is that the singularity pointed out by these articles is a result of our math breaking down, most likely because our knowledge of physics at that density and energy level is incomplete. Word around the forums is that most professionals do not believe there was an actual singularity, but that we simply need to learn more.
 
  • #16


Mordred:

...to learn if that is against forum policy to try and assist others,

You will be 'lectured' here when you post inaccurate, unproven or misleading statements. In class, you get points deducted for mistakes; here you will be critiqued.
[I've gotten my share of 'lectures'...]

Man up when you are wrong and you have a good chance of learning something. That's what's so good about this forum; if I say something crazy, somebody will hopefully catch it and set me straight. On the other hand, when you read something like

.
...an infinitesimal small point...
it is understandable you would be misled. No reputable physics source would state the origin of the big bang that way.

[By the way, I only read a few paragraphs from that source and but not like it. Very loosely written, I suspect hardly edited. One of the positive aspects of these forums it that you will be referred to scientifically correct sources. One solid source I learned from these forums:
http://www.astro.ucla.edu/~wright/cosmolog.htmIf the big bang were a POINT,say in space and time, why do we see relic radiation the same from all directions?? That is what has led scientists to conclude it happened everywhere. [Either that or we are by mere chance at the very center of the universe?]A few other speculations you posted:
Energy does not require space to exist.

No such theory exists.
When we refer to the universe we are stating the visible, Observable universe.

no, when someone refers to the portion of the universe we can observe, you will almost always see it in the context of 'OBSERVABLE' universe. For example, Wikipedia says it this way:

http://en.wikipedia.org/wiki/Universe#Definition_as_observable_reality

[The Universe is commonly defined as the totality of existence,...The farthest distance that it is theoretically possible for humans to see is described as the observable Universe. ...Since we cannot observe space beyond the limitations of light (or any electromagnetic radiation), it is uncertain whether the size of the Universe is finite or infinite./QUOTE]

But even what is 'observable is tricky...to learn more you can search these forums or do some reading on 'horizons'. [Some parts of the universe are causally disconnected from others.] Two common ones are the Hubble and cosmological event horizons, and of course there are also black hole horizons. Objects at the Hubble limit have a 'speed' of c relative to an observer here on the Earth but the Hubble parameter is decreasing as time passes, so that the Hubble limit does not, in general, coincide with a cosmological event horizon. This means in the future we can detect signals [observe] of some entities receding at superluminal [greater than c] speed...somewhat past that horizon. A cosmological event horizon is one beyond which we'll never detect signals.
The 'universe' encompasses all that.
 
Last edited:
  • #17


If the big bang were a POINT,say in space and time, why do we see relic radiation the same from all directions?? That is what has led scientists to conclude it happened everywhere. [Either that or we are by mere chance at the very center of the universe?]

I never stated it was a point in space/time nor did the paper I posted as far as I read I took it to mean that space/time was infitismally small. but anyways
a question on that in regards to CMB detection. with the expansion of space time the CMB would also expand at the same rate would it not? So the CMB would never show it as a point that wasn't my intent on the mention of the CMB. I probably needed to be more specific on what they detected in regards to the CMB to support the big bang model.
Thank you for pointing out some of the errors or what you referred to as speculative, Your previous comment makes more sense now
 
  • #18


Drakkith said:
Don't let Phinds upset you. He is notoriously grumpy in the mornings, afternoons, and nights. In fact, I recently went to dinner with him and his teeth leaped out of his mouth and nearly bit my finger off! I had to leap from table to table using a makeshift rapier to defend myself! It as quite a spectacle!

Hey, don't be telling everybody about my semi-autonomous teeth !

And I'll have you know I sometimes go for a full hour or two without being grumpy. In fact, it happened just last month.
 
  • #19


Lol your secrets safe with me
 
  • #20


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)
 
  • #21


osxraider said:
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.
 
  • #22


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?
 
  • #23


osxraider said:
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.
 
  • #24


Hey, what about my original question? :D

I guess it turns out it's not exactly consensus 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.
 
  • #25


Yeah, watching shows like that don't really get you anywhere.
 
  • #26


Drakkith said:
Yeah, watching shows like that don't really get you anywhere.

But the pictures are so pretty !
 
  • #27


Hey, what about my original question? :D

I guess it turns out it's not exactly consensus 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.:biggrin:
 
  • #28


phinds said:
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 :bugeye:...later on :zzz:. 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. :biggrin:
 
  • #29


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/indepth/2012/dec/06/the-why-and-how-of-it-all
 
Last edited:
  • #30


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.
 
Last edited:
  • #31


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.
 
  • #32


CCWilson said:
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.
 
  • #33


Mordred said:
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 [Broken]

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
 
Last edited by a moderator:
  • #34


...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...
 
  • #35


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 (?).
 
<h2>1. What is the Big Bang theory?</h2><p>The Big Bang theory is a scientific explanation for the origin of the universe. It proposes that the universe began as a singularity, a point of infinite density and temperature, and has been expanding and cooling ever since.</p><h2>2. What is the concept of time before the Big Bang?</h2><p>According to the Big Bang theory, time did not exist before the universe began. This is because time is a measurement of change, and without matter, energy, or space, there can be no change.</p><h2>3. How did Stephen Hawking contribute to our understanding of the Big Bang?</h2><p>Stephen Hawking was a theoretical physicist who made significant contributions to our understanding of the Big Bang through his work on black holes and the theory of general relativity. He proposed that the universe had no boundary in space or time, and that time began at the moment of the Big Bang.</p><h2>4. Are there other universes besides our own?</h2><p>According to some theories, such as the multiverse theory, there may be an infinite number of universes besides our own. These universes may have different physical laws and constants, making them vastly different from our own.</p><h2>5. Can we ever know what existed before the Big Bang?</h2><p>It is currently impossible for us to know what existed before the Big Bang, as the laws of physics as we know them break down at the singularity. However, scientists continue to study and theorize about the origins of the universe in an effort to gain a deeper understanding of our existence.</p>

1. What is the Big Bang theory?

The Big Bang theory is a scientific explanation for the origin of the universe. It proposes that the universe began as a singularity, a point of infinite density and temperature, and has been expanding and cooling ever since.

2. What is the concept of time before the Big Bang?

According to the Big Bang theory, time did not exist before the universe began. This is because time is a measurement of change, and without matter, energy, or space, there can be no change.

3. How did Stephen Hawking contribute to our understanding of the Big Bang?

Stephen Hawking was a theoretical physicist who made significant contributions to our understanding of the Big Bang through his work on black holes and the theory of general relativity. He proposed that the universe had no boundary in space or time, and that time began at the moment of the Big Bang.

4. Are there other universes besides our own?

According to some theories, such as the multiverse theory, there may be an infinite number of universes besides our own. These universes may have different physical laws and constants, making them vastly different from our own.

5. Can we ever know what existed before the Big Bang?

It is currently impossible for us to know what existed before the Big Bang, as the laws of physics as we know them break down at the singularity. However, scientists continue to study and theorize about the origins of the universe in an effort to gain a deeper understanding of our existence.

Similar threads

Replies
1
Views
1K
Replies
22
Views
2K
Replies
7
Views
730
  • Cosmology
Replies
9
Views
1K
Replies
3
Views
1K
Replies
25
Views
2K
  • Cosmology
Replies
17
Views
2K
  • Cosmology
Replies
20
Views
1K
Back
Top