BIG BANG

What you are talking about is a theory called "cosmic inflation". The first 10E-36 seconds saw a rapid expansion of space many multiples of speed of light. In this time the universe grew from a singularly to the size of our solar system.

There are physicists who theorize that this inflation never stopped but continues at points in the universe.  This has been tied into the bigger multiverse theory.

Did it actually expand at more than the speed of light or did the meaning of distance change?

That millionth of a second comprehended and calculated by our present perception of time, could of taken several millions of years in actual time as it was unfolding.

The big bang.

It’s only a theory. It could have happened, theoretically, apparently, but it didn’t, it’s nothing more than a theory.

Multiverse, it’s only a theory, could have happened, theoretically, maybe, but it didn’t. This is even more far fetched than the big bang theory.

And don’t get me started on dark matter, over 50% of the universe is made of the stuff and we can’t find a single trace.

You couldn’t make this stuff up. Oh wait a minute.

In 300 years time, if humanity survives that long, they’ll be having a good chuckle about this.

And there's me thinking this thread was about Hugh Hefner's passing 

"That pivotal moment of being"

Big Bang, or no Big Bang, did that "singularity" always exist (as matter, or energy or whatever). Or did it emerge from absolute nothingness (zilch !). Or is there some other option.

And if necessary, replace "singularity" with something bigger or smaller.

TOBYJUG posted:

That millionth of a second comprehended and calculated by our present perception of time, could of taken several millions of years in actual time as it was unfolding.

Time did not exist at the singularity.  If you were an observer sitting "outside" the singularity [in a universe identical to our own] , the big bang would appear to take an infinite amount of time to occur. Given time perception is related to gravity and density => infinity when age of universe => 0, the "observer time" at the earliest points in the history of the universe would => infinitely slower than [the observer - the "new universe"]. However, if you removed all mass of the new universe from the observer, the big bang would be perceived "in real time". 

There is no such thing as "actual time". Even on Earth today we all experience slight differences in elapsed time. Our most accurate measure of time uses the decay of a cesium isotope. This might be considered "actual time" but cesium did not exist for the first billion+ years after the big bang. In fact even our physics did not exist at plank time.

fatcat posted:

The big bang.

It’s only a theory. It could have happened, theoretically, apparently, but it didn’t, it’s nothing more than a theory.

Multiverse, it’s only a theory, could have happened, theoretically, maybe, but it didn’t. This is even more far fetched than the big bang theory.

Typical layman's response using a layman's definition of "theory". Fortunately, the scientific and mathematical communities hold the tenet of a "theory" to a scrupulous standard. Unfortunately, laymen attempt to marginalize a scientific theory based on the synonymous and more mainstream notion of a theory as being a conjectural opinion or explanation, with or without any corroborative basis.

joerand posted:

fatcat posted:

The big bang.

It’s only a theory. It could have happened, theoretically, apparently, but it didn’t, it’s nothing more than a theory.

Multiverse, it’s only a theory, could have happened, theoretically, maybe, but it didn’t. This is even more far fetched than the big bang theory.

Typical layman's response using a layman's definition of "theory". Fortunately, the scientific and mathematical communities hold the tenet of a "theory" to a scrupulous standard. Unfortunately, laymen attempt to marginalize a scientific theory based on the synonymous and more mainstream notion of a theory as being a conjectural opinion or explanation, with or without any corroborative basis.

Theoretically speaking, at least! 

Seems to me that since the two most significant pieces of evidence for a Big Bang, red shift and the cosmic microwave background radiation, fit predictions for the Big Bang then it is by far the best theory we have.

I can't get my head around the concept of a singularity. But Hubble and those two guys with the big horn shaped thing found some remarkably convincing information. I'm pretty convinced.

s.

Singularity, like most of quantum physics doesn't have a corresponding concept in the macroscopic world, hence we can't draw rational parallels from our experience.

There has recently been some parallels between quantum and general relativity theories,  in which quantum phenomenas that collapse can give rise to gravity.

Don Atkinson posted:

"That pivotal moment of being"

Big Bang, or no Big Bang, did that "singularity" always exist (as matter, or energy or whatever). Or did it emerge from absolute nothingness (zilch !). Or is there some other option.

And if necessary, replace "singularity" with something bigger or smaller.

Since time started post singularity, the words "always" and "exist" are meaningless at the singularity. Always = at all times. Exist = having objective reality or being. In the context of our universe the singularity probably never existed and would not be considered part of objective reality. Our language is not well equipped to communicate ideas requiring the complete absence of space and time. [Nobody really knows what happened before plank time (10E-43 seconds (?))] Certainly "time" did not exist until after gravity broke free from the "super force" at which point the singularity does not exist.

So...yeah.... singularity never existed but still somehow provided all the energy and laws of physics that rule our universe.

Now my question for my Christian friends. If God always existed and he created the universe, why did he wait so long? I mean the universe is only 13.8 billion years old. According to some "expansionist" theories, the universe will grow for like 10 ^ 200 years before everything is broken down into quarks and radiation.

Personally.... I can not believe that "everything" came from "nothing". The only explanation that makes sense is that our universe was created by another universe. This parent universe would likely have very different physics. It is possible that there are an infinite generations of universes and some of them may have a reality where something can be made from nothing.

"In the beginning there was nothing, which exploded" the genius of Sir Terry Pratchett.  I met up with some old work colleagues in Seahouses last week for our annual drink and we spent some time talking this subject through and making sense of it; damned if I can remember our conclusion now though

TOBYJUG posted:

That pivotal moment of our being.

I have long followed this story. Perhaps even since the beginning.   Interesting how opinions change as to what really happened. What happened just before. What happened at a micrometorical level just after,  and what's happening now as a result of it all.    Even what will create another bang.

I can't help but imagine, what with the theory of super black holes - those things that can suck in and stop time itself as we know it.    That . That moment of expansion everything must have been so more super black hole like, time could itself could not have been able to get a look in.  I'm thinking not so much a Big Bang - more a bbbbbiiiiiggggg     Bbbbbbbaaaaannnnnggggg.   In super slow motion for many many years before time could even catch up with itself.  In fact I recon that we are all still  witness to a Big that is still very banging.

The thing that has bothered me since childhood is not that the big bang happened but where did it happen? I mean.... If space is created by the universe, what exists outside of space? Again... probably limitations of language and our wanting to apply what we know about "every day reality" to cosmological events. Is it really possible for an infinite void to exist?

As a scientist.... I hate to fall back onto my internal beliefs but I am not smart enough to understand the maths. I have held a deep belief my entire life that: 1. If anything exists then everything exists 2. If everything exists then reality is infinite 3. If the universe is finite then there are an infinite number of universes.

I can not over emphasize how terrified I was as a kid by the prospect of the existence of an infinite void. Even now... I'm getting extremely depressed just typing this.

Why is space created by the universe?  If there is endless 'nothing' within which there was a singularity which exploded into our universe then surely there could, and probably are, other singularities scattered around within the nothing.  Perhaps billions of them.  It seems more likely to me that there are many many universes and that the death of one/many somehow starts another singularity.  Perhaps a singularity is the end product of the life cycle of black holes should they get big enough.  I find the idea that something/matter can come from nothing scarier and more difficult to imagine than endless nothing to be honest

dayjay posted:

"In the beginning there was nothing, which exploded" the genius of Sir Terry Pratchett.  I met up with some old work colleagues in Seahouses last week for our annual drink and we spent some time talking this subject through and making sense of it; damned if I can remember our conclusion now though

Conclusion: Alcohol transports you to a different instance of the multi-verse from which you can bring back no information! 

dayjay posted:

Why is space created by the universe?  If there is endless 'nothing' within which there was a singularity which exploded into our universe then surely there could, and probably are, other singularities scattered around within the nothing.  Perhaps billions of them.  It seems more likely to me that there are many many universes and that the death of one/many somehow starts another singularity.  Perhaps a singularity is the end product of the life cycle of black holes should they get big enough.  I find the idea that something/matter can come from nothing scarier and more difficult to imagine than endless nothing to be honest

Black holes disappear eventually, they decay through Hawking radiation.

There is always the statistical possibility for nothing to separate into something and anti-something, and this to cause a cascade reaction.

TOBYJUG posted:

There has recently been some parallels between quantum and general relativity theories,  in which quantum phenomenas that collapse can give rise to gravity.

Possibly dimensional transformations.  I can easily think in four dimensions, but I struggle with five (I can't do one of the necessary rotations in my head).

I remember watching a Brian Cox programme about the universe and his conclusion was that eventually everything would die out and the universe would be completely empty.  It was one of the most depressing things I've ever watched

dayjay posted:

I remember watching a Brian Cox programme about the universe and his conclusion was that eventually everything would die out and the universe would be completely empty.  It was one of the most depressing things I've ever watched

It's going to take more than 10⁷⁰ years though, so don't wait up!

Huge posted:

Did it actually expand at more than the speed of light or did the meaning of distance change?

[I was actually wrong it took like 1 minute (? I've forgotten where I read this was many years ago. But was an extremely short period of time) to reach the size of our solar system.]

http://www.smithsonianmag.com/...-universe-180961233/

There is an issue of understanding in all these measurements.  Whilst in both our macroscopic (relativistic) universe and in the quantum world pertinent to our current conditions we know the speed of light in vacuo is a constant; however, we also know that distance and time are not constant.  So, in the early universe, in much more extreme conditions, what do these times and distances really mean and how do they interact?

I suggest that to think of them in terms of the conditions of our current universe isn't particularly useful.

dayjay posted:

Why is space created by the universe?  If there is endless 'nothing' within which there was a singularity which exploded into our universe then surely there could, and probably are, other singularities scattered around within the nothing.  Perhaps billions of them.  It seems more likely to me that there are many many universes and that the death of one/many somehow starts another singularity.  Perhaps a singularity is the end product of the life cycle of black holes should they get big enough.  I find the idea that something/matter can come from nothing scarier and more difficult to imagine than endless nothing to be honest

Well the idea of an "infinite void" begs the questions..... why? how? The idea of a "thing" possessing the attributes of both "being" and "nothingness" fills me with an overwhelming existential dread. This "thing" would be so incredibly alien and unknowable. It would have 0 dimensions, exist outside time\space, and still, somehow, have a quantity. I just can not imagine a 0 dimensional "space". It literally could be both infinite and nonexistent at the same time. It just gets so unimaginably strange that I hope it is not true. If it does "exist" then the reality outside our universe becomes infinitely more interesting than anything in our little bubble. The fact that it is unknowable makes it all so depressing.

Huge posted:

There is an issue of understanding in all these measurements.  Whilst in both our macroscopic (relativistic) universe and in the quantum world pertinent to our current conditions we know the speed of light in vacuo is a constant; however, we also know that distance and time are not constant.  So, in the early universe, in much more extreme conditions, what do these times and distances really mean and how do they interact?

I suggest that to think of them in terms of the conditions of our current universe isn't particularly useful.

That really is the problem. We can only view things from the POV of the Universe existing long enough for humans to become intelligent and pose these types of questions.