Let's talk about the "Big Bang" (theory)

[YoursTrue]

More accurately, there was no 'before the universe'. Time didn't even exist for the word 'before' to make sense.

So when did time start?

 

[joelr]

The background radiation was formed when the universe was about 11,000 times smaller than currently, which would still have made it just over a million light years in diameter at that point.

Even during nucleosynthesis, the scale factor was a couple of billion, which would have made the observable universe tens of light years across.

To get a scale factor making the observable universe subatomic in scale would take us back to Planck time or so. So, no, the CMBR does NOT give evidence of this.

When I read George Smoot's book about mapping the CMB they mentioned that quantum fluctuations in the early big bang expanded through inflation and caused the small temperature variations in the CMB.
It causes matter to be more or less dense in regions and that effects the photons in the CMB. Photons coming from a region with more matter lose more energy due to gravitational redshift.

 

[PruePhillip]

More accurately, there was no 'before the universe'. Time didn't even exist for the word 'before' to make sense.

Love how it puts it in the bible, with the end of the world there is no time.
No sun, no sea, no more time.
Fact is we don't know what time is. Could the universe have created time in the process of coming into being? Wouldn't 'time' have been the first thing necessary to stop everything happening at once? Or not happening at all?

 

[PruePhillip]

More accurately, there was no 'before the universe'. Time didn't even exist for the word 'before' to make sense.

How do you know?

 

[Polymath257]

Are you sure that the peach idea is true?

Which aspect?

That the observable universe was once that size? I would say moderately confident. it is beyond any energy level that we have tested so far, but well below that for quantum gravity effects. So it would have been after any 'bounce' or 'budding' process for the early universe. There is a lot we don't know about this time period, but there is no reason to doubt the expansion factor would not have happened.

That the observable universe was once the size of our solar system, I think is almost certain. That *is* within the energy ranges we have tested with temperatures in the trillions of degrees, which corresponds to what we have do in our particle accelerators.

That the rest of the universe was very similar to what the small part that represents our observable universe? Very confident. At these temperatures and pressures, things are actually fairly simple to model because things are so uniform. If the fluctuations at this stage were large at all, we would see the effects on the cosmic background radiation. This is true until at least 300,000 years after the expansion started.

 

[Polymath257]

Love how it puts it in the bible, with the end of the world there is no time.
No sun, no sea, no more time.
Fact is we don't know what time is. Could the universe have created time in the process of coming into being? Wouldn't 'time' have been the first thing necessary to stop everything happening at once? Or not happening at all?

Well, once again, the modern viewpoint is that space and time together make up a four dimensional structure. This structure 'just exists' because time is within it.

We know what time is at least as well as we know what space is.

 

[Polymath257]

So when did time start?

There is disagreement about this point.

In the classical version of the Big Bang theory, time started at the start of the expansion, 13.7 billion years ago.

But, those theories that take quantum gravity into account suggest that time is infinite into the past and the current expansion in 'our universe' is part of a much larger expansion process int he multiverse, which had no beginning.

 

[Polymath257]

How do you know?

See my other answer. The two possibilities are the time started when the expansion started or that time is infinite into the past in a multiverse. In both scenarios, there is nothing before time began (which, if you think about it, is clear).

 

[PruePhillip]

See my other answer. The two possibilities are the time started when the expansion started or that time is infinite into the past in a multiverse. In both scenarios, there is nothing before time began (which, if you think about it, is clear).

There might not be a 'thing' called time at all. It might just be something derrived from physical process, ie there's no time when everything is so cold that nothing moves, or it could be that time is a field, and continues to 'tick' even when all nature's physics are frozen. We just don't know.
Interesting that a Big Bang process could begin, AND START TIME, when in fact time is needed to get the Big Bang going in the first place.

 

[Polymath257]

There might not be a 'thing' called time at all. It might just be something derrived from physical process, ie there's no time when everything is so cold that nothing moves, or it could be that time is a field, and continues to 'tick' even when all nature's physics are frozen. We just don't know.
Interesting that a Big Bang process could begin, AND START TIME, when in fact time is needed to get the Big Bang going in the first place.

I'm not sure what you mean when you say time is not a 'thing'. Is space a thing? is momentum a 'thing'? Is charge a 'thing'?

And how is 'derived from physical processes' any different than 'being a thing'?

Yes, these are philosophical questions, not scientific ones. They represent how we label things, not what actually happens.

When you say time is necessary to 'get the Big Bang going', what, precisely, do you mean?

 

[gnostic]

So when did time start?

I think you need to remember that the Big Bang cosmology is based on the “Observable Universe”.

At the very least, our technology have been able to observe the universe right up to the Recombination Epoch, an epoch that started 378,000 after the Big Bang.

The Recombination Epoch marked the point, when the electrons were able to bond with the earliest elements (hydrogen being the most abundant atoms, followed by helium atoms and fewer lithium atoms) that exist at the time, where atoms were ionized (positive-charged) and the universe exist as opaque and plasma universe, to neutral atoms and a more cooler and transparent universe.

This transition point between plasma and non-plasma universe, can be observed by the relic radiation, that exist throughout the universe, when photons decoupled from the newly neutral atoms, the earliest light.

Because light tends to lengthen its wavelength to microwave end of the spectrum, over time, hence the Cosmic Microwave Background Radiation (CMBR).

CMBR is one of the two most important evidence for the expanding universe model - predicted in 1948 but discovered in 1964. It required radio telescopes for such observations, including the space telescopes - COBE, WMAP & the Planck spacecraft - which confirmed CMBR prediction (Alpher & Herman) and consolidated the original discovery (Penzias & Wilson, 1964).

Both WMAP & the Planck provided a much higher resolution, and gathered enormous amount of data, which included refining their calculations of the age of the universe, to 13.798 billion years old.

Anyway, these findings only provide the age of the “Observable Universe”, where the BB theory place its limits as to when the Planck Epoch, which is the start of the “expansion”.

That’s the scope of this theory. The time t=0 second is when the Big Bang started, and the start of the universe as we know it - the Observable Universe.

Now there are other theoretical cosmologies that explained and predicted to the time before the Big Bang, where time could be infinite in the past and the universe is eternal, but these models are still “theoretical” and “untested”.

My point, @YoursTrue , is that 13.798 billion years is the Big Bang theory’s scope (its limit). So if you want more, then you need to explore other cosmological models.

 

[Polymath257]

When I read George Smoot's book about mapping the CMB they mentioned that quantum fluctuations in the early big bang expanded through inflation and caused the small temperature variations in the CMB.
It causes matter to be more or less dense in regions and that effects the photons in the CMB. Photons coming from a region with more matter lose more energy due to gravitational redshift.

Yes, but in this 'early Big bang' corresponds to the inflationary period, which is still speculative. Going back to the Planck era, we have no evidence, even from the CMBR.

 

[PruePhillip]

I'm not sure what you mean when you say time is not a 'thing'. Is space a thing? is momentum a 'thing'? Is charge a 'thing'?

And how is 'derived from physical processes' any different than 'being a thing'?

Yes, these are philosophical questions, not scientific ones. They represent how we label things, not what actually happens.

When you say time is necessary to 'get the Big Bang going', what, precisely, do you mean?

Ok, the Big Bang begins, and creates space, time etc..
How could it 'begin' before it created time?

The point isn't about physics but our hubris. We can 'explain' something like lightning and evolution, but our explanations go only so far.
And will ONLY go so far.

 

[gnostic]

Ok, the Big Bang begins, and creates space, time etc..
How could it 'begin' before it created time?

The point isn't about physics but our hubris. We can 'explain' something like lightning and evolution, but our explanations go only so far.
And will ONLY go so far.

You keep using the word “created”, which implies there have to be “creator”, like a god, a deity.

I think it is a bigger hubris to believe in all-powerful god that can create the universe and create life with magic or with supernatural powers.

A god that create daylight that divide day from light, simply because he said “Let there be light”, and light was created from nothing but magic, with no sun (the sun being created on the 4th day, but daylight created on the 1st day). That’s more believable?

A god that can create a fully grown human male from dust. That’s more believable?

To believe in the existence of a god, and relying on “God did it”, is simply relying on primitive superstition, and on the hearsay of Genesis. That’s a bigger hubris.

 

[PruePhillip]

You keep using the word “created”, which implies there have to be “creator”, like a god, a deity.

I think it is a bigger hubris to believe in all-powerful god that can create the universe and create life with magic or with supernatural powers.

A god that create daylight that divide day from light, simply because he said “Let there be light”, and light was created from nothing but magic, with no sun (the sun being created on the 4th day, but daylight created on the 1st day). That’s more believable?

A god that can create a fully grown human male from dust. That’s more believable?

To believe in the existence of a god, and relying on “God did it”, is simply relying on primitive superstition, and on the hearsay of Genesis. That’s a bigger hubris.

Think the sun is mentioned three or four times in the first creation account in Genesis 1.
But the sun was created in Verse 1, Genesis 1. God created the heavens and the earth, in that order.
The heavens include the sun, moon, stars.
The early earth, according to both Genesis 1 and science is this ---- dark, oceanic, sterile, no land.

Then the earth ceased being a cloud planet as the skies cleared
The earth ceased being an ocean world as the continents rose
Earth ceased being sterile as land brought forth life (fresh water, more likely)
And then the seas brought forth life
Finally man.

I am find with that. Show me another 'creation myth' that gives you this.

 

[PruePhillip]

You keep using the word “created”, which implies there have to be “creator”, like a god, a deity.

I think it is a bigger hubris to believe in all-powerful god that can create the universe and create life with magic or with supernatural powers.

A god that create daylight that divide day from light, simply because he said “Let there be light”, and light was created from nothing but magic, with no sun (the sun being created on the 4th day, but daylight created on the 1st day). That’s more believable?

A god that can create a fully grown human male from dust. That’s more believable?

To believe in the existence of a god, and relying on “God did it”, is simply relying on primitive superstition, and on the hearsay of Genesis. That’s a bigger hubris.

Must be two forms of hubris
1 - God created the universe
2 - The universe created itself, before it existed.

Which is stranger?

 

[Polymath257]

Must be two forms of hubris
1 - God created the universe
2 - The universe created itself, before it existed.

Which is stranger?

The second is NOT claimed by anyone. The universe did NOT create itself. The universe (including all of space and time) simply exists. Creation only happens *within* the universe. There was no 'before' it existed since time is part of it.

In the first, God is uncreated, or self-created, so there seems to be little difference except that we *know* the universe exists, but we don't know the same about God.

 

[YoursTrue]

Ok, the Big Bang begins, and creates space, time etc..
How could it 'begin' before it created time?

The point isn't about physics but our hubris. We can 'explain' something like lightning and evolution, but our explanations go only so far.
And will ONLY go so far.

"IT" created time? How long was the "peach" type thing (yes, thing) there before it exploded? And was anything there before the peach?

 

[YoursTrue]

The second is NOT claimed by anyone. The universe did NOT create itself. The universe (including all of space and time) simply exists. Creation only happens *within* the universe. There was no 'before' it existed since time is part of it.

In the first, God is uncreated, or self-created, so there seems to be little difference except that we *know* the universe exists, but we don't know the same about God.

The universe did not create itself? It just is--was? The word 'creation' is a bit offsetting, considering you don't believe there is a creator, do you?
Insofar as God is concerned, IF there were not the Bible, I wouldn't know God existed (exists) either. So to me it's like putting things together, even though many do not believe what the Bible says. But again -- to me it's like adding up the writing and history of the Bible, along with seeing life and the world around me that convinces me there IS a God. You probably do know that the Bible says that the heavens cannot contain God. 1 Kings 8 makes this clear when Solomon stated, "Look! The heavens, yes, the heaven of the heavens, cannot contain you; how much less, then, this house that I have built!"

Can I understand God? No, only from what I have learned from the Bible AND those whom I consider to be God's people, and those things I have personally experienced. Do I say this is every religious person's experience? No. Even then I don't have to agree with everyone's interpretation.

 

[gnostic]

Think the sun is mentioned three or four times in the first creation account in Genesis 1.
But the sun was created in Verse 1, Genesis 1. God created the heavens and the earth, in that order.
The heavens include the sun, moon, stars.

Except verse 1 says nothing about the Sun, Moon and stars...

...not until verses 14 to 18, the Sun and Moon being described as the 2 great lights or luminaries in the sky.

And stars were never mention until verse 16.