Time is just weird

[We Never Know]

Well, one aspect of this is that T=0 doesn't actually happen, only T>0. And, whenever there was time, there was also matter, energy, and space.

@Polymath257

By that statement one could claim time always existed because before the big bang(the expansion), matter and energy existed, it just hadn't yet expanded to become the universe.

Would that be correct?

I'm not seeking a hand wave of "there is no before" because evidently something was even if we don't understand it yet.
I'm seeking what are your thoughts about it.

 

[Polymath257]

@Polymath257

By that statement one could claim time always existed because before the big bang(the expansion), matter and energy existed, it just hadn't yet expanded to become the universe.

Would that be correct?

No. The model has time actually beginning at the BB.

I'm not seeking a hand wave of "there is no before" because evidently something was even if we don't understand it yet.
I'm seeking what are your thoughts about it.

You are waving away the exact point. Time *began* at the BB (in the standard model). Because of the geometry of spacetime, it literally makes no sense to talk about 'before the Big Bang' in exactly the same way it makes no sense to talk about 'north of the North pole'. At the north pole, the concept of 'north' is not defined. At the BB, the concept of 'before' is not defined.

Now, when you move away from the standard model, it is possible time, matter, energy *did* exist before the BB. This happens in most models with quantum gravity. In this situation, the BB is more of a 'phase transition' or a 'budding off' and time *does* make sense 'before the BB'.

But again, this is an *extension* requiring some form of quantum gravity to work. It is very speculative and not even close to being tested.

 

[We Never Know]

No. The model has time actually beginning at the BB.



You are waving away the exact point. Time *began* at the BB (in the standard model). Because of the geometry of spacetime, it literally makes no sense to talk about 'before the Big Bang' in exactly the same way it makes no sense to talk about 'north of the North pole'. At the north pole, the concept of 'north' is not defined. At the BB, the concept of 'before' is not defined.

Now, when you move away from the standard model, it is possible time, matter, energy *did* exist before the BB. This happens in most models with quantum gravity. In this situation, the BB is more of a 'phase transition' or a 'budding off' and time *does* make sense 'before the BB'.

But again, this is an *extension* requiring some form of quantum gravity to work. It is very speculative and not even close to being tested.

Did matter and energy exist before the expansion?
It had to being energy cant be created or destroyed, it just changes form.

 

[Polymath257]

Did matter and energy exist before the expansion?
It had to being energy cant be created or destroyed, it just changes form.

Once again, the beginning of the expansion is the beginning of time. There simply was not a 'before the expansion' if the standard model is correct. No matter, no energy, no space, and no time.

You have to be careful about the 'cannot be created or destroyed'. Technically, that is a law of physics that applies *within the universe*. So, the total amount of energy *at one time* will be the same as the total amount of energy *at another time*.

But that says nothing at all if time itself starts at some point.

 

[We Never Know]

Once again, the beginning of the expansion is the beginning of time. There simply was not a 'before the expansion' if the standard model is correct. No matter, no energy, no space, and no time.

You have to be careful about the 'cannot be created or destroyed'. Technically, that is a law of physics that applies *within the universe*. So, the total amount of energy *at one time* will be the same as the total amount of energy *at another time*.

But that says nothing at all if time itself starts at some point.

I understand what we know breaks down before we get to the expansion point but "if energy exists so does time/if time exists so does is energy" is true, then in my mind both always existed or both were somehow created.

 

[Polymath257]

I understand what we know breaks down before we get to the expansion point but "if energy exists so does time/if time exists so does is energy" is true, then in my mind both always existed or both were somehow created.

it's tricky talking about something like the beginning of time.

For example, the word 'always' is usually equivalent to 'for all time'. But, if time has a beginning, then 'always' may only be a finite duration. The same is true for a lot of other words like 'eternal', or 'forever'.

The usual notion that time might be infinite into the past may or may not be true.

The next issue is that causality depends on time. It makes no sense to talk about causes outside of time or outside of the universe. Further, causes are always *before* the events that they cause. But, again, 'before' is a 'time word'. To even talk about 'before' requires time. And so, to even talk about causality requires time.

Ultimately, this means, as far as I can see, that it makes no sense to talk about time being caused. The concepts themselves are in conflict.

 

[We Never Know]

it's tricky talking about something like the beginning of time.

For example, the word 'always' is usually equivalent to 'for all time'. But, if time has a beginning, then 'always' may only be a finite duration. The same is true for a lot of other words like 'eternal', or 'forever'.

The usual notion that time might be infinite into the past may or may not be true.

The next issue is that causality depends on time. It makes no sense to talk about causes outside of time or outside of the universe. Further, causes are always *before* the events that they cause. But, again, 'before' is a 'time word'. To even talk about 'before' requires time. And so, to even talk about causality requires time.

Ultimately, this means, as far as I can see, that it makes no sense to talk about time being caused. The concepts themselves are in conflict.

Still if energy can't be created or destroyed, then energy always existed. Meaning it didn't come into existence/or start with the big bang. The same can be said about matter.

So basically everything we see in the universe, the energy and matter that made/makes it up existed before it did.

 

[Polymath257]

Still if energy can't be created or destroyed, then energy always existed. Meaning it didn't come into existence/or start with the big bang. The same can be said about matter.

The actual conservation laws relate the amount of energy or matter at different times.

Once again, if time began at the BB, then 'always' only means the time back to the BB. There is no 'before'.

So, yes, if time began at the BB so did matter and energy. In that sense they have 'always existed' because they have existed whenever there was time.

So basically everything we see in the universe, the energy and matter that made/makes it up existed before it did.

Nope. If time had a beginning, it makes no sense to talk about 'before time'. Matter and energy have existed whenever time existed. This is true even if time began 13.7 billion years ago. In that case, there *was no 20 billion years ago*.

 

[We Never Know]

The actual conservation laws relate the amount of energy or matter at different times.

Once again, if time began at the BB, then 'always' only means the time back to the BB. There is no 'before'.

So, yes, if time began at the BB so did matter and energy. In that sense they have 'always existed' because they have existed whenever there was time.



Nope. If time had a beginning, it makes no sense to talk about 'before time'. Matter and energy have existed whenever time existed. This is true even if time began 13.7 billion years ago. In that case, there *was no 20 billion years ago*.

You misunderstood my post.

"So basically everything we see in the universe, the energy and matter that made/makes it up existed before it did."

Meaning stars, planets, gases, everything whether a million years old or 13.69999999999999 billion years old, the energy and matter that made/makes it up existed before it did."

 

[Polymath257]

You misunderstood my post.

"So basically everything we see in the universe, the energy and matter that made/makes it up existed before it did."

Meaning stars, planets, gases, everything whether a million years old or 13.69999999999999 billion years old, the energy and matter that made/makes it up existed before it did."

Oh, yes. For example, the Earth is about 4.5 billion years old. It was formed along with the sun and other planets from a cloud of dust and gas. The materials in that cloud were mostly formed from previous supernovas. The stars that went supernova were formed from hydrogen gas that existed previously. The hydrogen formed when lone protons and lone electrons joined together about 377,000 years after the BB. The protons were the result of neutron decay in the first few minutes after the BB, etc.

We can go back to the conditions within a second after the current expansion started. Before that (less than a second), the temperatures were high enough that the energies involved are ones we haven't fully explored, so there is still debate about what happened in that first second.

 

[We Never Know]

Oh, yes. For example, the Earth is about 4.5 billion years old. It was formed along with the sun and other planets from a cloud of dust and gas. The materials in that cloud were mostly formed from previous supernovas. The stars that went supernova were formed from hydrogen gas that existed previously. The hydrogen formed when lone protons and lone electrons joined together about 377,000 years after the BB. The protons were the result of neutron decay in the first few minutes after the BB, etc.

We can go back to the conditions within a second after the current expansion started. Before that (less than a second), the temperatures were high enough that the energies involved are ones we haven't fully explored, so there is still debate about what happened in that first second.

To me that leaves up two choices...

1. All matter and energy that made/makes up everything came to into existence in a nano second^1000(just throwing out a figure)

2. Energy and matter always existed.

I'm going with 2. But regardless, in reality each is out of our current understanding.