There are also quite a few other arguments that the universe cannot have existed ‘forever’: — Devans99

What's the alternative?

A start of time.

A start of time. — Devans99

How would that work?

The start of time would give everything an initial state from which it could derives its subsequent states - it would give everything its 'realness'.

Matter was either created at the start of time (see the Zero Energy Universe Hypothesis) or entered time at the start of time. Both possibilities are consistent with the Big Bang (the obvious candidate for the start of time).

What would cause the start of time? Shouldn’t a beginning have a place?

What is time, anyway?

The cause of the Big Bang is not known - all we have is an impossible prediction of the singularity (infinite density) from general relativity. The intense gravity involved suggests that time would slow to an almost stop. The Big Bang happened about 14 billion years ago. There is some debate over whether it took place at a single spacial location (I believe it did).

There are pre-Big Bang cosmologies too but the most successful is Eternal Inflation and that has a definite start so would also be compatible with a start of time (its eternal in the sense of future rather than past time). Other less successful cosmologies (like CCC) have the universe as eternal in time so are obviously not compatible with a start of time.

I’ve got myself confused. I was thinking along some other lines that I can’t even make sense of now.

My problem is with the idea that the universe contains everything. If it can’t have existed forever, if it was born, then it was born from something.

Yes I have perhaps not made myself clear. If we talk about spacetime as the thing that was created in the Big Bang, then there is a wider universe that contains spacetime and that wider universe would have 'given birth' to spacetime.

Through the Big Bang?

Yes, the Big Bang is conventionally seen as the start of spacetime.

Given birth by the wider universe.

Have you considered a cyclical phasic universe?
"An eternal clock. It would never have started keeping time so it can have no current time" But a circular clock can keep going forever.

It should also be known that our current models only accurately predict the perceived beginning of the universe down to a certain size where the big bang is a cloud of super dense and super hot matter and energy and it was like this for awhile before inflation took place. The singularity is just a theory as it has been noted that at a certain density the laws of physics are different, especially during this pre inflation phase.

Time is also relative to where we are. Our 12 hr clock is based on how earth relates to the sun. So our version of time here on earth is also cyclical and phasic. The sun is our clock really.

I don't see how god comes into it really as I don't believe in a creator god.

For me, the problem really rests on whether you can prove nonexistence. See, physicists always get into this weird problem when they try and discuss the beginnings of the universe (Some still prefer the cyclical universe because of this problem) Wherein they always try to explain a nothing with a something. Without a creator god, what can bring about a something from nothing? The god itself would have to be a something and therefore there wasn't nothing, there was god.

There was never a time outside of the beginning of time for there to be no time. Therefore time has always been. Same with the universe, there was never a time where there was a nonexistence and then existence. So whether the universe is cyclical or not, the universe has always been here. It's the only place that can have an always.

Circular time is an interesting possibility. I think there is something different from 'now' compared to past and future - else we would perceive now/past/future in the same way which we clearly don't. So with an eternalist circular time model, there must be some sort of pointer/cursor to the current time. That cursor would circle around the loop of time. But that cursor must have started circling at some point - which still seems to require a 'start of time'.

I don't see how god comes into it really as I don't believe in a creator god. — Mark Dennis

I am just using a god as a thought experiment to demonstrate the non-sensical nature of the universe existing 'forever' - an eternal clock can be substituted instead. I did not really want to get into a discussion of God on this thread as people get emotional and it clouds the issue.

Without a creator god, what can bring about a something from nothing? The god itself would have to be a something and therefore there wasn't nothing, there was god. — Mark Dennis

Matter was either created at the start of time (see the Zero Energy Universe Hypothesis) or entered time at the start of time. Both possibilities are consistent with the Big Bang and neither is 'something from nothing'.

There was never a time outside of the beginning of time for there to be no time. Therefore time has always been. Same with the universe, there was never a time where there was a nonexistence and then existence. So whether the universe is cyclical or not, the universe has always been here. It's the only place that can have an always. — Mark Dennis

I think that we should distinguish between spacetime (which seems to have come about at the Big Bang) and a wider, timeless universe (which seems likely to have given birth to spacetime via the Big Bang). Human experience says that time is required for events to happen. But more specifically, spacetime is required for spacetime events to happen. It is likely that of all the things in the wider universe, the human race is only aware of a tiny fraction. So events beyond spacetime I think are possible - they would just be of a different nature that is not understood by the human race.

"So events beyond spacetime I think are possible - they would just be of a different nature that is not understood by the human race." This makes sense. Although for myself I'm still not convinced there is a start to anything. Beginnings I think are something we as humans project onto the universe because we can verify our own individual non-existence. For example I started in 1993, before 1993 there was no me.

"(which seems to have come about at the Big Bang)" Where did you learn this? See this is what I mean, In order to explain a universe of spacetime with a beginning you've used a something (A wider timeless universe) to explain it. So no nothing. Where is the start supposed to have been?

Let me just explain how your argument is appearing in full.
"The universe cannot have existed forever"
"Why not?"
"Because it started in a wider and timeless universe that does exist forever."

Do you see the issue? Quantum fluctuations, false vacuums, all are states of something and are describing a before the big bang. Spacetime events before the introduction of spacetime supposedly.

We need to also be realistic about what the big bang really was, a great big destruction of evidence. If I drop a nuclear bomb directly onto a house, how would you ever know it was there? If there was a whole established universe here before the big bang would we be able to know that when we can't see anything beyond the cosmic microwave background radiation? So because we have beginnings, because our histories are full of this idea of a creation, our physicist buy into the dogma that our universe must have once been in one of the most illogically possible states. Nothingness. The simplest answer really is that there was something here before the big bang as nothingness is so incomprehensible. Proving the existence of a non existence lack of state of affairs and events is quite possibly the biggest exercise in futility our species has set out on.

Wtf? Did you get a notification that I'd replied? Where did my comment go? I just posted it?

I'm not sure where your comments went. Maybe the spam filter got them - you could ask the moderator. Still my reply is:

Beginnings I think are something we as humans project onto the universe because we can verify our own individual non-existence — Mark Dennis

I think that matter and energy need a temporal start to exist in spacetime. For example, a matter particle has position and momentum as state. The current state is determined by the previous state of the particle. If there is no first state (because it existed 'forever') all the subsequent states are undefined and the particle cannot exist.

See this is what I mean, In order to explain a universe of spacetime with a beginning you've used a something (A wider timeless universe) to explain it. So no nothing. Where is the start supposed to have been? — Mark Dennis

I did not say there was ever nothing - I said that the universe cannot have existed 'forever' in time. The timeless universe is timeless - it has no start or end - it just 'IS' - it has permanent existence.

It exists as an uncaused brute fact. For anything to exist at all, causality requires at least one brute fact. Brute facts cannot exist within time (Principle of Sufficient Reason - everything in time has a cause/reason) - so they must exist without time - else there would really be nothing.

So now you're confusing me. You were the one who made an argument for a universe not existing forever, I argued against and now you sound like you are arguing from my point while making it look like your argument was my argument?

"The Universe Cannot Have Existed ‘Forever’" That is the title of the post. You never mentioned time in your preliminary argument. Your argument is all over the place and doesn't really have much logical consistency and I don't think you're understanding my counter arguments.

I said that the universe cannot have existed 'forever' in time. The timeless universe is timeless - it has no start or end - it just 'IS' - it has permanent existence. — Devans99

Are you saying that ‘forever’ is a quality of time and therefore it cannot exist in timelessness?

(Principle of Sufficient Reason - everything in time has a cause/reason) That principle exists because of the already in place Dogma that things need a beginning. If we are arguing for something different you cannot use this principle because it is based on the very thing we are arguing about.

Why do you still assume time started?

The argument is the same, you cannot use the principle that things start (Time or spacetime) to prove that things start because your proposition is the same as your claim. Are we arguing about philosophy here or physics?

Your argument is literally when you boil it down to it's simplest form. "Things start because things start."

To clarify, I mean spacetime cannot have existed 'forever' - nothing can exist 'forever' within time - if you disagree with this statement, you should provide a counter argument to the argument I gave in the OP.

But something (the wider universe) can exist permanently outside of time - I say 'permanently' rather than 'forever' as the second term has no meaning in the absence of time.

if you disagree with this statement, you should provide a counter argument to the argument I gave in the OP. — Devans99

I’m not disagreeing about anything, I’m just exploring.

Why do you still assume time started? — Mark Dennis

Or Spacetime for that matter? They are all part of the same improvable dogam that things need starts. — Mark Dennis

I think I was meaning that if there was a start then it suggests something greater, or earlier in existence.

a system’s initial state determines all subsequent states. 'Forever' has no initial state so is impossible. — Devans99

So, there is no such thing as forever, because it doesn’t have an initial state. And if it did it wouldn’t be forever.

So, there is no such thing as forever, because it doesn’t have an initial state. And if it did it wouldn’t be forever. — Brett

That's the crux of my argument.

This implies we KNOW everything about the system. Unless you can prove all things have an initial state, then this argument isn't logically consistent. Our belief that all things have an initial state comes from our understanding of physics and our understanding of physics comes from the observable universe. We have observed things behaving a certain way and so have a number of different theories on how things came about. The time period known as the big bang can only be accurately predicted to a cloud of dense matter and energy pre-expansion. Whether or not it was a singularity or a previous phase of the universe going into the big crunch is what we are arguing about.

Do you understand my point yet? That you are using a circular arguments wherein the principle that supports the singularity big bang model is being used to argue for it. If the principle isn't true and the latter explanation is then how would you ever know when you dogmatically only argue from this principle being true.

I'm done now. I'll leave you guys to your circular arguments about physics. Next time try and do philosophy though otherwise you're just going to annoy people on here when you don't understand what is being said to you.

We can imagine as a thought experiment an eternal god.. etc — Devans99

Right there is the crux of your fallacious reasoning. For you everthing starts with god. In another attempt you failed to prove god existed. Now you try to prove that creation happened.

You are a very smart arguer, but you have very serious shortcomings (as reflected by your theories) in your qualification as a theorist or philosopher.

How do you imagine an eternal god? BECAUSE WHATEVER YOU DO, YOU CAN'T GO BEYOND IMAGINATION WHEN YOU TALK ABOUT AN ALLEGED GOD. THERE ARE NO REAL OBSERVATIONS TO ESTABLISH WHAT AN ALLEGED GOD IS LIKE.

Has your god eight legs and seventy-seven heads? Or what? You are too small to imagine an eternal god, and I am too biassed against god-beliefs to even start. So how is your proof going to work? What specifications does your eternal god have that you KNOW it has, not what you speculate it has or what you speculate it must have? Please don't answer this, this is a rhetorical question. Meaning, that you can give any attribute to an imaginary figure, and if you believe that's true, then you are not a philosopher, but a religious person. And religion is the single biggest obstacle to philosophical thinking.