This perennial "what if" assumes that, in contemporary physics terms, there is "time" independent of – "before" – spacetime, which seems as conceptually incoherent as "north of the North Pole" (i.e. edge of a sphere, torus, loop, etc). And if we do away with "spacetime", for the sake of discussion, we then lose more than a century of physical and cosmological grounds to even discuss "the expanding universe" and its retrodicted BB. What does an event mean "before" spacetime? – is the implication of that old "what if".

What does an event mean "before" spacetime? — 180 Proof

Easy to understand. I fail to see the dilemma.

Oh, then you can explain it to me. Please do. (NB: It's not a "dilemma"; I contend it's nonsense.)

I fail to see the dilemma. — Jackson

The big bang is conceived as being the beginning of space and time, with those two not being distinguishable at first. "Before the beginning of time" is not a phrase that can be given a meaning within the cosmology of big bang theory. There was never a 'before the big bang'. Of course folks come up with new theories and cosmologies on a regular basis, big bounce, etc, but such speculations need to be closely mathematically argued reformulations of the standard model beyond the scope of this forum.

Plus, the answer to the 'what if... question can easily be given, that exactly the world we see must follow from whatever came before.

The big bang is conceived as being the beginning of space and time, — unenlightened

By you.

Me and my army.

like wow man

This perennial "what if" assumes that, in contemporary physics terms, there is "time" independent of – "before" – spacetime, which seems as conceptually incoherent as "north of the North Pole" (i.e. edge of a sphere, torus, loop, etc). And if we do away with "spacetime", for the sake of discussion, we then lose more than a century of physical and cosmological grounds to even discuss "the expanding universe" and its retrodicted BB. What does an event mean "before" spacetime? – is the implication of that old "what if". — 180 Proof

Why couldn't there be more than one instance of space time? If it starts with a big bang then ends with something else then why couldn't each such space/time “bubble” be its own thing? Time space could have its own instances of time space within it, like the way time flows differently with different gravitational forces.

Our universe today is derived from this event. What if there were other universes before that? — Jackson

Or parallel universes to this one, sure. I dont see why not but “what if?”?
Ya suppose if there were other universes before this one we would need to adjust our models? They would be incorrect? What are you getting at?

Or parallel universes to this one, sure. I dont see why not but “what if?”?
Ya suppose if there were other universes before this one we would need to adjust our models? They would be incorrect? What are you getting at? — DingoJones

Big bang only shows how to derive our current universe from that situation. Says nothing about what happened before.

What if there were other universes before that? — Jackson

Then our universe isn't so special after all and it can take that smug look off its face.

Then our universe isn't so special after all and it can take that smug look off its face. — Cuthbert

Nothing in physics can describe what happened before the Big Bang, nor that it is a unique event.

We don't know. Anything else is speculative.

We don't know. Anything else is speculative. — emancipate

You don't know.

You neither.

You neither. — emancipate

And?

Two people not knowing makes a "we".

Is there a point? I see none.

Big bang only shows how to derive our current universe from that situation. Says nothing about what happened before. — Jackson

I agree with you, Im just not sure what answer you are looking for with “what if”…we would have to adjust our models in physics I would think, lest we lose out on some potential insight the before universe might provide for our current one.
I mention parallel universes as another possibility about where big bangs fit in the universe. There could be big bangs happening within big bangs.

I already made the point that it's pure speculation. Can you read?

There could be big bangs happening within big bangs. — DingoJones

Yes, logically.

I already made the point that it's pure speculation. Can you read? — emancipate

No.

That's why I kept it all about personality and left physics out of it. For someone who can't read you write very well.

Logical possibilities abound. However, I think it only make sense in philosophy to talk about what has already been established in physics and not to extrapolate non-evidentiary, or inexplicable, counterfactuals that philosophy is ill-equipped to establish. My point is: given the physics we philosophers have to work with, time before – independent of – spacetime doesn't make any sense; besides, a speculative fiat of "other spacetimes" is unparsimonious as well.

Multiple universes seems to push the question back, much like God. Who or what created God? What created the universe or the multiverse? Etc.

Human beings aren’t omnipotent. This could be a question we just can’t answer, and perhaps demonstrates our cognitive limits.

Personally I think since the question is a scientific one, and thus assumes a concept of “nature” (the universe), we should inquire about what we mean by universe, nature, causality and time.

If the explanation lies outside our capacities, or outside of naturalism, then we need to accept it or broaden our fundamental concepts of existence.

:up: The other point is that, even if there are other big bangs, universes and thus instances of spacetime, how could we know about them, and even if we could know about them, if time relations as we understand them are coherent only within our own spacetime, how could any putative big bangs, universes and instances of spacetime be counted as being "before" or "after" anything in our spacetime bubble?

:up:

I think it only make sense in philosophy to talk about what has already been established in physics and not to extrapolate non-evidentiary, or inexplicable, counterfactuals that philosophy is ill-equipped to establish. My point is: given the physics we philosophers have to work with, time before – independent of – spacetime doesn't make any sense; besides, a speculative fiat of "other spacetimes" is unparsimonious as well. — 180 Proof

This was Quine’s position, that pragmatism’s relativism must ground itself in the realism of physics, a notion referred to as scientism by Putnam.

Physics IS philosophy. That is , it is an applied language of philosophical thought. The problem is that the forms of metaphysics that today’s physics depends on may be ‘already out of date’ when it comes to effectively addressing questions concerning the nature of time, space and genesis. We philosophers don’t have to limit ourselves to the theories the physicist has to work with. We have at our disposal, if we are willing to make use of them, a host of more powerful conceptual tools to deal with these issues beyond a physical account of spacetime.

If the explanation lies outside our capacities, or outside of naturalism, then we need to accept it or broaden our fundamental concepts of existence. — Xtrix

Good point. I would say the explanation lies outside of the approach to naturalism that one finds in today’s physics.

Multiple universes seems to push the question back, much like God. Who or what created God? What created the universe or the multiverse? Etc.

Human beings aren’t omnipotent. This could be a question we just can’t answer, and perhaps demonstrates our cognitive limits. — Xtrix

Or perhaps the way we are forced to formulate these questions when we stick to the confines of physics’ scheme of thinking keeps us from noticing an entirely different, and I would argue more productive, way of approaching origins, time and space that is already available to us in philosophy.

This was Quine’s position, that pragmatism’s relativism must ground itself in the realism of physics, a notion referred to as scientism by Putnam. — Joshs

My position is not [philosophy] "must ground itself in the realism of physics". You're interpretation of what I've on this thread, if this is your interpretation, is mistaken. Btw, I prefer Sellars to Quine.

Physics IS philosophy.

However, philosophy IS NOT physics (i.e. not theoretical, or does not explain any aspect of nature).

[ ... ] how could any putative big bangs, universes and instances of spacetime be counted as being "before" or "after" anything in our spacetime bubble? — Janus

:cool: :up:

And? — Jackson

You are approaching my level of succinctness on this forum. But I stay a step ahead by not posting.