Borde-Guth-Vilenkin theorem...

JC 2K3

kelly1 wrote: »

After much digression, let me go back to my original point.

According the BGK theorem, the universe began at some finite time in the past and if it had a beginning, it means that no physical matter or energy existed beforehand. The implication of this is that something super-natural brought the universe into being. The thing which brought the universe into being couldn't be natural because then something physical would already exist.

Right, so let's say the theorem says that no physical matter or energy existed before the universe.

The conclusion is that since we don't know how something can come from nothing, we have no idea how the universe came into being.

The term supernatural means nothing, or at least, we don't know of anything which is not natural, so to say that something supernatural created the universe is to say we don't know how the universe began.

5uspect

kelly1 wrote: »

Oh so the maths changed? What caused the maths to change and why is that not weird?

All,
I'm sure you've all had enough of me by now. It's clear that you guys only want a debate on scientific grounds. I think it's unforunate that you won't engage in any kind philosophical argument.

If you want a philosophical argument have a read of this:
http://astroph.persiangig.com/Time%20before%20Time0408111.pdf

Rev Hellfire

wot he said

Sam Vimes

JC 2K3 wrote: »

The term supernatural means nothing, or at least, we don't know of anything which is not natural, so to say that something supernatural created the universe is to say we don't know how the universe began.

Excatly. We say "I don't know" but when someone uses the word supernatural what they're actually saying is "neither do I but I'll take a stab at it".

You're replacing something that appears impossible to our understanding with something that is by definition impossible.

The only difference is that you have said that it must break the laws of nature which is far less likely than the idea that it doesn't but we don't have a full understanding of the laws of nature.

And when you start tacking on things like the idea that this being gave us the bible, you're getting into fantasy territory.

kelly1

Sam Vimes wrote: »

The parts in bold are the flaws. The first part is flawed because it makes a massive leap in logic and makes the incorrect assumption that your personal understanding of what is "natural" is correct and complete. Do you know everything about the universe?

It's not a massive leap of logic. If you have pre-existing matter, then there's no creation. So whatever caused matter to exist, can't be made of physical matter.

Sam Vimes wrote: »

The second part is flawed because the theorem does not imply anything of the sort, it has merely been misinterpreted as robindch pointed out.

That's a different debate to the one above. And I'm not qualified to give a definite interpretation of the result of the theorem. But this is what Vilenkin says about it:

It is said that an argument is what convinces reasonable men and a proof is what it takes to convince even an unreasonable man. With the proof now in place, cosmologists can no longer hide behind the possibility of a past-eternal universe. There is no escape, they have to face the problem of a cosmic beginning (Many Worlds in One [New York: Hill and Wang, 2006], p.176).

Rev Hellfire

Sam Vimes wrote: »

Excatly. We say "I don't know" but when someone uses the word supernatural what they're actually saying is "neither do I but I'll take a stab at it".

Its actually worse than that, when someone says its supernatural, they're typically saying "we don't know and we'll never know so we should give up".

Rev Hellfire

kelly1 wrote: »

It's not a massive leap of logic. If you have pre-existing matter, then there's no creation. So whatever caused matter to exist, can't be made of physical matter.

If there's no creation then there's no need for something to create matter since its timeless by nature.

Zillah

kelly1 wrote: »

All,
I'm sure you've all had enough of me by now. It's clear that you guys only want a debate on scientific grounds. I think it's unforunate that you won't engage in any kind philosophical argument.

...

...


You are unbelievable.

You link a scientific article, then form some absurd philosophical arguments. We explain why it's both bad science and bad philosophy for eleven pages and you accuse us of not trying? What do you want, a parade down O'Connell Street with a different float for each flaw in your reasoning?

Naz_st

kelly1 wrote: »

All I'm looking for is an answer to post #123. I've had no real engagement with my line of reasoning and I don't see anyone refuting it by pointing out the flaw in my reasoning.

Ok, for the sake of argument, I'm going to accept the BGK paper and still point out the flaw in your argument. Here's how our universe came about (random explanation #1):

1) There is an elementary and infinitely large n-dimensional spacetime fabric of infinite mass that is both eternal and impossible to exist under the constraints of the physical laws of our universe. Let's call this the "Uber-Space".

2) Within the n-dimensional space-time manifolds of this uber-space there are random fluctuations in some fundamental parameters that produce localised pockets of finite dimensional spacetime. These localised pockets are "baby universes". Some fluctuations are 4-dimensional geodesic manifolds with random fundamental parameters (i.e. similar to our own universe)

3) Some of these manifolds have random fundamental physical parameters that allow for life forms to ultimately develop (like our own).

Therefore, our universe "began" a finite amount of time ago, but wasn't "created". It was a "natural" process under the fundamental physical laws of Uber-Space, but by definition "super-natural" under the localised physical laws of our universe. Since the BGK paper is based on the fundamental parameters of our universe (e.g. the Hubble parameter) and by definition is pointing out that the pre-bang physical model was different to our current universe, it cannot rule out the eternal Uber-space.

There you go - no God involved (unless you want to worship Uber-space, in which case I am now the head of the First Church of Uber-space and ergo infallible and in order to spread the one true word of Uber-space I'm going to need some cash donations ).

Sam Vimes

kelly1 wrote: »

It's not a massive leap of logic. If you have pre-existing matter, then there's no creation. So whatever caused matter to exist, can't be made of physical matter.

Which does not automatically translate to something supernatural. For example, energy is not physical matter. What about the second part of my point: "you're making the incorrect assumption that your personal understanding of what is "natural" is correct and complete".

Do you have a complete understanding of the laws of nature and if not, how can you be sure sure that the laws of nature must be broken to create the matter?

kelly1 wrote: »

That's a different debate to the one above. And I'm not qualified to give a definite interpretation of the result of the theorem. But this is what Vilenkin says about it:

As has been pointed out, he does not understand the theorem.

Rev Hellfire wrote: »

Its actually worse than that, when someone says its supernatural, they're typically saying "we don't know and we'll never know so we should give up".

Exactly what I was trying to say. Thanks for that

Zillah

All hail the Uber-Space, the Endless Sea, the Blind Watchmaker. We thank you for your impersonal potential for existence.

May you fluctuate unpredictably forever.

robindch

kelly1 wrote: »

Oh so the maths changed? What caused the maths to change and why is that not weird?

Didn't you read my response? The maths hasn't changed. The model has changed because you're dealing with a different system that isn't covered by the first model. That's all that Messrs BG and V have claimed.

kelly1 wrote: »

It's clear that you guys only want a debate on scientific grounds. I think it's unforunate that you won't engage in any kind philosophical argument.

As Zillah says, you were the guy who brought up a mathematical paper which, as far as I can figure out, you seemed to have sincerely believed destroyed any rational basis for non-belief. You seem to have believed this because you read Mr Craig and his friends and have not spent the time to understand the paper itself (which makes me wonder why you brought it up in the first place). With due deference to the yellow-jumpered Mr Craig, he is misleading you either intentionally or unintentionally and we have pointed out where this is happening in fairly minute detail. Not only have we shown that Mr Craig's notions are wrong at the mathematical level, we have also shown that the philosophical basis for Mr Craigs conclusions is broken too.

By all means start up a new thread on the philosophical implications of this, but for the moment, lets just try to stick to the discussion that you proposed at the beginning which is whether BGV being physically true would influence our non-belief in whatever current or former deity or deities that you happen to believe exist.

In my case, it certainly would not, for the simple reason that BGV and deities are as unrelated as chipmunks and cheese.

kelly1

robindch wrote: »

Didn't you read my response? The maths hasn't changed. The model has changed because you're dealing with a different system that isn't covered by the first model.

What you said was "It just says that the maths before the standard model of the big bang are different to the maths after it"! So did the maths change or not??

robindch

kelly1 wrote: »

So did the maths change or not??

I didn't say that the maths had changed (because things that are proved correctly now remain proved for all time). What I said is that the maths is different in the same way that a journey that needs a submarine and not a car requires you to choose a different mode of transport, and doesn't require you to transmute a car into a submarine. If BGV are correct, then what has changed is the mathematical model, which is the mapping of mathematics to physical reality. And that shouldn't surprise anybody, since the physics would appear to be quite different.

To reduce it to the simplest possible terms: Let's call the mathematics that underlies the inflationary big bang model "blue maths".

Some people think that "blue maths" works "before" the big bang. BGV have claimed that "blue maths" doesn't work "before" the big bang, and that maths of some other color is needed.

What Craig -- neither a mathematician, nor a cosmologist, I note -- has said is that since "blue maths" doesn't work before the big bang, therefore his own "god maths" (for want of a better term) is the only solution. That's complete nonsense. I've no doubt that there are plenty of other solutions and very few of them indeed, and perhaps none, support Craig's position.

I don't think it can be made any simpler than that.

marco_polo

Zillah wrote: »

All hail the Uber-Space, the Endless Sea, the Blind Watchmaker. We thank you for your impersonal potential for existence.

May you fluctuate unpredictably forever.

I bet Uber-space doesn't judge me when I take a copy of Hustler and an odd sock into the jacks.

Zillah

robindch wrote: »

therefore his own "god maths" (for want of a better term)

I want a better term :pac:

Sam Vimes

Zillah wrote: »

I want a better term :pac:

How about "not maths"?

Rev Hellfire

Zillah wrote: »

I want a better term :pac:

Mysticamatics

A system where a + b can be whatever you want it to be.

Zillah

Yah they're both good.

More seriously, Noel, do you see how the Uber-Space idea can suggest that God is not an inevitable conclusion even if we know the universe as we know it had a beginning?

Dades

Zillah wrote: »

I want a better term :pac:

How about dogmathics.

Goduznt Xzst

Zillah wrote: »

More seriously, Noel, do you see how the Uber-Space idea can suggest that God is not an inevitable conclusion even if we know the universe as we know it had a beginning?

Our survey says...

Tim Robbins

kelly1 wrote: »

Something cannot emerge from nothing.

Define "nothing"?

kelly1

Tim Robbins wrote: »

Define "nothing"?

I don't know the definition according to physics, but I would define it as the complete absence of space-time/energy/matter/anti-matter. Not sure if that covers it all?

EDIT: i.e. that "state" which is beyond the boundary of the inflating universe.

Tim Robbins

kelly1 wrote: »

I don't know the definition according to physics, but I would define it as the complete absence of space-time/energy/matter/anti-matter. Not sure if that covers it all?

Of course it doesn't. You can only define nothing as an absence of things you know about.

So it's a human construct. Which is where the argument "how you can something from nothing?" falls apart.

Something and nothing could be the exact same thing, but it may just appear as "nothing" because you can't detect the "something".

kelly1

Tim Robbins wrote: »

Of course it doesn't. You can only define nothing as an absence of things you know about.

So it's a human construct. Which is where the argument "how you can something from nothing?" falls apart.

Something and nothing could be the exact same thing, but it may just appear as "nothing" because you can't detect the "something".

So you think the universe could be inflating into something? Are any scientists making this claim?

EDIT: Couldn't we define nothing as the absence of everything, known and unknown?

Sam Vimes

kelly1 wrote: »

So you think the universe could be inflating into something? Are any scientists making this claim?

Eh?

kelly1

Sam Vimes wrote: »

Eh?

Tim, have I misunderstood you?

robindch

kelly1 wrote: »

[...]

Noel, did this post answer your question?

Zillah

Nothing isn't.

kelly1

I'll have to read the paper again but it's way beyond my knowledge. To be honest I'm going mostly by the quotation from Vilenkin's book i.e.

With the proof now in place, cosmologists can no longer hide behind the possibility of a past-eternal universe. There is no escape, they have to face the problem of a cosmic beginning (Many Worlds in One [New York: Hill and Wang, 2006], p.176).

robindch wrote: »

If BGV are correct, then what has changed is the mathematical model, which is the mapping of mathematics to physical reality. And that shouldn't surprise anybody, since the physics would appear to be quite different.

How can the model change before and after the big-bang? Is that what you're saying? I'd say the model is wrong and therefore needs modification, not that it changes at the instant of the big-bang.