Space-time, Big Bang and Black Holes.

FrumiousBandersnatch said:

No. The characteristic of black holes is that the singularity is in the future, and, by definition, nothing can escape the event horizon (except, possibly, Hawking radiation).

The singularity of the big bang is in the past. If anything, it was more like a white hole, the time reversal of a black hole, except it was not embedded in some outer spacetime into which it ejected its contents.

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While the singularity of the BB is in the past, the singularity of the black hole is in the future.
As the physics student correctly pointed out in the video of post #172 the mathematics predicts inside the event horizon space takes on properties of time and time takes on properties of space.

This can be explained using the light cones in a Minkowski space-time diagram.


As an object moves towards the event horizon the light cones narrow as the object approaches the speed of light.
When it passes the event horizon it "tips over" which can be explained by examining the Schwarzschild metric.


This is the metric as an exterior solution of the Einstein's field equations outside the event horizon.
All metrics for space-time are defined as having a positive coefficient for the time-like dt term and a negative coefficient for the space-like dr term.
When r < 2MG/c² which is an interior solution inside the horizon, the signs are interchanged and the time like term becomes space-like and vice versa.
This is geometrically equivalent to rotating the axes 90º.
The object reaches the singularity in the future hence the singularity is in the objects future light cone.


This is all well and good except if the object wants to escape the black hole it has to change direction and move away from the singularity but to do this it will have to travel backwards in time into the past since the space-like and time-like regions have been interchanged.
This is a problem putting it mildly if the BB originated from a supermassive black hole where the singularity of the universe and the black hole were one in the same thing, expansion can only occur into the universes' past.

Mark Quayle said:

You do what you can with even scientifically accessible concepts. I do what I can with a concept that is logically sound —i.e, that logic says fits the gap, (whether or not it is a logical fallacy to fit it, it does fit it) thus: Existence begs a cause. The simplest explanation is 'first cause'. IF there is first cause, it is also by definition the only 'brute fact'.

I was saying that there is no need to assume an end, where our conceptual constructs end.

Reason does support the notion of first cause. You may say it is logically fallacious to say it proves first cause, and that's fine, but that reason asks for further cause than where we have gone in science, and finds the notion repugnant that cause is infinitely regressive, is pretty obvious, I think. And to suppose that mere mechanical fact (the only alternative to 'mind') can be self-existent, is, at least to my mind, also repugnant to reason.

Correct. But I do what I can.

Just as science does with its pursuits. And no, I'm not saying they are the same thing nor the same kind or even the same kind of descriptions, nor based on the same thing. But they are both reasonable.

If you want empirical evidence for first cause, all I have is the obvious fact of existence itself and the particular form it takes. From there, I suppose, the reasoning is philosophical and not scientific, as far as I know.

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OK, I don't think we're going to make much more progress here - I thought about raising emergent causality, which would put a new perspective on it, but that's probably stuff for a different thread.

Thanks for your resilience under pressure!

FrumiousBandersnatch said:

OK, I don't think we're going to make much more progress here - I thought about raising emergent causality, which would put a new perspective on it, but that's probably stuff for a different thread.

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'Emergent causality'? Please elaborate.

'Emergent' already implies an assumed causality. Seems tautological(?)

Mark Quayle said:

I suppose by 'emergent causality' you mean something along the lines of mechanical fact that produces its own principles by which it exists and operates, as it develops. I've heard it called 'co-emerging'. Even if the notion was plausible, my question is, how did it begin?

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What I mean is that, in fundamental physics, all interactions are time-reversible, there is no direction or 'arrow' of time. So there's no meaningful distinction between 'A caused B' and 'B caused A' (in quantum mechanics, this becomes even more tricky).

The arrow of time emerges at the macro-scale as a statistical phenomenon, the result of entropy (roughly, disorder) increasing. Entropy increases because there are many more ways to be disordered than ordered, so an ordered system will tend to become disordered. At the time of the big bang, the universe had very low entropy (was very 'ordered'), and entropy has been increasing ever since (Second Law of Thermodynamics). Only with an arrow of time can one meaningfully say that A caused B, because of the implicit temporal ordering, that B followed, or was a result of, A.

Mark Quayle said:

And, by the way, thanks for your good humor and for not giving up on me. I have very much enjoyed our conversations.

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The goal, as I see it, is mutual understanding, if not agreement.

Mark Quayle said:

Time passage is not the only way of causality.

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Can you explain? how do you define causality without time ordering?

Mark Quayle said:

The quickest one that comes to mind, you wouldn't accept, but to me it is kind of funny: That we can pray for a certain outcome that we know has already happened, but we don't know what the outcome was yet!

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In what sense is that causal?

Mark Quayle said:

I might've mentioned the suggestion that some science writers (I don't often hear from the scientists themselves), that it seems we cause some things to happen before we even stepped into that causation — I don't remember if that was a comment on the double slit experiment and the fact that what happens not only seems to be caused by our observation, but that it appears to have happened before we observed it? —I don't really remember. Part of that, I suppose is derived from the thinking that all times exist just as surely as the one we occupy right now.

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Retrocausality has been suggested as an explanation for some quantum effects, but, as the name suggests, posits a reverse time ordering. It can be a matter of temporal viewpoint or interpretation (e.g. the idea that a positron is an electron going backwards in time). But, as I already said, without an arrow of time, causality isn't a particularly meaningful or useful concept - the statistical increase in entropy is what gives it meaning.

The block universe of Einsteinian relativity makes all points in time equally real, but doesn't change the experience/perception of causality its occupants have.

Mark Quayle said:

Anyhow, it is an assumption that it is dependent on time, but I say it is only dependent on logical sequence. If, for us, anyway, that depends on time, then ok, but for first cause, I don't see how time is relevant to it. Time may be necessarily caused with the first effect —I don't know— but I don't really think so. I think it is only us who seem to find it impossible to think outside of time.

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Causality is logical sequence reified; i.e. causal sequences are how abstract logical sequences are realised in the world. In the world, causality means effects follow their causes.

FrumiousBandersnatch said:

In what sense is that causal?
...
Retrocausality has been suggested as an explanation for some quantum effects, but, as the name suggests, posits a reverse time ordering. It can be a matter of temporal viewpoint or interpretation (e.g. the idea that a positron is an electron going backwards in time). But, as I already said, without an arrow of time, causality isn't a particularly meaningful or useful concept - the statistical increase in entropy is what gives it meaning.
..
The block universe of Einsteinian relativity makes all points in time equally real, but doesn't change the experience/perception of causality its occupants have.
...
Causality is logical sequence reified; i.e. causal sequences are how abstract logical sequences are realised in the world. In the world, causality means effects follow their causes.

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If human minds were incapable of recollecting experiences, I would argue that we would have no concept of time.

If humans were incapable of realising experiences, I would argue that we would have no objective concepts such as time's arrow, changes in entropy, ticking of a clock, causality, etc.

The origin of time would thus emanate from our own self-recognition of how our minds work at a fundamental level.
Everything else is just descriptions created by our minds, in order to make sense of that fundamental.

Mark Quayle said:

How does it matter what the experience of a thing is, as to the reality or the substance of what the thing is?

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You never experience reality?

MArk Quayle said:

The "follow" no more proves time passage than our experience does.

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Funny thing that is, eh?

Mark Quayle said:

My experience of the reality of any one thing is not the whole of the reality of that thing.
IF God is real, my experience of him may be real enough, but my experience of him is nowhere near the whole of what God is.

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Yes .. I can see that's your reality, which you experience then describe .. (just as you did right there).

Mark Quayle said:

If you fly by a star you will experience certain things concerning that star, and the star may be real, and your experience of it may be real, but your experience of it is not the star itself.

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Sure .. that would be my experience of 'flying by a star'.

There is no demonstrable difference between experiencing 'the star' and experiencing 'the star itself'. I mean the star is a star, yes?
To say otherwise, implies that the star is not the star.

Mark Quayle said:

Do you need me to tell you the story of the blind men describing the elephant?

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The story is of no concern. More significantly, the blind men's description would be one of their experience of what they mean by 'the elephant'.

Mark Quayle said:

I didn't say there's any difference between experiencing the star, and experiencing the star itself. But there IS a difference between one's experience of the star, and what the star itself IS.

So what it the big deal about the experience? It is not the reality. So what if the blind man experienced only what he did? Subjective experience is not the reality of the thing being experienced.

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Yea like 3D street art

Mark Quayle said:

I didn't say there's any difference between experiencing the star, and experiencing the star itself. But there IS a difference between one's experience of the star, and what the star itself IS.

So what it the big deal about the experience? It is not the reality. So what if the blind man experienced only what he did? Subjective experience is not the reality of the thing being experienced.

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Perceptions, either via the senses or not, are experiences.
You cannot separate your perceptions from experiences .. they are one in the same.

BeyondET said:

Yea like 3D street art

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Optical illusions are still perceived experiences.

Mark Quayle said:

Of course, but so what? Neither one is the reality of the thing perceived or experienced.

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Well that idea doesn't seem to be of any practical value(?)
Are you saying all our experiences are just a delusion?