The Transactional Interpretation

See the (series of) article(s) that I linked to in my above post to Chris.

Ah, I get the theoretical claim being made. But it seems to me this is taking aspects of the modeling language (math) and reifying them as actuality.

What would it actually mean for time to be spatial, or for someone to be "outside" of time and looking back "into" time?

From the physicist Adam Frank:

Was Einstein Wrong?

So, is this really how time works? Do all events already exist in this "block universe" of Einstein's relativity? Is everything that will ever happen already trapped in the 4-D chamber of space-time?

This view is sometimes called "chrono-geo-determinism" (the geo part comes because Einstein's theory is really about the geometry of space-time). It's one example of a philosophical theory about the nature of reality that grows out of a related, and validated, scientific theory. It is literally meta-physics and it's exactly the kind of thing Bergson was arguing against.

For Bergson, and others at the time, there was a difference between the mathematical physics/data and the higher-order interpretation — the philosophy — you glued on it. It's in this way that Einstein could be right and wrong at the same time. He is clearly right about the science, but he could be wrong about the interpretation of time attached to that science.

Now, what are we to make of Bergson's claims?

I don't know enough about Bergson's explicit philosophy of time to take a stand one way or another, but I do think his separation between valid scientific theories and the metaphysics that grows around them is worth considering.

The physicist David Mermin once pointed out that we physicists have a way of turning our mathematical equations into "things" existing in the world. We take their success at describing aspects of the world (like the behavior of read-outs in an experiment) to mean the equations are fully interchangeable for real things (often unseen) existing out there independently in the real world.

But for Mermin, the equations are always abstractions. They are immensely powerful and immensely useful stories we tell about the world that capture some essential truth but not all truth.

So, is this really how time works? Do all events already exist in this "block universe" of Einstein's relativity? Is everything that will ever happen already trapped in the 4-D chamber of space-time?

This is an example of what I meant about inappropriate language. "Already" means "by this moment in time." Surely it's inappropriate to use it of a region of space-time that extends into the future.

[Laird]

Well, I agree that interpretation of what they mean by a timeless observer would make a block universe deterministic. But if "timeless" means outside time altogether, I don't think it would be.

I think it would. To be "outside time" and "observing the block universe" is to be observing each "moment" of the block universe's time "simultaneously" (in some sense - and I agree with you that language becomes fraught here). And if this is the case, then at each moment of the block universe's time, each other moment is in some sense "simultaneously" occurring. And if at every moment t₀, the events at every other moment t₁ are "simultaneously" occurring, then at t₀, the events at t₁ are certain.

Anyhow, that's my defence, which I said I was prepared to make.

[Laird]

Ah, I get the theoretical claim being made. But it seems to me this is taking aspects of the modeling language (math) and reifying them as actuality.

What would it actually mean for time to be spatial, or for someone to be "outside" of time and looking back "into" time?

Fair question. I suppose it's one thing to hypothesise it and another to describe what it actually means as a possibility. One possibility is that rather than being literally "timeless" (whatever that means), one enters a separate timeline from which one views the block universe of the first timeline.

In any case, I think the elephant in the room - as it often is on this forum - is consciousness. I don't see that physics adequately includes consciousness in its description of reality.

I think it would. To be "outside time" and "observing the block universe" is to be observing each "moment" of the block universe's time "simultaneously" (in some sense - and I agree with you that language becomes fraught here). And if this is the case, then at each moment of the block universe's time, each other moment is in some sense "simultaneously" occurring. And if at every moment t₀, the events at every other moment t₁ are "simultaneously" occurring, then at t₀, the events at t₁ are certain.

Anyhow, that's my defence, which I said I was prepared to make.

I think we'll have to agree to differ about this.

[Laird]

I think we'll have to agree to differ about this.

Bah. That's no fun. Where's your spirited opposition? ;-)

But seriously, that's OK. Happy to agree to differ.

Bah. That's no fun. Where's your spirited opposition? ;-)

But seriously, that's OK. Happy to agree to differ.

Actually, the more I think about it, the less I understand what it means to believe in a block universe. If it's purely descriptive, then a finite block is no more than a record of events for a certain set of positions and times, and I can't see that the existence of a record has any implications for free will. Or is particularly interesting in any way.

I think it's the idea of an observer standing outside space-time and perceiving it that causes the difficulty. It's not surprising that's a difficult concept, because it's beyond any intuitive understanding we have (or at least any I have). But is the possibility of such an observer necessary for belief in a block universe? Does the concept of a block universe have any practical consequences, or lead to any testable predictions? (Maybe it could in parapsychology, but does it in conventional physics?)

[Laird]

I can't see that the existence of a record has any implications for free will. Or is particularly interesting in any way.

I think it's the idea of an observer standing outside space-time and perceiving it that causes the difficulty.

Which seems to be a reiteration in slightly different terms of your earlier post #11, and so it seems best then to simply re-offer my original response of post #12, in particular its second-last paragraph.

Coincidentally, Michael Prescott has a new blog post entitled "The 4D Man" (5D Man?), in which he muses that reality may be five-dimensional, and that if we sometimes have access to a "5D mind," that may explain paranormal phenomena:
https://michaelprescott.typepad.com/mich...d-man.html