“Remember, on the block universe model, the past is no different than the future or the present.
Everything is relative: what is past to you, will be future to someone else.
So if I travel back to the past I’m travelling to what is someone else’s future. That means the past won’t be any different, in kind, to the present. “

http://www.abc.net.au/news/science/2018-09-02/block-universe-theory-time-past-present-future-travel/10178386

Enjoy.

Peak Warming Man said:

“Remember, on the block universe model, the past is no different than the future or the present.
Everything is relative: what is past to you, will be future to someone else.
So if I travel back to the past I’m travelling to what is someone else’s future. That means the past won’t be any different, in kind, to the present. “

http://www.abc.net.au/news/science/2018-09-02/block-universe-theory-time-past-present-future-travel/10178386

Enjoy.

> Confused yet?

Yes. It this a theory dating to pre-1920, or one of Tegmark’s early topological multiverses?

It contradicts the second law of thermodynamics. https://www.youtube.com/watch?v=VnbiVw_1FNs

¿Who was crazy enough … oh Catalyst. That explains it.

>On this view, the past, present and future all exist — and are equally real.

I don’t know of anyone who believes otherwise. I don’t see why this requires any “new theory”.

>For all we know, the reason the past is the way it is, is in part due to the presence of time travellers.

Actually: for all we know, the reason the past is the way it is, is not at all due to the presence of time travellers.

It’s a poorly written article.

Bubblecar said:

>For all we know, the reason the past is the way it is, is in part due to the presence of time travellers.

Actually: for all we know, the reason the past is the way it is, is not at all due to the presence of time travellers.

It’s a poorly written article.

Yeah might be someone after a grant, are they saying that time is stationary and we move through it or something? dunno.

Any modern mathematical cosmological model includes the past, present and future as real parts of the spacetime continuum.

But that’s just a model.The world described by physics ensures that observers are stuck at the junction of past and future light cones.

Bubblecar said:

Any modern mathematical cosmological model includes the past, present and future as real parts of the spacetime continuum.

But that’s just a model.The world described by physics ensures that observers are stuck at the junction of past and future light cones.

I wondered where Observer had got to.

Bubblecar said:

Any modern mathematical cosmological model includes the past, present and future as real parts of the spacetime continuum.

But that’s just a model.The world described by physics ensures that observers are stuck at the junction of past and future light cones.

By fiddling around with the spacetime geometry time travel can be introduced, but whether that will ever be feasible in real life is another matter.

Bubblecar said:

> On this view, the past, present and future all exist — and are equally real.

I don’t know of anyone who believes otherwise. I don’t see why this requires any “new theory”.

Any modern mathematical cosmological model includes the past, present and future as real parts of the spacetime continuum.

But that’s just a model.The world described by physics ensures that observers are stuck at the junction of past and future light cones.

By fiddling around with the spacetime geometry time travel can be introduced, but whether that will ever be feasible in real life is another matter.

There’s a difference between geometry (i.e. mathematics) and physics. My personal opinion is that we can never travel into the past or see into the future, but can see into the past and travel into the future.

> I don’t know of anyone who believes otherwise.

I don’t either, which comes as a surprise to me as I’ve struck people who have believed a lot of very strange things.

Peak Warming Man said:

Bubblecar said:

Any modern mathematical cosmological model includes the past, present and future as real parts of the spacetime continuum.

But that’s just a model.The world described by physics ensures that observers are stuck at the junction of past and future light cones.

I wondered where Observer had got to.

He is stuck at the junction of past and future.

I told him his observations were dodgy, he never listened.

Tau.Neutrino said:

Peak Warming Man said:

Bubblecar said:

Any modern mathematical cosmological model includes the past, present and future as real parts of the spacetime continuum.

But that’s just a model.The world described by physics ensures that observers are stuck at the junction of past and future light cones.

I wondered where Observer had got to.

He is stuck at the junction of past and future.

I told him his observations were dodgy, he never listened.

He’s on the wrong side of history.

mollwollfumble said:

Bubblecar said:

> On this view, the past, present and future all exist — and are equally real.

I don’t know of anyone who believes otherwise. I don’t see why this requires any “new theory”.

Any modern mathematical cosmological model includes the past, present and future as real parts of the spacetime continuum.

But that’s just a model.The world described by physics ensures that observers are stuck at the junction of past and future light cones.

img src=”/uploads/6367be2e-3135-4399-a2b4-48685ad25cde.jpe” />

By fiddling around with the spacetime geometry time travel can be introduced, but whether that will ever be feasible in real life is another matter.

There’s a difference between geometry (i.e. mathematics) and physics. My personal opinion is that we can never travel into the past or see into the future, but can see into the past and travel into the future.

> I don’t know of anyone who believes otherwise.

I don’t either, which comes as a surprise to me as I’ve struck people who have believed a lot of very strange things.

I’m confused.

Bubblecar says that the “block universe” model is just what everyone accepts, and he doesn’t know of anyone who believes otherwise, then Moll expresses a different personal opinion, but then says he doesn’t know anyone who believes otherwise either.

Personally, I think it’s quite possible that past and future have no real existence.

I also think it is possible that they have a real existence, but it is constantly changing.

I also think it is possible that they have a real existence and it is unchanging.

I can’t think or any way to check these hypotheses.

The Rev Dodgson said:

mollwollfumble said:

Bubblecar said:

> On this view, the past, present and future all exist — and are equally real.

I don’t know of anyone who believes otherwise. I don’t see why this requires any “new theory”.

Any modern mathematical cosmological model includes the past, present and future as real parts of the spacetime continuum.

But that’s just a model.The world described by physics ensures that observers are stuck at the junction of past and future light cones.

img src=”/uploads/6367be2e-3135-4399-a2b4-48685ad25cde.jpe” />

By fiddling around with the spacetime geometry time travel can be introduced, but whether that will ever be feasible in real life is another matter.

There’s a difference between geometry (i.e. mathematics) and physics. My personal opinion is that we can never travel into the past or see into the future, but can see into the past and travel into the future.

> I don’t know of anyone who believes otherwise.

I don’t either, which comes as a surprise to me as I’ve struck people who have believed a lot of very strange things.

I’m confused.

Bubblecar says that the “block universe” model is just what everyone accepts, and he doesn’t know of anyone who believes otherwise, then Moll expresses a different personal opinion, but then says he doesn’t know anyone who believes otherwise either.

Personally, I think it’s quite possible that past and future have no real existence.

I also think it is possible that they have a real existence, but it is constantly changing.

I also think it is possible that they have a real existence and it is unchanging.

I can’t think or any way to check these hypotheses.

Cosmological models normally look at the whole thing, not just a snapshot at a particular time. So of course they treat what we see as the “past and future” as having “real existence”.

…also, GR models that don’t include thermodynamics are usually time-reversible, i.e., it doesn’t make any difference whether it’s “going” forwards or backwards. So moll was correct to introduce thermodynamics as a missing factor.

Bubblecar said:

…also, GR models that don’t include thermodynamics are usually time-reversible, i.e., it doesn’t make any difference whether it’s “going” forwards or backwards. So moll was correct to introduce thermodynamics as a missing factor.

Never mind that, get on with your packing.

Bubblecar said:

Bubblecar said:

…also, GR models that don’t include thermodynamics are usually time-reversible, i.e., it doesn’t make any difference whether it’s “going” forwards or backwards. So moll was correct to introduce thermodynamics as a missing factor.

Never mind that, get on with your packing.

Yes. Seconded.

Peak Warming Man said:

I’m not even following this thread but serendipity made me click on this post. And I was amused.

Bubblecar said:

…also, GR models that don’t include thermodynamics are usually time-reversible, i.e., it doesn’t make any difference whether it’s “going” forwards or backwards. So moll was correct to introduce thermodynamics as a missing factor.

I’m still not clear what the Mollwoll position on all this is though.

As for my position, I’m saying that there might well be some meta-time, in which some Great Omnipresent Djin might sit and observe our Universe, and if it did so, it might observe our universe passing through this space, with a particular position in time at any given meta-time.

Or it might be continuous through meta-time, and unchanging, or continuous and changing.

I am not aware of any evidence to choose between these options.

The Rev Dodgson said:

Bubblecar said:

…also, GR models that don’t include thermodynamics are usually time-reversible, i.e., it doesn’t make any difference whether it’s “going” forwards or backwards. So moll was correct to introduce thermodynamics as a missing factor.

I’m still not clear what the Mollwoll position on all this is though.

As for my position, I’m saying that there might well be some meta-time, in which some Great Omnipresent Djin might sit and observe our Universe, and if it did so, it might observe our universe passing through this space, with a particular position in time at any given meta-time.

Or it might be continuous through meta-time, and unchanging, or continuous and changing.

I am not aware of any evidence to choose between these options.

If there’s no evidence for it, there’s not much point considering it.

Bubblecar said:

The Rev Dodgson said:

Bubblecar said:

…also, GR models that don’t include thermodynamics are usually time-reversible, i.e., it doesn’t make any difference whether it’s “going” forwards or backwards. So moll was correct to introduce thermodynamics as a missing factor.

I’m still not clear what the Mollwoll position on all this is though.

As for my position, I’m saying that there might well be some meta-time, in which some Great Omnipresent Djin might sit and observe our Universe, and if it did so, it might observe our universe passing through this space, with a particular position in time at any given meta-time.

Or it might be continuous through meta-time, and unchanging, or continuous and changing.

I am not aware of any evidence to choose between these options.

If there’s no evidence for it, there’s not much point considering it.

that seems unprogressive

Bubblecar said:

The Rev Dodgson said:

Bubblecar said:

…also, GR models that don’t include thermodynamics are usually time-reversible, i.e., it doesn’t make any difference whether it’s “going” forwards or backwards. So moll was correct to introduce thermodynamics as a missing factor.

I’m still not clear what the Mollwoll position on all this is though.

As for my position, I’m saying that there might well be some meta-time, in which some Great Omnipresent Djin might sit and observe our Universe, and if it did so, it might observe our universe passing through this space, with a particular position in time at any given meta-time.

Or it might be continuous through meta-time, and unchanging, or continuous and changing.

I am not aware of any evidence to choose between these options.

If there’s no evidence for it, there’s not much point considering it.

Au contraire.

If we (or should I say I) see no evidence then we should go and look for some, rather than just picking one possibility and treating it like it was the only one that should be considered.

The Rev Dodgson said:

Bubblecar said:

The Rev Dodgson said:

I’m still not clear what the Mollwoll position on all this is though.

As for my position, I’m saying that there might well be some meta-time, in which some Great Omnipresent Djin might sit and observe our Universe, and if it did so, it might observe our universe passing through this space, with a particular position in time at any given meta-time.

Or it might be continuous through meta-time, and unchanging, or continuous and changing.

I am not aware of any evidence to choose between these options.

If there’s no evidence for it, there’s not much point considering it.

Au contraire.

If we (or should I say I) see no evidence then we should go and look for some, rather than just picking one possibility and treating it like it was the only one that should be considered.

I’m happy to leave it to the experts, who are aware of what the observational tools at our disposal can and can’t do.

Bubblecar said:

The Rev Dodgson said:

Bubblecar said:

If there’s no evidence for it, there’s not much point considering it.

Au contraire.

If we (or should I say I) see no evidence then we should go and look for some, rather than just picking one possibility and treating it like it was the only one that should be considered.

I’m happy to leave it to the experts, who are aware of what the observational tools at our disposal can and can’t do.

I’m not sure that they are, in this context.

Peak Warming Man said:

Nice.

:)