Curvature and Free will (part 1)

[_Tarski]

I posted this a MA&D but it must have been a boring topic. Oh well. I'll try it here.
First a caveat. I am all for free will and I have felt the existential rush of an open future. But, physics seems to present a problem.
It starts off something like the following but gets more and more subtle as various philosophical points are raised and also as more physics is brought to the table.
Part of the point of the physics/philosophy that follows is that it seems to threaten our sense of free will and the sense that the future is open.

To start things off, let’s try and encapsulate some folk wisdom about time. It is usually thought, if only implicitly, that for every event (say the event of me seeing an explosion or deciding to sin), there is a division of time into the past, present and future relative to that event. It is also thought that there are three levels of reality here:
1. Real (0) The present is most definitely and clearly real. All events simultaneous with the explosion are completely real and definite.
2. Real (-1) The past is also real but in a weaker sense. Lincoln really was shot and the Berlin Wall really did fall. Those are real historical facts nestled solidly in the real past.
3. Real (+1) The events in the future are not real in that they do not (yet) exist. Furthermore, the set of future events is supposed to be open. There is, rather, a set of possible events and none are determined or yet real. Thus in this standard view, Real(+1) is actually unreal or at least not actual. It is thought that the structure of possible futures has a branching structure and depending in part on our choices we will go down one series of branches making those events first present, Real (0), and then past and thus Real (-1).

Now, it turns out that according to the highly successful special theory of relativity, the set of all events simultaneous with a given event (my “now”) is relative to my state of motion. In other words , there is no absolute fact of the matter about which events are in the past of a given reference event and which are in the present or future of the reference event.

But then the 3-fold ontological dichotomy above breaks down. There is no absolute present dividing past from future. It is also possible to show under mild assumptions, that the future must be just as real as the past. Real (-1) has the same definiteness as Real (+1). In fact, it looks like we are committed to a block universe picture of spacetime wherein the future is just as real as the past.

Another way of saying things is that there is no preferred way of slicing up the 4-d spacetime continuum into a series of “nows”, some of which are future and some of which are past. Such a slicing (think about space-time like a 4D loaf of bread) is called a foliation by space-like submanifolds (sorry for the jargon).

Now several other things must come in to play. One is quantum mechanics. Does it make a difference? (It seems not actually—at least not in a way that sounds anything less than bizarre). Second, it turns out that once gravitation is taken into account, the situation is mitigated slightly. This has to do with possibility of picking out a preferred notion of “now” intersecting any event and thus preferred notions of future and past. A curved spacetime that is symmetric enough can end up having a special foliation which could serve as our preferred way of reckoning what is past present and future and maybe allow some kind of resurrection of the notions of actual past and potential future. However, a closer look reveals that we don’t get off so easy.

[_Loquacious Lurker]

How do you factor Erwin Schrödinger into this? Until an observer collapses a wave function, the present is also fluid.

[_Sethbag]

I think you should get as little more specific on just how special relativity blurs the now and makes it hard to find the cutoff between the future and the past.

[_truth dancer]

Well, there have been those spiritual masters and psychics who believe the past, present, and future are one, and we are just experiencing a moment of the one time.

The example of Edgar Cayce and the Akashic records comes to mind. Everything already exists and we can tap into the truth at any time.

But then of course free will becomes an illusion.

OTOH, those religions that assert God is all knowing, the Alpha and Omega also imply that the future is already real.

I have a sense of an unfolding universe but I have experienced a sense of lack of time as well.

So my questions for you... :-)

As Loq said, how does the collapse of the wave function figure in, do you see a myriad of possibilities in any given moment?

And, what is your personal opinion on free will? Does it even exist from a physics perspective?

~dancer~

[_Thama]

Certainly Special Relativity shows that the relative rate of event progression is dependent on an object's state of motion. However, I don't see how this is equivalent to non-simultaneity of events. Events will occur at a slower rate (to the "motionless" observer) in an object approaching c, but the order of these events is preserved.

For example, to use the classic "twin" example, one on a starship approaching c and the other on Earth, the traveling twin will reach his 20th birthday at a later date than the motionless twin, but he may reach his 20th birthday at the same time that the motionless twin reaches his 50th birthday. Are the latter two events not simultaneous? Did the 19th birthday of the first twin and the 49th birthday of the second twin not occur in the "past" for both? Perhaps my understanding of Special Relativity is incomplete.

[_Tarski]

I think you should get as little more specific on just how special relativity blurs the now and makes it hard to find the cutoff between the future and the past.

Let us say that there are two spaceships passing each other (say very fast for effect). Let say close enough that their passing can be considered a single event at a single location. Now your inertial frame gives you a set of numbers, x,y,z,t for every event in the universe (so far flat Minkowski space). But, I would have a different set of numbers for those events--say, X,Y,Z,T. The relation between those numbers is via a Lorentz transformation. Let us set clocks so that our clocks agree at the moment of passing, say t=T=0. Let us now suppose that we both refer to a single event like the act of Joe committing adultery on Earth. Let's call this event A. Now it is quite possible that for me Joe has already committed adultery, so T(A)<0, while for you event A is still in the future, so t(A)>0.
We disagree on what events have happened and what events have not. This is no illusion, we have taken everything into account. There is no fact of the matter about who is right.

More: Suppose we somehow are able to conceive of the set of all events simultaneous with the event of out passing each other.
For me it is the set of all events with T=0, but for you it is the set of all events such that t=0. But these sets disagree! We do not agree on which events are happening elsewhere as we pass each other. Some of the events that are happening at that moment with respect to my frame have already happened in your frame.
Past and future are are not cleanly divided by a single universal "now" applicable across space. If we assume that the actuality of an event should be a Lorentz invariant then we must take all events past and future as equal actual. In other words, if we reasonable assume that one thing we should not disagree about is whether an event is definite and real or not, then since past events are definite and present events are real and definite it must be that all events anywhere and anytime are equally definite and actual. At least, this is the idea.


The basic idea of the resulting block universe picture is that being in the here and now is like being "here" at a location. If I say that the Eiffel tower is not "here", this does not make the Eiffel tower any less concrete or actual. Similarly, if I say that my death at sea 300 miles west of London is not here and now this is not to say that may death at sea is any less actual, defnite or real. In this picture, events past and future are more like locations north east west and south; over here is me saying my death is not here and over there is me dying at sea.

[_Tarski]

Certainly Special Relativity shows that the relative rate of event progression is dependent on an object's state of motion. However, I don't see how this is equivalent to non-simultaneity of events. Events will occur at a slower rate (to the "motionless" observer) in an object approaching c, but the order of these events is preserved.

For example, to use the classic "twin" example, one on a starship approaching c and the other on Earth, the traveling twin will reach his 20th birthday at a later date than the motionless twin, but he may reach his 20th birthday at the same time that the motionless twin reaches his 50th birthday. Are the latter two events not simultaneous? Did the 19th birthday of the first twin and the 49th birthday of the second twin not occur in the "past" for both? Perhaps my understanding of Special Relativity is incomplete.

This is not a good description of the twins paradox or time dialation. One reason is that you are using the phrase "same time" as if that were an absolute notion for both twins. The story should be told in terms of the so called proper time durations for each twin. This is what is measured by clocks they carry with them including their biological clocks etc. Avoid talk of universal nows and "same times" for spatially separated events.
As for simultaneity, see this: http://en.wikipedia.org/wiki/Relativity_of_simultaneity

[Guest]

I think you should get as little more specific on just how special relativity blurs the now and makes it hard to find the cutoff between the future and the past.

Let us say that there are two spaceships passing each other (say very fast for effect). Let say close enough that their passing can be considered a single event at a single location. Now your inertial frame gives you a set of numbers, x,y,z,t for every event in the universe (so far flat Minkowski space). But, I would have a different set of numbers for those events--say, X,Y,Z,T. The relation between those numbers is via a Lorentz transformation. Let us set clocks so that our clocks agree at the moment of passing, say t=T=0. Let us now suppose that we both refer to a single event like the act of Joe committing adultery on Earth. Let's call this event A. Now it is quite possible that for me Joe has already committed adultery, so T(A)<0, while for you event A is still in the future, so t(A)>0.
We disagree on what events have happened and what events have not. This is no illusion, we have taken everything into account. There is no fact of the matter about who is right.

More: Suppose we somehow are able to conceive of the set of all events simultaneous with the event of out passing each other.
For me it is the set of all events with T=0, but for you it is the set of all events such that t=0. But these sets disagree! We do not agree on which events are happening elsewhere as we pass each other. Some of the events that are happening at that moment with respect to my frame have already happened in your frame.
Past and future are are not cleanly divided by a single universal "now" applicable across space. If we assume that the actuality of an event should be a Lorentz invariant then we must take all events past and future as equal actual. In other words, if we reasonable assume that one thing we should not disagree about is whether an event is definite and real or not, then since past events are definite and present events are real and definite it must be that all events anywhere and anytime are equally definite and actual. At least, this is the idea.


The basic idea of the resulting block universe picture is that being in the here and now is like being "here" at a location. If I say that the Eiffel tower is not "here", this does not make the Eiffel tower any less concrete or actual. Similarly, if I say that my death at sea 300 miles west of London is not here and now this is not to say that may death at sea is any less actual, defnite or real. In this picture, events past and future are more like locations north east west and south; over here is me saying my death is not here and over there is me dying at sea.

How can one party make an equation on what is going to occur in the future? How can the other party even see what would be in the future? I don't understand creating an equation of the future. I don't really understand what you're saying, I suppose. How can one party think something is going to happen in the future and make a model on it and see it in the future? That seems like psychic abilities and I must be missing the point.

~edited for clarity~

[Guest]

I saw you mention blindsight: let's say the equations of xyztittiddlywink and XYZTIDDLYWINK of the same exact event are not what is in dispute or actually of concern or even there's not concern about future for one party, really. Is it not just as important with the use of blindsight to wonder why that equation even came to be? What occurred before hand to make that passing happen and how it was perceived by both parties regardless of what occurred at the exact passing or what may have potentially occurred after?

[_moksha]

A curved spacetime that is symmetric enough can end up having a special foliation which could serve as our preferred way of reckoning what is past present and future and maybe allow some kind of resurrection of the notions of actual past and potential future. However, a closer look reveals that we don’t get off so easy.

What if we triangulate a series of Heisenberg Compensators to focus on this particular event horizon?