B Theory Of Time...

[seer]

Sorry I've been away for a bit, gentlemen. I've perused back through the last few pages, and I saw that Sparko was doing a good job of answering a number of questions, but I figured I would come back in where I left off as this still seems to be a bit of a sticking point, from what I can see.

Yes. As I mentioned earlier in the thread, Time is almost universally recognized by philosophers, theologians, and physicists alike to be a physical thing.

Time doesn't change speed. Time doesn't have a speed. Time doesn't move. In General Relativity, the amount of time which an entity passes through is dependent upon the path which it carves out through space-time as measured from a particular point of perspective.

OK so time doesn't move. Then how do we know it exists? How do we measure it?

[Boxing Pythagoras]

OK so time doesn't move. Then how do we know it exists?

I presume you mean to ask how we know that it exists as a dimension of measure, rather than asking how we know Time exists at all. The mathematical models of Relativity allow us to make certain predictions about the behavior of the world around us, so we construct experiments to test these predictions and compare the collected data to the predicted results. This has been done to astonishing levels of precision in the case of General Relativity.

Literally every time you use a device that makes use of GPS, you're using technology which is built around the implications of Relativity on Time.

How do we measure it?

With clocks of varying levels of precision.

[seer]

I presume you mean to ask how we know that it exists as a dimension of measure, rather than asking how we know Time exists at all. The mathematical models of Relativity allow us to make certain predictions about the behavior of the world around us, so we construct experiments to test these predictions and compare the collected data to the predicted results. This has been done to astonishing levels of precision in the case of General Relativity.

Literally every time you use a device that makes use of GPS, you're using technology which is built around the implications of Relativity on Time.

With clocks of varying levels of precision.

I'm sorry, I don't get it, how do clocks measure something that is tenseless and static?

[Boxing Pythagoras]

I'm sorry, I don't get it, how do clocks measure something that is tenseless and static?

Much in the same way that rulers measure something that is tenseless and static: by having demarcations at regular increments over the particular dimension of measure.

[JimL]

I know. I'm just honestly not understanding which particular issue is confusing, so I'm having difficulty figuring out what needs to be explained more.

Whether we are talking about the A-Theory or the B-Theory, the state of a thing at time t1 and the state of a thing at time t2 are two different states of a single object. The state at t1 doesn't change on either model. It is the object, itself, which is changing. The only difference is that, on the A-Theory (at least on Presentist views) the state at t1 doesn't exist when t2 is the present moment.

I understand that much, but if as in B-theory the whole thing, all of time, every state at every point in all of time has always been, how can the things themselves be said to have changed? They are different states at different points in time, but they have always been different states at different points of time, yes?

There are several reasons why I don't like the film strip analogy. For one, it is completely inadequate and misleading for models in which Time is continuous rather than discrete. For another, even assuming a discrete theory of Time, people latch on to the idea of the film strip moving in Time rather than thinking of it as a depiction of Time, meaning that it is rather useless for actually illustrating the differences in the models for people already having difficulty wrapping their head around it.

But I'm not doing that, I'm thinking of the film as an analogy, as a depiction of time, in which the film itself, like time, is continuous. Would you not say that the film is a good analogy for a block universe in which time itself is static, and the film cells being analogous to the points in time? Neither the things in time nor the cells in the film are moving, but the positions of the same objects differ at each point in time and in each cell in the film.

Everything. Right now, our eyes see in three spatial dimensions. You're asking me what the entirety of a possibly-infinite, 4-dimensional space-time "looks" like. The best answer I can give is that it wouldn't look like anything you or I could understand.

Well, hypothetically say, if we thought of the universe as a 1 dimensional object as viewed from the outside, would you see motion, or would you simply see static objects at each point in the whole of a static time?

All of those components form the same object despite being spread out in Time in exactly the same way that your big toe, foot, ankle, shin, thigh, stomach, chest, arms, neck, and head all compose a single object despite being spread out in Space. Whether on the A-Theory or the B-Theory, the entity that is You at 6:30pm is the same entity that is You at 6:31pm, despite being in different states at those different times.

That much I understand. But is my body, being that it is spread out in time, forever spread out in time, or does it actually move from one state to the other, from position A at t1 to position B at t2. That's what I'm trrying to understand. What does change actually mean with respect to static time?

[37818]

There is only the now. And its past events. The future is only what the now becomes. Every place has its now which is a different now being a different place. The order of common past events are different order to each now of each place. The B theory is never true.

[Boxing Pythagoras]

I understand that much, but if as in B-theory the whole thing, all of time, every state at every point in all of time has always been, how can the things themselves be said to have changed? They are different states at different points in time, but they have always been different states at different points of time, yes?

I think that you are confusing yourself when you say that these things "have always been." You're mistaking the notion that these moments exist for thinking that they are somehow the same moment.

Imagine if someone asked you the question, "Do all locations on Earth exist for someone in New Jersey?" Now, if you answer that these locations do exist even for a person in New Jersey, imagine the other person saying, "How can people be in different places on Earth if all of those places exist in New Jersey?"

This is precisely akin to the confusion you seem to be having, here. All moments of time are coextant. That doesn't make them the same moment. So, while it is technically true to say that time t2 exists at time t1, that does not make them the same time; in exactly the same way that the North Pole exists in New Jersey, but it is not the same location as New Jersey.

But I'm not doing that, I'm thinking of the film as an analogy, as a depiction of time, in which the film itself, like time, is continuous. Would you not say that the film is a good analogy for a block universe in which time itself is static, and the film cells being analogous to the points in time? Neither the things in time nor the cells in the film are moving, but the positions of the same objects differ at each point in time and in each cell in the film.

You're actually making the mistake even as you're saying that you don't intend to do so. When you say that "time itself is static," you are saying that time does not change with respect to time. When you say that the cells in the film are not moving, you are imagining a film strip remaining unchanged as time passes. This is precisely the wrong way to think about it.

Well, hypothetically say, if we thought of the universe as a 1 dimensional object as viewed from the outside, would you see motion, or would you simply see static objects at each point in the whole of a static time?

If it's 1-dimensional, then we have either a dimension of space or a dimension of time, in which case motion is not even coherent. However, presuming that you mean either a 2-dimensional (one space, one time) or a 3-dimensional (two space, one time) universe, how do you propose a person could actually see such a thing? Sight requires both space and time. If we are "outside" of space-time, we haven't got these things available to us. We could make a model of such a thing within our own space-time, but what that model looks like depends entirely upon how we construct it and would fall prey to the same problems of analogy as the film strip.

That much I understand. But is my body, being that it is spread out in time, forever spread out in time, or does it actually move from one state to the other, from position A at t1 to position B at t2. That's what I'm trrying to understand. What does change actually mean with respect to static time?

Again, the definition of change which we've been discussing is exactly the same whether we are talking about the A-Theory or the B-Theory. This is why I think you are still conflating the idea that all of time is coextant for the idea that all of time is the same moment in time.

[seer]

Much in the same way that rulers measure something that is tenseless and static: by having demarcations at regular increments over the particular dimension of measure.

OK, so if I follow this logic, in this universe the 1969 me is still experiencing 1969. As a matter fact there are millions and millions versions of me experiencing every moment I experienced - all this contained in this very same universe.

[Sparko]

There is only the now. And its past events. The future is only what the now becomes. Every place has its now which is a different now being a different place. The order of common past events are different order to each now of each place. The B theory is never true.

Then how can God know what happens in the future?

[Sparko]

OK, so if I follow this logic, in this universe the 1969 me is still experiencing 1969. As a matter fact there are millions and millions versions of me experiencing every moment I experienced - all this contained in this very same universe.

They are not different versions of you. You are YOU throughout all of your lifetime that exists in every moment of time from your birth to your death. you only "experience" each moment once.

[JimL]

They are not different versions of you. You are YOU throughout all of your lifetime that exists in every moment of time from your birth to your death. you only "experience" each moment once.

So, what then are all the other we's that you say also exist in the past and the future, what are they doing? Are they all experiencing their own present? This evening when you are having dinner, will the past you still be experiencing having breakfast in the past? And is your future you already there in the future experiencing having lunch in their present?

[seer]

They are not different versions of you. You are YOU throughout all of your lifetime that exists in every moment of time from your birth to your death. you only "experience" each moment once.

So the 1969 me is not in the universe experiencing 1969? If this is really like the frames of a film that frame still exists.

[JimL]

I think that you are confusing yourself when you say that these things "have always been." You're mistaking the notion that these moments exist for thinking that they are somehow the same moment.

Exactly, but if you could explain how all points in time have always existed can also be said to be different moments it would help. In B-theory, all of time has always existed, so how could the points in time be distiguished from the whole of time? In your example of the ruler, the first inch and the last inch are basically indistinguishable with respect to the existence of the ruler as a whole itself. They have both existed as long as the ruler itself has existed.

Imagine if someone asked you the question, "Do all locations on Earth exist for someone in New Jersey?" Now, if you answer that these locations do exist even for a person in New Jersey, imagine the other person saying, "How can people be in different places on Earth if all of those places exist in New Jersey?"

But the point is that those locations on the earth all do exist, and as locations they, like the points in time, have always existed as long as the earth has existed. That fact doesn't change. So if all of time exists, and has always existed, like all locations on earth exist and have always existed, how does actual change with respect to time, fit into that picture?

This is precisely akin to the confusion you seem to be having, here. All moments of time are coextant. That doesn't make them the same moment. So, while it is technically true to say that time t2 exists at time t1, that does not make them the same time; in exactly the same way that the North Pole exists in New Jersey, but it is not the same location as New Jersey.

Again though, that doesn't explain change. different locations in space, and different locations in time doesn't explain change, it only explains the differences concerning the locations within in space and time. the north pole is always the north pole, and t1, t2 and t, 100, the past, present, and the future, are always the past, present, and the future.

You're actually making the mistake even as you're saying that you don't intend to do so. When you say that "time itself is static," you are saying that time does not change with respect to time. When you say that the cells in the film are not moving, you are imagining a film strip remaining unchanged as time passes. This is precisely the wrong way to think about it.

Again, if all of time exists and has always existed, then how can it be said that t1 existed before t2? Every marking on a ruler has existed as long as the ruler existed, there is no actual chage taking place with respect to the ruler as a whole. How is that not analogous to the B-theory of time?

If it's 1-dimensional, then we have either a dimension of space or a dimension of time, in which case motion is not even coherent. However, presuming that you mean either a 2-dimensional (one space, one time) or a 3-dimensional (two space, one time) universe, how do you propose a person could actually see such a thing? Sight requires both space and time. If we are "outside" of space-time, we haven't got these things available to us. We could make a model of such a thing within our own space-time, but what that model looks like depends entirely upon how we construct it and would fall prey to the same problems of analogy as the film strip.

But with all do respect, I don't think your explanation of motion with respect to B-theory makes sense, BP. If something actually moves through time, from t1 to t2, it's past self doesn't remain behind in t1. That isn't change, that's just two images, like the images on a film reel cell, of the same object at different locations in the whole of time. Like the cells on a film, the positions of things in time don't change, like the positions of things in the cells on the film, the positions of things at each point in time remain the same.

Again, the definition of change which we've been discussing is exactly the same whether we are talking about the A-Theory or the B-Theory. This is why I think you are still conflating the idea that all of time is coextant for the idea that all of time is the same moment in time.

I don't think that points in time is actually a coherent idea unless time itself changes, unless time itself flows into the future. B-theory doesn't admit of that, in B-theory, time is all there and so have all things and position of things in time, all there. If the whole doesn't change, then like the ruler example, afaics - neither do the points within it actually change.

[Jim B.]

Then how can God know what happens in the future?

God may not know what happens in the future, beyond highly accurate predictions. He could still be omniscient.

[Jim B.]

They are not different versions of you. You are YOU throughout all of your lifetime that exists in every moment of time from your birth to your death. you only "experience" each moment once.

I don't get it. Each moment of my life is coextant with every other moment of my life. The moment I'm experiencing as "Now" is just a psychological trick of some kind as is the linear journey from my birth to my death, right? Every moment is on parity with every other moment. I still don't have a grasp on what that exactly means.