Is time physical?

[Machinist]

To me, that sounds a lot like the analogy of the film strip. The strip itself is unchanging, but all the frames together comprise a picture of change.

I was thinking it was something more like an ancient eastern idea, like yin and yang. It sounds like it. When you were talking about taking a 3D cross section of a 4D universe, the result would be a 3D slice. Slice however, invokes 2D in my mind, so I think i'll start using diorama for now, until a better word is offered. Anyhow, if you take this 3D cross section, wouldn't it require a 3D plane? That's what I mean by eastern. It just seems that there are many ideas from the east that reconcile opposites like that. A 3D plane, while contradictory, at least isn't far from being reducible or derivative to one another.

It's got a lot more difficult to think about this now. Before, it was easy to visualize 2D slices being stacked to form a block, but ever since you mentioned 3D cross sections, i'm more confused than ever. You're not stacking slices, your stacking 3D universes to make this block. How, where, who, what, when is the interface between these universes?

[Sparko]

I can grasp the idea of me being a baby somewhere in the universe (of course I don't believe it). But when we are speaking of the whole universe that is a completely different story. That dot universe that contained all space, times and frames still exists. When I ask where it exists, I mean how could it exist. If we look at the Block universe the entire universe exists as its large present or future size, and the entire universe exists as a dot. There is no place in the Block universe for the dot sized universe to exist with the large sized universe. Since both contained the entirety of space and time. I will hit this again, you need to give up Big Bang Cosmology because that does not work with B Theory.

We keep telling you that it didn't include all of time, just the moment in time that it existed in.

blockuniverse.jpg

[Sparko]

Although, from my first girlfriend there, I did learn that there is no time from the perspective of a photon. If light isn't affected by time, then it should be able to traverse these slices, or successions of frozen 3D dioramas... basically time travel.

It does, but in one direction. The photons from the big bang are still around, and what make up the Cosmic Microwave Background Radiation.

[seer]

We keep telling you that it didn't include all of time, just the moment in time that it existed in.

Sparko, that does not change my conclusions. First, the hot big bang or expansion was not necessary to created the universe. Second, it undermines the second law of thermal dynamics. The sun as we see it today, in this slice of time, will burn forever. Which also means that in the SAME block universe all suns will die and no sun dies. These conditions logically follow.

[Stoic]

I was thinking it was something more like an ancient eastern idea, like yin and yang. It sounds like it. When you were talking about taking a 3D cross section of a 4D universe, the result would be a 3D slice. Slice however, invokes 2D in my mind, so I think i'll start using diorama for now, until a better word is offered. Anyhow, if you take this 3D cross section, wouldn't it require a 3D plane?

Exactly! Though to avoid confusion, it's referred to as a hyperplane.

If "diorama" helps you think about it, fine. Otherwise, you could just stick with "cross section", to allow for more dimensions.

In higher dimensions
In analogy with the cross-section of a solid, the cross-section of an n-dimensional body in an n-dimensional space is the non-empty intersection of the body with a hyperplane (an (n − 1)-dimensional subspace).

That's what I mean by eastern. It just seems that there are many ideas from the east that reconcile opposites like that. A 3D plane, while contradictory, at least isn't far from being reducible or derivative to one another.

It's got a lot more difficult to think about this now. Before, it was easy to visualize 2D slices being stacked to form a block, but ever since you mentioned 3D cross sections, i'm more confused than ever.

I agree. Thinking about more than 3 dimensions gives me a headache, so I try not to do it too much.

You're not stacking slices, your stacking 3D universes to make this block. How, where, who, what, when is the interface between these universes?

To the extent that that question makes sense, I would say that the universes are adjacent to each other in the time dimension, in the same way that two slices of bread are adjacent to each other in the direction of the length of the loaf.

[Machinist]

The sun as we see it today, in this slice of time, will burn forever.

Wouldn't it be frozen in time forever? That's the way I am visualizing things. All activity ceases, even the sun. What is left is a paradoxically frozen ball of fire.

[Machinist]

To the extent that that question makes sense, I would say that the universes are adjacent to each other in the time dimension, in the same way that two slices of bread are adjacent to each other in the direction of the length of the loaf.

An idea that came to me yesterday was that each of these new universes are literally on top of each other. If it were possible to take two adjacent ones some indivisible unit of time apart, they would most likely look the same. It's the same location, just one disappears into ontological hibernation and the new one takes its place. The only difference I would think, that is, if expansion of space is really happening, is that each successive one gets a little bigger.

[seer]

Wouldn't it be frozen in time forever? That's the way I am visualizing things. All activity ceases, even the sun. What is left is a paradoxically frozen ball of fire.

In a sense it is frozen in time, but not. Presently our sun is very active, and it will always be active at this moment. Forever...

[Machinist]

In a sense it is frozen in time, but not. Presently our sun is very active, and it will always be active at this moment. Forever...

Not seeing it. In each of these universes that we are calling slices, when they pass, B theory holds that they still exist in some sense. The way I am seeing things at the moment, is that in whatever sense they are stored in, all activity has ceased. The only activity there is in all the universe is the present and eternal Now.

[Sparko]

Sparko, that does not change my conclusions. First, the hot big bang or expansion was not necessary to created the universe. Second, it undermines the second law of thermal dynamics. The sun as we see it today, in this slice of time, will burn forever. Which also means that in the SAME block universe all suns will die and no sun dies. These conditions logically follow.

Yes, each moment is eternal when viewed from OUTSIDE of the universe. Because there is no time outside of the universe. So what? That doesn't change the fact that an object only exists at specific time slices in the universe and not in others. Abraham Lincoln exists from 1809 to 1865. But he doesn't exist in any time slices before that. Just like if you had an ice cube with a fly embedded in it. The fly exists at a specific location in the ice cube and not in others.

The laws of thermodynamics exist within that block universe and not outside it. Entropy is built-in and only works in one direction.

[seer]

Not seeing it. In each of these universes that we are calling slices, when they pass, B theory holds that they still exist in some sense. The way I am seeing things at the moment, is that in whatever sense they are stored in, all activity has ceased. The only activity there is in all the universe is the present and eternal Now.

There are not universes though. There is one universe. But if they still exist, in this moment of time, our sun will burn forever. So in this one Block universe all suns will stay active, all suns will die.

[seer]

Yes, each moment is eternal when viewed from OUTSIDE of the universe. Because there is no time outside of the universe. So what? That doesn't change the fact that an object only exists at specific time slices in the universe and not in others. Abraham Lincoln exists from 1809 to 1865. But he doesn't exist in any time slices before that. Just like if you had an ice cube with a fly embedded in it. The fly exists at a specific location in the ice cube and not in others.

So our sun, in this moment of time, will burn forever. Never run out of energy?

The laws of thermodynamics exist within that block universe and not outside it. Entropy is built-in and only works in one direction.

How does entropy work when our sun will never experience entropy?

[Sparko]

So our sun, in this moment of time, will burn forever. Never run out of energy?

It isn't "burning" at all, is it? We are talking of one moment in time. Burning would require multiple moments and entropy over those moments. Is the sun "burning" in this photograph?

sun.jpg

this photograph could exist forever and the sun (and the clouds in the photo) will never change. Even if the sun were to go out today, this photograph would continue to exist. Because it is a single moment in time captured to a picture. The sun in that photo will never run out of energy.

How does entropy work when our sun will never experience entropy?

Because it does experience it over its existence in time. Each moment contains more entropy than the last. That's the way the universe is made.

[seer]

It isn't "burning" at all, is it? We are talking of one moment in time. Burning would require multiple moments and entropy over those moments. Is the sun "burning" in this photograph?

Our sun is producing energy, the photo isn't. So in our slice of time the sun will be producing energy for eternity.

this photograph could exist forever and the sun (and the clouds in the photo) will never change. Even if the sun were to go out today, this photograph would continue to exist. Because it is a single moment in time captured to a picture. The sun in that photo will never run out of energy.

The sun in that picture is not producing energy. Our sun would be, in this moment, forever.

Because it does experience it over its existence in time. Each moment contains more entropy than the last. That's the way the universe is made.

So in the same Block universe all suns burn for ever and all suns die. So entropy happens and doesn't happen.

[Sparko]

Our sun is producing energy, the photo isn't. So in our slice of time the sun will be producing energy for eternity.

Producing energy is a function of time. A single moment isn't "producing" anything at that specific moment. There is no motion of atoms at all. It is a nothing but a picture in 3D.

So in the same Block universe all suns burn for ever and all suns die. So entropy happens and doesn't happen.

It happens over time. Just like motion does.