Time does.?

I would imagine that at one instance the whole of reality is in a certain state.

But now tends to be experienced from a first person perspective. It seems to be the subjective observer that is at the centre of a time measurement.

A unified "now" only makes sense for collections of objects which are moving sufficiently slowly relative to each other. (Relative) speed changes how fast time flows; so there's no unique temporal succession of nows; "now" is attached to a coordinate system. Worse, there's more than one time; time flows more slowly at lower elevations on Earth compared to higher ones.

I am thinking about causal explanations, the arrow of time and temporally organised histories.

How does relativity effect the accounts of WW2 for instance?

I don't understand "backward" causation but I feel the future cannot cause the past.but also that "now" cannot cause things happening simultaneously. I could not have done X at location C because I was at location B.

I am thinking about this from a personal phenomenological standpoint about how many things that are happening around me that I am not involved in as If they are somewhere completely different and almost irrelevant to me. For example think of isolated tribes in the pacific and Indian ocean or Amazon that may have been totally unaffected by WW2. It does seem like a fractured narrative of time.

However individual conscious is a particular dominant location. I suppose the opposite view is the Gods eye view of absolute time and a clockwork universe completely determined. There seems to be a tension between the subjective and the determined.

For which collections of objects does a unified now make sense?

What exactly does (relative) speed change?

Is anything worse (like there being more than one time, for example)?

And finally, where does time flow more slowly?


Edit - forget it, I see you've already answered all my questions prior to me posting them. Teach me to post from the bottom of the Mariana trench. Your answers show up before my questions!

I am interested in power relations and how one person becomes more significant or influential than another. Can you escape your now and enter a wider more influential sphere interacting more influentially with reality?

History is an interesting narrative of causal importance and influence where you measure yourself against legends but when you die these things fall out of significance. But we are led to believe that certain temporal events have more importance and value.

In this sense I suppose I am adding a dimension of ideology and power relations to accounts of time where time is described in a kind of biased way.

In relation to all this my older brother died recently. He had a terrible long illness. I feel now he is dead he is no longer suffering but also that he is released from the concerns of this realty/world and hopefully somewhere better.

I suppose it is preferable that your personal timeline does not coincide with to many horrid events.

Your question seems to run distinct things together.

For instance, you ask us to imagine several events happening simultaneously. So the first thought experiment involves simultaneity. To imagine it we do not need to imagine the events happening 'now', it is sufficient that we simply imagine them all happening 'at the same time' (whether past, present, or future).

And we can do it. That is, we can imagine numerous events occurring simultaneously. By hypothesis, doing that requires imagining that all the events have something in common. And what we imagine them having in common is the same temporal property.

Clearly, then, we can imagine temporal properties, else how could we pull off the imaginative feat described above?

And it is possession of one kind of temporal property rather than another that disguishes the 'now' from the past and the future. What we take to be 'now' is that which we take to have the property of presentness.

You ask 'when is now?'. The question answers itself. For now is now and not another time.

I don't understand "backward" causation but I feel the future cannot cause the past. — Andrew4Handel

Unlike some on this forum I don't have many weird ideas. But I've had the sneaking suspicion that in some way or shape the present might influence the past. Many-worlds notions might come into play. Just speculation. :nerd:

What differentiates one time location from another? — Andrew4Handel

Space.

For which collections of objects does a unified now make sense? — Isaac

Strictly speaking, none, but the approximation for there being a single sense of time common to all the objects gets better the slower they are moving.

What exactly does (relative) speed change?

How fast something is going (relative to something else) shows up in the coordinate transform in special relativity, measuring how much relativity weirdness is required to account for the change between two coordinate systems (one attached to a moving point from an object, one attached to the object). It's a scaling factor, so it contracts/expands what it multiplies. Specifically, time and space terms.

All true, and thanks, but my post was actually just a bad joke. Had way too much wine last night and no excuse for anything I wrote during the entire evening I'm afraid. Read our posts as if mine came before yours (we were talking about different speeds of time). But don't hold your breath as the whole venture is not anywhere near as amusing as the wine-soaked reading presented it to be last night!

There exists a relatively non-weird take on backward causation: Laws of physics are time-reversible; if you are physicalist who believes that physics exhausts all the truths about the world, then you have to conclude that causation, if there is such a thing, is time-symmetric. It is no less true to say that the future causes the past than it is to say that the past causes the future.

(Of course, as is usual with philosophy, not everyone is a physicalist, and even among physicalists there are different takes on causation, so that the above line of reasoning will not satisfy everyone, or even most.)

And we can do it. That is, we can imagine numerous events occurring simultaneously. — Bartricks

We can imagine events together that didn't happen simultaneously such as we can imagine three historical figure who were not alive at the same time but in our imagination they appear to us simultaneously.

It is like we are imposing a temporal structure on what we experience.

But how can we measure time without a perceiver and speculate about event order?

From a physics book: events are temporally related (or not) in three ways, as they are or are not within the light-cone of an "earlier" event.

https://en.wikipedia.org/wiki/Light_cone

These are called time-like, light-like, and space-like. Defining "now" with respect to these is a little bit tricky. It seems clear, though, that if you experience an event E that happened somewhere else, like an explosion in the distance, it happened before even you saw it. Maybe not by much. If you happen to record the time that you first saw it, then as a practical matter, that when it happened, but in fact it happened earlier.

I would say that true simultaneous events are space-like related. They are necessarily outside of each other's light-cone. That means that there is no clear answer to the the question of what happened first - that depends on the observer, and where he is and his velocity. Paradox! If the relation of events is space-like separated, how can they be said to have happened at the same time? The answer seems to be that "now," and simultaneity, are determined by the observer, and they are now or simultaneous with respect to his frame of reference.

Correction welcome!

You ask 'when is now?'. The question answers itself. For now is now and not another time. — Bartricks

somewhere between before and later.

↪jgill There exists a relatively non-weird take on backward causation: Laws of physics are time-reversible — SophistiCat

That's true, however sometimes mathematical models of physical processes are not isomporphic to those processes and give answers that are not appropriate. This may or may not be the case with time reversal. A comment by a physicist would be welcome here. :cool: