Is Time an illusion?

Who can say? :smiley:

Well, that would be quite a lucky “hit” for me, as I wasn’t responding to anyone really. Just going on a philosophical rant.

On a quick reading of McTaggart’s theory…I don’t get it. It smacks of logical sleight of hand, like the ontological proof of god, or all the various proofs of 1 = 2. But I haven’t quite got my head round it to say for sure.

It’s a singular illusion.

That’s not what he said. It was the other way around.

He said gravity made it possible for the universe to exist without a God to create it.

There could still be a God.

If this is true, it’s also false, because if there’s no time, then the term ‘simultaneous’ is meaningless.

Well… yeah… I guess I thought that was a given. We live in a 4-dimensional matrix with position defined by (x, y, z, t).

I have heard the idea that the apparent flow of time is driven by entropy. Since thermodynamic processes are not reversible, it isn’t so simple to move back in time. If moving north required us to reverse entropy, we’d all be headed south.

And I have also heard the idea that the speed of light isn’t so much a cap on speed in the three dimensions as it is an absolute measurement of total speed in all four dimensions. In other words, the sum of the velocities in all four dimensions always comes out to c. Thus, you have time dilation - for things traveling very close to c in the three “traditional” dimensions, they have less velocity left over for traveling through time.

I don’t know how strictly scientific those two ideas are, but I like them.

Meatros, shall I give you $100 tomorrow, or a thousand years from now? I guess it doesn’t matter: time is an illusion! So, bewitched by the illusion, I think I’ll give it to you a thousand years from now. It’s all the same to you, right?

I don’t think it is a given - at least not as I understand it. It seems to me that most people still think in terms of the “A” theory. Most people will talk of ‘time’ coming into existence, for instance, with the big bang.

I’ve heard of this as well.

I haven’t heard that, but it seems to make sense.

Cite on this?

As for this “A time and B time” business, I’d be willing to wager that all of the main philosophers involved were completely ignorant of any of Einstein’s work. Anyone can sit in their armchair and come up with something to fill a philosophy book, but it ain’t worth squat unless it’s based on observations of the real world.

You are confusing our perception of the flow of time and it’s ontology; You are perceiving the flow of time as an actual thing, not simply a dimension (a characteristic of a thing).

I would say that if I receive $100 from you tomorrow, that it is set in stone - the time and place of my receiving the $100 cannot change. Whereas you, presumably, would say that it remains to be seen whether I will get the $100 tomorrow.

The difference between our two views is that hypothetically, I could step into a wormhole, check to see if I did get the $100 and then report back to this thread today.

You, on the other hand, could not - hypothetically speaking. Rather, I should say, it doesn’t seem clear at all how you could.

Actually if you’ll check out the posts, this is not the case. It’s primarily because of Einstein’s work that the B theory has adherents.

The B theory makes sense out of relativity and simultaneous presents, whereas the A does not. This is, in my view, the selling point of this view.

Did you read this thread?

*It should be noted that we aren’t saying you don’t exist, Chronos… :wink:

From the Carrier link above:

Bosh and nonsense. Any reasonable person would like $100 tomorrow rather than have to wait so long (with the certainty that we’d both be dead by then), thereby acknowledging that time is not an illusion.

Interesting, I’ve never heard of this view of his. Could you elaborate/point me to some elaboration? (Not wanting to cry ‘cite’, as I don’t doubt your claim, I just want to know more…)

Anyway, as to the OP, Carlo Rovelli has been putting forward an argument (or a series of arguments) that in the still hypothetical theory of quantum gravity, there probably won’t be any fundamental notion of time. The reason for this is that 1) the notions of time in quantum field theory and general relativity are fundamentally incompatible – the former regards it essentially as an external parameter relative to which dynamical evolution is to be measured, while to the latter, it is an inextricable part of the dynamics of the theory itself --, an inconsistency which getting rid of time altogether would solve neatly, and 2), as you go ‘deeper down the rabbit hole’ of physical theories, time gradually loses most of the properties we intuitively ascribe to it – going from thermodynamics to mechanics, it loses its directionality; going to special relativity, it is no longer unique, but rather, there are as many ‘times’ as there are Lorentz observers; in general relativity, time is no longer external, but a dynamical quantity of the theory; in quantum mechanics, there is no really ‘exact moment’, time being subject to an uncertainty relation with its conjugate quantity, energy; and so on.

In this sense, time might actually be regarded as an illusion, or at least, as non-fundamental; rather, it emerges from a timeless underlying theory.

The perception of the flow of time is the illusion. Time is a dimension.

Your ‘question’ doesn’t actually deal with the heart of the issue. It seems to be a red herring, to be honest.

The issue is this:

A theory:

The past existed (but doesn’t any longer), the present exists, and the future has yet to exist (it doesn’t currently exist).

B Theory:

The past, present, and future all exist - they are just various ‘places’.

From the wiki:

In short, what you seem to want to target is how we experience ‘time’; ie, the sense of flow (from the wiki):

There are some other interesting objections on that wiki page.

What you are aiming your sites at though, isn’t a valid objection. It doesn’t actually deal with the issue.

Just demonstrating how the future never becomes the past. Just a story that is part of the past.

I think this came from today’s piece in the guardian regarding Hawking’s new book: Stephen Hawking says universe not created by God | Stephen Hawking | The Guardian

Whatever you think of the guy, he does know how to get people interested in his books :slight_smile:

There is also the concept of Plank time. Literally that is the unit of time that it takes light to travel one Plank length and the math is such that any event shorter than that can be said (by some theoreticians) to not exist. So the present becomes the past in one Plank time.

Terry Pratchett had fun with the idea that within that time unit the universe is literally destroyed and recreated in a never ending series of single static moments that we then perceive as travelling through with continuity.

Ah, but that’s not what you flatly stated earlier, providing the spark to get this thread underway. You said, “Time is an illusion.” Now you say it is a dimension. A dimension could not be an illusion, could it?

I presume you still have no objection to being given your hundred bucks a thousand years from now. And only a fool would say that, here in what we call “the real world.”

Ah, but I clarified in that thread, several hours ago:

"I should, perhaps, clarify - the passage of time, IMO, is an illusion. Time is a dimension. I’ve continued this in the other thread. "

As to a dimension being an illusion, I’m not sure how that makes sense. A dimension is part of a description of something, not a thing in and of itself. Unless you are a Platonist…

:rolleyes:

I’ve pointed out how this misses the point.

Ironically, you seem to be living in the past… I wonder if this proves my contention or yours… :stuck_out_tongue: