The Unreality of Time | Hacker News Reader

The Unreality of Time

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39 pointsvinchuco48 comments

McTaggart's objection to the B-series sounds equally applicable to space. As I understand it, B-series conceptions of time consider it essentially another dimension. The summary of McTaggart's objection could be rephrased:

> [spacial dimensions] involves change, but because [north-south] relationships never change (e.g. [Atlanta] is always [South of New York]), [geometry] must be an inadequate account of [space].

Then again, McTaggart was an idealist, so he might actually try to lodge that sort of objection.

Thomas Metzinger studying phenomena of neural correlates wrote "The Ego Tunnel". After reading his book I realised that perceived time and space and perception itself are just complicated models, run on our wetware, and these are result of evolution by abaptation, including culture as factor. So there is no 'time'. But for convenience, we can assume that it is. Otherwise who shall buy watches?

If time is an illusion, what explains the illusion? What's the illusion made of? How can I get more of it, or lose it?

Sure, there are time-dilation effects in special and general relativity, but those are theories that explicitly mention time and timelike dimensions. Time, in those theories, is not at all an illusion.

So: if it's an illusion, what is the illusion made of?

I wouldn't call it an illusion. Perception of motion maybe?

More like humans agreed that X oscillations of element Y counts as 1 second. We all agree on the length of 1 second on earth and go from there.

We use that time unit as a reference to explain the motion we perceive.

right you are. Clocks measure distance, that by common agreement we call 'time'. It is practically useful only because we have memory.

    > if it's an illusion, what is the illusion made of

Would the inability of prehistoric desert tribes to explain mirages or the movement of the stars have made those things less real?

One explanation I picked up in a book some time ago was that the illusion could be explained as a series of moments (like the frames of a movie), due to the fact that each such moment contained an encoding of the previous frame (your memory) and an anticipation of future frames (your expectations) the illusion that the individual moments are connected in a linear progression emerges, much like the illusion of motion emerges from watching movie frames.

Just brain dumping here but I have this thought that maybe the universe unfolds like a grammar. You start with a description of everything that can exist according to some laws of physics, if you do this recursively, like a grammar. You would have a root node (this would be the Big Bang) from there you generate every possible state.

This would result in a tree where each node (present) is either the Big Bang or hangs of some other tree (the past) and has branches for each possible configuration (futures) to generate from that state.

That's still a causally structured universe, which does thus actually have a kind of time (the causal arrow of time) built into it.

it is made from neural correllates of consciousness. Your brain basically runs this gfx. its complicated, but can be understood. I pointed earlier to Metzinger's popular narration about that.

Unless you are convinced that time or even the entire universe will end when the last human (or animal or alien) dies, this is nonsense.

you do not know that, there is no method to prove. For practical purposes we can have 'time'. But it does not mean it exists. Look, it is uneasy concept, I know. But it is not Kantian at all. The thing is that we build tools to augment our limited senses, but we cannot build tools to augment depth of our understanding. If the language has no word for phenomena, it cant be explained or exposed. But its reality is undeniable. Ever had something you know but you cant explain? It does not mean the thing you know does not exist, right? Such is the uneasy truth that there is no 'time' or 'self'.

There is solipsism, the idea that nothing but your mind exists. And it is a valid idea because you can not be sure that anything exists. The entire universe, everything you think you see, hear, smell or feel might just be an illusion created by your mind. The idea that things change with time or that time exists, that you can move your body through space or that space exists or you have a body to begin with, all this may just be an illusion of your mind.

But while this is an interesting idea to ponder about it is also not very helpful. If true you are lost and there is nothing you can ever learn about the world. Maybe you can explore the illusion created by your mind but even this only if your mind behaves nicely and does not randomly decide to completely change the illusion or whatnot.

It seems to make a lot more sense to assume not everything is just an illusion, believe that there is a real world accessible by your senses and then explore this world. And once you have decided that there is a real world it no longer makes sense to ascribe a special role to you or your mind because that is part of the position you just left behind.

it is made from neural correllates of consciousness. Your brain basically runs this gfx.

This is also inconsequential - you say that time is an illusion created by your brain but that still requires that your brain exists in some reality and that it is doing things which prerequisite time because doing means change over time.

It might of course be the case that there is a time in the real world that allows things to happen and your mind might create an internal representation of that, the thing we call time, that is a poor representation of the true nature of time, but that does not mean time does not exist, it means there is the real thing and the thing we perceive.

And this may actually be the likely scenario because there are hints in physics that neither time nor space are fundamental things but are the result of something more fundamental in a similar way that atoms are made out of quarks and electrons.

The point is you cannot distinguish between reality and illusion even if your model accurately describes reality. In the absence of mind everything else exists, but there is no one to _know_ about that and exploit that knowledge. It reminds me classy 5th form physics lesson, when our teacher explained limitations of Newtonian mechanics before lesson on basics of electrodynamics. For those kinds of "physics" time is parameter, coordinate, models make sense. But Einstein came and here we are. And we are not even in the beginning of understanding what "spacetime" _really_ is. That is why I everywhere state in this discussion that we can have 'time' for practical purposes only. Yes, there is the real thing. But we lack tools and senses to perceive it.

I'm not sure if this is what the GP meant, but the universe doesn't need to "end", as such (it's a bit hard to word properly, as "to end" also implies some (very final) notion of time), just the perception of time?

Like if the universe is this Block Universe, being the complete state space of everything, wherein these "conscious structures" exist (that are us), which are connected by causal steps (possibly branching), these steps being tied by the rules of physics as we experience them. Perception of time exists completely within these structures. The concept of "when the last human (or animal or alien)" dies, in this context, just points to a region of this state space beyond the boundaries of these conscious structures. Doesn't mean "there" does not exist.

You are an illusion, basically. You, the observer who goes through time from past to the future at some rate, is just an abstraction that evolved in a process of evolution because created with higher cognitive abilities were better at survival, and at some point their cognitive abilities developed a very useful illusion of "self".

There are still causal arrows between the different moments of conscious cognition, and it's the causal arrows that are Time on a reality-level, not the awareness thereof.

Non-atomic objects are not illusions: http://www.jerf.org/iri/post/2896

The word "illusion" ought to be all but struck from philosophy, in my opinion. It seems to lead philosophers down a road of reductionism until they explode into a paroxysm of reductionism so complete that they won't even admit subatomic particles "exist". Further the idea that either A: I can explain it or B: it doesn't "exist" really ought to be struck too... even in 1908 I would have called that sheer ivory tower arrogance but in light of what we know today is it simply absurd. There are true, meaningful, and incomprehensibly large statements, such as "a true specification of the full state of the world economy". (In theory nothing prevents such a statement from being produced, but you won't be fitting that into your head anytime soon.) There is always C: I can't explain it but it exists.

It remains a current theory that time is not an atomic element of our universe, and that it may arise from something else (entropy? the connections in loop quantum gravity? something something holographic principle?), but regardless of what the truth is, "time" as a useful concept won't go anywhere.

> Non-atomic objects are not illusions: http://www.jerf.org/iri/post/2896

Quite right! It's the folk-theories of those objects that are illusions, in the sense of providing intuitive but false causal explanations for the phenomena in question.

>The word "illusion" ought to be all but struck from philosophy, in my opinion. It seems to lead philosophers down a road of reductionism until they explode into a paroxysm of reductionism so complete that they won't even admit subatomic particles "exist".

The word should be doubly struck-out because the same philosophers, in the attempt to get out of that paroxysm, tend to start reifying more and more concepts into metaphysical "existence", until they wind up claiming that reductionism just doesn't really work and we were bloody idiots to try it in the first place. Reversing idiocy doesn't get you accuracy.

>It remains a current theory that time is not an atomic element of our universe, and that it may arise from something else (entropy? the connections in loop quantum gravity? something something holographic principle?), but regardless of what the truth is, "time" as a useful concept won't go anywhere.

Since "time" as we talk about it really means causal ordering, I can't see how any of those other things can replace time. It's not exactly a radical statement to say, in a post-relativity physics, that time isn't a real scalar but instead a more complex causal ordering that happens to look like a real scalar when you work at Newtonian scales.

This 1908 paper he wrote in the journal 'Mind: A Quarterly Review of Psychology and Philosophy' is a little bit clearer on his meaning:

http://www.ditext.com/mctaggart/time.html

But it still comes across as a bit too much like 'woo' or maybe I just don't understand his way of explaining his idea.

From a university lecture slide note:

"His central philosophical conviction was that reality was fundamentally spiritual; and his central aim was to show this by deriving contradictions from the assumption that the material world exists"

https://www3.nd.edu/~jspeaks/courses/2009-10/20229/LECTURES/...

Written three years after Einstein's paper on special relativity, which kills the idea of an absolute order of events (if they're far enough apart in space). Would McTaggart have had knowledge of Einstein's work?

On the other hand, relativity gives very concrete rules for how time behaves, Which would make time a very well behaved unreality.

So, much depends from the observer, right?

His education is in morals and logic and his conclusion in subsequent books is that everything is related by souls. I would say even if he had heard of or read about real science regarding spacetime, he wouldn't even have been able to understand it anyway. It would be like an alchemist understanding atomic numbers and nuclei, they are completely different fields.

this is dangerous speculation. Bright minds easily pick up different systems of explanations. Deliberate exposition of knowledge is completely other thing. For example being chrystian on public for political purpose. It is the same with scientific publications. Those rarely describe actual level of understanding that writer may have.

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

The debate over presentism vs. eternalism (https://en.wikipedia.org/wiki/Presentism_(philosophy)) is alive and well, and conducted by many people who are well aware of Einstein's theory.

Still, of the main arguments for the eternalist view comes from special relativity (one source: http://www.amazon.com/Four-Dimensionalism-Ontology-Persisten...), and I think it's rather compelling, as far as it goes.

"time" may not exist but the second law of thermodynamics does and cycles that humans observe in the second law of thermodynamics is what we usually use to measure time.

I thought it's been known for a while that "time" isn't exactly a property of the Universe the same way as 3 dimensions are, but more something we use to help ourselves understand and explain the actions around us.

That is, "time" doesn't exist, but we created it.

I really wish I remembered where I read ideas such as this, but I think most of it came as a consequence of Relativity theory.

If you listen for example to Nima Arkani-Hamed - there are a couple of lectures by him available, for example the 2010 Messenger lectures [1] - then neither space nor time are likely to be fundamental properties of the universe but phenomenons emerging from something more fundamental.

[1] http://www.cornell.edu/video/playlist/nima-arkani-hamed-on-f...

afaik it's certainly not any kind of established fact that time isn't a property of the universe. Time is fundamental to causality, which makes it hard to reduce away. I've heard it theorized that a linear conception of time may be a product of consciousness, i.e. time flows in many directions but we are only able to perceive it in the direction we flow.

I thought general relativity actually proved that time was a fundamental dimension of our universe [1]. I'm really unsure because I have never studied general relativity, but I thought it used Reimanian geometry [2] to solve a bunch of things using 4D manifolds [3]. Is the reason you say that a consequence of relativity theory is that time isn't exactly a property of the universe because the 4 variables of spacetime are all distances [(c*t, x, y, z)] as opposed to having 3 variables being distances and one time [(t, x, y, z)]? Or is it simply because Relativity proves that time isn't universal etc ?

> That is, "time" doesn't exist, but we created it. Honnestly, I very much like the Wikipedia introductory paragraph on time: "Time is a measure in which events can be ordered from the past through the present into the future, and also the measure of durations of events and the intervals between them" [4] I think time is just a measure used when describing dynamic systems (where past, present, and future make sense). Assume for a moment that the Big Bang happened at t = t_BB, and assume that for all t < t_BB, there was absolutely nothing in the universe and nothing was happening. Would time make sense in such a pre-Big Bang universe ? I think time is a fundamental property of a dynamic system because without it, the said system would not be dynamic. I'm not sure however that time is a fundamental property of the universe. Maybe of a dynamic universe ? In which case time would be a fundamental property of our current universe, in accordance with Einstein's theory or relativity, but not in a pre-Big Bang universe such as the one mentioned just a few lines ago.

Finally, from the article: > McTaggart argues that time is unreal because our descriptions of time are either contradictory, circular, or insufficient I think Einstein would probably agree with him in that time is at least contradictory [5]. Although I'm not sure they would mean that in the same way. To take McTaggart's A-series argument: > Specifically, [McTaggart] argues that since every event that occurs will at one time be the future, at another time be the present, and at a third time (and forever henceforth) be past, every event exemplifies or instantiates every temporal property: futurity, presentness, and pastness. Since these properties are mutually exclusive (they cannot be co-instantiated), the A-series conception of time generates an absurdity, a contradiction. If both parts of his argument are sound, then time must just be an illusion; it has no genuine ontological status. I disagree with this logic. Notions of past, present, and future are mutually exclusive at any given time t; but events can of course go from future to present to past. It just can't be more than one at the same time. Kinda like when you're sprinting a 100m race, you can't be before, on top, and after the finish line at the same instant. But you can go from one to the other without questioning the notion of distance. The analogy is far from perfect, but that's how I see it. I may have misunderstood his argument though.

[1] https://en.wikipedia.org/wiki/Spacetime [2] https://en.wikipedia.org/wiki/Riemannian_geometry [3] https://en.wikipedia.org/wiki/4-manifold [4] https://en.wikipedia.org/wiki/Time [5] https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experim...

> Is the reason you say that a consequence of relativity theory is that time isn't exactly a property of the universe because the 4 variables of spacetime are all distances [(c*t, x, y, z)] as opposed to having 3 variables being distances and one time [(t, x, y, z)]? Or is it simply because Relativity proves that time isn't universal etc ?

Yes, pretty much that. The "units" of z remain constant/consistent independent of the values of x,y. However, t, cannot be thought of separately in the same way. The experience of/speed of/duration of/distance of/... of t is dependent upon the x,y,z location.

You're perhaps thinking of the https://en.wikipedia.org/wiki/Arrow_of_time

All this really shows is that our descriptions of time are inadequate, not that time is unreal. In essence, he's confusing the map with the territory. He's arguing that, because the map is inadequate, the territory must not exist.

> Attacking the A-series, McTaggart argues that any event in the A-series is past, present, and future, which is contradictory in that each of those properties excludes the other two.

Can somebody please explain the logic used here, because I got lost here?

P1. Any given moment must be designated past, present, or future.

P2. The designations "past", "present", and "future" are a true trichotomy, such that it is impossible for any moment to not have any of these designations.

P3. The designations "past", "present", and "future" are mutually exclusive; it is impossible for a moment to be in the past and the future, the future and the present, etc.

P4. According to the A-Series model of time, every moment is at some point designated future, present, and past.

C. From (P3) and (P4), via reductio ad absurdum, an A-Series interpretation of time produces a contradiction.

I don't buy it because (P3) is more accurately phrased "it is impossible for a moment to be in the past and the future, the future and the present, etc. simultaneously" and (P4) is better phrased "every moment is at some point designated future, present, and past, but never simultaneously", so (C) breaks down.

The designations "past", "present", and "future" are a true trichotomy [...]

This is at least in some sense wrong - past, present and future are no absolute things but only defined relative to the moment in time one calls present and therefore there are many pasts, presents and futures.

The designations "past", "present", and "future" are mutually exclusive [...]

This in turn is only true if one is referring to the past, present and future defined relative to the same present. Today is in the future of yesterday and in the past of tomorrow.

All in all past, present and future are binary relations, not unary ones. Mystery solved.

> past, present and future are no absolute things but only defined relative to the moment in time one calls present and therefore there are many pasts, presents and futures.

That's basically what I meant when I said "(P3) is more accurately phrased 'it is impossible for a moment to be in the past and the future, the future and the present, etc. simultaneously'".

> only true if one is referring to the past, present and future defined relative to the same present. Today is in the future of yesterday and in the past of tomorrow.

That's basically what I meant when I said "(P4) is better phrased 'every moment is at some point designated future, present, and past, but never simultaneously'".

So yeah, I think we're on the same page :)

The same event can be in the past, present or future of an observer placed at different points in time, relative to that event. How the author finds a contradiction in this is beyond me. A simple model with points on a line should clear most of those unconvincing contradictions.

From the article: >1.All events have the properties of past, present and future, at the same time.

>2.That these A-properties are incompatible (or mutually-exclusive) with one another.

>A person may object to the first premise, accusing McTaggart of assuming that all events have these properties at the same time. It is in assuming that all events start out with a contradiction that requires tensing that creates the regress, but once we reject this, the contradiction does not even take off. An event is said to be past, but is not also present nor future, and as well, an event is said to be present, but not past and future.

>He concludes these arguments by stating that "Our ground for rejecting time, it may be said, is that time cannot be explained without assuming time."

He's saying that any event was at one point in the future, at some point was in the present, and eventually went into the past. This makes sense, right?

However, to judge where the event is at some point in time (past, present, or future), you need another point in time by which to reference it. For a concrete example, on "Monday July 13th, 2015", "Wednesday July 15th, 2015" was in the future. On "Wednesday July 15th, 2015", "Wednesday July 15th, 2015" was in the present, and by "Thursday July 16th, 2015", "Wednesday July 15th, 2015" is in the past. Without a specific reference point, any point in time is just a point in time and exists in all three states at once (because it is the future for any time before it, present for any time during it, and past for any time after it).

Like most philosophical works... I can't really see why it's right, but I can't obviously point out why it's wrong; it won't affect my day to day life, but it's fun to think about.

> Without a specific reference point, any point in time is just a point in time and exists in all three states at once

This is like saying that without a reference point any point in space is simultaneously left, right, in front, behind, above, and below. It's incoherent; all these words necessarily must be expressed in relation to a reference point. McTaggart's argument commits a sort of linguistic fallacy in thinking that you could possibly talk about "past", "present", and "future" without a point of reference.

What I don't understand is the validity of these arguments. The very language it's presented in casts doubts (at least in my mind) of its rigor. Do these arguments actually hold water?

I'm not sure how charitable I have to be here. Let's say I personally don't find any of this convincing at all, and I don't feel a single statement rises to the level of an actual argument. It's gobbledygook.

What other "things" that "do not exist" everybody experiences "similarly?"

Color, probably

oh man. Color perception is pure biology. You can train neural networks in your brain for distinguishing colours. Average Japanese sees more than one hundred colours, where average British sees only "black". Not to forget tetrachromatic vision inherited by some human females.

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