6 ms·

The Unreality of Time

39 points by vinchuco 11y ago

deleted 11y ago
[deleted]
howeyc 11y ago
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.
- danbruc 11y ago
  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-future-of-fundamental-physics http://www.cornell.edu/video/playlist/nima-arkani-hamed-on-f...
- kenbellows 11y ago
  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.
- globuous 11y ago
  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 https://en.wikipedia.org/wiki/Spacetime [2] https://en.wikipedia.org/wiki/Riemannian_geometry https://en.wikipedia.org/wiki/Riemannian_geometry [3] https://en.wikipedia.org/wiki/4-manifold https://en.wikipedia.org/wiki/4-manifold [4] https://en.wikipedia.org/wiki/Time https://en.wikipedia.org/wiki/Time [5] https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experim...
  - howeyc 11y ago
    > 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.
- JonnieCache 11y ago
  You're perhaps thinking of the https://en.wikipedia.org/wiki/Arrow_of_time https://en.wikipedia.org/wiki/Arrow_of_time
zitterbewegung 11y ago
"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.
dghf 11y ago
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?
- pdpi 11y ago
  On the other hand, relativity gives very concrete rules for how time behaves, Which would make time a very well behaved unreality.
  - ommunist 11y ago
    So, much depends from the observer, right?
- lnanek2 11y ago
  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.
  - ommunist 11y ago
    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.
  - dempseye 11y ago
    https://en.wikipedia.org/wiki/Scientism https://en.wikipedia.org/wiki/Scientism
- hyperpape 11y ago
  The debate over presentism vs. eternalism (https://en.wikipedia.org/wiki/Presentism_(philosophy) 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-Persistence-Association-Occasional/dp/0199263523 http://www.amazon.com/Four-Dimensionalism-Ontology-Persisten...), and I think it's rather compelling, as far as it goes.
rokhayakebe 11y ago
What other "things" that "do not exist" everybody experiences "similarly?"
- kenbellows 11y ago
  Color, probably
  - ommunist 11y ago
    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.
eli_gottlieb 11y ago
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?
- howeyc 11y ago
  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.
  - ommunist 11y ago
    right you are. Clocks measure distance, that by common agreement we call 'time'. It is practically useful only because we have memory.
- peteretep 11y ago
  > 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?
- deleted 11y ago
  [deleted]
- CuriousSkeptic 11y ago
  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.
amelius 11y ago
> 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?
- kenbellows 11y ago
  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.
  - danbruc 11y ago
    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.
    - kenbellows 11y ago
      > 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 :)
kenbellows 11y ago
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].
- kenbellows 11y ago
  Then again, McTaggart was an idealist, so he might actually try to lodge that sort of objection.
ommunist 11y ago
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?
fengwick3 11y ago
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?
- oldmanjay 11y ago
  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.
AnimalMuppet 11y ago
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.
deleted 11y ago
[deleted]
lingben 11y ago
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 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/4-mctaggart.pdf https://www3.nd.edu/~jspeaks/courses/2009-10/20229/LECTURES/...

39 points by vinchuco 11y ago

deleted 11y ago

[deleted]

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.

danbruc 11y ago
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-future-of-fundamental-physics http://www.cornell.edu/video/playlist/nima-arkani-hamed-on-f...
kenbellows 11y ago
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.
globuous 11y ago
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 https://en.wikipedia.org/wiki/Spacetime [2] https://en.wikipedia.org/wiki/Riemannian_geometry https://en.wikipedia.org/wiki/Riemannian_geometry [3] https://en.wikipedia.org/wiki/4-manifold https://en.wikipedia.org/wiki/4-manifold [4] https://en.wikipedia.org/wiki/Time https://en.wikipedia.org/wiki/Time [5] https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experim...
- howeyc 11y ago
  > 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.
JonnieCache 11y ago
You're perhaps thinking of the https://en.wikipedia.org/wiki/Arrow_of_time https://en.wikipedia.org/wiki/Arrow_of_time

zitterbewegung 11y ago

"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.

dghf 11y ago

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?

pdpi 11y ago
On the other hand, relativity gives very concrete rules for how time behaves, Which would make time a very well behaved unreality.
- ommunist 11y ago
  So, much depends from the observer, right?
lnanek2 11y ago
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.
- ommunist 11y ago
  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.
- dempseye 11y ago
  https://en.wikipedia.org/wiki/Scientism https://en.wikipedia.org/wiki/Scientism
hyperpape 11y ago
The debate over presentism vs. eternalism (https://en.wikipedia.org/wiki/Presentism_(philosophy) 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-Persistence-Association-Occasional/dp/0199263523 http://www.amazon.com/Four-Dimensionalism-Ontology-Persisten...), and I think it's rather compelling, as far as it goes.

rokhayakebe 11y ago

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

kenbellows 11y ago
Color, probably
- ommunist 11y ago
  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.

eli_gottlieb 11y ago

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?

howeyc 11y ago
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.
- ommunist 11y ago
  right you are. Clocks measure distance, that by common agreement we call 'time'. It is practically useful only because we have memory.
peteretep 11y ago
> 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?
deleted 11y ago
[deleted]
CuriousSkeptic 11y ago
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.

amelius 11y ago

> 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?

kenbellows 11y ago
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.
- danbruc 11y ago
  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.
  - kenbellows 11y ago
    > 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 :)

kenbellows 11y ago

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].

kenbellows 11y ago
Then again, McTaggart was an idealist, so he might actually try to lodge that sort of objection.

ommunist 11y ago

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?

fengwick3 11y ago

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?

oldmanjay 11y ago
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.

AnimalMuppet 11y ago

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.

deleted 11y ago

[deleted]

lingben 11y ago

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 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/4-mctaggart.pdf https://www3.nd.edu/~jspeaks/courses/2009-10/20229/LECTURES/...