Fun facts about the nature of time

Back in September, Discover Magazine blogger Sean Carroll assembled "Ten Things Everyone Should Know About Time" pulled from Setting Time Aright, a scholarly/scientific conference on the nature of time.

4. You live in the past. About 80 milliseconds in the past, to be precise. Use one hand to touch your nose, and the other to touch one of your feet, at exactly the same time. You will experience them as simultaneous acts. But that’s mysterious — clearly it takes more time for the signal to travel up your nerves from your feet to your brain than from your nose. The reconciliation is simple: our conscious experience takes time to assemble, and your brain waits for all the relevant input before it experiences the “now.” Experiments have shown that the lag between things happening and us experiencing them is about 80 milliseconds. (Via conference participant David Eagleman.)...

6. Consciousness depends on manipulating time. Many cognitive abilities are important for consciousness, and we don’t yet have a complete picture. But it’s clear that the ability to manipulate time and possibility is a crucial feature. In contrast to aquatic life, land-based animals, whose vision-based sensory field extends for hundreds of meters, have time to contemplate a variety of actions and pick the best one. The origin of grammar allowed us to talk about such hypothetical futures with each other. Consciousness wouldn’t be possible without the ability to imagine other times. (Via conference participant Malcolm MacIver.)

Ten Things Everyone Should Know About Time (via Kottke)


  1. One of my favorite points of temporal trivia is that, unless I’ve misunderstood and/or misremembered this one over the years, according to the folks with the atom smashers and the slide rules the arrow of time should show no preference for either direction. Yet clearly it does, at least from our perspective in this universe.

  2. So … right above where I’m entering this comment, it says “Real-time updating is enabled.” I’m thinking it really isn’t.

  3. Technically #1 isn’t true; the only thing that is real about time is our perception of it. Its like saying inches or centimeters exist (they don’t, just in case your wondering). If anything time is a measurement more than it is a static thing.

    1. You have a category error there. Inches and centimeters may or may not exist, but length certainly exists. Likewise, you could argue (though I wouldn’t) that seconds don’t exist, but time certainly exists. It’s as real as length and mass. 

      If time doesn’t exist, then the theory of relativity is seriously wrong and none of modern physics holds together.

      1. Length is like time, in so much that it is a measurement between two points; a measurement that can change based upon perception.

        1. Proving something is a matter of perception is not the same thing as proving it doesn’t exist. That’s the whole point of the theory of *relativity*. If things that are a matter of perception don’t exist, Einstein’s whole theory goes ‘poof’ and blows away. BTW so does the uncertainty principle and all of Quantum Mechanics. So I think that you can safely say that time is *as real as* General Relativity and Quantum Mechanics — no less and no more.

        2. I wondered about this as well; if we are simply a “solid” object that discretely snakes through existence, then “time” is merely a measurement of where we are in relation to other objects, much like length. It is easy to conceptualize this for the past, we know exactly where we “were” a few moments ago, but that perception is based on our inability to properly perceive the fourth dimension (time), it should also apply to the future as well.

          We break down length into discrete parts to “measure” things, but the objects are contiguous with no physical breaks, why would time be any different?

          PS: I felt weird using all those quotes but it was the only way I could think to punctuate these ideas as perceived, not actual.

  4. Meh, some of this is misleading. 
    Like Number 6: Consciousness depends on manipulating time. 
    I would consider a perception of time via memory as a series of events (ie. imagintation/thought) a precursor to consciousness. To say that it is dependent upon ‘manipulating time’, i think, is the author trying to sound fanciful, which is weird considering the subtle nature of understanding the nature of time. 

    Number 2: The past and future are equally real. This isnt completely accepted…

    A theory stating that all events are implicit in the now (which i would give David Bohm a lot of credit for) does not mean, necessarily that there are simultaneous events outside of the fabric of reality which encompasses the entire movement of the universe. That it may bend (ie. in the sense of relativity) is not the same as, ‘the past and future are equally real’. Its a local phenomenon, it seems to be dependent on speed. Like… if i think of a past event, its not as if i can jump back to it. Its just that it is implicit in the now. There is a definite direction to time. So i suppose it depends on what you call ‘real’ when one says “the past and future are equally real”. This is just another misleading pointless statement, IMO.

    Number 1: Time ExistsHa, i would say just the opposite. Because of the very nature of ‘time’, or better yet, reality, as being this flexible fabric, it seems more correct to say that (1) energy exists and (2) it is moving in a certain direction. Where, why, how, is another matter. Time as a ‘stuff’ is more likely to be a phenomenon of our perception. Basically, the flexibility of reality gives us a view that ‘time’ is not this universal ‘click clock’, but instead, a movement of  ‘something’ in a certain direction… and that something can change velocities in relation to itself (its connected like a fabric). I think that Einsteins theory of relativity supports this view, if anything.All in all, this article seems to have a biased mechanistic view of time.

  5. “Experiments have shown” that we exist about 80 milliseconds in the past… I think they’re talking about experiments my sister’s been doing at the University of Aberdeen. But AUGH! there’s no direct link to the research, so I can’t do a happy dance and send her the link to tell her she’s been quoted on BoingBoing. However – that was one of her recent discoveries. Dr. Amelia Hunt. Check it out.

  6. 9. Aging can be reversed.    

       Umm, what? Was this written by a 5th grader? This has nothing to do with the nature of time… relatively speaking. This is like some random biology fact thrown in here. I can see trying to water down facts, but this is just an off the wall random crap.

    and lol “[Update: all of these are things I think are true, after quite a bit of deliberation. Not everyone agrees, although of course they should.]” what does that even mean? im not sure… was he saying everyone should agree with him? thats quite a scientific attitude, not.  im sure there was just so much perspicacious deliberation going on in that room….

    1. Yeah, that whole update seems rather snot-nosed and against what the community should be aiming for.

      It’s great to have opinions, but its another thing to call them Facts.

  7. No one hears the first few words you say. Introduce yourself later, and you’re more likely to be remembered. 

    It’s also true with incoming & outgoing messages, no one hears the first few words. Wait 2-5 seconds, then start speaking. 

    Perception is a time killer too, it’s based on expectations.  What doesn’t fit into your expectations are called surprises, or a new learning experience.

  8. In contrast to aquatic life, land-based animals, whose vision-based sensory field extends for hundreds of meters, have time to contemplate a variety of actions and pick the best one.

    Since when was sight the only sense that shaped one’s perception?  While I don’t disagree with #6, this statement is likely untrue.  Aquatic life, e.g. dolphins and whales, are known to perceive their environment over a range of miles via hearing.  Further than landlubbers, for that matter.

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