Thought for the day: Why is “now” now? 2 Apr 2010 I am something of an amateur block theorist (which means that I only imperfectly instantiate a spacetime worm). Actually, it means I think that the universe exists as a single unitary entity extended in however many dimensions it is, including time. It’s, as it were, a block, not a river. This also means I am a determinist of sorts, but, as Mark Colyvan has recently convinced me, since causality at the level of physics is an unnecessary concept, it’s rather more that I think what is is, no matter when it is. But a problem for block theories is why the now is now and not some other time, or, indeed, why there is a now at all. I suppose someone has already come up with this solution, but here’s mine: If we are just physical entities, and I think we are, then the state of being aware of things at a time is a physical state. Since every location along my spacetime worm is a physical state, it follows that at t it will be the state of being aware of things a little before t. I saw my hand a moment ago, and my physical state is such that I am aware of it now, because the physical processes that make me aware of things occurred between then and now. I am not aware, like Billy Pilgrim, of things in my future or my past in quite the same way because the physical processes that go to constitute “direct” awareness of those things either will occur in the future or did occur in the past. Since being aware of is the outcome of a physical process with a location in the spacetime of my life, I am aware of nowishness because a few milliseconds before, the physical processes that cause it occurred. I should add that this is distinct from the question why entropy increases; I’m only concerned about why we consciously experience a now. Okay, now who already came up with that idea, and who did the decisive refutation? Crowdsourcing, please… Metaphysics Philosophy
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So would that mean that “nowishness” occurs (I suppose I should say “occurs”) along the entire length of the person-worm? “Nowishness” is just a physical property of the person-worm that can disappear (if the person is unconscious), just as “red-hair-ish-ness” (which can disappear with balding or grey hair?)
Yes, although our consciousness of “now” will be impaired at some times, latent at others, and beyond our capacity at yet others (blastocysts have little awareness of time).
I’ve thought about this too, and the existence of the present is the reason I believe in the reality of time and am not a determinist (I have nothing to say about how great a degree of freedom there may be and I certainly don’t think it awards anything like libertarian free will). I think there really is something special about now, and it’s this: Now is when the possibilities for existing worldlines settle down into a definite configuration and “solidify” into the past. The past can be viewed as a “block” but the future is more like a fluid medium, and the present is like the border between the two states. I don’t know anything about entropy, but maybe it’s increasing due to the inherent randomness of the process. It’s very limited, but there must be some, or else this really would be a block with no past, present, future, or consciousness. I bring up consciousness because I think that “now” is experienced as a moving point because human brain function is sensitive to this process of settling down of worldlines/solidifying of configurations. Here’s a thinker: Maybe we will eventually develop a technology capable of causing major disruptions in spacetime. If this is a possibility, the indeterminacy of the unfolding of possiblities might be a kind of “anticipation” of such disruptions. I understand that this is unpracticed, woolly speculation and I expect it to be taken as such. I hope fun is had with it.
Strange, are you suggesting multiple, changed repeats of already unfolded events? Even if it were possible to disrupt spacetime, any now that happened would not have changed, there would be a new now and one would anticipate a new set of possibilities.
I wasn’t suggesting repetition of anything, though I guess you could get that from the “backwards causation” of future disruptions anticipated in the preset. I suppose the “anticipation” concept doesn’t add anything to the idea that the uncertain futures may include some in which major spacetime disruptions occur (if this is even possible, about which I can only offer fanciful guesses). I think it’s just a question of how pliable spacetime is.
So as not to offer nothing but my own insubstantial speculation, here’s someone else’s: http://fqxi.org/data/essay-contest-files/Nikolic_FQXi_time.pdf He suggests toward the end that consciousness is some variety of “unmatter” that is influenced by matter but does not influence it, and scans along the time dimension of block time. I’m not a fan of this idea because matter only influences anything through the flow of energy, so there would be some kind of observable energy leak into unmatter. Also, since we talk about consciousness so much, it seems simpler to suppose that consciousness is influencing us, and since we’re made of matter, consciousness can’t be cut off from matter. We also talk about the idea of free will, which (I agree with the author about this) seems to be an illusion created by the inability of consciousness to track all brain states/processes. Again, we have a feature of consciousness apparently influencing material organisms to talk about it, suggesting that consciousness is material too.
Basically this runs up against Princess Elisabeth’s objections to Descartes’ notion of Mind: if it affects and is affected by the material world, then it is material (including, for now, energy among the material realm). If it is not material, it can neither affect nor be affected by the material. So it’s a non-solution. Really, don’t they teach basic philosophy of mind to physics students these days? [Rereading that it looks like I was having a go at Strangebeasty. I was actually making a “young people today, don’t know what’s what” sort of curmudgeonly snark. It was meant to be funny, not pissy…]
What’s with the metaphysics? Here I thought this was a philosophy of science blog. We’re supposed to be the empiricist curmudgeons who don’t have time for these speculative pseudoproblems.
The following is adapted from Robert Merrihew Adams paper “Theories of Actuality” (which addresses a similar problem about possibility, rather than time). You want to know what’s special about now. There are three possible sorts of answers. * The present moment has some kind of special property: it’s bright and all the other moments are shadowy. This leads to serious epistemological worries. If someone were at a shadowy moment, could they see that it was shadowy? If not, how can we be so sure that we’re at a bright moment rather than a shadowy one? * Only present things exist. On this view, there’s no problem about why present things are special. They’re real; isn’t that special enough? John, I’m not sure exactly what being a block theorist entails, but it might entail rejecting this section option. * “Now” is indexical like “here” or “I”: it refers to when the speaker is, just like “here” refers to where the speaker is. There’s not much of a problem about why I know more about me than I do about you, or more about here than I do about the middle of the Indian Ocean: I’m closer to me than to you, and I’m closer to here than to the middle of the Indian Ocean. If you ditch the first theory for the third theory, there’s no problem. David Braddon-Mitchell has a nice paper called “How Do We Know it is Now Now?”, which pushes an objection the kind of view Strangebeasty has proposed. Basically, Braddon-Mitchell thinks that Strangebeasty’s view commits you to accepting the first account of what’s special about now: now is bright and other times are shadowy. And he thinks that if that’s your account of what nowness is, John’s problem is insoluble. (And Noumena, fancy meeting you here! I have never been cured of my love for speculative pseudoproblems, but John is nice to me anyway.)
Rachael, thanks. I now have a feel for where I am located. And you are always welcome to come and inform me of my lacunae in knowledge, speculative or not.
Like John, I’m a bit of a blockhead. The notion the the future does not yet exist, only the present exists and the past has ceased to exist I find to be nonsense – not necessarily wrong, just nonsense. Why should my viewpoint be privileged? In my present, Abraham Lincoln is an historical figure, dead and buried 155 years ago. In his present, we are unimagined people in his distant future. The time between our two presents is his mystery and my history. The comforting thing about block time, though, is that it offers a little hope. If it is true then all those loved ones, human or other animal, whose little pink worms did not stretch to the present are still out there. If Einstein is right, if somehow we could travel faster than light (or find an antique British police call box that is bigger on the inside than on the outside) we could travel back in time and find our loved ones still there, right where we left them. Wouldn’t that be nice?