A PBS Space Time series on time and the block universe

Somewhat related to the previous post, I just saw this video from Matt O’Dowd discussing why the block universe is such a compelling concept.

The second video in the series discusses the effect quantum mechanics might have on this concept. It reminds me why cosmologists seem to be more comfortable with the Many Worlds Interpretation rather than the orthodox Copenhagen one. The idea of uncollapsed wave functions in the future is complicated by the relativity of simultaneity.

What’s interesting about this is that, while the Many Worlds Interpretation definitely leads to an overall block universe, or block multiverse if you prefer, it still has each of us living in an emergent classical world with the experience of randomness in it. So in the block universe, not only does all the past, present, and future have an eternal existence, but every possible variation of that past, present, and future does as well.

Whether you find that comforting, alarming, or merely interesting, it seems to neatly split the difference between a rigid universe and one with an evolving future.

There are plenty of other interpretations of quantum mechanics out there, but it’s not clear that any of them fit quite as nicely with overall cosmology as Many Worlds. Of course, many, like Copenhagen, are anti-real interpretations, in that rather than attempting to describe reality, they merely describe our interactions with the quantum realm, and so aren’t necessarily expected to reconcile with cosmological models. The problem is they provide little help with cosmological questions.

Anyway, the rest of this series looks like it’s going to be interesting.

16 thoughts on “A PBS Space Time series on time and the block universe

  1. I really like this Matt O’Dowd guy. He seems to be really careful. He managed to discuss the Block Universe without making any grammar-o’s with tensed verbs, at least that I could detect.

    I can’t wait for the episode he promised on the direction of time. That oughta be good.

    Liked by 1 person

  2. I’ve been a fan of PBS SpaceTime since it started. (Also was a fan of PBS Infinite Series, their math channel, but sadly it died a long time ago.) O’Dowd is clearly a science fiction fan, as well!

    Liked by 1 person

    1. I think you were the one who tuned me in to this series!

      When you say “science fiction”, do you mean he discusses sci-fi entertainment somewhere? (If so, I’d like to find that.) Or are you making a statement about the concepts discussed here?


      1. I meant he makes a lot of science fiction references as asides in his videos. (Perhaps more in the Q&A section than in the video topic.)

        That said, some videos do venture more into speculate topics than others, and I do prefer the less speculative ones. 🙂

        Liked by 1 person

          1. I find the Q&A (usually) worthwhile. It’ll delve deeper into details of previous videos, and it is a bit more casual in tone (hence many of the SF references).

            I liked that Penrose video; I’ve read that paper. (I even understood bits of it. Little bits.) I think you know I’ve long had a high regard for Penrose; you can blame him for planting the seeds from which my skepticism about computationalism grew! 😀

            Liked by 1 person

          2. Penrose is undoubtedly a brilliant theoretical physicist. Unfortunately, the consensus of most cognitive scientists is his theory of mind is woefully uninformed by the relevant scientific fields. It seemed like every announcement I saw of his Nobel on Twitter, the person felt it necessary to clarify that it had nothing to do with his views on consciousness.

            Liked by 1 person

          3. In fact, I’m not hugely compelled by his theory of mind. It was his arguments against computationalism that got me re-thinking that.

            And, of course, his math is impeccable, and Penrose tiles are really cool. 🙂

            Liked by 2 people

          4. I vehemently disagree with Penrose on his reasons for anti-computationalism, but his arguments are no more silly than those of many professional philosophers and a damn sight more interesting than most.

            As it seems to be wrong to judge the worthwhileness of philosophical views based on their correctness (if you did, almost every view advanced by professional philosphers would fail the test, although different people will disagree as to which succeeded) I think he deserves to be credited for making significant contributions to the philosophy of mind.

            (Although on second thought, perhaps not so much, as the argument he advances against computationalism was first proposed by J R Lucas. I’m not sure if Penrose got it from there or if he came up with it independently.)

            My point is that I don’t think this is another case of Nobel laureate crank syndrome (e.g. Linus Pauling with vitamin C). If Penrose is a crank, then so is Searle. Penrose is wrong on consciousness, but his arguments deserve to be taken seriously even so.

            Not that you called him a crank, I know. I just think that it’s perhaps unfair to call him or his ideas “woefully uninformed”. I suspect there may be a little bit of anti-amateur bias in play here which I’m perhaps over-sensitive to as an amateur myself.

            I’m a big fan of PBS Space Time too, by the way.

            Liked by 2 people

          5. Well, I stand by what I said. I think Penrose is a cautionary tale for us amateurs. Apparently, every prominent physicist regularly receives mail from amateurs claiming to have solved quantum gravity or an overall theory of everything. (I’m sure Penrose gets his share of these.) Reportedly, most of these efforts fail due to basic mistakes. The more intelligent make mistakes an undergraduate physics student might make. The exceptional cases make mistakes of a first year grad student.

            But physicists who try to ride in and solve problems like consciousness while ignoring all the fields between theirs and the problem: chemistry, biology, neurology, psychology, etc, are making a similar mistake. When experts in one field weigh in on another, they’re basically just intelligent lay people, at best. At least unless they spend years learning the new field, as Francis Crick did when he switched from microbiology to neuroscience, and even then his switch was between two fields that are very close and already overlap.

            All of which is to say, expertise matters.

            Liked by 1 person

          6. It’s one thing to disagree with Penrose on his arguments, but I don’t think you realize how your disdain for his abilities reflects back on you. If a Nobel Prize winning brilliant theoretical physicist’s opinions on a topic outside his field of study are worth so little, what does that say about yours? That man has spent his life dealing with extremely complex topics, challenging math, and learning difficult new material. His opinions deserve respect. Argue against them on their merits. Even amateurs can contribute. Fresh eyes do sometimes see something that’s been missed by everyone else.

            Liked by 1 person

          7. As I’ve said many times Wyrd, I have no illusions about my own expertise, or more accurately, lack thereof. No one should listen to me if I start saying everyone in a scientific field is wrong and I have the answer. There’s a reason you haven’t seen the Mike theory of consciousness, or quantum gravity, or anything else along those lines.

            As to Penrose, I’ll listen to him on theoretical physics. But I’ll listen to people like Stanislas Dehaene, Michael Graziano, Joseph LeDoux, or Christof Koch a lot more when it comes to the brain.

            Liked by 1 person

          8. We touched on this recently didn’t we. I just don’t pay that much attention to the provenance of an idea. It can be interesting, even enriching, but I think the idea itself is what matters most.

            Liked by 1 person

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