Infinity and the Expanding Universe

  • Hmmm. I've definitely got to read up on the multiverse. I have no idea about spaces between or different sets of laws....

    I'm happy to provide some resources:

    Just the tip of the multiverse. If you're still interested, I recommend Dr. Greene, Dr. Sean Carroll, PBS SpaceTime. Please feel free to let me know if you find these interesting.

  • I've never really had any major issue with the idea of "multiverses" so long as the presumption is still there that everything is natural and there's no supernatural creeping in. In fact it's pretty clear in the letter the Herodotus that Epicurus was describing "worlds" as something like "star systems" and not just "planets,'" and that seems to me to be very compatible with what i understand to be the basic thrust of any "multiverse" theory (though I have certainly not studied them like Don has).


    But at the same time I've also sensed that there was never any reason to transmute the word "universe" from meaning "everything" as it traditionally did to something less than everything. I've always sensed that there was an "agenda" of some kind in doing that, and that part of that agenda was to suspend all rules of extrapolating that what we observe here can be of any use in predicting what would be expected to exist elsewhere in the universe. Obviously there are great hazards in extrapolating like that, but there are also great hazards in taking an "anything goes" approach (such as opening the door to the supernatural).


    There's not much to do with that concern other than to note it and move on, but I think the implications of accepting in the distant past that "maybe God lives on Mars and it's possible because we've ever been there" are pretty much the same as "maybe god lives in another part of the multiverse." There are always going to be people who use science in support of their agendas, and its probably safer to say that every scientific theory should be presumed to have an agenda and examined for it at the beginning rather than to accept the alleged sincerity of every theory that comes down the road.


    Even saying that, however, I am firmly convinced that most if not all people who really get into Epicurean philosophy are going to be keenly interested in "science" and never put aside that interest as long as they live - too much depends upon it to ever do that. I see the issue as kind of like the question of "logic" - we're always going to be "threatened" by people who use science and logic for their own agendas, and therefore a certain amount of training in it is essential for everyone for self-protection.

  • Good point, Cassius , on the necessity of some scientific literacy for everyone. You seem to also be making an argument for the need for some critical thinking skills which I also agree with wholeheartedly.

    One thing that struck me just now (literally, just before I saw your post and replied) was that this feeds back into my earlier query about Epicurean attitudes to multiple explanations. On our current thread's topic here, there are multiple explanations (at least 4) for different multiverse theories. All appear to have parts of real possible approaches for getting at the real nature of reality. But we *can't* know for sure at this point, and that's okay. I can accept a possible multiverse and wait for more evidence of study to hone that idea. Just like the causes of lightning or earthquakes to Epicurus or Lucretius. They *couldn't* know for sure (no instruments, no theory of plate tectonics, etc.), but they thought about it, came up with multiple plausible (to them) fully-natural explanations, and decided to live under those parameters but be open to more study or evidence of it came along.


    One of the things that attracted me to Epicureanism is that, from my perspective, it can incorporate an idea like the multiverse or evolution or the possibility of alien life or other science with barely a shrug. "That's very interesting," Epicurus says, and goes on about his writing. I don't think many systems of thought can do that. Concepts like the Atonement (What happens if there's aliens? Can they be saved too?) or evolution can tie Christian theology into knots! Epicureanism can look at those (aliens, evolution, etc.) and go, "Yep. No problem." Even classical Stoics saw the Logos at work in the universe. Epicureans didn't. They saw atoms and void and random movement. The fact that we have seen particles and anti-particles pop into and out of existence through energy changes of the quantum fields in particle accelerators doesn't affect the overall worldview of Epicurus one bit. There are fundamental physical building blocks of the universe. Whether you call them "atoms and void" or something else, the universe is built of matter without divine intervention. And even if "gods" exist, Epicurus demonstrated they have no concern over what we do nor could they have built the universe. That is incompatible with blessedness and happiness.

    That's one of my reasons for finding Epicurus's philosophy compelling and worthy of study for myself.

  • it can incorporate an idea like the multiverse or evolution or the possibility of alien life or other science with barely a shrug

    As to the alien life, of course we know that Epicurus specifically predicted that to occur, which I think is an example of how he did take the position that we could use logic based on observation to produce rules in which we can have confidence ("nature never makes only a single thing of a kind") to extrapolate what we see here to other places which we have not seen. (Pretty much the same goes with a theory of evolution, at least of a kind, and also "other worlds" if you consider "worlds" to be analogous to a universe.)


    I do think it is important to consider what seem to be the rules of extrapolating. Seems to me that epicurus is saying that those rules include preference (or at least, accepting it as more substantial evidence) that if we see a thing here, then we know it CAN exist. That gives the thing a head up over pure speculation of something that has never been observed, such as the kind of speculating that says that something MAY exist somewhere else just because we haven't been there to eliminate it.


    That's probably not well stated on my part, but I think that's what's going on in our current example of where we are in Book 2. Where we are now, Lucretius has been saying that there must be a limit to size of an atom because to not have a limit would be inconceivable. (Presumably because or else we would see them? Or else if there were not a limit, then a single atom would take up the full universe?)


    In other words, it seems to be a premise that Epicurus held that it is legitimate to hold that conditions that we observe here (never seeing an atom; no one thing of a single kind) are at least to some extent extrapolatable throughout the infinite universe. ("At least to some extent" meaning that if we observe them here there is a good reason to expect we will observe them elsewhere where conditions are similar.)


    Now what I have just said may not be a good summary at all, but these are the issues I think they were getting at, and they deserve a lot of thought:

    Are we not justified in having confidence in certain conclusions about the entire universe (that there is no supernatural god) based on extrapolation of what is observed here? And we have confidence of that even in face of the argument that "But you've never been there!" The answer to that question would have to be "yes i can be confident in some things (no supernatural god there either)" or else we'd never have confidence in much of anything. If we admit any possibility just because we've never been there, no confidence would ever be possible, it would be possible for the supernatural god from the next universe over to pop in at any moment. It seems clear to me that Epicurus did (and was justified in) ruling out that sort of argument.

    We're dealing in complex logical issues but the only way to get confident in our conclusion is to think about what we're saying and consider the alternatives, just as he said in suggesting we think about infinity. Because infinity can either be our worst enemy ("the anything is possible argument") or our best friend (Godfrey's it eliminates supernatural gods, for one thing) in getting confident about our decisions on how to live.


    I'm going to drop this here without elaboration but we also need to keep in mind in thinking about infinity the related issue we've discussed elsewhere about PD3 and the "limit of pleasure" in how Plato , Seneca, and others argued that a thing cannot be "the best" unless it has a limit, and they alleged pleasure to be something that is unlimited and therefore rejected from competition for the role of "best life." I would expect there to be a clear connection between getting comfortable with discussing limit vs infinity in the field of pleasure (ethics) and limit vs infinity in the field of physics.


    Is it possible that one of the issues Epicurus saw was that we need to get comfortable with the idea of the unlimited universe being the highest there is so that we can get comfortable with allegedly unlimited pleasure as the highest goal of life?


    Stated another way, maybe one way to get comfortable that there is no single goal of life that is the same for everyone is to compare that question to the size of the universe, for which there is also no single set "end" that everyone would reach if they traveled infinitely in the same direction? No single "best life" might be comparable to no single "end" of the universe in any direction. In both cases we are tempted to think that a supernatural god is the answer for both, but in fact there is no supernatural god and the entire question is logically illegitimate (because we have never observed evidence for a supernatural god, but we have observed lots of evidence that things work naturally, and we reject the "it's possible because we haven't been there to eliminate it" argument).

    Having confidence in our answer to one of these questions helps (I think) with our confidence in answering the other one.

  • Thanks for the links, Don! I'll take a look at those over the weekend.


    I recently listened to a podcast with Alan Alda interviewing Brian Greene. You're right, he's a very good speaker and presenter of ideas; I've been thinking of reading one of his books but haven't yet. I'm also considering Victor Stenger's book God and the Multiverse: it looks like it has less to do with god and more to do with presenting a history of the ideas leading up to current cosmological thinking, which could be a good (if challenging) read. Stenger is an experimental as opposed to a theoretical physicist, which is something I like about him. I don't recall where Greene is on that spectrum but he seemed quite grounded.


    Both Greene and Stenger, at least to some extent, consider the philosophical implications of the conclusions of physics. From what I've read or listened to, Stenger addresses the fallacy of god, while Greene addresses the implications of living in a world devoid of meaning. And they both reach ethical conclusions compatible with those of Epicurus. Greene, however, is adamant that free will doesn't exist. I personally don't buy that, and I'm not sure I'm ready to go down that rabbit hole although I would like to read his reasoning at some point.

  • Heat "death" is somewhat misleading. While we are no more after death, the universe exists without being alive and will still exist when it reaches heat death.

    The way I learnt this as a student in a cosmology class, heat death means that there is only infrared radiation and matter in the form of the most stable element (iron in that lecture, nickel according to another reference), and on the way toward there, conditions will become too adverse for any lifeform to survive.

    However, this class was taught before the apparent acceleration of the expansion of the universe was discovered, which should be a major game changer.


    Another correction of what was mentioned in the thread: The energy will never be used up, it will just be distributed more evenly / the entropy will be much higher.

  • It is cool that theoretical physicists develop various concepts of a multiverse which are mutually exclusive and that there is considerable public interest in this.

    However, those theories (or rather: so far untestable hypotheses) are highly speculative such that I still go with just one universe (of which parts might go or be outside of our horizon of observation and cause-and-effect).

    Except for reading the occasional article for physicists who are not experts in this, I largely ignore the multiverse.

    I still take a wait and see position on the accelerated expansion of the universe, too, but there is at least some evidence to base that one on.

  • Heat "death" is somewhat misleading. While we are no more after death, the universe exists without being alive and will still exist when it reaches heat death. ..... conditions will become too adverse for any lifeform to survive.

    Martin, I think you mentioned this aspect briefly in the podcast, that the "death" part in "heat death" does not refer to the universe ceasing to exist, but to conditions for life (at least as we know it) not being possible.


    I meant to backtrack and bring that out but I think I failed to get back to it. My concern with the subject was that we were planting the notion in less-read peoples' minds that we were entertaining a view in which the universe ceased to exist entirely. But I definitely remember your saying that so it's in the podcast episode and can always be referred to if anyone got really confused and thought we were totally off base from Epicurus.


    In general that's really my main concern with most of the terminology like Krauss' "A Universe From Nothing." (Is Lawrence Krauss a Physicist, Or Just a Bad Philosopher?) I just came across that article and have only read it once, but I think the writer pretty much has the attitude I have. I am not sure if this attitude I am describing is that of a philosopher, or a "theologian" as the article mentions, but I think that whatever the issue really boils down to, Epicurus himself would be accused by Krauss of being a philosopher rather than a physicist in taking a position on the eternality of the elemental particles, and that there is no reason from a philosophical perspective to ascribe their existence to a supernatural god.


    So I get the impression Krauss and people like him would not be on the side of Epicurus, and would actually be significantly opposed to many of his conclusions, or at least his procedures for reaching his conclusions, and that makes me concerned about seeming to cite their arguments without clarification.


    The modern use of words like "nothing" (and maybe I should add "heat death") appear to the untrained to be making claims about ultimate traditional logical issues that are counterintuitive from/against the traditional Epicurean perspective, and should not be accepted on that level.


    Plus, I have always been concerned, and continue to be concerned, that people like Krauss did not pick up their terminology because it was really compelled by the science, but exactly because it "tweaked" those who held to the older views, and that's an attitude I personally associate with radical skepticism and nihilism. That's just my personal viewpoint, of course, and it isn't necessarily implied or true in the case of any particular individual or theory, just something that seems to me to be worth considering in writing/talking about these issues to wider audiences.


    (Sorry that this post is disjointed - i came across the article in mid-post and added it in. I need to pick up some of those points from that article in a separate post.)

  • From that article I just cited, here is the part that seems to me to be the centerof the criticism against "A Universe From Nothing: Why There Is Something Rather Than Nothing," both the book and the terminology. I think the questions I underlined here are things we have to wrestle with in thinking about "Infinity and the Expanding Universe":


    Quote

    That brings me to South African physicist George Ellis. When I interviewed Ellis last year, I asked him if Krauss’s book answers the question posed by its subtitle. Ellis responded:


    Certainly not. He is presenting untested speculative theories of how things came into existence out of a pre-existing complex of entities, including variational principles, quantum field theory, specific symmetry groups, a bubbling vacuum, all the components of the standard model of particle physics, and so on. He does not explain in what way these entities could have pre-existed the coming into being of the universe, why they should have existed at all, or why they should have had the form they did. And he gives no experimental or observational process whereby we could test these vivid speculations of the supposed universe-generation mechanism. How indeed can you test what existed before the universe existed? You can’t.


    Thus what he is presenting is not tested science. It’s a philosophical speculation, which he apparently believes is so compelling he does not have to give any specification of evidence that would confirm it is true. Well, you can’t get any evidence about what existed before space and time came into being. Above all he believes that these mathematically based speculations solve thousand year old philosophical conundrums, without seriously engaging those philosophical issues. The belief that all of reality can be fully comprehended in terms of physics and the equations of physics is a fantasy. As pointed out so well by Eddington in his Gifford lectures, they are partial and incomplete representations of physical, biological, psychological, and social reality.


    And above all Krauss does not address why the laws of physics exist, why they have the form they have, or in what kind of manifestation they existed before the universe existed (which he must believe if he believes they brought the universe into existence). Who or what dreamt up symmetry principles, Lagrangians, specific symmetry groups, gauge theories, and so on? He does not begin to answer these questions. It’s very ironic when he says philosophy is bunk and then himself engages in this kind of attempt at philosophy.


    So as to: "The belief that all of reality can be fully comprehended in terms of physics and the equations of physics is a fantasy. " I think Epicurus would say that statement is exactly correct. Our human reality cannot be fully understood as "physics." Our human reality is real to us through the canonical faculties, including not just the bodily senses, which are "more" understandable in terms of physics, but also the feeling of pleasure and pain and anticipations, which arise from physical processes but in effect constitute a separate playing field of understanding. On that playing feel we are competing with supernatural religion and philosophical questions to which our nature impels us toward finding answers, and I think Epicurus would say that the best (most pleasurable) life requires that we address these issues as best we can.

  • My heavens (pun intended)! This thread has been active since I've been sleeping! Wonderful, thought-provoking comments and clarifications! I'm looking forward to digging in and responding!


    One thing that hit me this morning was that I wanted to go back and see what Epicurus actually said when talking about other worlds in the Letter to Herodotus:

    Quote

    "Moreover, there is an infinite number of worlds [κόσμοι ἄπειροί εἰσιν], some like this world, others unlike it. For the atoms being infinite in number, as has just been proved, are borne ever further in their course. For the atoms out of which a world might arise, or by which a world might be formed, have not all been expended on one world or a finite number of worlds, whether like or unlike this one. Hence there will be nothing to hinder an infinity of worlds [τὴν ἀπειρίαν τῶν κόσμων].

    I admit I assumed that he used a word like Earth or something. I was pleasantly surprised and amused that the word he uses throughout is κόσμος kosmos or, if you will, cosmos. So, "there will be nothing to hinder an infinity of worlds" could just as readily be translated as "There is nothing impeding an unlimited number of cosmos." The ambiguity of that word "cosmos" is fun to play with. Don't misunderstand! I'm not saying Epicurus was a proponent of the multiverse interpretation (necessarily) but I don't think he'd rule it out. As I understand, cosmos can refer to a world or a world and its associated system or the universe, the sum total of "order" (cosmos) that arose out of Chaos (and we know Epicurus was unsatisfied by his early teachers' attempts to explain Hesiod's Chaos).

    The poetry of a phrase like "an infinity of worlds" has a certain allure and power to my ears. That whole last sentence of that paragraph would make a great Tshirt or bumper sticker :)

    Quote

    οὐδὲν τὸ ἐμποδοστατῆσόν ἐστι πρὸς τὴν ἀπειρίαν τῶν κόσμων.

    "Ouden to empodostatēson esti pros tēn apeirian tōn kosmōn."

    That empodostatēson carries the connotation of feet (..podo...) being put into shackles or fetters. So, there's nothing (ouden) binding the feet of reality for the existence of innumerable (apeirian) cosmos.

    Ah! That concept - and the way Epicurus expresses it - just sings for me in the original language! ^^

  • Yes Don - I hate to be so dependent on the commentators, but this is one of those areas that has sunk into my mind I think from a variety of sources - and not just DeWitt - that the "cosmos/world" reference in Herodotus is intended not just to refer to the Earth, but (I presume) pretty much everything we see in the sky as well. And yes that would certainly lend itself to interpretation that Epicurus was distinguishing "our visible universes" from "all other infinitely numbered other universes that are out there beyond those that we can see ourselves. "

    However all along the way I drag my feet about using the word "universe" in this phrasing, since I grew up on the definition that "universe" means "everything" and "everything" in fact means "every thing" ! ;-)

    But times change and if people want to use "universe" to mean some segment of the whole then that is OK with me, just like I acknowledge that there are all sorts of languages other than English, and in the end the terms are matters of convention. :-)

  • Don your comment on feet is interesting too, since it has always struck me how odd Lucretius' formulation is in the discussion of those who deny the existence of any kind of knowledge, which also contains a "foot" analogy -


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    I see Munro uses "where his feet should be" to pursue the analogy, but I was expecting to see some variation of "pedes" here and see "vestgia" instead so I am not sure how firmly the foot analogy holds. (However since I think Munro tried very much to be literal, I bet it does.)


    pasted-from-clipboard.png

  • Interesting. It looks like vestigia carries the idea of footprints ("vestigial" marks left over from someone walking):

    • vestīgium n (genitive vestīgiī or vestīgī); second declension
    • footprint, track
    • trace, vestige, mark
    • sole of the foot
    • horseshoe
    • (figuratively, of time) moment, instant
  • Quote

    So as to: "The belief that all of reality can be fully comprehended in terms of physics and the equations of physics is a fantasy. " I think Epicurus would say that statement is exactly correct. Our human reality cannot be fully understood as "physics." Our human reality is real to us through the canonical faculties, including not just the bodily senses, which are "more" understandable in terms of physics, but also the feeling of pleasure and pain and anticipations, which arise from physical processes but in effect constitute a separate playing field of understanding

    Maybe I'm stating the obvious, but this is my intuitive answer to the idea that there is no free will.

  • Yes, Godfrey I agree. I can understand the technical issues being discussed by those who challenge "free will" - at least I think I can - but I also observe that those who really get into arguing against "free will" seem to have an agenda with implications that go far more deep than just a desire to be technically correct. Some version of "free will" is something that seems to be just as real to us as pleasure and pain, and from a practical point of view that pretty much ends the discussion of whether it is "real" or not.

  • Yes, Godfrey I agree. I can understand the technical issues being discussed by those who challenge "free will" - at least I think I can - but I also observe that those who really get into arguing against "free will" seem to have an agenda with implications that go far more deep than just a desire to be technically correct. Some version of "free will" is something that seems to be just as real to us as pleasure and pain, and from a practical point of view that pretty much ends the discussion of whether it is "real" or not.

    I agree, Cassius . I can follow their arguments but I find them unpersuasive most of the time. And I agree that, from a practical perspective, free will is "real."

  • Don I've just watched the Economist video and the Brian Greene video and find them quite thought provoking. However what I'm finding is that, for me, physics videos are basically appetizers: just enough to get some idea of the issues but not a full understanding. For me, doing some reading will provide the chance to follow the arguments more carefully as well as to reflect on the implications. But if this subject was simple, we wouldn't be discussing it!


    More specifically, the string theory as presented by Greene seems profoundly unsatisfying: too many machinations for too few results. Of course there is the factor of my admitted ignorance.... X/ But I tend to prefer the Ockham's razor approach; the approach in the video seems way too convoluted to suit my simplistic taste.


    Thanks for the links though!