Leonard Susskind - What's Fundamental in the Cosmos? (Part 1)

Leonard I want to know what reality is all about and a lot of my friends like you tell me I got a no physics to to do that and if where are we today in in the progress of getting more and more fundamental in physics okay the use of the word fundamental raises hackles who's to say that it's more fundamental to understand the proton than it is to understand life or who's to say that it's more fundamental to understand the neutron than it is to understand the superconductor and in fact it really does raise hackles when elementary particle physicists say we're studying something fundamental convinced matter physicists go off the the ballistic and say we're doing something just as fundamental and they're right they're right so the use of the word fundamental is a very loaded word here and I think we shouldn't use it I think we should think of it differently I think we should think of reductionism reductionism means understanding a thing as the sum of its parts taking things apart into smaller and smaller and more fundamental things oh I just used it I said fundamental whoops reductionism raises be more and more smaller and simpler parts parts with less movable structures in them that's been one of the goals of physics the reductionist goal of reducing things to the smallest number of parts as the number of parts gets smaller and smaller it seems or as the objects get smaller and smaller it seems that in a certain sense they get simpler and simpler and describable more and more by fairly simple mathematics it takes a very complicated mathematics to describe a bug I mean a living bug it takes very much more limited mathematics to describe a single electron so we go on this reductionist march down to smaller and smaller objects and some people will use the word fundamental where have we gotten down to we've gotten down to something like a hundred thousand times smaller than a proton experimentally and that is remarkable of you right that's that's quite remarkable that we've gotten experimentally to something like a hundred thousand times smaller than electron we are smaller than a proton and we're gonna get to us like what a hundred the nucleus itself is like a hundred thousands the time of an ad of an atom yes so we're a hundred thousandth of a hundred thousand yeah really small stuff from the point of view of macroscopic objects on the other hand us or we who are interested in quantum gravity are trying to get the scales a billion billion hundred billion billion times smaller than a proton and so we're inclined to think of these scales where experiment is going on as being these enormous Liebig scales so it's a matter of relativity if it's relative who's who's small and who's big but that's what we've gotten we've gotten experimentally to ten to the minus sixteen centimeters or 17 centimeters 17 centimeters and we're gonna push it another decade we're gonna push it another factor of 10 smaller probably find new structure of some sort but still a long way to go but a very very long way to go a very very long way to go you use the term reductionism which also raises hackles among perhaps a different sort how do you characterize that and what what do you when people criticize reductionism either from an emergent point of view like condensed matter physicists may do more others in the non science world would criticize reductionism well my friend Philip Anderson for example is a hardliner about these kind of things but I don't think he criticizes reductionism I think what he would say is reductionism is not the only game in town now reductionism is simply means you want to understand your car first understand your carburetor you want to understand your carburetor understand the little Springs and the muzzles in it and just take it apart that's all it means it doesn't mean anything very controversial well it begins to mean that I can explain the entire thing the way the car works if I'd understand the sum of all of its parts there is that implication but it also may be that and understood understand the car you have to understand principles of organization that are new principles of organization that that you wouldn't have thought about if you only thought about atoms and things and some people would not would call that something else other than reductionism yeah yeah yeah yeah it is something else other than reductionism it's understanding principles of organization at different levels at different levels it's car at different levels different new principles of organization needed and is that any less fundamental I don't think so okay and I I would say that somebody like Philip Anderson mostly would say that that reductionism is I'm using the term is just not the only game in town and there's not the only thing you need to do to understand nature and you're comfortable with that yeah I'm very comfortable with that yeah I'm absolutely comfortable with that you could ask the question whether those principles of organization are implicit in the in the understanding of the very small things perhaps that's so but so what if it's implicit but almost impossible to understand well there's a fundamental difference though it really is it's a good question you've asked because the question is in principle can you ultimately in some ultimate science deduce those emergent or whatever you want to call them principles of organizations from the properties at the small level because then the emergence is is a as a as a question of lack our knowledge of science right so then exactly do have a reduction in the corners can you understand the human being just as the sum of its parts well I'm not sure because I'm not sure that it makes sense to think of a human being in the absence of its environment what a human being function as a human being if it wasn't in in an environment and that involves an additional complexity additional complexity but it happened a baby I mean before it comes into its environment in a vacuum it isn't gonna it doesn't gonna do anything very interesting in a vacuum well so it still I think you're evading the question about whether emergent properties really do have a an independent existence that in principle cannot be predicted from the anything you'd want to know about thee it may be that they understand the human being you have to understand the atmosphere to understand the atmosphere you might have to understand the planet to understand the planet you may have to understand the solar system to understand the solar system you have to understand all of cosmology what you are I mean that's in principle and you can do and we don't understand all of cosmology from microscopic physics okay we have quantum mechanics oh I want to understand from quantum mechanics how are we going to get to is it possible in principle in some ultimate science to have a reductionist wholly reductionist view of the world where the so called emergent self-organizing principles are in fact predictable entirely from the from the fundamental activities or is there something special about these levels that we can never predict I'm not sure there's something special about these levels but I am fairly sure that the reductionist March will end and reverse itself at the Planck scale I have absolutely no doubt that when we try to start taking apart things smaller than the Planck scale we are going to wind up going in the opposite direction and describing bigger and bigger and bigger things it's part of this issue of the holographic principle that the world is not made up out of little things which fit into space in the obvious way there is no doubt in my mind that the reductionist March is going to end and that it's gonna reverse itself and we're gonna start finding that to understand smaller and smaller things we're gonna have to understand bigger and bigger things I have no doubt about that but down to that point maybe it's true that we can understand almost everything without any new principles I don't know I think so I think we duction ISM probably works at the level of from chemistry upward for example that's my feeling I wouldn't want to get into a fight about it but yes I do think that if you understand chemistry sufficiently well you can probably understand life

Channel: Closer To Truth

Views: 42,894

Rating: 4.9238901 out of 5

Keywords: leonard susskind, closer to truth, robert lawrence kuhn, cosmos, universe, robert kuhn

Id: Gbbfeh1-p_Q

Length: 9min 4sec (544 seconds)

Published: Thu Jan 10 2019