Leonard Susskind - Is the Universe Fine-Tuned for Life and Mind?

Lenard what is it about the fine-tuning of this universe that causes such energy such controversy among scientists philosophers theologians everyone today is talking about fine-tuning why well it seems and we don't completely understand why that the laws of physics laws of cosmology laws of how the universe evolved seemed to be very special of course they're special everybody would expect them to be special but they're special in a way that's unexpected they seem to be special in the way that is just very very conducive to our own existence laws of physics could have been very different you could imagine a world that didn't have electrons in it there's nothing wrong with that in basic theory of the mathematical theory of physics you could just throw away the electron or what happened if you throw away the electron no chemistry no atoms no chemistry no biology no people to ask the question we just wouldn't be here to ask the question you could change the rules in other ways you could make gravity stronger gravity is very very weak you know normal people think gravity is very strong when I wake up in the morning especially the older I get the harder it is to get out of bed so I think oh boy wouldn't it be nice if there wasn't much gravity well in fact gravity really is very very weak if you were to compare in an atom the gravitational force between the electrons and protons compared to the electrical force the gravitational force is completely negligible and why is gravity so much weaker than the other forces well we don't really know but here's what we do know if it were just even a little bit stronger stars would burn out too quickly they wouldn't live long enough for life to evolve instead of stars instead of galaxies we'd have black holes we can't live in a black hole I mean you know science fiction maybe you can live in a black hole but we can't really but most likely the universe would expand and contract too rapidly and so everything seems to be almost on a knife edge that if you were to change the rules of physics the laws of physics even a little bit ever the world as we know it wouldn't exist how many of these constants or laws of physics would fit into this category of fine-tuning where it has to be on a knife-edge or close to that there's debate about that this debate about just how how sharp the knife edges now almost everything if you changed it very much this electric charge of the electron the mass of this or that particle various constants of nature how strong gravity is if you changed it by a few percent 10% some of them 20% some of them 30% you would really be in trouble the universe wouldn't look as it as it does are we dealing with a couple of dozen are we dealing yea we're dealing with a couple of dozen the owner of an apple of dozen order magnitude a couple of dozen constants all right let's talk about one of them though that has some particular strangeness to the so called cosmological constants that's right that's the one which is really on a knife edge okay it is on such a narrow knife edge that it's almost inconceivable if you were to change it just the tiniest tiniest bit we couldn't be here this cosmological constant is a kind of it's almost a kind of anti-gravity it's kind of repulsive force that's implicit in Einstein's equations for general relativity it could be there physicists had every reason theoretical reason not experimental reason theoretical reason to think that the world should have this kind of anti-gravity and that gravity would cause everything to separate at an enormous rate repulsion the actual magnitude of it is incredibly small it is so tiny that the anti-gravity force is only felt on the largest possible scales in the universe it takes an enormous ly large space and volume and time for the cosmological constant to create any real Poulsen this is not because the mathematics tells us that this is just because for some unknown reason this constant whatever made the universe I hate to say whoever you made the universe physicists have a habit of talking in that language who ever made a universe they don't really mean it but whoever made the universe made it with an incredibly small tiny cosmological constant it is so small that it is point zero zero zero zero zero we can sit here for a while a hundred and twenty three of them and they don't want and then a one I think it's actually a two but it is incredibly small and nobody really knows why the one thing that we do know is that if it were very much stronger and would have blasted apart the galaxies it would have prevented stars from forming so you have to understand galaxies and stars and planets formed because gravity pulled them together in the very early universe this counteracting anti-gravity could have prevented that could have prevented the formation of stars planets and so forth so if it were just a little bit bigger just a little bit bigger than this point zero zero zero zero zero zero it would have prevented our existence physicists have never understood why it's so small again that is the sharpest part of this knife edge okay we have fine-tuning we've got to deal with it now there are a number of ways that we can explain that I mean it cries out for explanation yes we cannot say oh yes fine and let's go on we have to explain it one way or another basically there were three explanations okay number one okay God number two accident okay that's racist for duty just by ow so it's an accidents just that way and it happens to work out perfectly right a hundred and twenty three decimal places zero not likely to be an x-ray well there's a fourth way a third way I did you want it let me let me put the fourth way in before I get to the third yeah the fourth way is who knows maybe someday somebody will figure it out oh sure there is one over I'm at solution all of these constants are agent can be devolved maybe somebody will do a fundamental equation there's some fundamentally Express all of these as derived for that one that would partly fall into the category of accident you take some fundamental equation and you solve it it would take an incredible accident for it to have a solution which was all that small the last way which physicists don't like they don't like it because it runs against their ambitions the ambition was to explain every constant every number to understand everything about the universe the other way goes as follows the universe is enormous ly big we know that incidentally and when I say enormously big I don't mean like we used to think ten billion light years I mean 10 to the 10 to the 10 to the 10th we have no idea how big it is enormous ly big we suspect that it is very much bigger than the region we can see we also have reason to believe that it's diverse that that in different places it has different properties there's good theoretical reason to believe that in some places maybe there is no electron in other places gravity is stronger and in some places this cosmological constant may be may be much bigger the picture is that there's some very small fraction of the universe where the conditions just happened to be right for the existence of life and it's not a surprise that's where life is it's more or less like asking why do we by accident happen to live on a planet which happens to be at just the right temperature for liquid water to exist that's a narrow range not as narrow it's not as much of a knife edge is the cosmological constant why is that well the answer is very simple on planets where they can't be water they can't be life so it's true a very small fraction of the planets in the universe are at the right temperature for water to exist where do we live we live in the only place we can live where water exists same kind of picture universe very big very diverse many different environments huge huge slew of different possibilities and among these possibilities in a few small pockets of the universe conditions are right for life and that's where life exists with planets we know that there are large numbers of planets where a small number would be in the habitable zone where we have liquid water and the vast majority or not we have that with universes we are relying upon theoretical ideas to say there are different bubble universes pocket universes inflation Theory chaotic and eternal inflation creating different situation each one of which has different laws so we need to have that status right we need not only to have a vast number of possibilities possibilities are like blueprints they're blueprints for different kinds of universes I like to think of the possibilities as the possibilities analogous to the possibilities of life DNA is the blueprint for life DNA has a vast number of ways of being rearranged and so there's a vast number of possibilities for life but that in itself doesn't say that there are a vast number of living creatures around it took something to make those blueprints into actual houses right or whatever it happens to be so part of the story is cosmological that the expansion of the universe the what you called inflation of the universe the very very rapid expansion that took place at very very early times created a lot of quantum fluctuation and that quantum fluctuation created patches of space with different properties those patches are sometimes called pocket universes or some kind of times called bubble universes but we live in one of them that's the picture that's a picture there's mathematics that goes with it and for those of us who believe in this particular picture of a tremendously diverse some people call it a multiverse you like mega verse I like mega verse and as I as I said in my book the reason I like mega verse has nothing to do with any ideology multiverse just reminds me of multiplex cinemas which I go like telling a small movement you don't say coined this term landscape I describe I did I did but there was a background and the background comes from biology the landscape of biological biological designs and it means all the possible ways you could put DNA together it's a tremendously large number of possibilities describing life biologists have used the term landscape and I was kind of borrowing it from biology there all the various possible ways you could put the elements of physics together to make different kinds of universes different kinds of pocket universes so I did coin it in the context of physics but as I said it had a prehistory as the landscape and biology so the answer to the fine-tuning as you would frame it would be this landscape of possibilities populated right populated by how does a knife raise it by populated by a multiverse or I'm sorry I'm mega verse of actualities but there is one element to it that's extremely important just as the number of ways that you can rearrange a DNA molecule is enormous you have a DNA molecule with a billion base pairs in it you know the base pairs are the rungs of the ladder you can rearrange them in a humongous number of ways and that's why there are so many different possibilities for life it's important not only that the universe has this fluctuation it which creates different environments but it's important that the number of possibilities the number of different blueprints is enormous and that's what string theory came into it string theory somewhat to the chagrin of those who invented it produced in coding years including myself produced this huge huge number of possible ways of arranging its elements to create an enormous diversity of possibilities this was not something that the string theorists had been looking for they wanted to find a unique possibility for the universe which would be just like ours and more or less by accident just to just have the properties that life could exist in that's not the way the theory evolved the theory evolved instead to create this tremendously big number of possibilities different ways of rearranging it just like different ways of rearranging DNA produced an enormous number of ways of making a universe some very very small fraction of those ways would be conducive to the existence of life so as you as I think you're getting at two things are necessary a huge number of possibilities and a way of populating those possibilities to create environments of all different kinds

Channel: Closer To Truth

Views: 328,585

Rating: 4.8701911 out of 5

Keywords: Leonard Susskind, Robert Lawrence Kuhn, Closer to truth, Universe, Fine-Tuning, Science, Fine-tuned Universe, Physics (Field Of Study), Cosmology (Field Of Study)

Id: 2cT4zZIHR3s

Length: 14min 45sec (885 seconds)

Published: Tue Jan 08 2013

Reddit Comments

[u/Remseey2907]

Atoms and spacetime interact. Like Newton discovered that a feather and a big chunk of iron falls at the same speed. They showed that on the moon. Spacetime pushes objects to the surface of the moon. We always learned that the Moon or Earth attracts objects and us. Einsteins relativity proved that one wrong. Spacetime pushes you towards Earth. Earth does not pull you. Atoms and spacetime, interact with forces we can measure and forces that are always constant.

But what if aliens and their craft that consist of atoms from other regions of space, are not interacting so much with our spacetime in our region of space? It means they can travel faster, without becoming so infinitely heavy they need incredible amounts of energy to transport themselves like we do.

If so they could fly faster than light perhaps.. In a way that is what Leonard Susskind is describing. Regions of space that have different physics laws. And physicists don't like the idea. The world is complex enough already. We cannot handle more complexity😂