Jim Gates: What is String Theory, Its Status, Its Open Challenges? | AI Podcast Clips

we have to talk a bit about the magical the mysterious string theory super string theory sure there's still maybe this aspect of it which is there still for me from an outsider's perspective of this fascinating heated debate on the status of string theory can you clarify this debate perhaps articulating the various views and say where you land on it so first of all I mean I doubt that I will be able to say anything to clarify clarify the debate around string theory for for general audience part of the reason is because string theory is a has been something I've never seen the Iraq war physics do it is broken out into consciousness of the general public before we're finished you see string theory doesn't actually exist because when we use the word theory we need a particular set of attributes in particular it means that you have an overarching paradigm that explains what it is that you're doing no such overarching paradigm exists or string theory what string theory is currently is an enormous lis large mutually reinforcing collection of mathematical facts in which we can find no contradictions we don't know why it's there but we can certainly say that without challenge now just because you find a piece of mathematics doesn't mean that it's applies to nature and in fact there has been a very heated debate about whether string theory is some sort of hysteria among the community of theoretical physicists or whether it has something fundamental to say about our universe we don't yet know the answer to that question but those of us who study string theory will tell you are things like string theory has been extraordinarily productive in getting us to think more deeply even about mathematics that's not string theory but the kind of mathematics that we've used to describe elementary particles they have been spin-offs from string theory and this has been going on now for two decades almost that I have allowed us for example to more accurately calculate the force between electrons with the presence of quantum mechanics this is not something you hear about in the public there are other similar things the kind of that kind of property I just told you about is what to call weak strong duality and it comes directly from string theory there are other things such as a property called holography which allows one to to take equations and look at them on the boundary of a space and then to know information about inside a space without actually doing calculations there this has come directly from string theory so there are there are a number of direct mathematical effects that we learned a string theory but we take these ideas and look at math that we already know and we find suddenly we're more powerful this is pretty good indication there's something interesting going on with string theory itself so it's the early days of a powerful mathematical framework that's what we have right now what are the big first of all most people will probably that which as you said most general public would know actually what string theory is which is a at the highest level which is a fascinating fact well string theory is what they do on the Big Bang Theory right one can you maybe describe what is string theory and two what are the open challenges so what is string theory well let the simplest explanation I can provide is to go back and ask water particles which is the question you first ask me what's the smallest thing yeah what's the smallest thing so particles one way I try to describe particles to people a star I want you to imagine a little ball and I want you to let this size of that ball shrink into it has no extent whatsoever but it still has the mass of the ball that's actually what Newton was working with when he first invented physics he's the real inventor of the massive particle which is this idea that underlies all of physics so that's where we start it's a mathematical construct that you get by taking a limit of things that you know so what's a string well in the same analogy I would say now I want you to start with a piece of spaghetti so we all know what that looks like and now I want you to let the thickness of the spaghetti shrink until it has no thickness mathematically I mean worse this makes no sense mathematically this actually works and you get this mathematical object out it has properties that are like spaghetti it can wiggle and jiggle but it can also move collectively like a piece of spaghetti then it's the mathematics of those sorts of objects that constitutes string theory and does the multi-dimensional 11 dimensional however many dimensional more than four dimension is that a crazy idea to you is that is that the stranger aspect of string theory to you not really and also partly because of my own research so earlier we talked about adding these strange symbols that we've discovered inside the equations it turns out that to a very large extent add incres don't really care about the number of dimensions they kind of have an internal mathematical consistency that allows them to be manifest in many different dimensions since supersymmetry is a part of string theory then this same property you would expect to be inherited by string theory however another little-known fact which is not in the public debate is that there are actually strings that are only four dimensional this is something that was discovered at the end of the 80s by three different groups of physicists working independently I and my friend Warren Siegel who were at the University of Maryland at the time were able to prove that there's mathematics that looks totally for admission oh and yet it's a string there was a group in Germany that used slightly different mathematics but they found the same rizzo and then there was a group at Cornell who using yet a third piece of mathematics found the same yourself so the the fact that extra dimensions is so why they talked about in the public is partly a function of how the public has come to understand string theory and how it's the story has been told to them but there are alternatives you don't know about you