Lawrence Krauss - Are the Laws of Nature Always Constant?

Lawrence I know as a scientist you don't like a why question but I'm going to give you one anyway okay why is it that the laws of physics laws of nature are both intelligible and discoverable because no but uh I mean that that's that's the big question the physicists have wrestled with uh why why is the universe explicable apparently because it is uh Eugene vigner actually wrote a whole a whole beautiful essay and why why does mathematics describe nature so well didn't have to but it does uh it is a language of nature I think at some level it the basis of of modern science people become scientists because they have a belief system at the one place where belief enters into science in my opinion and and I don't I'm not a big fan of using the word belief is the belief that the universe is explicable and the proof of the pudding is that it is and and um and maybe at some level at some time in physics we'll have a meta physics argument or a meta-argument for why it couldn't be any other way really I mean that's the key question that's the key thing that drove Einstein he put it away the mentioned God I don't like the way he said it but he said did God have any choice in in creation he didn't use God the way most people would use it yeah he meant it yeah in a very different way but but the idea is is there only one set of laws of nature that hold together if you took one piece and changed it could it be would it the whole edifice Fall Apart or could you have lots of consistent universes we don't know the answer but I I have to say that's the question that really drives at a fundamental level most physicists because what you'd like to do you'd like to believe there's only one and there's all and and your job is to find it well but but it's not logically necessary that even if you had the one that that would be intelligible and discoverable to a human being it's not logically necessary and by the way it could it may even be that it isn't I mean we you know when where we've come a long way and we've discovered an incredible amount about the universe we should be very proud of what we've done but we don't know ultimately if a if there is a final Theory and B if that theory uh will be explicable even if we have the theory we don't even know if we'll be able to to understand it to be able to make predictions to make it might be like the mathematical case of uh of unprovable propositions or uh or or Goodell's theorem that that that at some level there within any uh philosophical or mathematical construct there are things that are that are true that are Beyond proof nature may be that way so we don't know it right now we've been very very successful we're on a roll and we figure we might as well get there and we have some guiding principles and God and those we use words like Beauty and elegance and things like that what do those mean physicists or mathematicians you know I'm a little worried they mean different things to different people they're they're time varying I think to some extent Beauty used to mean Simplicity in physics the simpler the explanation the more beautiful now the word Elegance says it cropped up up a lot and and I think that's really worrisome in fact the physicist Wolfgang Paoli used to say Elegance is for Tailors and I think that's a really good a good uh line which which I like to use nowadays uh when people claim that their ideas are elegant I think to some extent we have been uh because of of lack of experimental Direction on what the next Forefront is in in understanding the laws of nature people have been developed very complicated mathematical Frameworks which may appear to be elegant but and so if there's a generation I think of young physicists who don't really know what a beautiful idea is they just know what an elegant one is a beautiful idea is one that explains nature and and does it simply and lately to some for some people Elegance is the same as complexity which is the opposite of beauty so I think you're seeing people say Elegance is it may be complex but it has to be complex as Einstein said something like you know I want things to be simple but not more simple than it really is then they have to be exactly you don't want to make it too simple but so I mean the world is a complicated place but what's wonderful about physics is you can show the many complicated phenomena of arise out of some underlying things which are which are simpler than the than the diversity of phenomena they predict to be if you had as many laws of physics as you have phenomena would be it wouldn't be useful so but so it's a it's a key question I think most and it's really in the eye of the beholder I think most physicists and most scientists do what interests them and they inevitably find whatever they're working on to be beautiful and it's up to the rest of us to to prove them wrong basically and so we have to realize uh and in different contexts in in society I I've argued this very importantly the easiest people to fool are is yourself the easiest person to fool is yourself anything you do appears to have significance and beauty and wonder and I've written lots of beautiful wonderful theories down that are wrong and um sometimes other people have to convince me that they're wrong and that's the way it works and so it's really what the Arbiter of what's beautiful ultimately is nature as we have the laws of physics which are beautiful and that are real can these change there's been some talk recently that the fundamental laws of nature can change well that's of course the really the most one of the most fundamental questions because the fact that the laws of nature appear now to be time invariant is is really a profound importance in fact it's the origin of one of the most important laws of physics called the conservation of energy turns out you can Define the quantity energy why you know kids often ask why is it so big deal this is concerned why should I believe it it turns out you can show mathematically that that derives from the from the fact that the laws of physics are invariant over time female mathematician Emmy nurther proved it and and and and she's not as heralded as she would be she never got a position in Germany and the and and because she was a woman in the famous mathematician David Hilbert said what are we running a university or a bath house and uh and and but but her theorem is beautiful well is are the laws of physics invariant over time and the question is only answerable by measuring it and there are certain bits of evidence that recently suggested that maybe some of the fundamental constants of changing in fact by the way one of the best arguments that was earlier given by Dirac for why gravity is so much weaker than all the other forces is the following he said the universe is old there's a big number the age of the universe if the strength of gravity changes over time at the beginning they could have all been the same and gravity could have slowly been getting weaker and the universe is old it's weaker now this the large number hypothesis he called so it's a good explanation it doesn't seem to be true in the sense that we've been able to measure that gravity hasn't changed very much by more than a factor of two between time the universe is one second old and today it's part of the research I've done for example but we need to know if those laws can change over time and they're now very good well very acceptable theories that suggest that at the very early times at least the fundamental constants did change and eventually settled down to the values they have and so this is not a question of philosophy it's a question for physics and we'll know the answer when we measure it does that threaten the foundation of physics if the either the constants or the laws themselves can vary I mean it depends what you of course what you define by physics will change but I think no because physics is based on understanding How the Universe works and if that's the way the universe works that's the job of physics so I don't see anything threatening I'm not threatened in fact no exactly in fact that's the best thing about being a scientist is nothing should be threatening

Channel: Closer To Truth

Views: 11,368

Keywords: closer to truth, robert lawrence kuhn, Lawrence Krauss, cosmos, cosmology, laws of nature, nature, lawrence m. krauss

Id: adeTe9gu-KE

Length: 8min 25sec (505 seconds)

Published: Fri Aug 04 2023