Brian Greene - Should We Ditch String Theory?

as we know chapter one full of holes lacks  mathematical support our comprehension of the   universe as it currently stands Harbors a profound  Paradox on one side we have quantum physics which   is like a detailed guidebook for tiny particles  and the forces that they use to interact with each   other on the other hand we have general relativity  which with equal success describes the way that   matter and energy move through space and time  as well as how space and time themselves evolve   in the presence of matter and energy each Theory  works great on its own but when we try to use both   at the same time things get messy and confusing  for more than a century scientists have been on a   quest for a Theory of Everything a comprehensive  solution that would not only reconcile this   puzzling contradiction between quantum physics  and general relativity but also makes sense of   all the forces particles and interactions in the  universe through one all-encompassing equation   string theory is one such proposed solution it  suggests that everything in the universe at its   most basic level is made of tiny vibrating strings  of energy well it's a theory that tries to answer   the question what are the basic fundamental  indivisible uncuttable constituents making   up everything in the world around us the idea  is like this so imagine we look at a familiar   object just a candle and a holder and imagine  that we want to figure out what it is made of   so we go on a journey deep inside the object  and examine the constituents so deep inside we   all know you go sufficiently far down you have  atoms we also all know that atoms are not the   end of the story they have little electrons that  swarm around essential nucleus with neutrons and   protons even the neutrons and protons have smaller  particles inside of them known as quarks that is   where conventional ideas stop here is the new  idea of string theory deep inside any of these   particles there is something else the something  else is this dancing filament of energy it looks   like a vibrating string that's where the idea  of String Theory comes from and just like the   by vibrating strings that you just saw in a cello  can vibrate in different patterns these can also   vibrate in different patterns they don't produce  different musical notes rather they produce the   different particles making up the world around  us so these ideas are correct this is what the   ultra microscopic landscape of the universe  looks like it's built up of a huge number of   these little tiny filaments of vibrating energy  vibrating in different frequencies the different   frequencies produce the different particles  different particles are responsible for all   the richness in the world around us and there you  see unification because matter particles electrons   and quarks radiation particles photons gravitons  are all built up from one entity so matter and   the forces of nature all are put together under  the rubric of vibrating strings and that's what   we mean by a unified theory and here is the catch  when you study the mathematics of string there you   find that it doesn't work in a universe that just  has three dimensions of space it doesn't work in a   universe with four dimensions of space nor five  nor six finally you can study the equations and   show that it works only in a universe that has  10 dimensions of space and one dimension of time   the extra dimensions are thought to be compacted  or hidden from our perception despite the Allure   of string Theory's elegant mathematics and  unifying potential it has yet to provide testable   predictions or experimental evidence leading some  to question whether string theory is dead or still   a viable candidate for The Theory of Everything  you say the problem is just hard rather than we   are barking up the wrong tree so that's kind  of how I think about it plus it assumes that   their fun coherent theoretical understanding of  all phenomena in the universe it assumes that   and you're putting your philosophical  mission statement on the universe that   you're investigating and the history of that  exercise has never proven to be successful so   I just like to take a step back and stay open to  the possibility that there's a whole other idea   that could supplant everything they're doing  that wouldn't take 30 people 40 years to try   to figure it out because that's a lot of brain  power going in there in all fairness to them they   made certain progress with their string theory in  interpreting using it to interpret things that we   Now understand more deeply okay so that works  and by the way how close are we to proving it   experimentally you can have a hypothesis that is  untestable in its core but if the hypothesis is   true some other things might be true that you  can then test so you can test the edges of it   that can still make progress on the thing that  you're waiting to test if you can't do it today   testing for the existence of hidden Dimensions  is a complex problem and a major challenge in   theoretical physics especially given that many  theories which propose these Dimensions like   string theory suggest they are incredibly  small possibly Compact and inaccessible   through conventional means if I take the most  straightforward approach to string theory you   really are imagining that these dimensions are  there they're real I mean just as you would   say that the three space dimensions around us  you know left right back forth up down they're   real they're here we are immersed within those  Dimensions these other dimensions are as real as   these with the one difference being their shape  and their size differs from the shape and size   of the dimensions that we have direct access to  through through human experience and one approach   imagines that these extra dimensions are tightly  coiled up curled up crushed together if you will   into a beautiful geometrical form that's all  around us but just too small for us to detect   with our eyes too small for us to detect even  with the most powerful equipment that we have   nevertheless according to the mathematics the size  and the shape of those extra Dimensions leaves an   imprint in the world that we do have access to so  one of the ways that we have hoped yet to achieve   to make contact with experimental physics is  to see a signature of those extra dimensions   in places like the Large Hadron Collider in Geneva  Switzerland when you slam protons together at very   high speed of the Large Hadron Collider if there  are these extra dimensions and if they have the   right form and that's a hypothesis that may not  be correct but when the protons Collide they can   create debris energetic debris that can in  some sense leave our dimensions and insert   itself into the other dimensions and the way you'd  recognize that is there'd be more energy before   the Collision than after the Collision because  the debris would have taken energy away from the   place where our detectors can detect it so that's  one real concrete way that you could find evidence   for extra dimensions and it hasn't happened yet  doesn't mean it won't happen but that would be a   stunning moment in the history of the species  if data that we acquired in these dimensions   gives us kind of incontrovertible evidence that  these dimensions are not the only Dimensions I   mean how mind-blowing would that be despite  Decades of research String Theory hasn't yet   provided a single prediction that could be  experimentally verified is the string theory   dead it's a question many have asked due to the  Theory's glaring predicament lack of empirical   evidence now that doesn't mean it's a scientific  dead end quite the contrary as a field matures you   need to judge it by a different standard you  need to judge it by is it making progress on   foundational issues deepening our understanding  of the subject and by that measure string theory   is scoring in very high now at the same time you  also need to judge whether it makes contact with   experiment too and in that measure we're  still challenged so I would say that many   string theorists myself included are very sober  about the theory it has the tremendous progress   that it had 30 40 years ago that hasn't gone away  but we've become better equipped at assessing the   long journey ahead and that was something that we  weren't particularly good at back say in the 80s   and that's the nature of science quick hits that  resolve everything few and far between and so if   you were in for the quick solution to the big  questions of the world then you would have been   disappointed and I think there were people who  are disappointed and I moved on and work on other   subjects if you're in in the way that Einstein was  in for a lifetime of Investigation to try to see   what the answers to the Deep questions would be  then I think string theory has been a rich source   of material that has kept so many people deeply  engaged in moving the frontier forward from the   smallest particles to the Grandeur of the cosmos  science has always been our tool to peel back the   layers of the unknown to illuminate the darkness  of ignorance with the light of understanding one   thing is certain the pursuit of science never  ends each answer uncovers new questions each   Revelation leads to new Mysteries we move forward  in our journey understanding that in the grand   scheme of the cosmos we are just beginning  to scratch the surface of the vast unknown foreign

Channel: Science Time

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Keywords: brian greene, brian greene string theory, brian greene black holes, brian greene quantum mechanics, brian greene documentary, Brian Greene, String Theory, Quantum Physics, General Relativity, Theory of Everything, Quantum Mechanics, Hidden Dimensions, Particle Physics, Gravitons, Vibrating Strings, Einstein, Subatomic Particles, Space-Time, Quantum Field Theory, M-theory, The Fabric of the Cosmos, Quantum Gravity, Extra Dimensions, Particle Accelerators, science time

Id: ZsTWqlmNGak

Length: 10min 6sec (606 seconds)

Published: Sat Jun 24 2023