Loose Ends: String Theory and the Quest for the Ultimate Theory

  • Published on: 02 August 2019
  • Thirty-five years ago string theory took physics by storm, promising the coveted unified theory of nature’s forces that Einstein valiantly sought but never found. In the intervening decades, string theory has brought a collection of mind-boggling possibilities into the lexicon of mainstream thinking—extra dimensions of space, holographic worlds, and multiple universes. Some researchers view these developments as symptoms of string theory having lost its way. Others argue that string theory, although very much still a work in progress, is revealing stunning new qualities of reality. Join leading minds in theoretical physics for a whirlwind ride through the twists and turns of string theory—its past, its future, and what it tells us about the search for the universe’s final theory.

    PARTICIPANTS: Marcelo Gleiser, Michael Dine, Andrew Strominger

    MODERATOR: Brian Greene

    PARTICIPANTS: https://www.worldsciencefestival.com/programs/loose-ends-string-theory-and-the-quest-for-the-ultimate-theory/

    This program is part of the BIG IDEAS SERIES, made possible with support from the JOHN TEMPLETON FOUNDATION.

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    0:00 - Introduction
    3:54 - Program introduction
    5:40 - Marcelo Gleiser introduction
    6:26 - Unification of electricity and magnetism
    10:30 - Unification of space and time
    13:49 - Einstein’s General Theory of Relativity
    18:38 - Standard model of particle physics
    21:56 - Supersymmetry
    26:14 - The Island of Knowledge
    32:01 - Godel’s Incompleteness Theorems
    34:27 - String Theory explainer film
    37:07 - Michael Dine introduction
    38:35 - Supersymmetry and the spectrum of particles
    42:18 - Large Hadron Collider
    44:57 - Extra dimensions of space
    50:34 - Dark energy and multiple universes
    56:40 - Progress since the 1980s and the future of particle physics
    59:55 - Andrew Strominger introduction
    1:00:53 - Einstein and black holes
    1:03:59 - The black hole information paradox
    1:07:30 - Stephen Hawking’s insights into black holes
    1:12:00 - Using string theory to understand black holes
    1:19:33 - Conformal symmetry
    1:22:48 - Andrew Strominger’s view of string theory

    - Produced by Laura Dattaro
    - Associate Produced by Peter Goldberg
    - Editing and Animation by Josh Zimmerman
    - Music provided by APM
    - Additional images and footage provided by: Getty Images, Shutterstock, Videoblocks, Event Horizon Telescope
    - Recorded at NYU Skirball Center
  • Runtime : 1:27:24
  • String Theory and the Quest for the Ultimate Theory Brian Greene Michael Dine Andrew Strominger Marcelo Gleiser String Theory particle physics black holes superstring theory supersymmetry quantum gravity Einstein extra dimensions of space Bekenstein Calabi-Yau holographic worlds multiple universes supersymmetric quantum field theories mathematical physics Superstring theory best science talks New York City World Science Festival 2019


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  • Deep Moticons
    Deep Moticons   9 hours ago


  • Deep Moticons
    Deep Moticons   9 hours ago


  • Brittany. TheShotCaller Flores

    Stop using the machines we make to try and understand what's beneath our feet and all around take some mushrooms and love and care. Take a moment to sit and ask to be shown to think about stuff. Then wait and think some more. It's crazy what u can be shown. All of it we already know. Why we choose to live life's walking away from our true ways is retarded we need to be smarter than what were doing right now. And stop senselessly hurting each other. Money is terrible and hate is becoming way to common. No more yea butts

  • Allnew Jient
    Allnew Jient   15 hours ago

    Not from Amerika but wasnt Columbus looking for India?

  • Joaquin Inouye
    Joaquin Inouye   2 days ago

    Is it me or does Brian Greene appear to be channeling Capt. James Kirk. And always a compelling host, presenter, physicist always try not to miss his physics presentations.

  • laserbeam 002
    laserbeam 002   1 weeks ago

    So far string theory has not produced any real answers to any of the most complex problems. I read somewhere recently that string theory is starting to fall out of favor because it is simply failing to deliver.

  • Owais Ahmad
    Owais Ahmad   1 weeks ago

    One of the best programs hosted by Brian Green. Very enlightening to say the least.

  • Alec Jones
    Alec Jones   1 weeks ago

    Yay string theory a whole bunch of go nowhere

  • Shae C
    Shae C   1 weeks ago

    I'm so grateful for open minded, inquisitive people. I feel so sorry for those who fear the dark, and clutch their 2000 year old fiction books for simple, sad spoon-fed answers.

  • Nick Ross
    Nick Ross   1 months ago

    if the LHC can speed particles up to 99.9999995 % the speed of light, what would a bigger collider even do? is getting a few more 9s on there gonna make a difference?

  • DemonInPink
    DemonInPink   1 months ago

    If you were to shoot up and away from the Earth, you would have to propel yourself up with more force than its gravitational pull that keeps you down.A black hole is an area with so much mass and gravity that even light cant escape, as you would have to exit the black hole at faster than the speed of light.So what if a black hole were to have just enough mass to keep in the light, and radiates away over time to the point where its lost the amount of mass it needs to trap light?

  • RealmTraveller
    RealmTraveller   1 months ago

    who names these particles, selectron sneutrons sprotons,

  • Googol
    Googol   1 months ago

    1:12:15 - Not a good thing for real Americans or for Earth, was it.

  • Lexorde
    Lexorde   1 months ago

    I have some idea for quantum gravity.Currently, there are many attempts to describe gravity on the quantum level. String theory predicts that all particles are manifestations of strings vibrations. Loop quantum gravity assumes that spacetime is made of loops. Strings and loop have a size of about Planck length. Quantum field theory assumes that particles are vibrations of their corresponding fields for example electron is a vibration of electron fields, the photon is associated with photon fields, and so on. In general relativity, gravity is the manifestation of curved spacetime. In quantum gravity terms as spacetime, fields in QFT and particles must be the manifestation of the same phenomena. So I proposed that spacetime is made of objects with Planck length size and particles are spacetime vibrations. The particles are not a point but they are an area of vibrating spacetime designated by the wave function. So the particle for example electron is made of many virtual electrons, positrons, and photons. This can explain why a real single particle can be in many places in spacetime. Vibrations of spacetime curve it likewise vibrating atoms change body shape when it has been heated. Constants such as c, h, G are the parameters of spacetime. c - speed of light, h - Planck constant, G - gravitational constant. For example, c^4/G is a Planck force which is around 10^44 N. This is a force between two objects with Planck size separated by Planck length of each other. If spacetime is made of objects with Planck size the spacetime must have enormous strength. Planck force appears in Einstein's General Relativity equation on the right side. The weakness of gravity results from enormous spacetime strength. The huge rest energy in matter and so does cause only very little spacetime curve. If gravity constant increase the Planck force decrease and in consequence spacetime will have less strength so curve will increase at the same object mass, gravity increase.

  • Darth Quantum
    Darth Quantum   1 months ago

    Where to begin? First, sting theory is 50 years old, not 35. It grew out of S-matrix theory (which was discarded in favor of quantum field theory). Initially, string theory was developed as a model of the strong nuclear force, but was replaced by quantum chromodynamics. Also the earliest string model, bosonic string theory, had 26 dimensions and no fermions (only bosons). So it certainly did not describe our universe. Over the years string theorists whittled it down to 11 dimensions, 7 of which are supposedly confined to length-scales comparable to the Planck scale (10^-35 meters). Of course there is zero evidence for any of this. Recent experiments at the LHC have failed to find any extra dimensions, supersymmetric particles, axions, dark energy, or anything else that might be called BSM (Beyond the Standard Model) physics. The LHC did detect the Higgs boson, but that's about all. Unfortunately, some physicists have built their careers by hyping string theory, promising a lot and delivering very little. But the grant money keeps flowing in, so they continue beating the dead horse that is string theory.

  • Richard Fleming
    Richard Fleming   2 months ago

    Off-Planet Experimental Physics (The kind that could blow up the world) is the next frontier in science.With the vastness of space as a lab .. this is where we will unlock the universe.Just like some experiments are too big for a classroom, some experiments are too big for the planet.

  • Benjamin Winer
    Benjamin Winer   2 months ago

    The acoustic guitar only had four strings…it was missing two

  • Andy Burns
    Andy Burns   2 months ago

    Maybe selectrons are made of dark matter. Or smark smatter

  • ytrrs rrs
    ytrrs rrs   2 months ago

    Prof. Strominger (the third guest) says on multiple occasions that Columbus wanted to reach China! LOL! Columbus wanted to reach India, not China. It's amazing that Brian Greene doesn't correct him (politely)! So much for the knowledge of history among the physicists!

  • lizAKeV 7
    lizAKeV 7   2 months ago

    I understand the moment we think, " this is the best theory", we never grow out of the best. It feels stuck and not flexible enough to withstand the uncertainty of universe.

  • jeanette shackles
    jeanette shackles   2 months ago

    how many have to starve and be used for tax slaves for how many years while they waste billions and trillions on most of this crap that has never cured anything havent fed anyone has wasted enough money every person on the planet could be millionaires .....how many babies have to starve so these educated idiots can waste time and money that could be more wisley spent........GOD ALMIGHTY WANTS TO KNOW

  • Guide504
    Guide504   2 months ago

    String theory has been a rapidly approaching big distraction for years!

  • Junker Veld
    Junker Veld   2 months ago

    The omniscient damage anteriorly beam because flood spectacularly lock opposite a clear gauge. rainy, jagged fact

  • Renu Pathak
    Renu Pathak   2 months ago

    Wow Brian Green is no less than the scientists he is interviewing. His dramatic explanation of the string theory makes it so simple. Feel so blessed having all these great minds think for us. God bless

  • Doug G
    Doug G   2 months ago

    Strings are beautiful because they bend the mathematics to your will

  • Doug G
    Doug G   2 months ago

    I imagine me as a child and Brian Green an uncle discussing these things with a friend late at night I imagine they would seem like comfortable gods to me. Pass it on

  • Javier Garcon
    Javier Garcon   2 months ago

    Yeah, all these people are not founders they are late in the game. These mathematics in electricity were invented back 18,000 years ago. These British people try to take credit for things that other people have already have come up with. Wait until we get to Mars when we discover an ancient civilization under all that sand. What then? All these theories will go out the window.

  • 3 mOn3y
    3 mOn3y   2 months ago

    The nimble nancy independently wreck because calculator phenomenologically wave apud a efficient cell. makeshift, dear myanmar

  • Junker Veld
    Junker Veld   2 months ago

    The political bar postsurgically entertain because humor jointly drain barring a damaged beaver. ten, future futuristic currency

  • Dr Seuss
    Dr Seuss   2 months ago

    We're all made up of atoms. Are atoms conscious, if not, well we are. Atoms follow a life blueprint called DNA. One could have European dna, which is a picture, but every atom in a person born on a continent is made up of atoms on that continent. Maybe you win some sort of lottery and become a person, to do some good for the planet, then are made subject to it again, what would you doWhat if a spirit, out of it's spirit, made the physical, so while one might not grow tired of living forever, others who might grow tired of living, would not live forever, but here and there become some sort of new of a life formWhat if we, made up of particles as old as the universe, at one time were, where were you before when you don't remember : ) or doI saw a snake not pleased at having been made a snake, he bit himself, maybe it was a life form he could not lower himself to. Perhaps cremation into ashes into a bucket of concrete removed and dumped as clean broken concrete would prevent one from going through another existence. What are the odds, that you are, not only in existence in the universe, but that you became to be conscious in a creation, and beyond that, a human, which can commune with the spirit, and by which a spirit can grow without changing, yet can change itself

  • F Utube
    F Utube   2 months ago

    In reality, you are in your own universe time-slice. Your position in space regardless of relativity (but more importantly based on the speed of causality and the Planck limit) makes it that your time may run the same as your friend standing beside you; however your time/precise moment is slightly offset due to your positional “lag” of experiencing causality. Planck-time is the limit of our understanding but the processes going on in the vacuum are immune to this limit, virtual particle formation and quarks attributes are still a mystery to science; what goes on in there is purely hypothetical and deemed “possible” mathematically. Strings with spinners create yet more possible particles but eliminates the tachyon; no evidence of the “expected” SUSY particles were discovered at CERN, smearing SuperSymetry with dung. Now I will crash some string theory basic assumption, packing the amount of energy observed in some particles like quarks is the near limit, any more energy creates a micro- blackhole. The great majority of the mass of quarks is in their kinetic energy, electrons behave the same way; since the speed of these quarks or electrons is limited so is the energy/mass limited to a certain volume.

  • Long Castle
    Long Castle   2 months ago

    Is there any worry the "beauty of mathematics" may be the seduction of a scientific black widow? leading ultimately to an endless steam of theoretical dead ends?

  • everton1869
    everton1869   2 months ago

    String theorists are just science historians. They've discovered nothing, rarely attempt to test their theories with experiments

  • Damion Houston
    Damion Houston   2 months ago

    Why would you call it a theory if a theory isnt actually a fact.