String Theory Explained – What is The True Nature of Reality?

  • Published: 01 March 2018
  • Is String Theory the final solution for all of physic’s questions or an overhyped dead end?

    This video was realised with the help of Dr. Alessandro Sfondrini and it was funded by SNSF under Agora Grant n. 171622 and through the NCCR SwissMAP: The Mathematics of Physics.

    See also our video on the black-hole information paradox:

    Kurzgesagt Newsletter:

    Support us on Patreon so we can make more videos (and get cool stuff in return):

    Kurzgesagt merch:


    The music of the video here:



    Flavio Storino, Alice Balcon, Hari Krishnan, Warren Wiscombe, Sara Zeglin, Asiryan Alexander, maarten sprengers, William Northern, Kerem Mimaroglu, Yana Kultysheva, Josh, Keaton Anderson, Croconaw, Peter Steinberger, Jonathan Diamond, Troy McConaghy, Paddy, Darko Sperac, Peter Burkhalter, Chris Amaris, Tyler Lovell, John Ruble, Chase Henson, Arpita Singh, Edward C.P., Andreas Edlund, Ryan Bubinski, Paul Greyson, Jerry Ding, Austin Sundquist, Daniel Link, Tim Johnson, kayleigh dreste, Johan Sjöblom, Max Stuart, Mush Rain, Andor Baranyi, Eduardas Afanasjevas, Bill Clem, Jake Smith, Stephen Woerner, Jeff Sorensen, Christopher Damsgaard, Eduardo AV, Michael Gawenka, Florian Hoedt, Lucas Nyman, Nathanael Baker, Martin Wierzyk, Mauricio Streb, Karl, Rameet Chawla, Joachim Andersen, Avinash, Erik Golden, Glenn Stoltz, Elliott Nelson, Andrew Averett, Ben Wei

    Help us caption & translate this video!

    String Theory Explained – What is The True Nature of Reality?

Comments • 13 964

  • Kurzgesagt – In a Nutshell

    There's brand new stuff in the Kurzgesagt Merch Shop. Check it out here:

    • Ritesh Verma
      Ritesh Verma  3 weeks back

      I love your videos kurzgesagt

    • TheShunmu
      TheShunmu  1 months back

      I have doubt. Please explain me. When gravity is considered as a geometry then why should we add a particle graviton to the quantum equations as in @4.35 of the video

  • Israel T
    Israel T  13 hours back

    Like religion

    • Soni Studios
      Soni Studios  14 hours back

      OMG SUCH A GD VIDEO!!!! 😏🤙

      • Retroke
        Retroke  14 hours back

        Bois, why would you guys know the reason of logic and reality when login itself makes no logic

        • dungen of dragons
          dungen of dragons  14 hours back

          Multiple times for over a year. Help me i need a Lamborghini

          • Theicarbros
            Theicarbros  16 hours back

            This may seem alittle left field but it said they were trying to work out the additional 6? This may sound completley stupid but ik in algebra in a graph if u have (x-2) and (x-2) or (x-2)^2 your x is just 2 not 2 and 2 cause obviously they are one in the same . what im trying to get at is what if multiple overlap with one another ? As in multiple parts to the string theory are one in the same but have diffrent outcomes as we know in math as well you can have the square root of 25 is positive or negative 5 two solutions , i also dont know anything about anything so pardon my logic if its just mad trash

            • Matthew Mazzetti
              Matthew Mazzetti  17 hours back

              Gravitons for the win.

              • trainer ruby
                trainer ruby  18 hours back

                Why no hindi captation

                • Elee
                  Elee  20 hours back

                  Video starts at 0:00

                  Thank me later

                  • Epicly Derp
                    Epicly Derp  21 hours back

                    Why is the music so corrupt?!?!?!

                    • Bennett Frazier
                      Bennett Frazier  1 days back

                      That...was really informative!

                      • Sonali sophie Bilung
                        Sonali sophie Bilung  1 days back

                        thanking for posting this video on youtube and not on any tuition website <3 <3 <3

                        • Seven States
                          Seven States  1 days back

                          My true nature of reality is a woman in a G-String. Anyone?

                          • Ammar Elbehery
                            Ammar Elbehery  1 days back

                            So is seeing elementary particles the theory of everything?

                            • Dimitris Anagnostopoulos

                              The uncertainty principle is not the same as the observer effect. It's often times being confused. Different things though. The uncertainty principle expreces the nature of reality and has nothing to do with how an observation can alter the thing being observed. Thank you for your great videos by the way. Love them.

                              • Fares Alwakeel
                                Fares Alwakeel  2 days back

                                i mean watching this got me thinking why don't we think of gravity as an emergent property rather than a fundamental one like waves, one particle cant create a sound or tidal wave but multiple molecules together do, ya get it. so rather than gravity being a particle we can observe it can be a property of the universe that emerges due to the masses and particles in it.

                                • King jeff
                                  King jeff  2 days back

                                  I clicked this because of Sheldon Cooper

                                  • slender boy4z
                                    slender boy4z  2 days back

                                    "Touch's things

                                    • Glenn Roberts
                                      Glenn Roberts  2 days back

                                      String theory is like a fart. It came out of someone's ass.

                                      • Dorothy Isidro
                                        Dorothy Isidro  2 days back

                                        I Like String Theory
                                        Tell Me More Kurgesagt!

                                        • Michael’s Garage
                                          Michael’s Garage  2 days back

                                          And yet people actually believe that they know the birth of the universe

                                          • 5upremists
                                            5upremists  2 days back

                                            5:47 8th spatial dimension,is a ring

                                            • Tou Iij
                                              Tou Iij  2 days back

                                              Heisenburg isn't looking at something will change it. That's the observer effect. Heisenburg says the more you know an objection position, the less you know it's velocity and vice versa because the wave function collapse.

                                              • Oholibama
                                                Oholibama  24 hours back

                                                You are the second Einstein, aren't you?

                                                No. You're Not. Please use ur brain. Please

                                            • iRox Studios
                                              iRox Studios  2 days back

                                              4:41 Shisno Paradox? Redvsblue viewers would know

                                              • Felsmak
                                                Felsmak  3 days back

                                                The dislikes are from Ultron.

                                                • JOHNDOE
                                                  JOHNDOE  3 days back

                                                  metaphysics is annoying to me.

                                                  theories built ontop of theories.

                                                • Edward Galliano
                                                  Edward Galliano  3 days back

                                                  More With Respect to String Theory
                                                  In good spirit of Divine will let us consider what protective geometry tells us about dark matter and dark energy. This is easy. The following we owe to Albert Einstein, but sorry Albert the protective plane is always flat.
                                                  Light travels through space and photons encounter gravitons traveling back to their sources. That is antipodes on the elliptic plane which is spherical for the most part. Antipodes are points on opposite sides of a sphere and represent the same points in elliptic geometry.
                                                  Light in our Euclidean space is red-shifted by elliptic gravity and is eventually lost to our reality if it travels beyond 13.7 billion light years in any direction, from any place, then becomes gravity on level 4.

                                                  • Don't, Jim
                                                    Don't, Jim  3 days back

                                                    “It’s dangerous to theorize alone” haha

                                                    • Sunflower Shine
                                                      Sunflower Shine  3 days back

                                                      Watching while the pic of Einstein on my wall stares back at me and low key makes me feel dumb.

                                                      • Muhammad Ahmad
                                                        Muhammad Ahmad  3 days back

                                                        Can u please work on biology tooooo

                                                        • Nia Marie
                                                          Nia Marie  3 days back

                                                          Wow learned more then I ever did in school

                                                          • CoolCreeper39
                                                            CoolCreeper39  3 days back

                                                            Who else is watching youtube videos late at nights

                                                            • Julio Cesar
                                                              Julio Cesar  3 days back

                                                              Heisenberg's uncertainty principle has nothing to do with our ability to measure things. It is fundamental in nature.
                                                              Great vid though.

                                                              • Jon Doe
                                                                Jon Doe  3 days back

                                                                It's videos like this where you really understand what you're capable of.......i'm going to be a plumber

                                                                • U Miami
                                                                  U Miami  4 days back

                                                                  ZELDA REFERENCE!!!!!

                                                                  • Solomon Grundy
                                                                    Solomon Grundy  4 days back


                                                                    • Joshua Noriega-Allen
                                                                      Joshua Noriega-Allen  4 days back

                                                                      All those different dimensions of that bird made sense until 6

                                                                      • Edward Galliano
                                                                        Edward Galliano  3 days back

                                                                        The universe has five spatial dimensions the sixth might as well be describing the singularity inside a black hole.

                                                                    • vwarke
                                                                      vwarke  4 days back

                                                                      They are on the right track with superstring theory. The yogis have always talked of extra dimensions that can be experienced but are not in the sensory, so called ‘objective’ realm. As per the yogis -This whole creation is just a vibration, albeit of different frequencies ranging from gross to such subtle ness that it is beyond matter, they call this ‘Naada Brahma’ or the cosmic vibration that condenses to form matter at a gross level and yet also exists in subtle suprasensory states. Just as we have ice and then water (different states of condensed heaviness existing together) and also water vapour or water in its subtlest state of gas that is non cognizant to our physical senses, but can be condensed into reality as liquid water or ice. The string folks also say the same - this whole creation is ‘just a vibration’, the strings are nothing but vibrations of different frequencies, gross and subtle. Dark matter and Dark energy are something that exist all around us and they are completely unknown to us. In fact they are so dense that Brian Greene’s likened physical 4% matter to the holes in Swiss cheese where the cheese does not exist ( dark matter and energy are the crucible of physical matter that we know and are made up of). Now Shiva, is known as ‘that which is not’, or the one who transcends this physical creation but is the basis of it. Shiva is also the dark one.
                                                                      The ancients and the yogis talk of ‘Maya’ - which is an illusion. Thus this reality that we perceive as real is non existent. The very act of interaction with this creation (even looking at it with our eyes) actually causes the collapse of the electrons probability wave function by an act of measurement ie as simple a thing as looking at this creation. This causes it to then take a certain fixed position for us to perceive it and thus the matter around us on a extrapolated larger scale. This is Maya, to perceive things the way they are not in reality. To add to this are the consciousness and cognitive neuroscientists like Donald Hoffman, who are saying that the reality that actually exists is very different from the way we perceive the world as an objective reality. So actually we project the reality out there, again to add to this is the ‘holographic universe’ where the universe is projected out there are a hologram and perceived by us. Some things interesting in this vein of thought are echoed by Leonard Susskind, in his talks on the universe as a hologram.
                                                                      Fundamentally, the yogis said that, not only is this world an illusion or Maya’ but it also does not exist. Einstein has put forth -‘Space and time do not exist’, Brian has covered this beautifully in the ‘Fabric of the cosmos’- ‘the illusion of time’. So when there is no space and no time there is only ‘Now’ and that is why those who have realized this non-dual state of this creation talk of ‘the power of now’ or ‘there is eternity in a moment and that moment is now’.
                                                                      Science will get there as it is on the right track, but to prove 11 dimensions, 7 more than the 4 of space and time is still not possible. They are using the wrong tools to get to the correct goal.

                                                                      Trying to connect the dots here. It is possible to perceive with the meditative mind that can either still the mind or distance itself from the physical nature of the body and the mind itself by creating a space between oneself and the world around.
                                                                      If anyone has read so far, my sincere thanks to their patience 😊. I guess I have written enough. But please know that there is something beyond and that can be experienced. Science will get there eventually.

                                                                      • Edward Galliano
                                                                        Edward Galliano  3 days back

                                                                        Okay one more time. I finally found you! I got your reply this morning.
                                                                        If you have seen my comments on protective geometry and string theory don't be discouraged it's what led me to the protective plane that is the key to all understanding. I fully subscribe to the insights you presented in your original comment. Keep up the good work.

                                                                      • Edward Galliano
                                                                        Edward Galliano  3 days back

                                                                        Okay I hope you get the reply I just sent. If we don't get to see our reply right after we send it. If not I will try again later.

                                                                      • vwarke
                                                                        vwarke  3 days back

                                                                        Edward Galliano - Thanks a lot dear friend. I will look up your suggestions 😊. The ancient Mayans were yogis, with access to higher and subtler dimensions of this creation.

                                                                      • Edward Galliano
                                                                        Edward Galliano  3 days back

                                                                        Hi I just had a chance to study your comment again. My father came from central America. I have Maya blood. I think my career as a mathematical theorist is no accident. Protective geometry gives us a conceptual tool that explains the entire universe. That's the elliptic plane. N J Wildberger is a good reference you might want to look at. At least the protective plane is a simple enough concept. To bad the math is so horrendous, but that's the way it is! I hope you can find more to add to all your insights on this subject.

                                                                      • Edward Galliano
                                                                        Edward Galliano  4 days back

                                                                        Thank for your thoughtful comment. I will study it some more later. You have obviously seen as many science programs as I have. I have a more "metaphysical" take on this. I think there is a bridge between science and religion. "Cast your yoke evenly"

                                                                    • Iliana Is Trash
                                                                      Iliana Is Trash  4 days back

                                                                      Anyone else here after learning about a bunch of loona lore(stan loona btw)

                                                                      Just me ok...

                                                                      • basket1099
                                                                        basket1099  4 days back

                                                                        Are there people from adventure time on this or something? So many references and sounds. Plus the German lol

                                                                        • Jena Carter
                                                                          Jena Carter  4 days back

                                                                          someone dumb this down for me i don’t have smarts

                                                                          • Jack Reacher
                                                                            Jack Reacher  2 days back

                                                                            Jena Carter the universe fucks us with no strings attached

                                                                        • Bryce Mikos
                                                                          Bryce Mikos  4 days back

                                                                          5:28 that's a Tom drum, not a snare. The snare is on the right of the screen.

                                                                          • Namit Prasad
                                                                            Namit Prasad  4 days back

                                                                            This was trippy and epic!

                                                                            • edwong3
                                                                              edwong3  5 days back

                                                                              I thought that back in the late 90s, theoretical physicist Ed Witten had come up with an equation that explained string theory and would be the closest thing to finally coming up with the elusive, "Theory of Everything". I guess we''re still searching for more answers.

                                                                              • Lu Ja
                                                                                Lu Ja  5 days back

                                                                                Don't get it

                                                                                • Alex Lanoux
                                                                                  Alex Lanoux  5 days back

                                                                                  The uncertainty principle is not about measurement. It is how things actually behave at scales in question.

                                                                                  If a particle has entirely defined position, its momentum is entirely undefined. Although it is impossible to entirely define position because scale can be infinitely small, if a particle's theoretical position were infinitesimal, it would need an infinitely small wave-function to define its location. Since an infinitesimal wavelength is needed, the frequency of the wavelength is infinity. Frequency having infinite value means energy is infinite. Momentum is directly related to energy.

                                                                                  This means a particle is literally traveling everywhere infinitely fast, thus it is everywhere. No measurement involved, no observer dependence.

                                                                                  • Theresa Blake
                                                                                    Theresa Blake  4 days back

                                                                                    Alex Lanoux this really helped me for my physics exam tomorrow lmao😂 a lot better than how my teacher explained it 👌

                                                                                • The Laptop Lagger
                                                                                  The Laptop Lagger  5 days back

                                                                                  Few channels get so many views consistently and you deserve them all and more

                                                                                  • Angel Wings in Hell
                                                                                    Angel Wings in Hell  5 days back

                                                                                    god this was confusing but also incredibly fascinating. i love how you’re so positive in this video, that somebody we WILL know more, it’s really cool