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


What is the true nature of the universe? To answer this question, humans come up with stories to describe the world. We test our stories and learn what to keep and what to throw away. But the more we learn, the more complicated and weird our stories become. Some of them so much so, that it’s really hard to know what they’re actually about. Like string theory. A famous, controversial and often misunderstood story, about the nature of everything. Why did we come up with it and is it correct? Or just an idea we should chuck out? To understand the true nature of reality, we looked at things up close and were amazed. Wonderous landscapes in the dust, zoos of bizarre creatures, complex protein robots. All of them made from structures of molecules made up of countless even smaller things: Atoms. We thought they were the final layer of reality, until we smashed them together really hard and discovered things that can’t be divided anymore: Elementary particles. But now, we had a problem: They are so small that we could no longer look at them. Think about it: what is seeing? To see something, we need light, an electromagnetic wave. This wave hits the surface of the thing and gets reflected back from it into your eye. The wave carries information from the object that your brain uses to create an image. So you can’t see something without somehow interacting with it. Seeing is touching, an active process, not a passive one. This is not a problem with most things. But particles are But particles are very, But particles are very, very, But particles are very, very, very small. So small that the electromagnetic waves we used to see are too big to touch them. Visible light just passes over them. We can try to solve this by creating electromagnetic waves with more and much smaller wavelengths. But more wavelengths, means more energy. So, when we touch a particle with a wave that has a lot of energy it alters it. By looking at a particle, we change it. So, we can’t measure elementary particles precisely. This fact is so important that it has a name: The Heisenberg uncertainty principle. The basis of all quantum physics. So, what does a particle look like then? What is its nature? We don’t know. If we look really hard, we can see a blurry sphere of influence, but not the particles themselves. We just know they exist. But if that’s the case, how can we do any science with them? We did what humans do and invented a new story: A mathematical fiction. The story of the point particle. We decided that we would pretend that a particle is a point in space. Any electron is a point with a certain electric charge and a certain mass. All indistinguishable from each other. This way physicists could define them and calculate all of their interactions. This is called Quantum Field Theory, and solved a lot of problems. All of the standard model of particle physics is built on it and it predicts lots of things very well. Some quantum properties of the electron for example have been tested and are accurate up to 0, 0,00 0,0000 0,000000 0,00000000 0,0000000000 0,000000000000 0,0000000000002 %. So, while particles are not really points, by treating them as if they were, we get a pretty good picture of the universe. Not only did this idea advance science, it also led to a lot of real-world technology we use everyday. But there’s a huge problem: Gravity. In quantum mechanics, all physical forces are carried by certain particles. But according to Einstein’s general relativity, gravity is not a force like the others in the universe. If the universe is a play, particles are the actors, but gravity is the stage. To put it simply, gravity is a theory of geometry. The geometry of space-time itself. Of distances, which we need to describe with absolute precision. But since there is no way to precisely measure things in the quantum world, our story of gravity doesn’t work with our story of quantum physics. When physicists tried to add gravity to the story by inventing a new particle, their mathematics broke down and this is a big problem. If we could marry gravity to quantum physics and the standard model, we would have the theory of everything. So, very smart people came up with a new story. They asked: What is more complex than a point? A line- A line or a string. String theory was born. What makes string theory so elegant, is that it describes many different elementary particles as different modes of vibration of the string. Just like a violin string vibrating differently can give you a lot of different notes, a string can give you different particles Most importantly, this includes gravity. String theory promised to unify all fundamental forces of the universe. This caused enormous excitement and hype. String theory quickly graduated to a possible theory of everything Unfortunately, string theory comes with a lot of strings attached. Much of the maths involving a consistent string theory does not work in our universe with its three spatial and one temporal dimensions. String theory requires ten dimensions to work out. So, string theorists did calculations in model universes. And then try to get rid of the six additional dimensions and describe our own universe But so far, nobody has succeeded and no prediction of string theory has been proven in an experiment So, string theory did not reveal the nature of our universe. One could argue that in this case string theory really isn’t useful at all. Science is all about experiments and predictions. If we can’t do those, why should we bother with strings? It really is all about how we use it. Physics is based on maths. Two plus two makes four. This is true no matter how you feel about it. And the maths in string theory does work out. That’s why string theory is still useful. Imagine that you want to build a cruise ship, but you only have blueprints for a small rowing boat. There are plenty of differences: the engine, the engine, the materials, the engine, the materials, the scale. But both things are fundamentally the same: Things that float. So, by studying the rowing boat blueprints, you might still learn something about how to build a cruise ship eventually. With string theory, we can try to answer some questions about quantum gravity that have been puzzling physicists for decades. Such as how black holes work or the information paradox. String theory may point us in the right direction. When used in this spirit, string theory becomes a precious tool for theoretical physicists and help them discover new aspects of the quantum world and some beautiful mathematics. So, maybe the story of string theory is not the theory of everything. But just like the story of the point particle, it may be an extremely useful story. We don’t yet know what the true nature of reality is but we’ll keep coming up with stories to try and find out. Until one day, Until one day, hopefully Until one day, hopefully, we do know. This video was supported by the Swiss National Science Foundation and realized with the scientific advice of Alessandro Sfondrini.

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Comments

  1. Isnt the "observer effect" what is described as heisenbergs uncertainty here? I think I am correct in thinking that heisenbergs uncertainty is Not the principle by which the interaction of light with something alters its measurement; rather, it is the "trade off" in the accuracy of measuring two related observables due to QM effects (i.e. pos and momentum) ?

  2. Thank you for the great video. I especially appreciated the part about the Heisenberg Uncertainty Principle and the interactions between light and elementary particles.

  3. im sorry, this video didn't really explain anything. with the pretentious "in a nutshell" profile name and "explained" in the title i was hoping for more. call me a troll or a hater but its hard to find string theory as a realistic viable solution with the math was beautiful and worked out. we can't see it or interact with it cause of the restrictions of physics, we can't disturb it due to the uncertainty principle and the current theories basis is that "we thought of it as a dot and so it was". as uncertain as quantum physicist are about the location and momentum of a subatomic particle are, you can at least do us enough justice not to pretend string theory can be explained in a nutshell.

  4. Shadow Spin String Theory. by Kenneth William Feemster.
    01/20/2016

    About The shadows caused by charged particle. The shadow behind the proton caused by electrons presents, must be very narrow and radiate out. Just like the shadow behind the electron must be a tight beam. A like a long narrow
    straight, like string,
    shadow radiating out.
    But electrons and proton have spin so these shadows, spiral around the whole system, bent by the spinning
    electro static fields. The shadow bend forward into the spin electrostatic charge and then at a certain distance, farther out, where the spin starts to be come a fraction of the speed of light the shadow change direction.
    Kind of like a flatten out spring. The way atoms hold onto each other by hooking on to the spiraling shadows.

    The hydrogen atom and neutron creation.
    When a electron comes near a hydrogen atom, the electron will move toward the proton, the proton will start to spinning faster. The electron will change coarse into the spinning electrostatic breeze, going into orbit. Because of a
    Doppler like effect of a negative electron moving head on into a spinning positive electostatic field.
    Electrostatic field can spin a up to superluminal speeds.

    The electron does not pick up much spin, but move laterally. It goes into orbit. The electron will pick up spin from the proton within a certain distance. On the steep part of the positive electrostatic, from the proton slope on a 1/f^2 mathematical curve. None or little on the flat part.
    When a electron move toward a proton, and by luck chance that it flies toward it on a perfect bulls eye, which very very rare. When the electron does get get very close to the proton they both spinning up to the speed of light, and
    greater. This is where the MC^2 energy is at. And a neutron is born.

    Electrons in the spin of a positive proton electrostatic field that are spinning at fraction of the speed of light, or greater, time will slow down in the spinning disc of the electrostatic field. Particals will get stuck in the thickest of honey. And will be dragged with proton where ever it goes. A electron will be frozen in orbit, and also spiraling shadow tail structure.
    A star ship moving at the speed of light, cutting through all of the ambient back ground positive spin, time will slow down. A spinning black hole dragging its space time with it.
    When a electron spins at at a fraction of the speed of light time speed up. Like the effect between entangled electrons.

  5. ok so with string theory lets say the multiverses theory was real and string theory says that maybe another universe is having the heat death theory and everything is closing in on each other creating too much gravity which creates worm holes to othe universes in what we call black holes and thats how black holes are able to suck anything and everything into them untill the other universe cant close in on itself anymore that starts expanding again which is the big bounce theory and no one will be able to prove this because no one will ever live long enough to know (am i crazy here )

  6. (The universe is held in balance with this number +0.007 for dark energy) As
    beautiful as it sounds String Theory is purely hypothetical like imagining
    that all women want to wear a thong or string theory. Sorry, butt I have to say
    this the theory is like a fairy tale and will make you go crazy
    thinking how I can get the string theory in all the cracks.

  7. He got the Heisenberg uncertainty principle mistaken for the observer effect. A common fluke and can go unnoticed but the difference between the two is the Heisenberg uncertainty principle states that the more precisely the position of some particle is determined, the less precisely its momentum can be known, and vice versa. This sounds simple because it is. This is just one of its implications but the generic explanation is that it is any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle, known as complementary variables or canonically conjugate variables such as position x and momentum p, can be known or, depending on interpretation, to what extent such conjugate properties maintain their approximate meaning. The observer effect in simplest form states that measurements of certain systems cannot be made without affecting the systems, that is, without changing something in a system. As stated in the video to see something is to interact with it, an active process, certain things can be altered by said interaction.

  8. The more I understand science the more of believer I become. Science just doesnt offer any explanation and only God is our only strength in darkness. Its more and more sure this all is not accident.

  9. Me , before the video: Wow , String Theory sounds interesting , I want to learn more .

    Me , after this useless video: Wow , String Theory sounds dumb , whoever made it should go to Hell .

  10. GOD not only created it but created people who believe in it.
    Theories, they're all theories. Theory and facts are 2 different things.

  11. ok what you are describing, i.e. hitting smaller stuff with high energy short wavelength light, is NOT the heisenberg uncertainty principle. that is called the observer effect. the heisenberg uncertainty principle has to do with something much more fundamental: information about certain pairs of related variables cannot be known to arbitrary precision. this has nothing to do with our instruments or how good our experiments are. this is something completely fundamental to the universe that cannot be overcome with more precise calculation.

  12. a quantum field may have different types,a photon,neutron,proton, etc.That means that different types of quantum fields can include graviton. This is the perfect way to mary the two theiries together,and can also work with and without higher than 3 D . it can also help the fact that the fabric of spacetime ALSO applies to quantum mechanics,as in it has a probability or amount of force depending on the chance of gravitons, higher when probability is higher.

  13. This video is by far the best explanation of the Heisenberg uncertainty principal I've ever seen in a video. Like, you wrote it in such a way that it is understandable to almost anyone.

  14. I am skeptical about string theory being the theory to everything. On paper it seems like it could be the theory to meld quantum mechanics and Einstein’s theory of relativity. However even string theory struggles to do this. They simply break down. We can learn a lot from string theory as it’s still valid. But there are still a lot to be proven like gravitons and anti particles which opposites to every particle there is. Although m theory beautifully links all string theories together the equations are still extremely difficult to calculate. Let’s see where string theory take us….

  15. So basically if string theory is true , which i guess is true(because with the help of this theory we are able do all maths correct in the quantom physics)then it means everything is made up of strings.can we say that strings are basic building blocks of everything instead of atoms

  16. Why do people dislike these videos? He show thing he and his team has found and shows no opinion yet people still dislike as he teches them things!

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