Michio Kaku Explains String Theory | Big Think

And what else could we do? We can also unlock the secrets of the Big Bang. You see Einstein's equations break down at the instant of the Big Bang at the center of a black hole. The two most interesting places in the universe are beyond our reach using Einstein's equations. We need a higher theory and that's where string theory comes in. String theory takes you before the Big Bang, before Genesis itself. And what does string theory say? It says that there is a multiverse of universes. Where did the Big Bang come from? Well Einstein's equations give us this compelling picture that we are like insects on a soap bubble. A gigantic soap bubble which is expanding and we are trapped like flies on flypaper. We can't escape the soap bubble and that's called the Big Bang theory. String theory says there should be other bubbles out there in a multiverse of bubbles. When two universes collide it can form another universe. When a universe splits in half it can create two universes and that we think is the Big Bang. The Big Bang is caused either by the collision of universes or by the fissioning of universes. If there are other dimensions, if there are other universes, can we go between universes? Well that of course is very hard. However, Alice in Wonderland gives us a possibility that maybe one day we might create a wormhole between universes. This is a wormhole. Think of taking a sheet of paper and putting two dots on it. The shortest distance between two points is a straight line. But if I can fold, if I can fold that sheet of paper, then perhaps I can create a shortcut. A shortcut through space and time called a wormhole. This is a genuine solution of Einstein's equations. We can actually see this in string theory. The question is how practical is it to go through one of these things? We don't know. In fact there's a debate among physicists today. Stephen Hawking. Many physicists are jumping into the game trying to figure out whether it's physically possible to go all the way through a wormhole. Because if you could, then you might be able to use this as a time machine. Since string theory is a theory of everything, it's also a theory of time. And time machines are allowed in Einstein's equations. But to build one is extremely difficult. Far more energy is required than a simple DeLorean with plutonium. You know trillions of years from now the universe is going to get awfully cold. We think the universe is headed for a big freeze. All the stars will blink out. Stars will cease to twinkle. The universe will be so big it'll be very cold. At that point all intelligent life in the universe must die. The laws of physics are a death warrant to all intelligent life. There's only one way to escape the death of the universe. And that is leave the universe. We are now of course entering the realm of science fiction. But at least we now have equations. Equations of string theory which will allow us to calculate if it is possible to go through a wormhole to go to another universe where it's warmer and perhaps we can start all over again.