One of the approaches to understanding the origin of the universe involves Brane theory. This reaches into the toolkit of multidimensional space-times. String theory in fact, invokes seven, eight, nine, or even 10 dimensional space-time to understand the fundamental nature of matter. Similar theories are being used to try and explain the universe itself. In the theory, time loses its meaning. We have a sense of the age of our universe and the clock stops there. In fact, at the Planck Era, time has no meaning, so neither space and time are definable at the genesis of end of our universe. In this backdrop theory for the multiverse, time also has no meaning. Time may be an emergent property in some of the universes that develop but it may not exist in many of them, and it's not necessary for the overall construct. Brian, I'm about to show you something that's going to blow your mind. Do you know what the Big Bang theory is? Yeah. The theory that the universe started with a massive outward explosion from a singularity of infinite mass and infinite density. Check out the big brain on Brian. Good, now take a look. The universe has cosmic background radiation, a kind of echo of the Big Bang, precisely matches the energy spectrum of my return pad. Well, what does that mean? It means my return pad's explosion was the Big Bang. But the Big Bang happened like billions of years ago. No, we were outside the space-time continuum. Time and space didn't exist until my explosion, which means I created the universe, Brian. But that doesn't make any sense. You were born in the universe, how could you create it? It's called a temporal causality loop. The universe created me so I could create it, so it could create me and so on. That's the most incredible thing I've ever heard. So wait, that means that I created the universe too. No. You're sort of the Art Garfunkel of the universe. You can see here that we ventured far beyond the Big Bang model and are addressing the question of where the universe came from, why there was a Big Bang in the first place, and whether that's all there really is. Difficult as it is, theorists have started to work with these models. These eternal universes, where our universe, the Big Bang and everything that follows, is just one set of events in a backdrop of many events, many possible universes. One of the most fruitful of these is called the Ekpyrotic Model. Ekpyrotic is from the Greek root of a word meaning endless fire. In this model, multidimensional space-times involving higher dimensional worlds lead to the creation of our three-dimensional space and one dimension of time. Essentially, our universe develops from the energy released when higher-order space-times or branes collide. That collision creates the motive force for the Big Bang and the subsequent expansion of our universe and the creation of all matter from pure energy early in the universe. Tension between the branes leads to them re-collapsing on a timescale of about a trillion years, so this is actually an oscillating universe model. Branes operating in these higher dimensions can cause other collisions, the creation of other universes with different properties than our universe. The people working with this theory are using fiendishly difficult mathematics to describe cosmology. Their first job is of course, to reproduce conventional cosmology and the Big Bang theory using the more difficult mathematical context of brane theory, but that's hard to do and they haven't got there yet. If they do get there, then they'll be able to explore the other possibilities of the theory. This is young and very speculative theoretical science. It's almost impossible to visualize higher dimension space-times but if we drop the number of dimensions and project them, we can visualize what the cyclic universe based on the Ekpyrotic theory might look like. At this point, we reach the bleeding edge of cosmology. Many of these ideas may be incorrect, but the cosmologists who are working on them are excited to be able to venture in a new regime. Since I'm going beyond my pay grade, I need some expert help in explaining this. So much to talk. I haven't spoken to you in a little while. What have you been doing with yourself lately? We'll get to the movie in a second, but I'm talking about you the man, what are you doing? A lot of things, I've been doing a lot of reading actually lately. Reading. Yeah. Yeah. Yeah. What stuff are you reading? Mostly road signs, prescriptions to make sure I take them right. You're right, pretty good idea. Yeah, I took a whole bottle of, what's called Vicodin. Yeah. Because of just, it looked yummy. That's not a good idea. Yeah. After I plowed my bulldozer into a store, I woke up in the hospital and I just thought, "I got to start reading more". Reading more. Yeah. Now. Seriously, I'm just curious and I think a lot of us are. What do you seriously like to read in the book world? I'm fascinated with science. Really? I'm fascinated with science. It's incredible. Have you heard about the new Brane theory? No. Whose Brane theory is this? It's Stephen Hawking. Stephen Hawking? Yeah, has been talking about this new Brane theory, about the universe opposed to the Big Bang theory, and they're coming out with some new concepts. It's really exciting. You actually read about it? Ekpyrotic universe, have you heard about this? Say it again. It's very difficult to say. The Ekpyrotic universe. Wow! Yeah. It's amazing that your reading that stuff. See, the model we have now Conan, is based on the idea that our Big Bang universe was created from the collision of two, three-dimensional worlds moving along a hidden extra dimension. But conceptually, the Ekpyrotic Model is very different. There is no inflation or rapid change happening at all. The approach to collision takes place very slowly over an exceedingly long period of time. It's quite fascinating that the rapid change and very slow change can produce nearly the same effects. The difference results in one distinctive observational prediction though. The inflationary cosmology predicts a spectrum of gravitational waves that may be detectable in the cosmic microwave background. The Ekpyrotic Model however, predicts no gravitational waves effects should be observable in the cosmic microwave background. I'm just so relieved by this, really. This is incredible. So I've been trying and trying to tell this to people for years. Really, I've been trying to drill it through their heads but they don't listen to me. They call me mad, they laughed at me. Excuse me Conan. All right. Hello. Hello, Jim. This is Stephen. Hello. Hi, Stephen Hawking. I can't believe this. Wow, that's amazing. I am well, thank you. I just wanted to call you to tell you how happy I am that you're excited about the new Ekpyrotic universe theory. It's amazing. But don't bother trying to explain it to them. Their pea brains cannot grasp the idea of the world on the brane. Yeah, I know. Well, it's been so frustrating for me because the moment I read it, I knew it was important and I wanted to tell them, but then you did. Well, I have to go now. I'm very busy watching "Dumb and Dumber". I marvel at the pure brilliance of it. You truly are a genius. No, you're a genius. No, you are. No, you are. No, you are. No, you are. No, you are to infinity. You got me there Stephen. That was insane, that was incredible. Theorists are working with multidimensional space-times, with Brane theory, to try and understand the Big Bang, the reason for the origin of the universe. Such theories have to start by explaining things that the conventional Big Bang theory already explains. Brane theory attempts to explain the reason the universe exist in terms of multidimensional space-time, the same mathematical theories that are used in String theory. It's very speculative. One variation of this theory, the Ekpyrotic theory, also finesses the Big Bang itself, and postulates an endless continuing universe with expansion and contraction of higher dimensional spaces. It's worth remembering that such theories are very speculative.
