Figuring out one-inch equations, making predictions about the future of the universe, and ice skating can all be extremely time-consuming activities. But our friend, Michio Kaku, has answered some of the gazillion questions you all sent in for him. Because there were so many questions, we had Michio answer 10 that seemed fairly representative of the group. Check out those questions and Michio’s answers after the cut. And many thanks for your patience, Secret Lifers!
QUESTION FROM SEBASTIEN CARASSOU: Hi Mr. Kaku. What was the event that pushed you in the physics field? Also, it seems like you are a big science fiction fan. How does your work influence the way you see scifi today?
Thank you very much!
MICHIO: When I was 8, two events pushed me in the direction of physics, and also science fiction. First, everyone was talking about the death of Albert Einstein when I was 8, and that he could not finish his greatest work. To me, that story was so fascinating that I wanted to help finish that work (his theory of everything). Second, I used to watch Flash Gordon on TV, and was hooked. Later, I realized that these two events were complimentary. If you understand fundamental physics, then you also understand whether certain of the devices of science fiction are possible or not. On one hand, I work on string theory, which we think is Einstein’s unified field theory. But understanding basic physics, I can also understand what technologies might or might not be possible centuries from now. (For details, see my latest book, Physics of the Future, about the next 100 years). So the key to understanding the future is to understand physics.
Science fiction today also forces physicists to understand the very limits of science. You cannot create new science unless you realize where the old science leaves off and new science begins, and science fiction forces us to confront this.
QUESTION FROM MAX R: With all the complexity and beauty that comprises the natural world and its workings, why do you believe it so important to reduce it to a single theory?
MICHIO: Everything we know about basic science leads us to believe that there are simple, unifying principles behind everything. In biology, for example, evolution and DNA allows us to explain the diversity of all life on earth. In geology, continental drift allows us to unify many diverse observations about the earth. In chemistry, the atomic theory allows us to decribe all matter. And all of these principles, in turn, are byproducts of elementary particle physics. So far, the leading candidate for a theory of all elementary particles is string theory, which in turn represent all particles as musical notes on a string.
So nature is based on simple, elegant principles. But to understand the interactions of these simple principles, you have to understand the vast complexity that we see in nature. So the natural world surrounding us is full of complexity, but this in turn is based on the interactions of a handful of basic principles.
QUESTION FROM MS NAYMARK’S SCIENCE CLASSES: Hi Michio, My students enjoyed watching your videos. They had a few questions for you: 1) Who is your favorite professional figure skater? 2) Since you like to skate, have you ever played hockey? 3) Have you or your daughter ever entered a skating competition? 4) Have you ever thought of an equation while spinning? 5) What is your favorite equation? 6) How would the theory of a parallel universe work? 7) Would you rather be sitting quietly in a room thinking or on the ice spinning? Thank you for sharing with us! Ms. Naymark’s Science Classes
MICHIO: Paul Wylie is my favorite men’s ice skater. Kristi Yamaguchi is my favorite women’s ice skater. Let me say that I love ice skating. I once thought of perhaps entering my daughter (or myself) in an ice skating competition, but I realized that you have to practice and train very hard, and we simply did not have the time. So ice skating is a hobby.
I have two favorite equations. The first is Einstein’s theory of general relativity, which can be summarized as: R_ij = 0. It’s amazing that the Big Bang, black holes, etc.all solutions of this simple four-dimensional equation, and it’s less than an inch long! Another favorite equation is Maxwell’s theory of light. It’s amazing that radio, TV, UV light, X-rays, gamma rays, and visible light can be summarized by the simple equation D F = 0. This leads me to believe, as Einstein did, that there must be a one-inch equation which summarizes ALL fundamental laws of our universe.
One fascinating aspect of all this is that the quantum theory makes possible parallel universes. An electron, for example, exists in many parallel states. It can be two places at the same time. This sounds ridiculous to us, but this is because we are very large objects, containing many electrons, so these bizarre quantum effects cancel out and we don’t see them. But at the atomic level, we see electrons moving about in the most bizarre way, being two places at the same time and disappearing and reappearing somewhere else. The quantum theory may sound strange, but it is the fundamental law of nature, and it has been measured to an accuracy of one part in 100 billion.
When I get bored, or get stuck on an equation, I like to go ice skating, but it makes you forget your problem. Then you can tackle the problem with a fresh new insight. Einstein liked to play the violin to relax. Every physicist likes to have a past time. Mine is ice skating.
QUESTION FROM MUSLIM:
#1: Has the Big Bang Theory been proven beyond doubt, or are there still aspects of it that require evidence and experimental support?
2: Is it possible scientifically for something to come out of nothing?
There are the principles of Conservation of Matter and Energy, where in nothing can be created or annihilated and matter and energy are interchangeable and transferable.
Is it possible according to the rules of science for something to come out of nothing?
3: Is there evidence for the existence of other Universes?
MICHIO: In science, nothing is ever 100% proven. All we can say is that the big bang theory helps to explain all the measurements we make of the universe. (If one experiment did not match the big bang theory, we have to abandon it. But so far, it explains all experiments). The major weakness of the big bang theory is that it does not explain what happened before the original cosmic explosion.
Einstein’s theory breaks down at the instant of the big bang, so we have to go to a higher theory, string theory, to explain the pre-big bang era. In string theory, our universe is a bubble of some sort, which is expanding. We live on the skin of this bubble. But string theory says that there might be other bubbles out there, creating a multiverse of universes, like a bubble bath. So perhaps our universe was created by the collision of two universe, or perhaps the budding or branching of one universe into two universes.
QUESTION FROM ALXVANYA: If E=mc^2, then how can a universe be created? If matter and energy can never be created or destroyed but only change forms than that would mean that the universe has always existed in some form and will always exist in some form? How did all the energy of the universe get here to begin with? Is it possible that something can manifest itself from absolutely nothing? Is an infinite universe a more likely possibility than a created universe?
MICHIO: Universe can pop out of nowhere because the matter of the universe is positive, but gravitational energy is negative. In fact, when we add the positive energy of matter to the negative energy of gravity, we get zero, or something close to zero. That is why universes are for free, i.e. it takes almost no net energy to create an entire universe. So the conservation of matter and energy is never violated.
In the multiverse picture, each universe had a beginning, but the multiverse itself is eternal with no beginning.
QUESTION FROM JORDAN ESPOSITO: Can anyone become a theoretical physicist? I’m 15 and interested in Physics…
MICHIO: To become a theoretical physicist, you need several things. First, you need to have a passionate love affair with the universe. You must be willing to study and sacrifice to learn about this universe, in order to make a contribution of your own. Second, it helps to have a role model. My role model was Einstein. Learning about his life, I learned precisely what I had to do, at what point in my life, to become a theoretical physicist. Third, it helps to have parental support and the support of your teachers. We are not an island. It helps greatly to have people give us the financial and moral support we need.
We must also have Plan B in case things do not work out. Life is full of twists, so we have to be prepared to have setbacks as well. Einstein himself, in 1902, was at the low point of his career, without a job, looking for jobs tutoring (from which he got fired), and finally getting a job as a lowly clerk. But 3 years later, this unemployed physicist would change the world. (One possibility for Plan B is to learn computer programming, so you can make money programming during the day and work on physics at night, similar to what Einstein did as a clerk.)
QUESTION FROM COJEMO5763: We are expending much effort toward finding other earth-like planets. Other than satisfying our curiosity and learning more about the universe, what is the long term objective? Humans, at least in our present form, will never be able travel to other systems to escape the destiny of the solar system. Comments? Thank you. Corey Moser
MICHIO: So far, astronomers have found 500 planets orbiting other stars using ground based telescopes. The Kepler satellite, by contrast, has found 1,200 potential planets, with 50 of them being in the habitable zone from their sun (in principle capable of having liquid water oceans). So, given the fact that 50% of the stars examined so far have planets, it is reasonable to conclude that there are about 100 billion planets in our own cosmic backyard, the Milky Way galaxy.
So the probability that life exists in our Milky Way galaxy is quite high. But, as you point out, they are very far away, and hence travel between them is quite difficult. But contact is not impossible. First, we might be able to receive radio signals from alien planets.
Also, they might be millions of years more advanced than us. Since the universe is 13.7 billion years old, there is plenty of time for advanced civilizations to rise, and fall, so contact cannot be ruled out.
In fact, we physicists believe that there may be 3 types of civilizations in space more advanced than us. A Type I civilization harnesses all planetary forces, and is perhaps 100 years ahead of us. They can control the weather, for example. A Type II civilization can control the power of an entire star (e.g. see Star Trek). A Type III civilization controls the power of an entire galaxy (e.g. the Empire of Star Wars, and the Borg of Star Trek).
So it is certainly conceivable that a Type II or III civilization could visit us.
QUESTION FROM ALLERGG: Dear Dr. Kaku: I’ve heard that the four known forces of nature were “unified” at the beginning. Since it is currently believed that matter did not come into existence for the first several thousand years, after the big bang, does this mean that gravity was “ordained” to exist? Does that mean that the laws of nature existed prior to the beginning? And, who wrote them?
MICHIO: No one knows who wrote the laws of physics, or where they come from. Science is based on testable, reproducible evidence, and so far we cannot test the universe before the big bang. But future experiments may be able to answer these questions. The Large Hadron Collider outside Geneva may be able to create Dark Matter, which makes up much of the universe, and is perhaps a higher vibration of the string. Also, LISA (Laser Interferometry Space Antenna) may be able to detect gravity waves from the very instant of the big bang, and hence give us clues to the pre-big bang universe. So there are experiments that we can conduct in our universe to prove the existence of other universes.
But where did the laws themselves come from? Einstein asked himself the question, if he were God, how would he make the universe? He concluded that there is only universe possible. String theory (or M-theory) seems to vindicate this idea, since we think there is only one theory in 11 dimensions that can describe our 4D universe.
QUESTION FROM CAPTAIN T-BONE: Do you think the public interest in things such as physics and space exploration is at an uncomfortably low level? And if so, what would you suggest to rekindle the public’s interests in these areas?
MICHIO: When I was a kid, Sputnik created a sensation, with people fearful that the Russians would dominate space. As a consequence, the President roused the American people to rise to challenge. It was almost your patriotic duty to become a physicist or engineer.
But those days are long gone. Today, our students rank near-last in every international math and science test. Hollywood, moreover, gives us negative sterotypes of young scientists being nerdy and unpopular.
But the importance of science eduation is real. Even the President has stated that learning science and math should be a priority for this country, as we compete with other nations of the world. How can we compete with the Chinese and Indians if our students are illiterate in science?
There are, however, several ways to rekindle our interest in science. We should give more emphasis on science fair projects (in high school, I built an atom smashser and also experimented with anti-matter as a kid). We should see young scientists as role models, not outcasts. We should raise the science level of our teachers (which, unfortunately, is rather low, with some exceptions).
QUESTION FROM SCIENCE GUY: Hi, I’m a 12 year old kid who’s read physics of the impossible about 15 times over the summer and I was wondering, is there any way that dimensions could exist in a sort of spheres within in spheres where the 1st and 2nd dimension are inside the third and so on? I got this idea after reading about how light may be a wave in the forth spatial dimension creating almost a shadow down upon ours.
MICHIO: You are right in stating that light may be a result of higher dimensions.Think of fish swimming in a shallow pond. They live in a 2D, flat universe, with no awareness of the 3rd dimension, which to them is a fiction. But if it rains, then ripples on the surface of their 2D pond appears as waves which they can clearly see. So, if we are the fish, then we live in a 3D world, but ripples on the surface of this 3D world (ripples in 4D) would be visible to us as waves, which might be light. In fact, light is described by Maxwell’s equations. And, if you take a 4D world and vibrate it, the vibrations obey Maxwell’s equations (as first shown by Theodr Kaluza in the 1920s). So light may indeed be vibrations in a higher dimension.
However, these dimensions are inside one another. These dimensions are at right angles to each other (like the corner of a cube).