I am a theoretical physicist, bestselling author, renowned futurist, and popularizer of science. As co-founder of String Field Theory, I try to carry on Einstein’s quest to unite the four fundamental forces of nature into a single grand unified theory of everything.

I hold the Henry Semat Chair and Professorship in theoretical physics at the City College of New York (CUNY).

I joined Commander Chris Hadfield, former commander of the International Space Station, for a cosmic road trip through the solar system. It’s a new show called Miniverse, available now on CuriosityStream.

Check out the trailer here: https://www.youtube.com/watch?v=MVKJs6jLDR4

See us getting into a little trouble during filming (Um, hello, officer…) https://www.youtube.com/watch?v=lQza2xvVTjQ

CuriosityStream is a Netflix-style service for great shows on science, technology, history and nature. Sign up for a free 30 day trial and check out Miniverse plus lots of other great shows on CuriosityStream here.

The other interstellar hitchhikers in Miniverse, Dr. Laura Danly and Derrick Pitts, answered your questions yesterday here.

Proof: https://i.redd.it/5suh2ba3ncsy.jpg

This is Michio -- I am signing off now. Thanks to everyone for all the questions, they were really thought provoking and interesting. I hope to chat with you all again in another AMA! Have a great day.

Comments: 1099 • Responses: 63  • Date: 

Aesop-Ben412 karma

What unanswered questions in physics are you contemplating the most these days ?

DrMichioKaku1275 karma

The fundamental problem facing string theory today is that it is too successful, i.e. it predicts millions of possible parallel universes. Originally, we hoped it could explain our universe. Yes, string theory can do that. It can explain the Standard Model of quantum theory and also all of Einstein's theory. But unfortunately, it doesn't stop there. String theory also describes universe which do no exist. The problem is, how do we select our universe from a multiverse of parallel universe?? If you find out the answer, we can split the Nobel Prize between us.

nohbudi358 karma

Dr. Kaku,

Where do you stand on Dr. Krauss' assertion that the net energy of our universe is zero?

DrMichioKaku949 karma

Einstein was once told that the net energy of star might be zero. The idea was so incredible that he stopped walking in the middle of the street, and almost caused an accident. You see, the energy of a star is positive, but its gravitational energy is negative, and the sum could be small. If the universe started out as a quantum fluctuation of nothing, then the two might balance out and hence universe are for free!

Chtorrr202 karma

How did you first become interested in science?

DrMichioKaku678 karma

My interest started when I was 8. Einstein had just died, and everyone was talking about how he could not finish his greatest work, the unified field theory. I said to myself, maybe I can help solve that unfinished problem.

papasmurf826183 karma

Hello Dr. Kaku, more on the lighter side, which fictional future would you most like to live in or visit? Thank you!

DrMichioKaku469 karma

I like Star Trek, the next generation, as one way to view the future. As a physicist, I think we will be a Type I civilization by the year 2100.

BulbStar179 karma

Where do you think geologists and geophysicist will fit in the future of space exploration and planetary discovery as we become a multiplanetary species?

DrMichioKaku277 karma

Yes, especially when we begin terraforming Mars sometime late in this century, we will need experts in a wide variety of areas.

Inetenbr171 karma

Hi Michio, what are your views on the US government reducing the funding for science related programmes?

DrMichioKaku824 karma

Science is the engine of prosperity. From the Steam Revolution, to the Electric Revolution, to the Computer Revolution, each wave generated the wealth we see around us. However, politicians think wealth comes from taxes, which is actually a zero sum game, since you tax Peter to Pay Paul. I believe that science will give us a bigger pie, rather than slicing or taxing the same pie so it is thinner and thinner.

WhatDefinesMe169 karma

As a person who doesn't know a lot about physics or mathematics but it still extremely curious, how should I learn about string theory?

DrMichioKaku537 karma

There are a lot of great popular books on string theory (e.g. try my book Hyperspace). To actually work on string theory, you need a Ph.D. in quantum physics, but the basic ideas, principles can be understood by everyone. My favorite Einstein quote is, if a theory cannot be explained to a child, the theory is probably useless.

chris_likes_science156 karma

Will the expansion of the universe ever speed up so fast that it will overcome the Nuclear Strong force and possibly rip protons and neutrons into their own quarks? Ive heard that is pretty much impossible to do this with conventional methods, but could an event like the expansion of the universe overcome this?

DrMichioKaku476 karma

I hope not. Right now, the universe seems to be expanding out of control. It appears to be entering a period of de Sitter expansion. This means that one day, we might encounter the Big Freeze much sooner than expected. No life as we know it can survive when the universe reaches near absolute zero. Even subatomic particles will be ripped apart. At that dismal point, I think we should leave the universe in an interdimensional wormhole to a warmer universe.

edenkl8134 karma

Hi Michio, I am a huge fan of your work. I have your books, and love reading them. I just want to ask, for the big bang theory, to my understanding before the big bang occurred all of matter was close to one another in an infinitsimal distance. What would have been outside of that "ball" of matter?

Thank you :)

DrMichioKaku380 karma

The latest picture, through string theory,is that our universe is a bubble (we live on the skin of the bubble) which co-exists with other bubble/universes. When these bubbles collide or split in two, that is the big bang. What exists outside these floating bubbles (in this bubble bath of universes) is 11 dimensional hyperspace.

Vaeloc133 karma

Neil deGrasse Tyson has shown in previous interviews that he is quite skeptical about the dangers of artificial intelligence. Do you believe that the concerns around advanced AI are justified or do you take an alternate position?

DrMichioKaku233 karma

Its still much too early to tell how dangerous AI can be. Right now, our most advanced robot is Asimo, build in Japan. I interviewed the creator of Asimo for BBC Tv, and he admitted that it has the intelligence of an insect. However, eventually robots will be as smart as a mouse, rat, rabbit, cat, dog, and finally a monkey. At that point, perhaps at the end of the century, they could be dangerous, so we should put a chip in their brain to shut them off if they get murderous.

Gator196130 karma

Do you think a black hole really could take us to another universe? Or that it is a bend in space and time like a worm hole? What is a black hole man, I don't get them and they blow my mind.

DrMichioKaku240 karma

Einstein's equations state that a spinning black hole collapses to a ring, and if you fell into the ring, you would enter a parallel universe. This is called the Kerr metric. However, entering this wormhole, the gateway might be unstable. We physicists are still debating this question. To solve it, we need a higher theory beyond Einstein, and this is string theory, which I do for a living.

netsgnut109 karma

Dr. Kaku, what are your thoughts on the EM drive experimental results? Do you think it'll pan out to be a new form of propulsion? How will it change space travel?

DrMichioKaku258 karma

I am skeptical of the EM drive, because it violates the known laws of physics. I am open to new, radical ideas, but, as Sagan once said, remarkable claims require remarkable proof. So an engine which uses "nothing" to power itself has to be analyzed very, very carefully.

perf3ctx92 karma

Dr. Kaku,

Do you believe sending humans to Mars is worthy of the task? Or would resources be better utilized heading a different destination?

Thanks for being awesome and doing an AMA.

DrMichioKaku306 karma

Carl Sagan once told me that we should be a two planet species, since its too dangerous to put humanity on a single planet. But he did not think we need lots of expensive crash programs that would bankrupt the country.Now, we have billionaires who are opening up their check books, and not depending on tax payers money so much, to send rockets to the moon and Mars. I am all in favor of watching other people bankroll worthy ventures with their funds. More power to them.

pighalf88 karma

Hi Dr kaku, last week it was announced that two of Jupiter's moons may contain water and could be earth like. Do you believe these moons can sustain animal and plant life?

DrMichioKaku191 karma

Possibly. Europa and Enceladus may have microbial life, maybe even aquatic life. But being underwater,they will have no electronics, so their level of civilization, if they have any, will be stunted.

DarkGamer87 karma

Do you ever hang out with the other scientific media personalities; as in, you, Neil Degrasse Tyson, Bill Nye, and Brian Greene drinking tea together and talking about the state of things?

DrMichioKaku175 karma

I have had dinner or lunch with all of the above. They are all great people. However, we are all very busy, so we sometimes see each other more often in a radio or TV studio than in a tea house.

introvin84 karma

How far are we from a single grand unified theory of everything?

DrMichioKaku201 karma

I think we already have it. It is string theory. But string theory is not in its final form. In 10 dimensions, we have a field theory for strings (which is my contribution to string theory) but in 11 dimensions we have no such field theory. That is what I am trying to solve now.

advertisingsucks79 karma

Did you enjoy Interstellar, the movie? Or was it totally wrong.

DrMichioKaku181 karma

The movie was great, but I was wondering how it would resolve the key question: where does the energy come from to manipulate wormholes and black holes. In the movie, I think it was our descendants in the future who somehow got this energy and sent it back to us to change the future. Also, the movie seems to end on string theory, as the hero enters another dimension.

LordShaxx78 karma

Hello Dr. Kaku,

I'm currently pursuing an undergraduate degree in theoretical physics.

Do you have any advice for somebody who is studying, or is interested in studying physics?

Thanks!

DrMichioKaku379 karma

Here is one thought. I discuss this with my friends, all of them theoretical physicists like myself. We all remember friends in high school or college who were smarter than they. They seemed quicker and more insightful and more knowledgeable. But in the end, they dropped out, often due to emotional problems, lack of maturity, etc. So the ones who win the race are often not the ones who are the quickest. In fact, Einstein once said to a bunch of school children, that no matter how much difficulty you have with mathematics, mine were greater.

freeze58868 karma

What are some big words of advice for someone who is going to become an astrophysicist, but is starting late? This starting late gives me quite a few setbacks that may put others ahead. But even though I am late to my interest to math and science, I am still determined to succeed. Thank you.

DrMichioKaku169 karma

In France, eventually you have to learn the French language, including how to conjugate verbs, etc. In physics, eventually you have learn the math. Math is the language of nature. Unfortunately, math is the dividing line separating amateurs from professionals. Sorry to say.

Rogeroga63 karma

If you were able to travel back in time to ANY moment of your own choosing, what event would you like to witness and watch?

DrMichioKaku161 karma

I would love to see the big bang (from a safe distance, of course) and also the moment when Einstein came up with the general theory of relativity in 1915.

linuxgeekmco60 karma

If the current crop of politicians in federal office do make notable cuts to research funding, do you think we may see researchers currently working in the US move to other countries, like Canada, in the search of replacement funding?

DrMichioKaku156 karma

Right now, there is a brain drain into the US, e.g. via the H1B program. Let us hope that the new restrictions on H1B do not stop the flow of brain power into the US. These top scientists do not take jobs away from Americans. They invent entire industries, which employ Americans. Think of the transistor and laser, two inventions by physicists who changed the world economy. So let us hope we do not eat the seed corn which makes our economy grow. Time will tell.

sergeyzykov59 karma

What is the most advanced math topic you feel comfortable with? What's your favorite one?

DrMichioKaku219 karma

I work with supersymmetric 11 dimensional tensor calculus. We think that is the ultimate language of nature.

Vaeloc59 karma

Hi Dr. Kaku,

What do you think the future of artificial intelligence is and is it something that can be utilized more in space exploration as technology progresses?

Thank you!

DrMichioKaku105 karma

Since space is dangerous and very expensive, AI will be essential to create the first cities in space. Also Musk and Bezos dream of cities in space, I think they are too costly unless we use AI.

i-am-qix56 karma

Hi Michio - your explorations into scientific 'what ifs' fundamentally changed the way I think. Thank you so much for what you do.

Is there anything in your lifetime that was once a "crazy what if" that has since become reality?

DrMichioKaku92 karma

When I wrote my book Visions, the reviewers all though I was nuts to make these predictions (all of which have come true, or will be true very shortly). I remember one biologist who flatly my prediction of personalized genomics was preposterous and crazy. Yet today, you can get personalized genomes.

gazongas00147 karma

What do you think about space x?

DrMichioKaku144 karma

Space X is great, if we can reduce the cost of space travel. Right now, it is $10,000 to put a pound of anything into near earth orbit. Space X sometimes can get it down to $1,000 per pound. If that can be sustained, its fantastic.

YeeahAboing43 karma

How do you respond to those who deny climate change by questioning the scientific method?

DrMichioKaku99 karma

I was once a skeptic. But, witnessing all the trends in the weather, I changed. But even skeptics today believe that the earth is heating up. We have to convince them that, with 95% confidence, that this is coming from human activity.

reddragon78942 karma

If matter can not be created nor destroyed, how was there a point where no matter existed? Does this prove the idea that time is a man-made creation, or the exact opposite?

DrMichioKaku65 karma

At the beginning of time, perhaps there was only a quantum fluctuation in 11 dimensional hyperspace. Matter as we know it only came afterwards, as the universe cooled. However, this not prove that time is man-made. Hyperspace existed before people, and even before the known universe existed.

Scrpn17w41 karma

How can individuals help with bringing more "science-minded" people in to the positions that influence national/global politicies?

DrMichioKaku94 karma

Eisenhower had to wisdom to have a science advisor, given all the great advances in sciences seen in World War II. However, since then, politicians have taken science for granted. But nature does not exist at the whims of politicians.

mrrockabilly39 karma

Dr. Kaku, with the recent discovery of dark matter filaments between galaxies - does that mean we're that much closer to actually being able to measure the element?

DrMichioKaku92 karma

We are still clueless about dark matter. Dark energy makes up 73%of the universe, dark matter makes up 23%, the stars make up 4%, and we make .05 % of the universe. So most of the universe cannot be explained using ordinary physics. But string theory says that dark matter is probably a higher vibration of the superstring.

ReportTresh38 karma

Hi Michio! Growing up throughout school I absolutely hated Physics and couldn't understand any of it. However, when I would listen to talks from you it always seemed so interesting to me and I could actually understand what you were talking about. What do you think is the main problem with the educational system when it comes to subjects like Physics and other sciences?

DrMichioKaku126 karma

Science is reduced to memorizing silly, irrelevant facts that you will never ever use again in your life. Students are smart enough to know this, so they forget the science (i.e. memorization) they learn as soon as they leave the exam room.But science is actually not based on trivial facts. Science is based on principle, concepts, and pictures, that a child can even understand. But that is not how we teach it in school.

Telsiph38 karma

Good Afternoon Dr. Kaku,

Typically whenever there is an idea or theory that is a bit more on the outlandish side; IE evidence of alien superstructures in the universe, the possibility of time travel, parallels universes, etc, your name always comes up with your opinions on how and why these things might/likely do exist. In stark contrast many of the other popular voices in the scientific community tend to be more skeptical and are quicker to shoot down these theories or possibilities.

My question is: Do you feel as though you are bit more "Open Minded" than your colleagues? A healthy amount of skepticism is important in any scientific field, but I tend to find your optimism and excitement refreshing/encouraging when compared to how quickly other voices dismiss these far fetched possibilities.

Thanks for your time and for the work that you do!

DrMichioKaku97 karma

There are two types of scientists who dismiss things like higher dimensions, wormholes, warp drive, time machines, etc. The first are scientists who are not specialists. They don't understand the math. Their knowledge of science ends around 1950. I don't take them too seriously. However, there are a handful of scientists that I do respect, who do know the math, and I have to take their objections, if they have any, very seriously. They, like me, tend to be more open minded.

Chazwozel36 karma

Dr Kaku. In addition to your miniseries, do you have any books in the works for the near future? Future of the Mind was great. In fact, all of your books have this great readability to them for the physics layman.

DrMichioKaku55 karma

Yes, I have a new book coming out next year. Watch for it on my web site www.mkaku.org.

backlashsid34 karma

Are you still teaching at CCNY ?

DrMichioKaku81 karma

Yes, although the university lowered my teaching load so I can do more public appearances. But my main interest is still doing research. Research is my main preoccupation.

MercuryCrest34 karma

Dr. Kaku, how do you actually go about solving some of these problems (like 11th Dimensional String Theory)?

How do you come up with equations that define the problem and how to you go about actually finding solutions?

Thanks for doing this AMA!

DrMichioKaku143 karma

I like to think of theoretical physicists being composers. Musicians will stare out the window, as fragments of melodies dance in their heads. Once in a while, these melodies begin to jell, and then they plunk out a few notes on a piano. And then they go back and stare out the window. That is how we physicists think. We stare out the window. We have memorized all the equations for string theory, so they dance in our heads, until they begin to jell. Then we write down a few equations, and then go back to staring out the window.

Chengweiyingji31 karma

Hi Dr. Kaku, I've enjoyed a few of your books. My question is what theory do you personally feel is the closest to being true in actuality?

Also, who's your favorite Star Trek captain?

DrMichioKaku71 karma

I think Captain Picard is the wisest of the star ship captains so far. He looks at things from all sides, and then consults with his staff, and then decides. I think the Future of the Mind and the Physics of the Future are the books which predict how things will unfold in the coming decades out to 2100.

Sunday231327 karma

What is your inspiration for what you do?

DrMichioKaku93 karma

My inspiration is a picture of Einstein's before he died, with the unfinished manuscript of the unified field theory on his desk. Today, I can read that manuscript, and see all the dead ends he was pursuing. Back then, he had no picture, no guiding principle to construct this theory. Today, we do.

shou43323 karma

If we ever set up base on Mars and are able to populate. How is Earth going to communicate with people on Mars and vice versa? Wont it take months for messages to go across?

DrMichioKaku52 karma

We will use radio, which travels at the speed of light, so a message to Mars would only take 10 to 20 minutes, depending on where you are with respect to Mars or the Earth.

Sunday231311 karma

I think we'll have better internet by then (interplanetary internet).

DrMichioKaku35 karma

Yes, if we become multiplanetary, we will need servers on different planets, communicating across the solar system. However, that is still decades in the future.

Nirelan23 karma

Dr. Kaku, I love your books (can I get a signed copy btw) and was wondering if you believe the Graviton is real and if it will be found?

DrMichioKaku65 karma

Yes, the graviton must exist, but finding it is really, really hard. The graviton is a quantum particle of gravity. Gravity itself is caused by the warping of the fabric of space-time. It has vibrations that move on this fabric. We quantum physicists take these vibrations and then we quantize them, so each vibration becomes a graviton. At present, the only way to successfully calculate with these gravitons is to assume they are also vibrations on a string moving in this fabric. That is string theory.

Wave-Of-Babies21 karma

This isn't necessarily related to your primary field, but what are your thoughts on cultured meat?

DrMichioKaku60 karma

What is cultured meat?

Injest_alkahest21 karma

Hello Dr. Kaku, I am curious about your current feelings towards Artificial Intelligence, specifically if you feel it is inherently dangerous, and if you personally think Neural networks and direct neural interfaces will be beneficial for our interactions with A.I. moving forward as a deterrent from falling behind or succumbing to it's ability to adapt and evolve through advanced computational machine learning?

DrMichioKaku50 karma

I don't think that AI machines will be dangerous for quite a while. (However, automatic killing machines used for the battefield, if they go crazy, are a problem, since they are designed to identify the human form and then attack it.) But sentient beings as smart as us I think are many decades away. I think it may take until the end of this century to have robots as smart as a monkey. But what happens after that, in the 22nd century when we might have robots even smarter than us? At that point, we may want to merge with them.

KMustard21 karma

What do you think are key fields of study necessary for ushering in a new era of humankind?

DrMichioKaku89 karma

I think the next era for humankind is when we leave being a Type 0 civilization and become a Type I civiilzation. Sadly, we still have the savagery of being a Type 0 civilization with us, since we only recently left the swamp. This will be the greatest transition in the history of humankind, but we may not make it. (Some people instinctly do not want a Type I civilization, since that civiliztion is scientific, prosperous, open-minded. These are the terrorists).

remixisrule21 karma

I got lucky to have you as a substitute for astronomy lecture one day at CCNY about 7 years ago. It was awesome, your passion for the subject shows. How did you end up teaching at CCNY of all schools?

Also...have you ever seen the dark side of the moon?

DrMichioKaku50 karma

Yes, I have seen the far side of the moon via space probes which orbit around the moon. I started working on string theory years ago, when it was unfashionable. The quark model was all the rage back then, so getting a job was extremely difficult. I was teaching at Princeton at that time. Sadly, I found some of my colleagues dropping out of physics altogether because they couldn't find a job. One was driving a taxi. I realized that, since string theory was unpopular at that time, that I had to make a compromise. At that time CCNY was building up its physics department and hiring a large number of top physicists, including several famous string theorists. So I left a position at Princeton to go to CCNY (as a professor). Now, of course, string theory dominates the entire field theoretical physics, but I feel very comfortable being here.

Usmanajmal4420 karma

Hi Dr Kaku what do you think would happen to a person if he fall into a Black hole? AND what is your plan about your new book? Thanks.

DrMichioKaku50 karma

No one knows what happens if you fall into a black hole. But the idea that you enter a parallel universe on the other side (a white hole) cannot be easily dismissed. We scientists have looked for white holes in space, but so far have not seen any. (But some physicists think maybe the big bang was actually a white hole, so everything spews out and not in. For my next book, see www.mkaku.org next year.

zeldamaster121720 karma

Hey Michio! I read your book, Physics of the Impossible. In the book where you classify time travel as a Class II impossibility, you also talked about the stability of time travel, and that lead me to this question.

Is there any sort of conditions we could create here on Earth (perhaps in the LHC) that could increase the chances of surviving time travel or ensuring a way back?

DrMichioKaku50 karma

Sadly the LHC,Large Hadron Collider in Geneva, is too small to open up gateways in space-time. To create a time machine, you have to access the Planck Energy (10 to the 19 billion electron volts) which is a quadrillion times more powerful than the LHC. But perhaps a Type II or III civilization has mastered the Planck Energy, and can manipulate time.

Quothe_19 karma

Hello Dr. Thank you for doing this AMA. I have two questions:

  1. If you were offered the opportunity to travel into space, maybe around the moon or into orbit of the earth, would you do it?

  2. What is the most compelling evidence for the string theory?

DrMichioKaku43 karma

No. Lets be real. 1% of the time, rockets fail, they blow up, and people die. Space travel is not for the weak. Even Musk has said there is chance that his astronauts my die on the way to Mars. The most compellling evidence for string theory is not experimental, but theoretical. a) it the only theory which can unify Einstein's gravity with quantum mechanics. All other theories can be shown to be incorrect. b) in string theory, gravity naturally unifies with matter (e.g. quarks, electrons, neutrinos). Gravity is just another musical note joining all the other quantum notes (e.g. particles ) to create a symphony (the universe).

Lunchyyy18 karma

I would like your input as a scientist on a hypothetical situation. In a future where we can actually colonise and travel between other planets, how do you personally believe we should go about administrating them? For example do we leave the planet to form its own form of autonomous government, or would it be time for the UN to step in and become the unified human government? Do begin to draw borders in space? Do we need to scrap the outer space treaty to ensure our military can react to any scenario?

Basically, how do we translate the politics of Earth, into space?

DrMichioKaku45 karma

By the time we can terraform other worlds, we will be a mature Type I civilization, so that our politics, our society, our ideas will be completely different than they are today, so we cannot use the template of our Type 0 civilization to describe what terraformed worlds will look like.

Usmanajmal4418 karma

Hi Dr Kaku do you think smartphones of today as we know it will completely disappear within next 10-15 years?

DrMichioKaku66 karma

I think beyond 20 years or so from now, the internet and cell phones might be replaced by Brain Net, i.e. we will send emotions, memories, sensations, and feelings. Of course, teenagers will go crazy if they can send memories of the senior prom, etc. on Brain Net. The movies will change, when you can feel what the actors feel. See my book, the Future of the Mind, for details.

tjs17pct16 karma

Hi Michio!

Advancements in technology are so insightful, especially with regards to space exploration and being able to study the universe. Years ago something like "FaceTime" was inconceivable with the ability to see someone through a phone. Do you believe that it is possible that we will be able to travel faster than the speed of light, even though it is currently inconceivable that we can do so?

Bonus: What would be the greatest benefit that, as humans, we will be able to get from faster-than-light travel?

DrMichioKaku56 karma

It is not possible, with todays technology, to break the light barrier. Einstein is still the cop on the block. Every once in a while, someone announces that Einstein was wrong, but they are all proven incorrect. To break the light barrier, you have to warp the fabric of space-time, which takes the energy of a star or a black hole. So you would have to be a Type II or Type III civilization to do this.

DiceDecides15 karma

if Einstein was still alive, what would you ask him?

DrMichioKaku50 karma

I would ask him if the entire universe could be explained using pure geometry, i.e. how can quarks and electrons be explained geometrically?

Astrosonix14 karma

Dr. Kaku

In your book "The Future of the Mind", you talk about potential alien intelligences using nano bot probes to explore and colonize the universe, so could there be any proof that life on earth was first started from another alien civilization? And if so, would it be possible to test fossils to see if any traces of alien nano bots were present?

Thanks

DrMichioKaku36 karma

So far, we see no evidence of alien technology on earth. However, the fastest way for any alien to colonize the universe is via self-replicating nano bots, which like a virus can spread across the galaxy. They might very small, so that you might have an alien nano bot in your backyard and you wouldn't know it. So maybe the aliens are already here, but we are too dumb to notice it.

shea_the_great11 karma

Hello Dr Kaku!

One of the coolest things I learned from you was the Kardashev Scale. As you well know, humanity has some major challenges on its way to reaching Type 1 status. In my mind, the greatest threats to our progress are nuclear war and climate change. Would you agree with that? Are there other challenges we must overcome on our way to the stars?

DrMichioKaku28 karma

The biggest transition in human history will be the transition from Type 0 to Type I.And that transition will happen around 2100. The transition is not inevitable, however. Nuclear proliferation, designer bio weapons, global warming, are some of the greatest challenges. In space, we don't yet see evidence of Type II civilizations, meaning that Type I civilization may be rare. Some think they committed suicide via nuclear war, global warming,e tc.

elseifthen8 karma

Dr. Kaku, what are your thoughts comparing holographic principle and string theory? What flaws do you see in them?

DrMichioKaku17 karma

One version of the holographic principle is found in string theory (where 10 dimensional string theory is mathematically dual to 5 dimensional super gauge theory). Some have tried to elevate this into a new physical principle, invoking black hole physics, but I am not so sure it is fundamental, since all of this can be derived from string theory. To me, what is more fundamental to understanding where strings came from in the first place.

Anthraciteglenn8 karma

Is it possible that black holes lead to other universes?

DrMichioKaku14 karma

Yes, the problems are a) stability of the black hole under quantum fluctuations b) positive feed back loops. The first problem will require string theory, which can "tame" these wild quantum fluctuations. Hawing believes, however, that feed back loops will prevent any time machines from opening up. The time machine will explode as soon as you enter it. But I am not so sure. In a many worlds theory of quantum mechanics, there are no positive feed back loops; you simply enter another time line, so time might be possible after all.

VicariouslyLateralus7 karma

Hi michio, for a person who is new to the subject astronomy, what would be your recommendations on where to start from?

DrMichioKaku7 karma

The most existing area is extra solar planets, of which we have discovered 3,600. We now have an encyclopedia of new worlds in space.

AmicableSnowman7 karma

So let's say I'm riding the subway (or tube, as we say in London). I'm travelling 99.99% of the speed of light and I shine a laser pointer out of the train window onto the wall of the tunnel. What do I see reflected back at me from the wall? Do I see a red dot just like I normally would? And what does it look like from the perspective of the stationary tunnel wall?

Love your work Dr. Kaku!

DrMichioKaku28 karma

The speed of any light beam would always be the speed of light, no matter which way its going. But the color can change. So the red light, reflected off the wall, is coming at you at the same speed of light, but it is blue shifted, because the light waves are being compressed as they move toward you.

AtroposHWG3 karma

What is your favourite movie?

DrMichioKaku10 karma

My favorite movie, which blew my mind when I was a child, was Forbidden Planet. Beings which can control everything by thought was a new idea to me. Unfortunately, they fell asleep, and destroyed themselves via nightmares. Great plot. So once we become telekinetic, do not fall asleep!

RaceHard3 karma

Dr. Kaku,

What is the likelihood if any that we are a computer simulation and if so should we try to prove we are in one thereby possibly having us be turned off?

Thank you for the time! And doing the AMA.

DrMichioKaku8 karma

In chaos theory, when modeling the weather, scientists say the smallest object which can simulate the weather is the weather itself. ie. no computer model can successfully describe every molecule in a thunderstorm. Perhaps the smallest computer than can simulate the universe is the universe itself. It gets worse when you add in quantum mechanics, because in the many worlds theory you have to factor in all possible univeses in order to simulate just one universe. In other words, our univese is probably NOT a simulation, so don't worry if someone is going to hit the OFF button.

marquinhoooo2 karma

Hi Michio, I'm big fan since I read your Hyperspace book back in 94.

As a descendent of japanese-americans who was incarcerated in USA's concentrations camp for japaneses during WWII, what's your opinion about Trump's politics against immigrants and terrorism prevention on USA?

DrMichioKaku14 karma

Yes, my parents were put in a camp and lived behind barbed wire and machine guns from 1942 to 1946. The mass hysteria behind that reached a feverish pitch, and even well-meaning people got swept up in the madness. My own parents were US citizens, hence legal immigrants. (My father was actually born in Palo Alto, currently the center of Silicon Valley.) Let us hope that things do not reach that level.

Astro-nerd23461 karma

Hi Dr. I am a huge fan, and first I must say it is an honor to be able to ask you anything. I am a huge astronomy nerd and plan on being an astronomer, and I was wondering, what's steps can I take to become a great astronomer like you? Like what college is best? Stuff like that

DrMichioKaku3 karma

I am actually a theoretical physicist, not an astronomer. But if you major in astronomy as an undergraduate, you will necessarily be a physics a major (since all colleges have a physics department, but very few have an astronomy department). The colleges which have great physics departments are the usual suspects, like Princeton, MIT, Cal Tech, Berkeley, etc

adamczyken1 karma

Are you going to publish new book?

DrMichioKaku2 karma

Yes I am working on a new book. See mkaku.org when it comes out next year.

Debakanta_gogoi1 karma

Sir,thank you to giving chance to ask questions. Can give a brief description about black hole?

DrMichioKaku2 karma

Simply, a black hole is an object whose escape velocity is c, the speed of light. Period. (The escape velocity of the earth is 25,000 miles per hour, the speed necessary to leap to the moon.) But if c is the maximum speed in the universe, this means that nothing can escape a black hole.