If alien life exists, how would we even recognize it? Physicist Michio Kaku argues that our search for intelligence beyond Earth forces us to question the assumptions behind our own definition of “intelligent.”

Our current criteria for intelligence might be too narrow. Here’s what that means for the search for extraterrestrial life.

MICHIO KAKU: What computers need is data. Data by which we can draw conclusions. And when we talk about intelligence in outer space, we have to be open to the idea that their intelligence may be quite different, quite different from our intelligence. And therefore, the question is how do we tell? how do we tell where real intelligence is, given the fact that there could be more than one type of intelligence?

- [Announcer] Are we alone in the universe?

- For the Science Channel, they once put me in a swimming pool with dolphins. Sensors picked up the squeals and chirps from the dolphins as I was swimming next to the dolphins, and then they ran it through a computer. The computer looked for regularities in the chirps and squeals of dolphins, realizing that they speak a totally different language than humans. And their criteria for intelligence would be different from our criteria of intelligence. So for example, the letter E is the most common letter in the English alphabet. And you can rank the frequency with which certain letters are used to pinpoint who wrote the article. For example, who wrote Shakespeare? Many people have claimed that other writers wrote Shakespearean plays, not Shakespeare himself. But you can run the set of information of Shakespeare's plays through a computer. And sure enough, the signature can be shown to be that of Shakespeare. The frequency of the letter E, the frequency of the letter I, and so on and so forth, allows you to pinpoint who wrote that article. So when you run the videotapes and the audio tapes of the dolphins through a computer, you find, bingo, yes, they are intelligent. Yes, there's a pattern, a regularity to their chirps and so on and so forth. And then you go down the evolutionary scale. You go down to dogs, cats, rabbits, mice, insects. By the time you reach insects, it's pretty much nonsense. They have a communication system, but very little intelligence other than to alert themselves for food, danger, and stuff like that. And so it is possible to rank intelligence using computers that look for an algorithm that allows you to see where intelligence lies. We'll do that in outer space now. We physicists have often wondered, are there signs of intelligent life in the galaxy? And if so, how advanced might they be? So we categorize these alien civilizations on the basis of energy, energy consumption. Type one would be planetary. They control the weather, they control earthquakes, volcanoes, anything planetary they control because they have the energy, the energy of a planet. Then there's type two. A type two civilization has exhausted the power of their planet and they use the sun. They basically take the energy from their sun to power their machines, sort of like the Federation of Planets in "Star Trek." "Star Trek" would be a type two civilization. Then this type three, galactic. They roam the galactic space lanes, they play with black holes, sort of like the Empire of "Empire Strikes Back." That would be a type three civilization. And then the question is, what are we? We are type zero. We get our energy from dead plants, oil, and coal. We don't even rate on the scale. We have not attained planetary energy at all. That would be type one. We're stuck at type zero. But what would it take to move between universes? What would it take to enter a black hole? What would it take to break the light barrier? You would have to reach the energy of type three. And the energy of type three is called the Planck energy. The Planck energy is the energy of the big bang. It's the energy of a black hole. It's the energy, the greatest energy in the universe, and that is the Planck energy. How long before we can attain the Planck energy and move between universes? Well, a modest calculation shows that you would have to be about maybe 100,000 years more advanced than us in order to go between universes to harness the Planck energy to leave our universe. So chances are, if one day we meet an intelligent civilization, they would be maybe 100,000 years more advanced than us. Then the next question is, how would we know of a type three or type two civilization if we were to bump into one? Let's say that scanning the heavens, we see evidence of a type two, type three civilization. How would we know? Well, we've looked. We've looked for type two, because type two civilizations give off an energy, a characteristic black body radiation that we can measure. So far we find none. Now, that doesn't mean that there aren't these civilizations out there, it just means that our devices are so primitive that we have not yet been able to conclusively show that they exist. But if they can break the light barrier, if they can go faster than the speed of light, then it's possible they may have the energy of a wormhole. And at that point, they would be type three. They would have the energy, the Planck energy, to create universes or to move between universes. Historically, when physicists were asked about flying saucers and UAPs and extraterrestrial civilizations, the bottom line is data. You have to have data. You just can't say that, "Gee, I saw something going across the sky last night." Maybe you did, maybe you didn't. But now we finally have data. The United States Navy has admitted that yes, there are hours of videotapes, videotapes that can be analyzed to calculate the characteristics of these things. We now realize that these objects, whatever they are, can travel up to mach 20. 20 times the speed of sound. And they can accelerate from Mach 5 to Mach 20 very, very rapidly. And they can even fly underwater, believe it or not, underwater in the air into outer space, and they zigzag. When you calculate the centrifugal force inside the rocket ship, you realize that any living thing would be crushed, crushed by the zigzagging of these objects, whatever they are. We're talking about a new law of engineering beyond anything that we can muster here on the planet Earth. the ability to fly up to Mach 20, the ability to fly underwater, the ability to zigzag. These things require technology beyond anything we have. So we now have the data. Is it an optical illusion or is it extraterrestrial? We don't know until we analyze the data. And now we have physicists looking frame by frame and perhaps coming up with a conclusion as to where these objects come from. Well, about 90% of these sightings can be explained using natural phenomenon or weather balloons or weather anomalies or meteorites. Most of them can be explained. 10% of them seem to defy the known laws of engineering. So we have to look at them very carefully, and some of them have multiple sightings by multiple modes. That's the gold standard. We met that gold standard on several occasions. Back in the 1980s, there was a JAL flight going across Alaska, and all of a sudden they found two objects flying next to it. These two objects were then tracked by radar, tracked visually. So there was multiple sightings using multiple modes. And then a third flying saucer came up next to it. So there were three objects now flying next to this JAL flight. Well, afterwards, when the flight landed, the pilots made the announcement that they saw flying saucer. But then what happened? Very important. At that point, the pilots were given desk jobs, basically demoted, and that sent a chill throughout the industry because if you say that you saw something unusual in your airplane, you would be given a desk job and you wouldn't fly again. So in other words, keep your mouth shut. As a consequence, no data, very little data has been collected until recently. And that's what we physicists need, data, so that we can make objective statements about what these things are. Now, the burden of proof has shifted. The burden of proof is on the military now to prove that these things aren't extraterrestrial, and that's a sea change. Now we realize that we're sitting on hours of videotapes. We're sitting on a mountain of data. The data has to be analyzed frame by frame to figure out what these objects are, what their flight characteristics are, and who is behind them. So things have changed now. Now we have access to videotapes, and now the burden of proof is to prove that these things aren't extraterrestrial. What happened was citizens' pressure put pressure on certain politicians. These politicians in turn put pressure on the military to declassify some of this information. So that's how it happened. That it is the FOIA Act, the Freedom of Information Act, that allows citizens to gain access to some classified information. But it's a long torturous process. But some of it is now reaching the press, that yes, the military is owning up to the fact that it's sitting on a gold mine of data that has to be analyzed frame by frame.