Michio Kaku: Future of Humans, Aliens, Space Travel & Physics

Lex Fridman introduces Michio Kaku as a theoretical physicist, futurist and professor at the City College of New York, author of books such as Einstein's Cosmos, Physics of the Impossible, The Future of the Mind, Parallel Worlds and The Future of Humanity. Fridman says it is beautiful and important when a scientific mind can fearlessly explore subjects just outside our understanding, which is where he places artificial intelligence today.

Fridman asks about Kaku's intuition that we might make contact with aliens this century. Kaku calls it pure speculation but notes that 4,000 exoplanets have been identified, that on average every star has a planet and about a fifth have Earth-sized ones, so the Milky Way holds billions of potential Earth-sized planets. With about 100 billion galaxies visible to Hubble, each with about 100 billion stars, he thinks believing we are the only ones is rather ridiculous.

Fridman asks what it takes to reach out and connect. Kaku says we must gauge an alien civilization's sophistication. This century we will probably pick up ordinary transmissions, and need to decipher their language and rank them on the Kardashev scale, which physicists use with two parameters, energy and information. A type one civilization harnesses planetary power, controlling weather and geological events; type two is stellar, using a whole star's output, like Star Trek; type three is galactic, like Star Wars.

He recounts a boy in London insisting on a type four, the power of the continuum. Kaku realized this could be dark energy, which is 73% of the universe's energy, with dark matter about 23% and ordinary matter 4%. Type four would harness dark energy, the energy of the Big Bang that pushes galaxies apart, the energy of nothing, producing an accelerating, exponential de Sitter expansion.

Type five, he says, would be the multiverse. As a quantum physicist, he does not believe the Big Bang happened only once, which would violate the uncertainty principle, so universes are being created all the time, consistent with inflationary theory. This reconciles his Presbyterian upbringing and his parents' Buddhism: Buddhism's timeless nirvana and Christianity's instant of creation can be melded. Our universe had a beginning, but other bubble universes exist in a bubble bath, expanding into 11-dimensional hyperspace. Nirvana is that timeless hyperspace where big bangs always happen, and a big bang is the collision or budding of universes.