Theoretically, there could be people and planets made out of antimatter rather than matter, but where are they?
Question: Is it possible for antimatter to form complex structures such as molecules or even entire life forms? (Submitted by Ron Or-El)
Michio Kaku: Ron, you ask a very interesting question. In fact, and I was in high school, I used to play with antimatter. It turns out that sodium 22 naturally emits positrons or anti-electrons. I put the antimatter inside a cloud chamber, put it into a 600 gas magnetic field and clearly, the positrons were bending in the wrong direction in a magnetic field, meaning that positive electrons were being created in my cloud chamber. Later, I built an atom smasher in hopes of getting a beam of antimatter. So antimatter has the opposite charge of ordinary matter. The antimatter that I photographed in high school had a positive charge. Electrons usually have a negative charge. So anti-electrons can circulate around anti-protons. And we did this at Cern, outside Geneva Switzerland, and also at Ferma Lab outside Chicago. In fact, if you read the novel, Angels and Demons, which was made into a movie starring Tom Hanks, the whole novel was based upon building an antimatter bomb that might be able to destroy the Vatican.
So if I had antimatter and, according to the novel, if I touch it with ordinary matter I would have complete annihilation, meaning that the efficiency of the bomb would be about 100 times greater than the efficiency of a hydrogen bomb. A hydrogen bomb is only about one percent efficient; antimatter bomb would be 100% efficient. So anti-people are also possible. Anti-planets, anti-galaxies are also possible. But the danger is that if the two touch each other. And they will annihilate into a burst of energy.
However, we've looked for antimatter in the universe. And we've looked everywhere for antimatter, and we see very little antimatter in the galaxy. There is a fountain of antimatter coming out from the center of the Milky Way galaxy. In the direction of the constellation Sagittarius; however, it's very small. And it leaves the mystery, why are we made out of matter and not antimatter? Why don't we meet anti-people out there? That's a big cosmological question. The Leading Theory Is, at the Beginning of the Universe, at the Big Bang, there were almost equal amounts of matter and antimatter. The two annihilated in the instant of the Big Bang and we are the leftovers. So everything you see around us today we believe is a leftover from the titanic annihilation of matter and antimatter at the beginning of the universe itself.