Now let me finish by telling you of the third use of these technologies which looks probably more fantastic than anything I've talked about and which, while being fantastic, is completely real. I talk about meteorites hitting the earth. It happens. Air Force observations have shown that in not very long time intervals, meteorites come and burn up in the atmosphere, whose total energy in their burn-up can easily become as big as the energy developed in Hiroshima. Actually such meteorites hit the earth - the last big event of that kind occurred when I was about five months old. It was called the Tunguska Meteorite; an object more than hundred feet in diameter came in over Tunguska in Siberia not far south of the Arctic circle. It did not hit the Earth, it approached the Earth on a tangential orbit and as it got into more and more dense atmosphere the pressure ahead of it built up. This uneven distribution of pressure caused the object to disintegrate into small parts which in turn vaporized and released an energy very many fold that of Hiroshima. The trees were uprooted, pushed away, over an area of a thousand square miles. Maybe one or two people were hurt, there were not many people around, fortunately. Such an event, which we estimate is likely to come in once in a hundred, once in a few hundred years, if it should occur over a big city could kill millions - not likely.