The best theory comes from string theory, which states that dark matter is nothing but a higher vibration of the string. We are, in some sense, the lowest octave of a vibrating string.

In string theory, all particles are vibrations on a tiny rubber band; physics is the harmonies on the string; chemistry is the melodies we play on vibrating strings; the universe is a symphony of strings, and the "Mind of God" is cosmic music resonating in 11 dimensional hyperspace.

I often think that we are like the carp swimming contentedly in that pond. We live out our lives in our own "pond," confident that our universe consists of only the familiar and the visible. We smugly refuse to admit that parallel universes or dimensions can exist next to ours, just beyond our grasp. If our scientists invent concepts like forces, it is only because they cannot visualize the invisible vibrations that fill the empty space around us. Some scientists sneer at the mention of higher dimensions because they cannot be conveniently measured in the laboratory.

It would take a civilization far more advanced than ours, unbelievably advanced, to begin to manipulate negative energy to create gateways to the past. But if you could obtain large quantities of negative energy-and that's a big "IF" - then you could create a time machine that apparently obeys Einstein's equation and perhaps the laws of quantum theory.

It's pointless to have a nice clean desk, because it means you're not doing anything.

Science is the engine of prosperity. All the prosperity we see around us is a byproduct of scientific inventions. And that's not being made clear to young people. If we can't make it clear to young people they're not going to go into science. And science will suffer in the United States.

You can mass-produce hardware; you cannot mass-produce software - you cannot mass-produce the human mind.