When I get bored, or get stuck on an equation, I like to go ice skating, but it makes you forget your problem. Then you can tackle the problem with a fresh new insight. Einstein liked to play the violin to relax. Every physicist likes to have a past time. Mine is ice skating.

I would like to believe that crop circles are evidence of visitation. But there have been too many people who have admitted to creating these crop circles, and too many people who have shown how to make one on TV programs, so I have my doubts.

If all our common-sense notions about the universe were correct, then science would have solved the secrets of the universe thousands of years ago. The purpose of science is to peel back the layer of the appearance of the objects to reveal their underlying nature. In fact, if appearance and essence were the same thing, there would be no need for science.

Time travel and teleportation will have to wait. It may take centuries to master these technology.

The human brain has 100 billion neurons, each neuron connected to 10 thousand other neurons. Sitting on your shoulders is the most complicated object in the known universe.

...the laws of physics, carefully constructed after thousands of years of experimentation, are nothing but the laws of harmony one can write down for strings and membranes. The laws of chemistry are the melodies that one can play on these strings. the universe is a symphony of strings. And the "Mind of God," which Einstein wrote eloquently about, is cosmic music resonating throughout hyperspace.

No one knows when a robot will approach human intelligence, but I suspect it will be late in the 21st century. Will they be dangerous? Possibly. So I suggest we put a chip in their brain to shut them off if they have murderous thoughts.