The big threat to the planet is people: there are too many, doing too well economically and burning too much oil.

NASA will send up a big sun shade that will be in orbit between the earth and sun and deflect 2 or 3 percent of the sunshine back into space. It would be cheaper than the international space station.

I'm a scientist, not a theologian. I don't know if there is a God or not. Religion requires certainty.

Composing computer programs to solve scientific problems is like writing poetry. You must choose every word with care and link it with the other words in perfect syntax. There is no place for verbosity or carelessness. To become fluent in a computer lnaguage demands almost the antithesis of modern loose thinking. It requires many interactive sessions, the hands-on use of the device. You do not learn a foreign language from a book, rather you have to live in the country for year to let the langauge become an automatic part of you, and the same is true for computer languages.

For each of our actions there are only consequences.

An inefficient virus kills its host. A clever virus stays with it.

We need a more authoritative world...What's the alternative to democracy? There isn't one. But even the best democracies agree that when a major war approaches, democracy must be put on hold for the time being. I have a feeling that climate change may be an issue as severe as war. It may be necessary to put democracy on hold for a while.