Just after World War II, this country led the world in science by every way you could measure it, yet the number of scientists was a tiny proportion of what it is now.

If you start any large theory, such as quantum mechanics, plate tectonics, evolution, it takes about 40 years for mainstream science to come around. Gaia has been going for only 30 years or so.

If we gave up eating beef we would have roughly 20 to 30 times more land for food than we have now.

If it hadn't been for the Cold War, neither Russia nor America would have been sending people into space.

I've got personal views on the '60s. You can't have freedom without paying the price for it.

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

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 suspect any worries about genetic engineering may be unnecessary. Genetic mutations have always happened naturally, anyway.

You never know with politicians what they are really saying. And I don't say that in a negative way-they have an appalling job.

Geological change usually takes thousands of years to happen but we are seeing the climate changing not just in our lifetimes but also year by year.

There is little evidence that our individual intelligence has improved through recorded history.

One pound of uranium is worth about 3 million pounds worth of coal or oil.

Nature favors those organisms which leave the environment in better shape for their progeny to survive.

The oil companies regard nuclear power as their rival, who will reduce their profits, so they put out a lot of disinformation about nuclear power.

There aren't just bad people that commit genocide; we are all capable of it. It's our evolutionary history.