You cannot study other planets without referring to Earth and without applying the techniques and the insights of Earth science. And you cannot really do a good job understanding the Earth without the insights from planetary exploration.

When you think about alien intelligences making art, you then have to think about what art is and how bound up it is in the nature of consciousness. Why do we make art? And what can we expect to have in common with other creatures in universe?

Among the radio astronomers of SETI - the Search for Extraterrestrial Intelligence - it's only sort-of a joke that the true hallmark of intelligent life is the creation of radio astronomy.

Why should we consider defining intelligence as something global and as something that hasn't actually yet appeared on Earth? It may be useful for envisioning the future of our own civilization and any others that may be out there among the stars. It might give us something to strive for.

Only when you drink from the river of silence shall you indeed sing. And when you have reached the mountain top, then you shall begin to climb. And when the earth shall claim your limbs, then shall you truly dance.

This is absolutely bizarre that we continue to subsidize highways beyond the gasoline tax, airlines, and we don't subsidize, we don't want to subsidize a national rail system that has environmental impact.

Hollywood is the perfect conduit for the urgent message about climate change. We raise awareness all the time. We routinely take a film that nobody knows about and get 80 percent of the public to know about it in just 30 days. That's called marketing. We need to harvest Hollywood for climate change awareness.

I was surprised to see how much the mainstream environmental movement hates the ELF.