Not wasting any water bottles is good. Not leaving the lights on is good. Turning the thermostat down in the winter, up in the summer, is good. But the best thing any of us in the developed world, especially in the United States, can be doing is talking about it.

But as the cerebellum degrades with age, so does the quality of memories. The memories are there, but they're not as good.

Climate change is happening, humans are causing it, and I think this is perhaps the most serious environmental issue facing us.

I like to regard myself as someone who's capable of critical thought, that is to say, who can evaluate claims.

When we see the shadow on our images, are we seeing the time 11 minutes ago on Mars? Or are we seeing the time on Mars as observed from Earth now? It's like time travel problems in science fiction. When is now; when was then?

There really is no such thing as race.

Winter lingered so long in the lap of Spring that it occasioned a great deal of talk.