I [do not know] when the end of science will come. ... What I do know is that our species is dumber than we normally admit to ourselves. This limit of our mental faculties, and not necessarily of science itself, ensures to me that we have only just begun to figure out the universe.

The history of exploration across nations and across time is not one where nations said, 'Let's explore because it's fun.' It was, 'Let's explore so that we can claim lands for our country, so that we can open up new trade routes; let's explore so we can become more powerful.'

Like a snowplow in overdrive, a supernova shockwave might sweep away any gas clouds in its path.

Today, scientists sound the alarm on other environmental dangers. Vested interests still hire their own scientists to confuse the issue. But in the end, nature, will not be fooled.

If the Sun exploded, we wouldn't know about it for 8 minutes and 20 seconds. Light and gravity take that long to reach us. Then we would vaporize.

Curious that we spend more time congratulating people who have succeeded than encouraging people who have not.

If Mars formed life, then life on Earth could have been seeded by life on Mars, making every life form on Earth descended from Martians.