When Kennedy said, 'Let's go to the moon,' we didn't yet have a vehicle that wouldn't kill you on launch. He said we'll land a man on the moon in eight years and bring him back. That was an audacious goal to put forth in front of the American people.

In whatever you choose to do, do it because it's hard, not because it's easy. Math and physics and astrophysics are hard. For every hard thing you accomplish, fewer other people are out there doing the same thing as you. That's what doing something hard means. And in the limit of this, everyone beats a path to your door because you're the only one around who understands the impossible concept or who solves the unsolvable problem.

Eventually, the Sun will swell to occupy the entire sky as its expansion subsumes the orbit of earth. Earth's surface temperature will rise until it matches the 3,000-degree rarified outer layers of the expanded Sun.... But not to worry. We will surely go extinct for some other reason long before this scenario unfolds.

But you will hardly ever read about them. Why? Because once again, the media has predetermined what is not worthy of coverage, even when the news item is something as uninteresting as the cosmic origin of every element in your body.

When you visit countries that don't nurture these kinds of ambitions, you can feel th absence of hope...people are reduced to worrying only about that day's shelter or the next day's meal. It's a shame, even a tragedy, how many people do not get to think about the future. Technology coupled with wise leadership not only solves these problems but enables dreams of tomorow.

What would aliens say when told earthlings shift clocks twice a year to fool themselves into thinking there's more sunlight?

I bet most of the crowd does not know that there are six moons in the solar system bigger than Pluto.