A common way to compute density is, of course, to take the ratio of an object's mass to its volume. But other types of densities exist, such as the resistance of somebody's brain to the imparting of common sense.

While we may lose track of certain goals intermittently throughout the decades, I think we as a nation can be nimble when we need to be. All the buzz today is on the need for science literacy. That is on the agenda in ways it hasn't been in previous decades.

As the plow pushes through a parking lot of light fluffy snow, the snow clumps together in bigger and bigger chunks. Out in space, pressure hitting a gas cloud has a similar effect, except, instead of snowballs, you get stars!

Curiosity is unknown. All adults were once kids and once curious, but as adults you don't remember that and you see curiosity when it's expressed in children as a pathway to household disaster. They're simply exploring their environment, manifesting their curiosity. So what you need to do is create an environment where curiosity is rewarded rather than punished, or thwarted.

95, 96 percent of all that drives the universe has no known origin.

The very nature of science is discoveries, and the best of those discoveries are the ones you don't expect.

If Earth ever suffers a runaway greenhouse effect (like what has happened on Venus), then our atmosphere would trap excess amounts of solar energy, the air temperature would rise, and the oceans would swiftly evaporate into the atmosphere as they sustained a rolling boil. This would be bad.