Here is the first thing I learned from the PffP podcast after two lectures on power and energy: hydrogen has three times more energy per kilo than gasoline, but it has three times less energy per liter. How is that? It is because of density. Gasoline is so much denser that you have more weight per measure of content. In other words: it takes up less space. The consequence is that hydrogen may be a really good alternative for gasoline, because it has more energy in it and also, very importantly, is less polluting, but for putting it in cars it will take up too much space. Then again, for trucks and airplanes space is much less a problem. So in the near future we may see trucks and planes hydrogen driven, but less likely cars.
On the subject of cars I also got a good explanation of why hybrids are the future. And even though this is a physics class at UC Berkeley, I did not drop out as I did in high school. Many more lectures to go; I am excited.
The physics for future presidents is a lecture series that intends to hand out the broad lines and important social relevant facts of physics to any student, regardless of majoring subject. The lecturer Richard Muller is very entertaining, yet well on track and persuasive on the important stuff. A gem in educational podcasts.