Here's why. A closed tailgate sets up a bubble of air that slowly circulates in the bed of the truck. Air coming over the cab of the truck treats the bubble as a smooth cover over the bed, and passes over this cover without ramming into the tailgate....
Many a bet has been made, and many a friendly, and not-so-friendly, argument has been waged over whether you get better gas mileage in a pickup truck with the tailgate up or down. Even those gurus of auto advice Click and Clack were thrown by it. The...
Last time we imagined a tunnel through the center of the earth. If such a thing existed, you could step into one end, fall all the way to the other side, and step out. Gravity would cause you to pick up almost exactly as much speed on the way down as...
Did you ever dream of digging a hole so deep it came out the other side of the earth? Let's play that game again, using a little physics. First we have to imagine that our tunnel is lined with super-heat-resistant material so we can pass through laye...
Sit on a swing, let someone push you, and away you go. But what happens if the person who pushed you walks away, and you want to swing faster and higher. If you've ever been in the second grade, you know the solution to that. Just start pumping your...
Which has more caffeine, coffee or tea? Ask this at a party and then watch the sparks fly. Everybody, it seems, has a definitive answer that is a little different from someone else's. What's the truth? Well, the real answer is a little more complex t...
Thats because when carbon and oxygen merge to form carbon dioxide, for example, they give off energy. If the merging process is very slowsay in a decaying woodpilethat energy will be very subtle. Speed it up a bit, though, and the energy can be felt...
Robert Frost once wrote a poem about coming across an old woodpile in the forest. In describing it he refers to the slow, smokeless burning of decay. What a great line of poetry. The neat part about it is, its also technically correct. Decay is an ex...
Ya?l: I've got a good trivia question for you, Don. Don: OK, Ya?l. Y: What animal's beak is one of the hardest known organic substances? D: Umm . . . I don't know. The bald eagle? Y: Nope. It's the giant squid. A squid beak can reportedly snap throug...
The answer is: gravity. Gravity sets an upper limit on how high a mountain can be. Heres why. Imagine you are the base of a mountain and you are holding a brick on your head. The top of the brick is the top of the mountain. Lets add another brick or...
On a previous Moment of Science we discussed one of the problems with turning yourself invisible. Sure, it sounds like fun. But a little physics showed us that the invisible man couldn't see anything either, because in order to see, light has to inte...
At some point in our childhoods it dawns on us how incredibly great it would be to turn invisible. Just imagine all the places you could sneak into! Think of all the things you'd get to see! Well, nobody knows yet how to make a person invisible. But...
Lot's of people want to live longer, and in this Moment of Science Don and Yael discuss some research that gives new insights into longevity. D: You know, when I watch sci-fi movies I notice everyone has a normal aging pattern. You don't encounter pe...
Don: Time once again for Surprise Finding. This is where we report on some experiment where you think you know the outcome, but then mother nature surprises us again. Ready? Ya?l: Ready. D: Analyzing data from a five-year study, Stephanie Brown, a ps...
The ancient Greeks knew a thing or two. Nowadays we say Copernicus discovered the earth was round, for example, but the Greeks had that figured out almost two thousand years earlier! How did they manage it? They had several different arguments for th...
