资讯

Here's a physics classic. Suppose you drop a golf ball and a bowling ball from the Empire State Building. Which hits first? Answer? They hit at the same time. You could also have used a marble and ...
What makes kitchen plastic wrap cling so maddeningly to itself, and so conveniently to the sides of bowls and plates? Plastic wrap clings for two reasons: it's elastic and it's sticky. That ...
Our last program talked about table salt, technically called sodium chloride, which is available in iodized formthat means that it includes a small amount of potassium iodide or sodium iodide ...
Paper towels are made up of cellulose fibers, which also make up cotton, wood, and most other plants. These cellulose fibers are actually giant molecules that consist of many small molecules ...
Our bodies need protein, and proteins contain nitrogen. The air we breathe has plenty of nitrogen to satisfy our needs. But-that nitrogen is not available to us directly from the air. The only way ...
Some fresh produce does well when we stick it in the refrigerator. Fruits and veggies like lettuce, apples, and oranges stay fresh even as the temperature approaches the freezing point. For these ...
Would you rather be bitten by a dog or by a human? Well, neither of course, but if you had to choose, which would it be? According to a widespread notion, a dog bite is the better choice since a ...
Yes, nitrogen. Did you ever notice how a potato chip bag feels a little bit inflated? It's almost like a little balloon. Potato chip bags are not full of air, but of nitrogen gas. This is done to ...
Part of the fun of eating walnuts or pecans is cracking the shell and getting the nut. However, some nuts, like cashews, are almost always sold shelled and roasted. Why aren't cashews sold in the ...
On this week's episode, we're catching up with films we've seen lately. We've been covering big events like the Oscars and SXSW lately, and haven't had time to talk about other films, so today we ...
D: Whew! I'm thirsty Yaël, would you pass that pitcher of water? Y: It is warm in here today, Don---luckily we've got plenty to drink. D: I've always ...
Why do regular incandescent light bulbs get hotter than fluorescent bulbs? An incandescent bulb becomes too hot to touch soon after you turn it on. A fluorescent bulb, on the other hand, takes ...