QUESTION: Why are there two high tides a day, rather than one?
ANSWER: Being a not totally dense person, you know the tides are caused by the moon. You cling like a drowning person to this thin fiber of knowl-edge.But if you visualize the situation, you might get confused. Picture the Earth and the moon, facing off against one another across a void of a quarter million miles. The moon is pulling on the Earth, right? The ocean is bulging up a little, right? And the Earth is spinning, right? So now ask yourself why a given piece of ocean shouldn't bulge up only once every 24 hours, rather than twice. Scratch your noggin on that.
The answer requires lots of verbiage, unfortunately. Here goes:
Gravity is pulling the Earth and the moon toward one another. But you may have noticed they never smash together. That's because they are also subject to the outward centrifugal force that's created as they go winging through space in orbit around one another. The gravity and the centrifugal force cancel each other out.
But hold on. This neat little balancing act works fine for the center of the planet, the core, but not so perfectly for the outer edges of the planet, the surface, where the oceans are. The side facing the moon is about 4,000 miles closer than the Earth's core, and so it feels a greater gravitational tug from the moon. It bulges. That causes a high tide. Easy to grasp.
Now shift to the other side of the planet, the side farthest from the moon. It is subject to significantly less gravity than the rest of the planet, and relatively more of that outward centrifugal force. So it bulges AWAY from the moon. There's your second high tide.
That said, tides vary. The bulge is only a matter of inches out in the middle of the big blue sea, but it can be magnified by coastal configurations. The Bay of Fundy has a 30-foot tide, which makes us seasick just thinking about it. (This may be one reason why, when you ask someone where he or she is from, the answer is never, "The Bay of Fundy.")
QUESTION: Why are men so much more violent than women?
ANSWER: There is something out there that you might call Male Pattern Badness.
It's so obvious we just ignore it. We take it for granted that women don't go around murdering people for pleasure, that women aren't rapists, that women don't videotape themselves beating up someone and laughing all the while.
One theory that we'll run up the flagpole (right along with our Free Pee-Wee banner) is that men are an extension of sperm - that the aggressiveness of men is the outgrowth of the competition between one man's sperm and another's.
This is not as absurd a theory as it sounds. It has actually been proposed by two British biologists, Robin Baker and Mark Bellis, and is the subject of a recent cover story in Discover magazine. Baker and Bellis argue that females of many species pursue multiple male partners, contrary to the stereotype of sexual passivity. As a result, male sperm have to be ready to fight against the sperm from a competing male.
This may explain why so many sperm don't actually seem to be designed for fertilization. Many are deformed-looking, with two heads or a missing tail. Most lack the "motility" to swim all the way to the egg. These deformed sperm can function like blockers on a football team, like mutant 290-pound offensive linemen.
The Discover article quotes evolutionary biologist Robert Trivers saying, "In one sense all male-male competition is just so much sperm competition."
This is the most extravagant sociobiological theory we've ever encountered. Whatever happened to the idea that men are aggressive because they're just a bunch of jerks? Richard Cone, a biophysicist at Johns Hopkins University who studies sperm, told us, "To imagine that there's any connection at all between our behavior and the actions of any cells in our body is absurd."
E.O. Wilson, the founder of sociobiology, wrote in his 1979 book "On Human Nature" that aggression is a far more complex business than we realize, with at least seven distinct categories, ranging from sexual aggression to defensive counterattacks.
In any case, human beings, according to Wilson, aren't so awful: "I suspect that if hamadryas baboons had nuclear weapons, they would destroy the world in a week. And alongside ants, which conduct assassinations, skirmishes and pitched battles as routine business, men are all but tranquilized pacifists."
We have to agree with Richard Cone's larger point: "This is an area where it is very easy for scientists to look in the microscope and see what they're expecting to see."
Some might see sperm cooperating, living in harmony. Others see Male Pattern Bad-ness.