Matt:

Why do humans produce so much sperm if only one will fertilize an egg? And why are they in competition with each other? It would seem simpler to have fewer with less competition.

— R.C., Escondido

When the system was created, simpler didn’t seem to be the object, I guess. One of the big design flaws, if there is one, is the distance sperm have to travel to get to where they’re going. It’s quite a haul for something so small. Consider that rat sperm is more than four times longer than human sperm and you’ll see what they’re up against. It can take up to one hour for freshly ejaculated sperm to stagger through the mucus-lined passageways to the finish line in the fallopian tube. So the competition is to see which sperm has the stamina to reach the egg. Like a long-distance run rather than a brawl among armed soldiers.

But at the beginning of the race there certainly are a lot of competitors. As many as 400 million, with an average around 280 million (same as rabbits; go figure). If you’re a mouse, not a man, the count is only 50 million. The number is high to make sure at least a few get to where they’re going. Not all sperm are created equal. Some don’t swim at all. Some swim in circles, which is pretty useless. Some don’t have the energy to make it and swim very slowly until they just poop out. And even if they make it to an egg, they find that the thing’s covered with a coating that actually keeps sperm at bay. There’s evidence that some sperm sacrifice themselves to make a frontal assault on the egg and batter away until one Wondersperm makes it through to fertilization.

Another bit of research is even stranger. It could be that sperm follow a scent to find the egg. Odorous molecules are released by the egg, and the sperm sniff along the trail. If that’s how it works, that’s a whole new thing for you to wonder about. Call me if you come up with a reason why.

Hey, Matt:

A long time ago I read a sci-fi story that was based on the idea that our universe is really just an atom in some huge universe and we’re only a tiny part of it. I’ve thought a lot about that. So is there any chance that it’s true?

— J, San Diego

What, like our universe is just an atom in the toenail of a giant? A speck of a cheese grater? A tiny corner of a birthday cake? Hmmm… I don’t think anybody can say that’s absolutely not true. But if we compare atoms and the universe, there are a couple of differences. First of all, atoms aren’t held together with gravity as the universe is. And in spite of the fact that most scientific illustrations make an atom look like the universe, atoms aren’t solid bodies circling a big center. Electrons are actually described as “fuzzy” and “smeared-out bodies” that live in standing waves inside the atom. There really isn’t any part of an atom that is like our universe. But if you want to ignore the scientists, go right ahead. Nobody can really say you’re wrong.

Matt Hew:

Say I was planning a life of crime and I wanted to hide my identity. Is it possible for me to change my fingerprints from those I was born with and involuntarily gave to the DMV and several banks? Can I cut them away and not have fingerprints at all? This is important for my future.

— Colita, via email

You’re not the first criminal to come up with this scheme. Most of them have found it to be more difficult than they thought, but a couple managed to do it. If you want to retain fingerprints, just make them not match anything on record, then try what a Miami drug dealer did about ten years ago. He cut his fingerprints into little squares and transplanted the squares to other fingers, giving him a crazy, whirligig finger pattern. I also have to believe he loaded up on pain meds, since the skin transplant would require a deep cut.

Not too long ago, an Arizona drug dealer asked a local physician to somehow change his fingerprints. The creative doc transplanted the dealer’s toe tips to his fingertips, and the dealer figured he was home free. Unfortunately, he was captured while lounging in bed, recuperating from the surgery. How about obliterating your fingertips completely? A bad guy and a surgeon figured a way to transplant skin from the crook’s side to his fingers. It required cutting wounds on all surfaces, taping his fingers to his sides and holding them there until the skin regrew. It worked, but he was caught soon after because he didn’t change his face and a cop recognized him.

An acid bath or deep knife cuts are always good too. Good luck with your career.