Topic
Human body
15 articles
Biology
Why do we have fingerprints?
Everybody knows they are there to help you grip. Somebody finally measured it in 2009, and discovered that ridged fingers grip smooth surfaces worse than smooth ones would. So the pattern is doing something else entirely.
Biology
Why can’t you breathe and swallow at once?
Every mouthful you take requires you to stop breathing for about a second. A cat does not have to. Neither did you, until you were about four months old, and what you got in exchange was the ability to say your own name.
Biology
Why does spinning make you dizzy?
The strange part is not the dizziness. It is that you feel almost nothing while you are spinning, and the whole world takes off the moment you stop. Something inside your head is still going round.
Society
Why can’t you remember being a baby?
You spent two whole years learning to walk and talk, and you cannot recall one minute of it. The obvious answer is that babies do not make memories. Babies make memories perfectly well, and then lose them.
Biology
Why do your ears pop on a plane?
Everything goes muffled, one ear starts aching, and then something clicks and the world comes back. It happens on the way down far more than on the way up, which is a strange thing for a plane to be fussy about.
Biology
Why do your knuckles crack?
Pull a finger and it goes off like a small firework. Try the identical pull again ten seconds later and absolutely nothing happens. Whatever made that noise has to be rebuilt before it can make it again.
Biology
Why do your fingers wrinkle in the bath?
Stay in the water long enough and your fingertips fold up like a plum left in the sun, while the back of your hand stays perfectly flat. Same bath, same skin, same half hour. So what decides?
Biology
Why can’t you tickle yourself?
Run a fingertip up your own arm and nothing happens. Let a friend do exactly the same thing and you fold in half. Your skin cannot tell whose hand it is, so something further in must be doing the deciding.
Biology
Why does a bruise turn purple, then green, then yellow?
You knock your shin, nothing bleeds, and days later a mark appears and works through three colors in a fixed order. Nothing else on your body behaves like that. So what is happening underneath?
Biology
Why doesn’t your stomach digest itself?
Your stomach can take a chicken drumstick apart in about two hours. It is built from the same stuff as the drumstick. So why is it still there?
Chemistry
Why do onions make you cry?
A whole onion can sit in the kitchen for a month without bothering anybody. Cut it, and within seconds something invisible has crossed the room to your eyes. It was not inside the onion a moment earlier.
Biology
Why did sailors’ old wounds open up again?
A man on Anson’s ship had been shot more than fifty years earlier, and the scar had healed long ago. Months from land, it opened again, with nothing touching it.
Biology
Why do you only catch chickenpox once?
An aunt who had it thirty years ago sits in a room full of spotty children and stays perfectly well. Her skin is no different from theirs. So what is she carrying?
Biology
Why does your own voice sound wrong on a recording?
Someone plays back a video from the school concert. Every other voice on it is exactly right. Yours belongs to a stranger, and the whole room insists the stranger is you.
Biology
How can pushing on someone’s chest keep them alive?
A stranger kneels down and pushes on the middle of someone’s chest, over and over, for ten minutes. No medicine, no machine, nothing fetched. So what is moving in there?