The Aha! Moment: A Scientist's Take on Creativity

16 A List of Silly Questions

226 16 A List of Silly Questions T his chapter is a tiny subset of the many things I don’t know. No textbook has satisfied my curiosity. Each question may, of course, have a perfectly good answer that I happen not to know. Even so, I sense that each topic hides something to be found out and is a promising browsing region for the creative mind. Everyone should keep such a list: partly to remind you of all the thing you don’t know and partly as a steady challenge to your RIG. We all accumulate such puzzles. I advocate noting them down and wondering about them every so often. Your list will change all the time and will in any case be entirely different from mine. But here is a snatch of mine at the moment. How Come We Get Motion Sickness? NASA runs a plane that travels in a vertical parabola and can maintain zero gravity for perhaps 20 seconds. It is called the “vomit comet.” Zero gravity induces motion sickness in many of those who volunteer for astronaut duty; the vomit comet helps to screen them out. Now any organism can be disturbed by variations to its inertial and gravitational world. But why does this cause stomach upset in humans? The theory of motion sickness, if there is one, alleges that some “toxins” cause upsets in the inner ear, which upsets a person’s balance. The body reacts by emptying the stomach to get rid of the toxins. Now I know only two such toxins, both products of civilization—alcohol and heavy water. And if humans evolved from creatures that swung in trees, we should A List of Silly Questions 227 be relatively immune to gravitational disturbances anyway. What other creatures suffer from motion sickness? Many humans, and most sailors, can get used to bodily motion. I do not understand. Why Do Leaves Have Chemicals? Chemicals in leaves include the alkaloids, cocaine, theobromine, caffeine , nicotine, and so on. I was told as a student that because plants cannot excrete, they dump everything they cannot use in their leaves. When they shed their leaves, they get rid of the unwanted material. Modern teachers say that leaves are designed not to be eaten. Insects are their worst enemies, so leaves tend to contain insecticides. Nicotine is the most famous, and pyrethrin may be the second most. Yet leaves seem very bad at not being eaten. Really effective insecticides , such as DDT, are human inventions. One day, perhaps, plants will invent the deadly organophosphorus insecticides. Meanwhile, all creatures depend on eating plants or eating the creatures that eat them. Plants seem to defend themselves mainly by putting a cellulose wall around each leaf cell. This discourages humans, but many animals can digest cellulose. And what about alkaloids? Medicine still values them. In the old days, it depended almost totally on chemicals made by plants. How come the plant spices? Did they evolve as insecticides? How Does a Baby Spider Migrate on a Thread? I once tried a calculation that completely failed to support my intuition about a fiber in the air and how it could drift down or rise up.1 Yet millions of baby spiders rise in the air this way. The baby spider matters, too. A detached thread just drifts down and becomes a piece of gossamer. Where Is the Oil Filter in the Blood? The manner of the circulation of the blood was proposed and proved by William Harvey in 1628. Venous blood, he said, is pumped by the right side of the heart to the lungs. Modern biochemistry asserts that it dumps carbon dioxide there and picks up oxygen. Then it goes back to a second pump unit, the left side of the heart. From there, arteries and capillaries 228 The Aha! Moment take it to all the tissues of the body. Each cell absorbs oxygen and food from a nearby capillary and dumps waste products such as carbon dioxide into it.The blood flows on, the capillaries reunite into veins, and ultimately one big vein empties that blood into the right side of the heart again. This reminds me of the circulation of oil in machines. A crucial component of such a system is the oil filter, which removes irregular suspended matter picked up by the oil in its travels. So where is the oil filter of the body? It must have...