20 things you don't know about the water
6 Ice is a lattice of tetrahedrally bonded molecules that contain a lot of empty space. That’s why it floats.
7 Even after ice melts, some of those tetrahedrons almost always remain, like tiny ice
cubes 100 molecules wide. So every glass of water, no matter what its temperature, comes on the rocks.
8 You can make your own water by mixing hydrogen and oxygen in a container and adding a spark.
Unfortunately, that is the formula that destroyed the Hindenburg.
9 Scientists have a less explosive recipe for extracting energy from hydrogen and oxygen.
Strip away electrons from some hydrogen molecules, add oxygen molecules with too
many electrons, and bingo! You get an electric current. That’s what happens in a fuel cell.
10 Good gardeners know not to water plants during the day. Droplets clinging to the leaves can act
as little magnifying glasses, focusing sunlight and causing the plants to burn.
11 Hair on your skin can hold water droplets too. A hairy leg may get sunburned more
quickly than a shaved one.
12 Vicious cycle: Water in the stratosphere contributes to the current warming of the earth’s
atmosphere. That in turn may increase the severity of tropical cyclones, which throw more
water into the stratosphere. That’s the theory, anyway.
13 The slower rate of warming in the past decade mightbe due to a 10 percent
drop in stratospheric water. Cause: unknown.
14 Although many doctors tell patients to drink eight glasses of water a day, there is no scientific
evidence to support this advice.
15 The misinformation might have come from a 1945 report recommending that Americans
consume about “1 milliliter of water for each calorie of food,” which amounts to 8 or 10 cups
a day. But the report added that much of that water comes from food—a nuance many
people apparently missed.
16 Call waterholics anonymous: Drinking significantly more water than is needed can cause
“water intoxication” and lead to fatal cerebral and pulmonary edema. Amateur marathon runners
have died this way.
17 Scientists at Oregon State University have identified vast reservoirs of water beneath
the ocean floor. In fact, there may be more water under the oceans than in them.
18 Without water, ocean crust would not sink back into the earth’s mantle. There would be no plate
tectonics, and our planet would probably be a lot like Venus: hellish and inert.
19 At the other end of the wetness scale, planet GJ 1214b, which orbits a red dwarf star,
may be almost entirely water.
20 Recent evidence suggests that when the solar system formed 4.5 billion years ago, comets had liquid
cores. If so, life may have started in a comet.
联系客服