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Is the Earth Alive?

How can we tell that something is alive? It reacts to its surroundings, and if it senses danger it runs away or defends itself. It responds to food and light. It does what it can to keep itself alive. Can Earth itself be classified as a living being? Some scientists think so.

Imagine drilling a hole eight miles deep. That's what Arthur Conan Doyle described in his short story titled “When the World Screamed.” In Doyle's story, drilling that hole turned out to be a bad idea. As the hole got deeper and deeper, the earth began to howlhowl v.咆哮;号叫 in pain.

Doyle's story was pure science fiction, of course. But some scientists think his image comes pretty close to the truth. These people say that our planet really is alive. It may not actually scream in pain. But it can and it does react to what we humans do.

The concept of the earth being alive may sound crazy. Most of us think of our planet as a kind of giantgiant adj.巨大的 rock spinning through space. It is true that living creatures swarmswarm v.挤满 all over this rock. But the rock itself is not alive. Or is it?

Dr. James Lovelock says it is. Lovelock is a British scientist. He calls his belief Gaia [pronounced guy-ah]. That means “Mother Earth” in Greek. Lovelock has written two books to explain his position. In 1979 he wrote Gaia. Nine years later he wrote The Ages of Gaia. “You may find it hard to swallow, ” Lovelock said, “... that anything as large and apparentlyapparently adv.显然地[dead] as the Earth is alive.”Yet that's how Lovelock sees it. And he's not the first one to look at things this way. A German scientist named Gustav Fechner (1801-1887) thought everything was alive.

Fechner believed that all planets have a life of their own. In fact, he claimed,a planetplanet n.行星 is a higher form of life than you and l.As proof, Fechner noted that the earth doesn't have arms and legs. Why? According to Fechner, the earth doesn't need them. The planet Earth already has everything it desires. Human beings, on the other hand, are not born with everything they need. They must find ways to feed and shelter themselves. So they have had to develop arms and legs in order to do that.

Fechner's weird view didn't catch on during his lifetime. Other scientists simply ignored him. They went on thinking of the earth as a mixture of lavalava n.火山岩浆;火山岩,rocks,water,soil,and plants.To be sure,these scientists said, the earth is a wonderful place. But it is not “alive” in any true sense of the word.

Then along came Lovelock. His bold views caught many people's attention. Even some scientists became interested in Gaia. Lovelock says Gaia is based on one key principle. It is this: Living things and the earth have a direct effect on each other. At first, that might not sound like a shocking idea. After all, it is clear that the earth affects life. There is no argument here. People who live in the cold mountains do things one way.Those who live in the warm tropicstropic n.热带 do things another way. Those who live in a desert do things a third way. So the conditions offered by the earth do indeed affect how we live.

But Lovelock believes the reverse is true as well. He says that life affects the earth. To show this, he built a simple model of the world. He called it Daisyworld. The main form of life in this model world is black and white daisiesdaisy n.雏菊. The daisies grow when it is warm and die when it is cold. But if it gets too hot or too cold, the daisies can fight back. They can get the earth to change its temperature. If the sunlight is weak,more black daisies will grow.Their black petalspetal n.花瓣 absorb the sunlight. This tends to warm the earth. If the sunlight is strong, more white daisies will grow. Their white petals then reflect the sunlight, which will cool the earth.

In the real world, says Lovelock, the same thing happens.Humans and other forms of life constantly cause the earth to react to what they do. Followers of Gaia believe that some of these reactions have been pretty strong. They say the earth has changed its temperature. They say it has changed the level of salt in the oceans. They even say it has moved continentscontinent n.大陆;陆地 around.

That does not mean humans have all the power. Lovelock notes that Mother Earth is one tough old lady. She can take a lot of abuse. After all, during her long history the earth has lived through ice ages, earthquakes, and volcanoes. The earth has even survived direct hits from meteorsmeteor n.流星.It is not likely to experience anything worse. In light of what this planet has already endured, Lovelock says, a nuclear war would be“as trivial as a summer breezebreeze n.微风.”

Does this mean it doesn't matter if we blow ourselves up? That's right. Gaia followers say that if this happened, the earth itself would go right on living. And sooner or later, some other form of life would take our place. Lovelock even thinks he knows what that life form would be—whales! He says whales have brain power far beyond what we have imagined.

Many people still think Lovelock and his followers are loonyloony adj.疯狂的. Still, Gaia has a magicalmagical adj.有魔力的 ring to it. The idea is catching on. There have been dozens of articles written about it. There have been Gaia lectures. There have been Gaia films. A 1984 book on Gaia sold more than 175,000 copies. No one yet claims to have heard the earth crying out like it did in Doyle's story. But maybe, just maybe, we're not listening hard enough.