Zeb Hogan is always traveling around the world to save endangered fish.
This famous ecologist(生态学家) grew up in a city in Arizona, America, but he had a big backyard with lots of trees. He spent his free time climbing trees and catching animals with his brother. They each had their favorite places in the biggest tree and they worked out ways to climb from tree to tree without ever touching the ground. Their family went camping in the summer and they would usually visit zoos and aquariums(水族馆) on their family vacations. His clearest memories as a child all had to do with animals and the outdoors. As he was older, he became interested in animal shows on TV and he would wake up early to watch Wild, Wild World of Animals before the other family woke up.
One day when we talked about fish, he said, “As an ecologist, Mr. White, you should know that fish in most parts of the world have a hard life, such as the Mekong giant catfish, the Chinese paddlefish, taimen, and the Murray cod. They are all in danger and have to do with all kinds of challenges all by themselves. Water pollution is one of them. So these fish really need our help."
Is there intelligent (有智力的) life on other planets? For years, scientists said "no" or "we don't know". But today this is changing. Seth Shostak and Alexandra Barnett are astronomers (天文学家). They believe intelligent life exists (存在) somewhere in the universe. They also think we will soon contact these beings (人；生物).
Why do Shostak and Barnett think intelligent life exists on other planets? The first reason is time. Scientists believe the universe is about 12 billion years old. "This is long enough for other planets to have intelligent life," say Shostak and Barnett. The second reason is size—the universe is huge. "Tools like the Hubble Telescope (哈勃望远镜) have shown that there are at least 100 billion galaxies," says Shostak. "And our galaxy, the Milky Way, has at least 100 billion stars. Some planets going around these stars might be similar to Earth."
In the past, it was hard to look for signs of intelligent life in the universe. But now, powerful telescopes (高倍望远镜) allow scientists to discover smaller planets. These planets might have intelligent life.
Have beings from space already visited Earth? "Probably not," says Shostak. However, intelligent beings may contact us in other way, such as radio signals (信号). In fact, they may be trying to communicate with us now, but we don't have the right tools to receive their messages. However, this is changing. By 2025, we could make contact with other life forms in our universe and we might help each other.
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