1In 1961, scientists set up gigantic, sensitive apparatus to collect radio waves from the far reaches of space, hoping to discover in them some mathematical pattern indicating that the waves were sent out by other intelligent beings. The first attempt failed: but someday the experiment may succeed.
What reason is there to think that we may actually detect intelligent life in outer space? To begin with, modern theories of the development of stars suggest that almost every star has some sort of family of planets. So any star like our wan sun (and there are billions of such stars in the universe) is likely to have a planet situated at such a distance that it would receive about the same amount of radiation as the earth.
Furthermore, such a planet would probably have the same general composition as our own; so, allowing a billion years or two — or three — there would be a very good chance for life to develop, if current theories of the origin of life are correct.
But intelligent life? Life that has reached the stage of being able to sent radio waves out into space in a deliberate pattern? Our own planet may have been in existence for five billion years and may have had life on it for two billion, but it is only in the last fifty years that intelligent life capable of sending radio waves into space has lived on earth. From this it might seem that even if there were no technical problems involved, the chance of receiving signals from any particular earth-type planet would be extremely small.
This does not mean that intelligent life at our level does not exist somewhere. There is such an unimaginable number of stars that, even at such miserable odds, it seems certain that there are million of intelligent life forms scattered through space. The only trouble is, none may be within hailing distance of us. Perhaps none ever will be; perhaps the appalling distances that separate us from our fellow denizens of this universe will forever remain too great to be conquered. And yet it is conceivable that someday we may come across one of them or, frighteningly, one of them may come across us. What would they be like, these extraterrestrial creatures?
2Tiny Tonga Launches Space Tourism Plan
The tiny poverty-stricken South Pacific state f Tonga has always had serious problems raising money, and so it has always been entrepreneurial. It his sold Tongan passports to Hong Kong businessmen; it sold possible satellite broadcasting locations in space; it even officially changed to a different time zone to be the first country to welcome the new millennium.1
Now Tonga’s latest money-making venture is a plan to become the world center of space tourism. The Tonga government has made an agreement with a US company to allow it to use on of its 170 islands to launch rockets that will take tourists on week-long trips into space at a cost of US$2 million each.2
For this price, space tourists receive 60 days’ training in a “resort setting”, followed by the holiday of a lifetime orbiting the Earth.3 Two astronaut pilots and four astronaut tourists will make the trip. However, skeptics say that these budgets are inadequate. Although they predict that space tourism will eventually bring an income of US$10-20 billion a year, they calculate that the budget of $8 million per trip will not be enough to pay for the required technology.
Comparison with the current space tourism programme suggests this maths may be accurate. To ride the Russian Soyuz (the only tourist ride currently available) costs more than US$20 million per person. However, other people, including one important ex-cosmonaut4, criticize the Russian government for raising money in this way, even though it uses the money for the space quota of space missions without achieving anything. He also believes that these inexperienced tourists would e a danger in a difficult or life-threatening crisis in space.5
3 Astronomy (天文學(xué)) is the oldest science known to man.Thousands of years ago man looked at the stars and wondered about the heavens.But man was limited (限制) by six planets that he could see with his eyes alone.
The Greeks (希臘人) studied astronomy over 2,000 years ago.They could see the size, color, and brightness of a star.They could see its place in the sky.They watched the stars move as the seasons changed.But the Greeks had no tools to help themselves study the heavens.
Each new tool added to the field of astronomy helped man reach out into space. Until there were telescopes (望遠(yuǎn)鏡), man knew a little about the moon.He did not know that the planet called Saturn (土星) had rings around it.His sight was so limited that he could not see all the planets.In the early 1700s, people thought there were only six planets.Pluto (冥王星), the last of nine planets to be discovered, was not seen until 1930.
Before the spectroscope (分光鏡), man did not know what kind of gases was in the sun or other stars.Without the radiotelescope (射電望遠(yuǎn)鏡), we did not know that radio noises came from far in space.
Today, astronomy is a growing science.We have learned more in the last fifty years than in the whole history of astronomy.