Joel Akenbach

1. Miracles appear in the universe. There is something called life-a form of matter; It is essentially different from rocks, gases and dust, but it is made up of the same substance and the same elements everywhere.

Life is obvious, but it is difficult to sum it up clearly. We can say that life continues to multiply. Life consumes energy. Life adapts to the environment. Some life forms have formed a huge central processing network system. At least one kind of life is deeply aware of its existence.

This kind of life holds a big question: What kind of life exists in outer space?

At the turn of the new millennium, it may not be as exciting as other scientific mysteries, but it is full of difficulties and difficulties. Whether there is life in space is the hollow direction of our understanding of nature. By using various instruments, such as the Hubble Space Telescope, scientists have discovered many puzzling space areas. However, the earth is still the only world we know where people can live.

We are all guessing and imagining. The late astronomer carl sagan once predicted that there are millions of high-tech civilized societies in our galaxy alone. His more conservative colleague Frank Derrick thinks there are 10000 such societies. There are also skeptical scientists, such as astronomer Ben zuckerman of UCLA, who thinks that we are the only life in this galaxy, if not the whole universe.

6. All estimates are just guesses. In fact, there is no conclusive evidence for the existence of life outside the earth. No evidence doesn't mean it doesn't exist. But after all, we have never found any alien microbes, let alone alien spacecraft.

7. Our understanding of life in outer space is actually Sagan's "specious argument", with many unknowns, intuition and imagination, and many random assumptions. Even if we convince ourselves that there is life in space, we still face another problem, that is, we know nothing about that kind of life. We don't know whether it is different from us; We don't know whether this life is based on carbon atoms, whether it needs liquid water as an intermediary, whether it is swimming, flying or living underground.

8. Despite numerous questions and nebulae, life in outer space is increasingly becoming an exciting field of scientific exploration. This field is called outer space biology, astrobiology or biological astronomy.

No matter what it is called, it is still a science full of optimism. We now know that the universe may be full of all kinds of planets. Astronomers have observed at least 22 planets orbiting other planets since 1995. NASA plans to build a telescope called "Earth-like Planet Detector". The purpose is to find planets similar to the earth and observe whether they have an atmosphere suitable for life. In the past few decades, organic substances living in extremely extraordinary and harsh environments have been discovered on our planet. If microbes can live in rock caves deep in the stratum, or near hot sulfur hot springs in Yellowstone National Park, they may think that places like Mars are not so bad.

10. At present, Mars is being attacked on a large scale by human beings on earth. From polar landers, global surveyors to Walker probes that collect fossils, they are all aimed at Mars. In 2008, a box of Martian stones will be launched back to Earth and thrown into the desert of Utah, where scientists will examine them carefully and thoroughly in a completely closed laboratory. In the next few years, such exploration will also be carried out around Europa, and Europa will even go deep into Jupiter. Because there are many signs that there is a shallow sea in the cold world-people think there may be a biosphere in this dark and cold place.

L 1。 While looking for alien microbes, people are constantly trying to find larger, intelligent and communicative life. Although SETI, the project of searching for intelligent life in outer space, has been tested for 40 years and has not received any signal from alien civilized society to prove its existence, the signal processing technology is developing more and more sophisticated year by year. Optimists speculate. It's only a matter of time before we tune the electronic signal channel of aliens.

12. However, no one knows when or whether these studies will make a breakthrough. Although this field is full of morale and joy, I bet this kind of breakthrough will not happen for many years, let alone ten or twenty years. There is a simple reason. What we call life in outer space is not so easy to find.

13. But there is still reason to continue the project of searching for alien organic matter. First of all, to put it simply, it seems that there may be life in the universe. The other is that life sends out information to prove its existence. If there is nothing, at least there will always be residue, marks, echoes and the like. If there are many other lives in the fish, that kind of life can't be closed in the unknown world forever.

14. Being able to communicate with aliens is of course an epoch-making event with great cultural significance, but even if tiny fossils are found, or just the residues left over by biochemical processes in space, space biologists will feel very gratified. This is exactly what we need when we begin the long process of putting human beings into the universe. It is for this reason that space biologists have traveled all over the world in the worst environment. Or the most extreme place-the driest and coldest place, in short, the place closest to the Martian environment they can find.

15. the most attractive possibility is that there is vitality in the universe and it will be discovered one day. As we all know, living things are basically composed of the four most common active chemical elements in the universe, namely, hydrogen, nitrogen, carbon and oxygen, which greatly inspires the continued optimism of biologists in outer space. Moreover, life and non-life are intertwined and inseparable; Even a sword cannot completely cut them off and separate them.

16. We also know that the running ecosystem does not need sunlight or photosynthesis. In the early 1990s, researchers discovered that there were a large number of microorganisms in basalt deep in Washington State, which were completely isolated from the photosynthetic world. Even more complex life forms can adapt to various unfavorable environments. When scientists roamed the submarine ridge in Alvin deep-sea submersible, they found that shrimp and tubeless worms were everywhere near the submarine crater.

17. It is a dramatic situation for many people that scientists try to find signs of life in the towel of the universe. People think that life in outer space is not sticky microbes, but intelligent and skilled creatures, hiding among us. People who believe in the existence of aliens will not believe that the so-called aliens are just fictional stories. Being able to avoid detection and confirmation, especially by mainstream scientists, is probably the characteristic of these alien visitor stories.

18. I visited several annual UFO conferences and UFO exhibition halls in New Mexico, and I came to the conclusion that the battle of aliens in outer space is doomed to failure. External existentialists and skeptics are irreconcilable. And I think there is no scientific basis for saying that aliens came to earth by flying saucer. If these aliens insist on disappearing like this, if they insist on hijacking humans in the middle of the night and no one else can prove that they have ever appeared, then they have no right to log in to the elegant hall of the natural history exhibition hall.

19. People who believe that aliens came to the earth by flying saucer are not logically confused, let alone irrational as people sometimes say. Most people start from the intuition of exploring the truth of the universe. So many people go against the mainstream scientists' views and insist on the theory of the existence of aliens, which just reminds us how fascinating the topic of life in outer space is.

20. As many writers have noticed, for some people, aliens are modern substitutes for fairy tale characters such as angels, demons and ghosts, and images inferred from the development of modern astronomy and engineering technology. Among them, people have been expecting that aliens will eventually come to the earth and become one with people on the earth since ancient times. This idea is exciting. In this way, the story of aliens visiting the earth is just like the tools they ride.

2 1. Scientists are not surprised at the idea that aliens will come to the earth by flying saucer. It is strange why the aliens haven't come yet. Physicist Enrino Fermi asked his colleagues a well-known question at 1950, that is, where are you? Theoretically speaking, man can conquer the whole galaxy in one million years. If this is possible, a civilized society older than human beings can do it even more. But why haven't they visited the earth yet? This is the famous Fermi fable. Do aliens observe us without interference? (Zoo Hypothesis) Did they reach the earth, leave such and such remains, and then leave because of boredom? The theory of "ancient astronomers" assumes that aliens built pyramids and other buildings. ) or is interstellar travel too expensive and time-consuming for these highly intelligent species? In fact, the distance between the earth and the nearest planet on the other side of the sun is less than 25 trillion miles. )

22. Or is it possible that at least in our galaxy, the species with the highest technology only exist on the earth?

24. It is worth noting that in this debate, no element constitutes a truly convincing argument: argument. Things seem to have changed a lot since the discovery of the Mars Canal. 1877, Italian astronomer Giovanni Sablari said that he had discovered canals or channels on the surface of this planet. On this basis, American astronomer percival Lowell and his colleagues began further exploration.

25./kloc-At the end of the 9th century, Lowell announced to the world with his space telescope built near Stafford, flaig, Arizona that he had discovered hundreds of canals on Mars, which he believed were created by intelligent and civilized people on Mars. He once wrote: In fact, Martians should be born better than us earthlings. His reason is that the great projects built by Martians all over the world are far beyond the ability of us earthlings, and a race can live in harmony on the whole planet. This ability itself tells us that they are more progressive than the earth people who fight all day. However, herbert george wells slightly distorted this idea in his novel Star Wars, in which Martians are equipped with deadly laser guns and dream of conquering the earth.

26. Since then, alas, the Martian theory has come to an end. They are just man-made cultural works of art, because when astronomers observe Mars with more advanced space telescopes, they find that there are no canals at all. Lowell's canal is nothing more than his own imagination-a typical subjective imagination of "believing what is true and seeing what is true". However, until the 1960s, people still had illusions about the seasonal shadows on the surface of Mars. Could this be a plant? By 1965, the grasslands and forests of Mars were finally "destroyed". At that time, Mariner 4 took 22 photos of the surface of Mars, indicating that Mars, like the moon, is a wasteland full of craters.

27. 1976 The Viking lander found that there were no signs of life on Mars, and there were no traces of organic molecules on the surface of Mars. This intercontinental trip is a great success in the development of science and technology. However, the conclusion that there is no observable life on Mars makes outer space biology cautious in the next 20 years.

28. By the 1990s, things had improved. Inspired by the exploration of organic matter in an environment similar to Mars, biologists began to think that other parts of the solar system might be suitable for life. They also found some signs of life in the early history of the earth. Interestingly, when life first appeared on the earth, the conditions on Mars were much better than now. Photos of the surface of Mars show that there are flowing rivers and perhaps oceans on Mars. It may even be that life originated from Mars and then spread to the earth with meteorites.

29. This leads to the topic of the most famous Martian meteorite: ALH8400l. 1996 A team of three NASA scientists announced in Houston that this potato-like rock found in Antarctica may contain Martian fossils.

30.1On August 7, 1996, NASA held an unforgettable press conference in Washington to announce the news. Everyone knows what a historic honor it is to really find these significant microbial fossils. If you make a mistake, everyone will feel humiliated. Dan Golding, director of NASA, cautioned that the results were uncertain, but added, "We may see life beyond the third rocky planet around our sun."

3 1. The team of NASA made a very touching demonstration at the meeting, which enriched a large number of charts and amazing pictures of biological fossils released to the public for the first time, one of which looked like a worm. However, opponents also appeared later. J William Sopf of the University of California said that the higher the scale, the greater the possibility of biological origin, and he could only give this so-called Martian fossil a second class. Therefore, from that day on, the protracted debate in the scientific community began.

32. The conclusions of NASA have come under fierce attack. A devastating study shows that some structures that look like microorganisms are actually just rock fragments. They are just like creatures in appearance because they are colored in the process of preparing slides. The researchers even found that there are pollutants from the earth inside the meteorite.

33. The NASA team improvised and responded bit by bit. But three years later, opponents felt that they had smashed the Martian stone theory to pieces. Lunan Becker, a chemical geographer at the University of Hawaii, told me, "I think we are flogging a dead horse, and the failure of the other side is a foregone conclusion."

34. However, everett Gibson, a member of NASA's Meteorite Team, believes that this is a typical act of scientific resistance to revolutionary ideas. "The scientific community," he said, "generally does not accept more radical views quickly. ,,

In the past, some scientists didn't believe that meteorites would fall from the sky. For a time, plate tectonic geology was considered as a very strange proposition. Plate geology refers to the movement, collision and subsidence of huge plates in the crust. Do Martian fossils belong to the same category? Or are they like those rejected canals?

36. If life was born on the earth through natural processes, it should also happen on other planets. But when we look into space, we can't see any environment with signs of life. We can observe all kinds of planets and satellites, but we can't see the possibility that life can survive on them. In fact, the planets and the moon are all kinds-hot, dark, cold and gaseous-and there seem to be more ways to show the inanimate here than to show the inanimate here.

37. In our solar system, the earth may be in a rather narrow zone suitable for survival, neither too cold nor too hot, and the distance from the sun is just right, which makes water splash on the earth's surface in liquid state. Perhaps there are many other factors that make it possible for life to exist on the earth. The movement of crustal structure enables the carbon of this planet to be recycled. Mars does not have these mechanisms, and this seemingly insignificant defect may be the reason why Mars lost most of its atmosphere.

38. Even on Earth, the origin of life remains a long-term mystery. Paul davis, a physicist and writer, once questioned: "How did several chemical elements get together without any external interference, and how did life come into being?" ? From the appearance of things, life itself is a phenomenon full of impossibility. No known theory of matter can clearly explain how life came into being. I am fortunate to believe rationally that we human beings live in a universe that is extremely friendly to life, because we can feel this harmony. But we haven't found the so-called life theory. "

39. Even people are not sure whether life needs liquid water, although this seems reasonable, even on earth. Liquid water in the universe may be quite scarce-Europa can prove it-but it is another hypothetical component of life: organic molecules mainly composed of carbon atoms are everywhere. Because of this, the indomitable scholar Jeffrey Bada believes that life is everywhere in the universe. "I really don't know how to avoid such an idea," he said, even apologetically. Well, we assume that life can be everywhere, but with it comes a huge mystery: how long will it take for life to evolve into intelligent conditions?

40. Some people think that there is only one highly intelligent species among the 654.38 billion species on the earth. Ernst Meyer, the greatest biologist in the 20th century, holds this view. In this way, a high IQ has only a one in a billion chance of success. However, Holovitz, a physicist at Harvard University, suggested that the same data could be reversed, that is, on the only planet where we know that life exists, there are highly intelligent species, and the ratio should be one to one.

4 1. Everyone I meet thinks that if you can rewind the evolution of the earth, you will never get a creature exactly like human beings. However, some people firmly believe that intelligent species are likely to be born under some basic conditions. Some people enthusiastically argue that alien life is absolutely different from human beings; Another school thinks that the evolution of life on earth may be the best evidence of what happened on other planets. 42. Due to the lack of reliable data, this field is still only the garden of thinkers and theorists. What exactly is "intelligence"? What is human's "thinking", "feeling" or "romance"? When we ask whether human beings exist alone, what we really want to know is whether there are humans who are roughly the same as us in the universe. We are looking for communicators, looking for creatures that can send signals-it is best to tell stories clearly.

43. Every three years, the leading thinkers in this field get together and hold a conference on biological astronomy. I attended the meeting held in August 1999 on the Big Island of Hawaii. The opening ceremony was held around the outdoor pond of a hotel. A sociologist named Allen Twitch of the University of Toronto made an inflammatory remark: "I think the exploration of aliens has begun. Maybe they have reached the earth."

44. He didn't mean UFOs. He said that the tools used by aliens to explore the earth are very few-the so-called "nano detector" is a small experimental robot device sent to the earth by a progressive civilized society. And aliens will deliberately make people on earth aware of certain aspects of behavior. So, how exactly do aliens act? Where the hell are they? "I think it will appear on the Internet." Tuhe said.

A dozen visionaries, such as Tu He, held a short meeting before the conference, and the topic of discussion was how to deal with "substantial" information from outer space if human society received it. At the meeting, everyone was not sure whether human beings were ready for such events. It is even difficult for humans to draft an answer. Can we just tell them about human defects? If we admit that there have been wars and slavery in history, will it be mistaken as a threat to their aliens? Even if thinkers of well-meaning international organizations can try to draft this information, what should a pheasant radio station do first if it catches it? It seems that biological astronomy really has a genuine side. This time it will remind me that there are so many things to know about our little galaxy. One morning, space biologist Jack Farmer put forward a simple but surprising idea. He noticed that neither the Viking probe of 1976 nor the pathfinder spacecraft of 1997 had the most important tool for geographers when landing on Mars: a magnifying glass. This device was not included in the polar lander program that landed on Mars in June 65438+February 0999 +65438. Farmer's comments still linger in my mind. Another oceanographer, Cindy Lee Van Dover, noticed that no one took a deep-sea submarine to look around the active crater in the Indian Ocean.

Therefore, before we worry about how to deal with the interstellar empire, we'd better do some serious field work not far from home.

47. Physicist Freeman Dyson's opinion is that human beings can cast new life, which will be able to adapt to the vacuum of living in space and survive on the surface of the frozen moon, comets and even quasars. In the universe described by Dyson, life is in motion, and stars are gravitational traps, which limit the free movement of life.

48. "Maybe our mission is to be midwives and help the birth of the life universe." He said recently, "Once life escapes from this small planet. Its development will be endless. "

49. However, life must first survive on the earth. It is only 125000 years since human beings appeared on the earth as modern people. It is not clear whether human thinking is a long-term advantage. We make mistakes. We make atomic bombs. We destroy the environment, pollute the water and pollute the air. As one of the species, the first thing human beings should do now is to continue modern civilization as long as possible.

50. I sincerely hope that all those who explore life will finally cherish human beings again. The universe is full of empty space, hot planet and cold world, but it's good that we are alive and exist! At the same time, we should bear in mind that even if highly intelligent life is found in the world outside the earth, these lives may be completely H; To our surprise, this is not even what we want to find.

5 1. Aliens may just ignore an important part of our consciousness, that is, our spirit. He may have nothing to learn. The greatest moment of contact with aliens may just remind us that what we need most is actually a more perfect replica of ourselves-a creature made of ready-made raw materials on our planet.