STAR MAKERS

ASK environmental specialist about the possibility of an encounter with an alien life form, and you will probably find that you asked "laugh factor." After rolling eyes, please note that the distances between stars are so large, it is virtually impossible for extraterrestrial visitation.

However, a potential flaw is the assumption of an extraterrestrial civilization would be only a few hundred years ahead of us in technology. What civilizations that could be a million years ahead of us?

The late scholar and writer Carl Sagan once asked: "What does it mean for a civilization a million years, we have had radio telescopes and spaceships for a few decades, our technical civilization is a few hundred years ... one million? advanced civilization many years is beyond us, as we go beyond bushbaby or a macaque. '

This issue is not only a matter of speculation. Soon, humanity may face an existential shock when we discover Earth-sized twin planet orbiting nearby solar systems. This could mark the beginning of a new era in our relationship with the universe, then we will never see the night sky in the same way. Realizing that scientists can get to compile an encyclopedia identifying the precise coordinates of perhaps hundreds of Earth-like planets, looking at the night sky, you will always ask if someone looks after.

Every few weeks, another planet the size of Jupiter was discovered outside our solar system, adding to the list of hundreds of extrasolar planets have been discovered in the short time we were looking for. The problem is that most are too large to sustain the kind of complex life, in our example, here on Earth, we know.

But in the coming years, new space telescopes will eventually become powerful enough to identify the twin of Earth. The Kepler telescope, which was launched in 2008, will probably be able to identify terrestrial planets - rocky worlds rather than gas giants like Jupiter and Saturn. Until 2012, it will scan up to 100,000 stars Sunlike up to 2,000 light-years, and perhaps identify hundreds of Earth-like worlds by detecting a slight loss of light caused by the transition to its parent star. Kepler should identify 185 planets with less than 1.3 times the radius of Earth, and not less than 640 terrestrial planets less than 2.2 times.

Kepler will pave the way for the Terrestrial Planet Finder, to be published in about 2014, which identifies a greater number of Earth-like planets. It will scan the brightest 1,000 stars within 50 light years from our planet small house, and focus on the brightest of 50-100 planetary systems. Also analyze the light reflected from the Sun planets to determine if it can support organic chemicals that make life possible.

All this, in turn, stimulate an active effort to find out if any of them harbor life, perhaps some with civilizations more advanced than ours. Although it is impossible to predict the exact characteristics of these civilizations around can be analyzed using the laws of physics. No matter how many thousand separate us from them, you still have to obey the laws of physics - which have been determined to the extent that we can explain the behavior of the subatomic world of the large-scale structure of the universe, through staggering 43 orders of magnitude (a factor of 10 billion billion billion billion billion).

Civilizations can be classified according to their energy consumption, according to the following principles:

• The four laws of thermodynamics describe the transport of heat and work. Even an advanced civilization is bound by the laws of thermodynamics, in particular the first and second place, and therefore can not be described by the available energy. The first law states that "energy can change from one form to another, but can not be created or destroyed." So that "in all energy exchanges, if no energy enters or leaves the system The total amount of disorder always increases "is the second law.

• The laws of stable matter. Of importance in the universe into three main groups: planets, stars and galaxies. It is a well-defined structural stellar and galactic evolution, thermonuclear fusion, etc.. Thus, the energy of a hyper-advanced civilization based on three different types, and the upper limits on the rate of energy consumption.

• The laws of planetary evolution. Any advanced civilization must grow in energy consumption faster than the frequency of fatal disasters such as meteor impacts, ice ages, supernova explosions, and so on. If the growth rate is slow, are doomed to disappear. Therefore, this place mathematical lower limits on the rate of growth of these civilizations.

In a seminal article published in 1964 in the Journal of Soviet Astronomy, Russian astrophysicist Nicolai Kardashev theorized that advanced civilizations must therefore be grouped into three categories: I, II and III, which means mastering, respectively, as consumption energy planetary, stellar and galactic. It is estimated that the energy consumption of three types of civilization would be separated by a factor of about 10 million.

Human civilization has only recently begun to master planetary energies: fossil fuels, passive solar, wind, geothermal and nuclear fission, and maybe someday soon break nuclear fusion. But how long it takes to get type II and III status? Less time than many people believe.

Any planetary energy production is now about $ 10 billion ergs per second (erg is a unit of measurement equal to 10-7 joules). It looks great, but it really is a small fraction of the energy we receive from the sun. Earth is bathed with about a billionth of the energy of its parent star - we use about one-millionth of that.

But the growth of our energy is increasing exponentially, and we can calculate how long it will take the height of type II or III status. "Look how far we have come in energy uses once we figured out how to manipulate energy, how fossil fuels really going, and how to create electricity from hydropower, and so on" says Donald Goldsmith, University of California at Berkeley astronomer and author. "We came into the uses of energy in an extraordinary number in just a few centuries compared to billions of years, our planet has been here ... and the same kind of thing can be applied to other civilizations ".

Freeman Dyson, a physicist at the Institute for Advanced Study in Princeton, New Jersey, estimated that within a century or two, we should achieve the status of type I. In fact, a more modest rate of 1 percent per year, Kardashev estimated that it would only 3,200 years to reach Type II status, and 5,800 years to reach Type III status.

A TYPE I truly global civilization that dominated most forms of planetary energy. His energy could be among the thousands and millions of our own times current production. Mark Twain said: "Everyone complains about the weather, but nobody does anything about it." This could change with a Type I civilization, which has enough power to change the climate. Has also sufficient to build cities under the oceans and changing the frequency of earthquakes and volcanic eruptions.

Currently, our energy production qualifies us to the state of type 0; Carl Sagan estimated that considered a type 0.7 civilization. We derive our energy not exploit global forces, but by the combustion of fossil fuels (oil and coal). But we can already see the seeds of a Type I civilization: When you read the newspaper, see evidence everywhere we are an emerging type I civilization. For example:

• The Internet will be "Phone System" of our planet. Already, the Internet is the universal communication for science, commerce, arts, politicians and individuals. If the leader of a nation have tried to ban the Internet, most people just laugh. He became unstoppable.

• The language of our future planetary type I civilization is English. This is already the number one second language on Earth, spoken by the majority of scientists, engineers, politicians, artists and business people. For people in Asia, in local languages, for many, the most convenient way to communicate through a second language for all. There will be a language that oversees the entire planet - French - but under this umbrella, there will be hundreds of local languages.

• The global economy will be global. We can see the emergence of the European Union, whose members nations have for centuries, killing other citizens. The EU, for its part, was formed as a result of competition from a united North America economically under NAFTA (free trade in North America, which includes Canada, the U.S. and Mexico).

• The global culture is mass culture and youth culture. Ya, movies, music, books, art,
and ideas are distributed worldwide. As
global language, this culture is everywhere on Earth, but coexist with local authorities.

By definition, an advanced civilization must grow faster than the frequency of catastrophic death. Since large meteor and comet impacts take place once every few billion years, a type I civilization must master space travel to deflect space debris within this period, it should not be a big problem. Glacial periods may occur on a time scale of tens of thousands of years, if a Type I civilization must learn to modify the time during this period.

Artificial and internal catastrophes must be negotiated. Global pollution is a deadly threat to a civilization type 0, but not a Type I civilization, who lived for several millennia as a global force and necessarily achieved ecological balance with its planet of origin. Internal problems such as wars are a serious recurring threat, but are emerging civilizations thousands of years to resolve their racial, national and sectarian. Since it would take centuries or even millennia for a Type I civilization to terraform planets relatives, people have plenty of time to solve their internal differences on the same planet before finally leaving the world in significant numbers.

Finally, after several thousand years, a Type I civilization has exhausted the energy of his home planet, and derive their energy by consuming the total energy available from the sun -
approximately one trillion trillion trillion ergs per second.

With a power comparable to that of a small star, should be visible from space. Freeman Dyson proposed a Type II civilization would even build a giant sphere around their star more efficient use of its total energy. Even if one tries to hide its existence, must - comply with the second law of thermodynamics - emit waste heat. From space, the planet can be seen to shine like a Christmas tree decoration. Dyson has even proposed looking specifically infrared emissions (rather than radio and television) to identify these Type II civilization. So far, no evidence of such a planet found infrared (although almost nobody looked).

Perhaps the only serious threat to a civilization type II is the explosion of a nearby supernova, whose sudden eruption could scorch their planet in a devastating explosion of X-rays, the destruction of all life. Therefore, perhaps the most interesting civilization is a Type III civilization, for it is truly immortal. He has exhausted the power of a single star, and approached other star systems. No natural disaster known to science is capable of destroying a Type III civilization.

Faced with a nearby supernova would have alternatives, such as changing the evolution of a dying red giant star will explode, or outside this star system and terraforming a particular planetary nearby.

However, there are obstacles to the new Type III civilization. Finally, he meets the theory of relativity of Einstein. Nothing can travel faster than light, which is about 300,000 kilometers per second (for a possible escape, see end of article). Since the universe is so vast and empty space, the absolute speed limit tends to slow the expansion of a successful civilization. Dyson believes that this obstacle could delay the transition from type II to type III civilization perhaps a million years or more.

But even with the barrier speed of light, there are alternatives to the expansion velocity of light short. For example, the ultimate measure of the capacity of a rocket is something called "specific impulse", defined as the product of the pressure and duration, and is measured in units of seconds. Chemical rockets can achieve specific impulses lasting hundreds Ion engines several seconds. thousand can achieve specific impulses of tens of thousands of seconds. However, to nearly the speed of light, we are able to achieve a specific impulse of about 30 million seconds, which is beyond our current capacity, but not a Type III civilization. Several propulsion systems available to probe sub-light speed, as ramjet fusion engines Photonic, antimatter engines, and others can not yet imagine.

Because the distances between stars are so large, and the number of solar systems inadequate, lifeless so great, a Type III civilization is faced with the following question: what is the most effective way to explore the hundreds of thousands of million stars in the galaxy?

On television, science fiction, the search for habitable worlds is presented as the prerogative heroic captains boldly commanding a single ship, or as the murderer of the company Star Trek Borg - a type III civilization which absorbs lower Type 'Civilization II (like Star Trek United Federation of Planets). However, mathematically the most efficient method to explore the space is much less glamorous: to send fleets "von Neumann probes" through the galaxy. They are named after John von Neumann, a mathematician of Hungarian origin, which defined the mathematical laws of self-replicating systems.

Von Neumann probe is a robot designed to reach distant star systems and create factories to reproduce copies of themselves to thousands. Von Neumann probes, a planet is a very ideal of a dead moon, but they have no atmosphere and no erosion, which means that the probes can land and take off and can "live off the land" using natural mineral deposits of iron, nickel and others to create replicants for dispersal in search of other star systems.

Similar to a virus often colonizes body size over time, increasing amounts of Von Neumann probes will extend in all directions, at a fraction of the speed of light. Thus, in this way, even the galaxy 100,000 light years everything can be fully explored in, say, half a million years.

If a Von Neumann probe only find traces of primitive life - as a warrior civilization unstable and wild-type 0 - simply can lie dormant in the moon, silently waiting for the Type 0 civilization to evolve into a stable type of civilization. After waiting in silence for several millennia, can be activated when the exchange is in the process of civilization advanced enough to establish a lunar colony. Physicist Paul Davies of the Australian Centre for Astrobiology in Sydney, has even raised the possibility that Von Neumann probe could rely on our own Moon, remnants of a previous visit to our system aeons ago.

If this sounds familiar, it is because it was the basis of the movie 2001: A Space Odyssey. Originally, Stanley Kubrick began the film with a series of scientists explaining how probes of this type would be the most effective method of space exploration. Unfortunately, at the last minute, Kubrick cut the opening segment of the film, and the famous monoliths - von Neumann - probes have become almost mystical entities.

This raises the question raised by the Italian physicist Enrico Fermi: If there are Von Neumann probes, where are they? If these advanced civilizations, and visited them years. However, we see no evidence for them. But, by analogy, consider walking down a country road and you come across an anthill. No, we look for ants and say, "I bring you trinkets and beads. I bring nuclear power and space travel. Take me to your leader "? Or is it perhaps the temptation to walk on some of them? Or ignore them completely?

It is humbling to see that the development gap between a tiny ant colony and our modern civilization is only a small fraction of the distance between 0 and a type of Type III civilization - a factor of 100 billion dollars, Indeed,. However, we have a very expensive for us, we believe that a Type III civilization would find us irresistible to contact us. The truth is, however, may also be interested in communicating with humans, we are eager to communicate with ants.

Of course, as an encounter with a Type III civilization has its dangers. The danger is not that the people we want to eat or steal our resources - problems that led intrigued in science fiction movies. Your DNA, if any, would be incompatible with ours, and therefore our proteins would be unpleasant for them and, in addition, there are many inhabited planets in the galaxy with more natural resources than the Earth, so why do you need plunder of inhabited real estate?

The greatest danger we face is the same as that facing our ant colony: the danger of being paved. Many forms of life on Earth are endangered because humans do not want to conquer and plunder, but because in the way that humans want to do. No ant include the construction of a road or a flood the dam, but would their victims.

In addition, citizens of a Type III civilization may seem like something that would be able to recognize immediately. Path of humanity with intelligence need three basic elements: eyes, hands and tongue. Beyond these requirements, almost anything goes. There is nothing sacrosanct about the human form or shape. You can, for example, imagine that it is possible to breed a race of octopus smart if we had millions of years to play. Finally, if you ever find a space ship, it is likely to be a Von Neumann probe robot of some sort, rather than a ship occupied by the aliens themselves.

But when I type a civilization reaches the stage of the development phase, you have probably discovered biotechnology and information technology. Therefore, it is likely that gradually leaving the hereditary form and shape and adopt radical evolution models. It is in the laws of biology and computer science to imagine a civilization that creates bodies that are immortal, they are, or have other key attributes.

ORIGINAL SINCE classification Kardashev civilizations, scientific advances have improved and expanded our perceptual analysis, including the latest advances in the field of nanotechnology, biotechnology and quantum physics.

For example, nanotechnology can facilitate the development of Von Neumann probes. As the American physicist Richard Feynman observed in his seminal essay "There's plenty of room at the bottom", there is nothing in the laws of physics to armed outlaw construction of molecule-sized machines. Today, scientists have already built atomic entertainment companies, anecdotes, ranging from atomic abacus with Buckyballs to atomic strings of the guitar, about 100 atoms wide.

Paul Davies speculates that a civilization space activities could make good use of nanotechnology to build miniature probes to explore the galaxy, perhaps no bigger than the palm of your hand. "The tiny probes which I speak are so discreet that it is not surprising that I have not found one," he said. "This is not the kind of thing that you encounter in your backyard So if this is how the technology develops. - I mean, smaller, faster, cheaper - and whether any Other civilizations have taken this path, then we could be surrounded by surveillance devices. "

The development of biotechnology has also opened the possibility that such probes can act as a way of life, reproducing their genetic information, changing and evolving in every phase of the game to improve their skills, and perhaps the artificial intelligence to speed up your search.

Information theory has changed the original analysis Kardashev. Current SETI (Search for Extraterrestrial Intelligence) project analyzing only a few radio frequencies and television 0 Type Management civilizations, but perhaps not an advanced civilization. Due to the enormous static in deep space in a single frequency number has a serious source of error. Instead of putting all your eggs in one basket, a more efficient system is to divide the message and spread it on all frequencies, then reassemble the only signal at the other end. Thus, even if certain frequencies are interrupted by static electricity, enough to survive the message reassemble the message accurately through error correction routines. However, any type 0 civilization to hear the message in a frequency band only hear nonsense. In other words, our galaxy can now be filled with messages from a number of types II and III civilizations, but through our telescopes type 0 only hear gibberish.

Finally, there is also the possibility that the civilization of Type II or III may be able to reach the legendary Planck energy with their machines - that is, to 1.019 million electron volts amazing, which is a quadrillion times larger than our particle accelerator more powerful.

The Planck energy occurs in the center of black holes and the instant of the Big Bang. But with recent advances in quantum gravity and superstring theory, there is a renewed interest among physicists about energies so vast that quantum effects rip the fabric of space and time. Although it is known that quantum physics allows for stable wormholes, there is the possibility that sufficiently advanced civilizations may be able to move over distances inconceiveably expanses of space in the blink of an eye, using a wormhole as a "backdoor" around the speed of light - a bit like Alice's mirror.

And if these civilizations can browse through wormholes stable, reaching a specific impulse of a million seconds is no longer a problem. They just take a shortcut across the galaxy. This will significantly reduce the time required to transition from a Type II to a Type III civilization.

This ability to rip holes in space and time can be very useful. Astronomers, analyzing light from distant supernovas, have concluded recently that the universe may have been accelerating rather than slowing down since the Big Bang - and what is still happening. If this is true, there may be anti-gravity force - perhaps the cosmological constant proposed by Albert Einstein and later retracted - that is counteracting the gravitational attraction of distant galaxies.

But it also means that the universe could be extended indefinitely, the stars burn fuel and darkening of the universe over time - which ends in a deep freeze, with temperatures close to absolute zero close. Several studies have recently shown that in a universe so sad may be similar. It will be a pitiful sight: any civilization which survives desperately piled beside the embers of neutron stars and black holes fading. All intelligent life must die when the universe dies.

Contemplating the death of the Sun, the British philosopher and mathematician Bertrand Russell wrote: "All the works of all ages, devotion, all the inspiration, all the noon brightness of human genius, are destined to disappear in death vast solar system, and the whole temple of man's achievement must inevitably be buried beneath the debris of a universe in ruins. '

Today, we realize that the propulsion system powerful enough for one day we can get rid of the death of our Sun in about five billion years, when the Earth boils oceans and mountains melt. But how to escape the death of the universe itself?

There may be a way out, according to John Barrows, a theoretical physicist at the University of Cambridge "Suppose we extend the classification [advanced civilizations] up Members of these civilizations hypothetical type IV, V, VI .. . well. leave, would be able to manipulate the structures in the Universe at scales larger groups encompassing galaxies, clusters and superclusters of galaxies. "Civilizations beyond Type III may have enough energy to escape our dying universe through the holes in space.

Finally, the physicist Alan Guth of the Massachusetts Institute of Technology, who helped create the inflationary universe theory, has even calculated the energy required to create a "new world born in the laboratory requires a temperature of 1,000 billion dollars degrees centigrade, which is within the range of these hypothetical civilizations.

Of course, until someone comes in contact with an advanced civilization, it all boils down to speculation - but tempered by the laws of physics - which is nothing more than a useful guide in our search for extraterrestrial intelligence.

But one day, many of us could see the encyclopedia containing the coordinates of perhaps hundreds of Earth-like planets in our sector of the galaxy. Then we will meditate with fear, as Sagan did, what an intelligent civilization millions of years ahead of ours will look like.