Part 21 (1/2)

A Type II civilization will probably be at peace with itself. Since s.p.a.ce travel is so difficult, it will have remained a Type I civilization for centuries, plenty of time to iron out the divisions within their society. By the time a Type I civilization reaches Type II status, they will have colonized not just their entire solar system but also the nearby stars, perhaps out to several hundred light-years, but not much more. They will still be restricted by the speed of light.

TYPE III CIVILIZATIONS.

By the time a civilization reaches Type III status, it will have explored most of the galaxy. The most convenient way to visit the hundreds of billions of planets is to send self-replicating robot probes throughout the galaxy. A von Neumann probe is a robot that has the ability to make unlimited copies of itself; it lands on a moon (since it is free of rust and erosion) and makes a factory out of lunar dirt, which creates thousands of copies of itself. Each copy rockets off to other distant star systems and makes thousands more copies. Starting with one such probe, we quickly create a sphere of trillions of these self-replicating probes expanding at near the speed of light, mapping out the entire Milky Way galaxy in just 100,000 years. Since the universe is 13.7 billion years old, there is plenty of time in which these civilizations may have risen (and fallen). (Such rapid, exponential growth is also the mechanism by which viruses spread in our body.) There is another possibility, however. By the time a civilization has reached Type III status, its people have enough energy resources to probe the ”Planck energy,” or 1019 billion electron volts, the energy at which s.p.a.ce-time itself become unstable. (The Planck energy is a quadrillion times larger than the energy produced by our largest atom smasher, the Large Hadron Collider outside Geneva. It is the energy at which Einstein's theory of gravity finally breaks down. At this energy, it is theorized that the fabric of s.p.a.ce-time will finally tear, creating tiny portals that might lead to other universes, or other points in s.p.a.ce-time.) Harnessing such vast energy would require colossal machines on an unimaginable scale, but if successful they might make possible shortcuts through the fabric of s.p.a.ce and time, either by compressing s.p.a.ce or by pa.s.sing through wormholes. a.s.suming that they can overcome a number of stubborn theoretical and practical obstacles (such as harnessing sufficient positive and negative energy and removing instabilities), it is conceivable that they might be able to colonize the entire galaxy. billion electron volts, the energy at which s.p.a.ce-time itself become unstable. (The Planck energy is a quadrillion times larger than the energy produced by our largest atom smasher, the Large Hadron Collider outside Geneva. It is the energy at which Einstein's theory of gravity finally breaks down. At this energy, it is theorized that the fabric of s.p.a.ce-time will finally tear, creating tiny portals that might lead to other universes, or other points in s.p.a.ce-time.) Harnessing such vast energy would require colossal machines on an unimaginable scale, but if successful they might make possible shortcuts through the fabric of s.p.a.ce and time, either by compressing s.p.a.ce or by pa.s.sing through wormholes. a.s.suming that they can overcome a number of stubborn theoretical and practical obstacles (such as harnessing sufficient positive and negative energy and removing instabilities), it is conceivable that they might be able to colonize the entire galaxy.

This has prompted many people to speculate about why they have not visited us. Where are they? the critics ask.

One possible answer is that perhaps they already have, but we are too primitive to notice. Self-replicating von Neumann probes would be the most practical way of exploring the galaxy, and they do not have to be huge. They might be just a few inches long, because of revolutionary advances in nanotechnology. They might be in plain view, but we don't recognize them because we are looking for the wrong thing, expecting a huge stars.h.i.+p carrying aliens from outer s.p.a.ce. More than likely, the probe will be fully automatic, part organic and part electronic, and will not contain any s.p.a.ce aliens at all.

And when we do eventually meet the aliens from s.p.a.ce, we may be surprised, because they might have long ago altered their biology using robotics, nanotechnology, and biotechnology.

Another possibility is that they have self-destructed. As we mentioned, the transition from Type 0 to Type I is the most dangerous one, since we still have all the savagery, fundamentalism, racism, and so on of the past. It is possible that one day, when we visit the stars, we may find evidence of Type 0 civilizations that failed to make the transition to Type I (for example, their atmospheres may be too hot, or too radioactive, to support life).

SETI (SEARCH FOR EXTRATERRESTRIAL INTELLIGENCE).

At the present time, the people of the world are certainly not conscious of the march toward a Type I planetary civilization. There is no collective self-awareness that this historic transition is taking place. If you take a poll, some people might be vaguely aware of the process of globalization, but beyond that there is no conscious awareness that we are headed to a specific destination.

All this might suddenly change if we find evidence of intelligent life in outer s.p.a.ce. Then, we would immediately be aware of our technological level in relation to this alien civilization. Scientists in particular would be intensely interested in which types of technologies this alien civilization has mastered.

Although one cannot know for sure, probably within this century we will detect an advanced civilization in s.p.a.ce, given the rapid advances in our technology.

Two trends have made this possible. First is the launching of satellites specifically designed to find small, rocky extrasolar planets, the COROT and Kepler satellites. The Kepler is expected to identify up to 600 small, earthlike planets in s.p.a.ce. Once these planets have been identified, the next step is to focus our search for intelligent emissions from these planets.

In 2001, Microsoft billionaire Paul Allen began donating funds, now more than $30 million, to jump-start the stalled SETI program. This will vastly increase the number of radio telescopes at the Hat Creek installation, located north of San Francisco. The Allen Telescope Array, when fully operational, will have 350 radio telescopes, making it the most advanced radio telescope facility in the world. While in the past astronomers have scanned little more than 1,000 stars in their search for intelligent life, the new Allen Array will increase that number by a factor of 1,000, to a million stars.

Although scientists have been searching vainly for signals from advanced civilizations for almost fifty years, only recently have these two developments given a much-needed boost to the SETI program. Many astronomers believe that there was simply too little effort and too few resources devoted to this project. With this influx of new resources and new data, the SETI program is becoming a serious scientific project.

It is conceivable that we may, within this century, detect signals from an intelligent civilization in s.p.a.ce. (Seth Shostak, the director of the SETI Inst.i.tute in the Bay Area, told me that within twenty years, he expects to make contact with such a civilization. That may be too optimistic, but it is safe to say that within this century it would be strange if we did not detect signals from another civilization in s.p.a.ce.) If signals are found from an advanced civilization, it could be one of the most significant milestones in human history. Hollywood movies love to describe the chaos this event might unleash, with prophets telling us that the end is near, with crazy religious cults going into overtime, etc.

The reality, however, is more mundane. There will be no need for immediate panic, since this civilization may not even know that we are eavesdropping on their conversations. And if they did, direct conversations between them and us would be difficult, given their enormous distance from us. First, it may take months to years to fully decode the message, and then to rank this civilization's technology, to see if it fits the Kardashev cla.s.sification. Second, direct communication with them will probably be unlikely, since the distance to this civilization will be many light-years away, too far for any direct contact. So we will be able only to observe this civilization, rather than carry on any conversation. There will be an effort to build gigantic radio transmitters that can send messages back to the aliens. But in fact, it may take centuries before any two-way communication is possible with this civilization.

NEW CLa.s.sIFICATIONS.

The Kardashev cla.s.sification was introduced in the 1960s, when physicists were concerned about energy production. However, with the spectacular rise of computer power, attention turned to the information revolution, where the number of bits processed by a civilization became as relevant as its energy production.

One can imagine, for example, an alien civilization on a planet where computers are impossible because their atmosphere conducts electricity. In this case, any electrical device will soon short-circuit, creating sparks, so that only the most primitive forms of electrical appliances are possible.

Any large-scale dynamo or computer would quickly burn out. We can imagine that such a civilization might eventually master fossil fuels and nuclear energy, but their society would be unable to process large amounts of information. It would be difficult for them to create an Internet or a planetary telecommunications system, so their economy and scientific progress would be stunted. Although they would be able to rise up the Kardashev scale, it would be very slow and painful without computers.

Therefore, Carl Sagan introduced another scale, based on information processing. He devised a system in which the letters of the alphabet, from A to Z, correspond to information. A Type A civilization is one that processes only a million pieces of information, which corresponds to a civilization that has only a spoken language but not a written one. If we compile all the information that has survived from ancient Greece, which had a flouris.h.i.+ng written language and literature, it is about a billion bits of information, making it a Type C civilization. Moving up the scale, we can then estimate the amount of information that our civilization processes. An educated guess puts us at a Type H civilization. So therefore, the energy and information processing of our civilization yields a Type .7 H civilization.

In recent years, another concern has arisen: pollution and waste. Energy and information are not enough to rank a civilization. In fact, the more energy a civilization consumes and the more information it spews out, the more pollution and waste it might produce. This is not an academic question, since the waste from a Type I or II civilization might be enough to destroy it.

A Type II civilization, for example, consumes all the energy that is produced by a star. Let us say that its engines are 50 percent efficient, meaning that half the waste it produces is in the form of heat. This is potentially disastrous, because it means that the temperature of the planet will rise until it melts! Think of billions of coal plants on such a planet, belching huge amounts of heat and gases that heat the planet to the point that life is impossible.

Freeman Dyson, in fact, once tried to find Type II civilizations in outer s.p.a.ce by searching for objects that emit primarily infrared radiation, rather than X-rays or visible light. This is because a Type II civilization, even if it wanted to hide its presence from prying eyes by creating a sphere around itself, would inevitably produce enough waste heat so that it would glow with infrared radiation. Therefore he suggested that astronomers search for star systems that produce mainly infrared light. (None, however, were found.) But this raises the concern that any civilization that lets its energy grow out of control may commit suicide. We see, therefore, that energy and information are not enough to ensure the survival of the civilization as it moves up the scale. We need a new scale, one that takes efficiency, waste heat, and pollution into account. A new scale that does is based on another concept, called entropy.

RANKING CIVILIZATIONS BY ENTROPY.

Ideally, what we want is a civilization that grows in energy and information, but does so wisely, so that its planet does not become unbearably hot or deluged with waste.

This was graphically ill.u.s.trated in the Disney movie Wall-E, Wall-E, where in the distant future we have so polluted and degraded the earth that we simply left the mess behind and lead self-indulgent lives in luxury cruise s.h.i.+ps drifting in outer s.p.a.ce. where in the distant future we have so polluted and degraded the earth that we simply left the mess behind and lead self-indulgent lives in luxury cruise s.h.i.+ps drifting in outer s.p.a.ce.

Here's where the laws of thermodynamics become important. The first law of thermodynamics simply says that you can't get something for nothing, i.e., there is no free lunch. In other words, the total amount of matter and energy in the universe is constant. But as we saw in Chapter 3 Chapter 3, the second law is the most interesting and, in fact, may eventually determine the fate of an advanced civilization. Simply put, the second law of thermodynamics says that the total amount of entropy (disorder or chaos) always increases. This means that all things must pa.s.s; objects must rot, decay, rust, age, or fall apart. (We never see total entropy decrease. decrease. For example, we never see fried eggs leap from the frying pan and back into the sh.e.l.l. We never see sugar crystals in a cup of coffee suddenly unmix and jump into your spoon. These events are so exceedingly rare that the word ”unmix” does not exist in the English-or any other-language.) For example, we never see fried eggs leap from the frying pan and back into the sh.e.l.l. We never see sugar crystals in a cup of coffee suddenly unmix and jump into your spoon. These events are so exceedingly rare that the word ”unmix” does not exist in the English-or any other-language.) So if civilizations of the future blindly produce energy as they rise to a Type II or III civilization, they will create so much waste heat that their home planet will become uninhabitable. Entropy, in the form of waste heat, chaos, and pollution, will essentially destroy their civilization. Similarly, if they produce information by cutting down entire forests and generating mountains of waste paper, the civilization will be buried in its own information waste.

So we have to introduce yet another scale to rank civilizations. We have to introduce two new types of civilizations. The first is an ”entropy conserving” civilization, one that uses every means at its disposal to control excess waste and heat. As its energy needs continue to grow exponentially, it realizes that its energy consumption may change the planetary environment, making life impossible. The total disorder or entropy produced by an advanced civilization will continue to soar; that is unavoidable. But local entropy can decrease on their planet if they use nanotechnology and renewable energy to eliminate waste and inefficiency.

The second civilization, an ”entropy wasteful” civilization, continues to expand its energy consumption without limit. Eventually, if the home planet becomes uninhabitable, the civilization might try to flee its excesses by expanding to other planets. But the cost of creating colonies in outer s.p.a.ce will limit its ability to expand. If its entropy grows faster than its ability to expand to other planets, then it will face disaster.

FROM MASTERS OF NATURE TO CONSERVATORS OF NATURE.

As we mentioned earlier, in ancient times we were pa.s.sive observers of the dance of nature, gazing in wonder at all the mysteries around us. Today, we are like ch.o.r.eographers of nature, able to tweak the forces of nature here and there. And by 2100, we will become masters of nature, able to move objects with our minds, controlling life and death, and reaching for the stars.

But if we become masters of nature, we will also have to become conservators of nature. If we let entropy increase without limit, we will inevitably perish by the laws of thermodynamics. A Type II civilization, by definition, consumes as much energy as a star, and hence the surface temperature of the planet will be scorching hot if entropy is allowed to grow unabated. But there are ways to control entropy growth.

For example, when we visit a museum and see the huge steam engines of the nineteenth century, with their enormous boilers and carloads of black coal, we see how inefficient they were, wasting energy and generating enormous amounts of heat and pollution. If we compare them to a silent, sleek electric train, we see how much more efficiently we use energy today. The need for gigantic coal-burning power plants, belching huge amounts of waste heat and pollution into the air, can be vastly reduced if people's appliances are energy efficient via renewable energy and miniaturization. Nanotechnology gives us the opportunity to reduce waste heat even further as machines are miniaturized to the atomic scale.

Also, if room temperature superconductors are found in this century, it means a complete overhaul of our energy requirements. Waste heat, in the form of friction, will be greatly reduced, increasing the efficiency of our machines. As we mentioned, the majority of our energy consumption, especially transportation, goes into overcoming friction. That is why we put gasoline into our gas tanks, even though it would take almost no energy to move from California to New York if there were no friction. One can imagine that an advanced civilization will be able to perform vastly more tasks with less energy than we use today. This means that we might be able to put numerical limits on the entropy produced by an advanced civilization.

MOST DANGEROUS TRANSITION.

The transition between our current Type 0 civilization and a future Type I civilization is perhaps the greatest transition in history. It will determine whether we will continue to thrive and flourish, or perish due to our own folly. This transition is extremely dangerous because we still have all the barbaric savagery that typified our painful rise from the swamp. Peel back the veneer of civilization, and we still see the forces of fundamentalism, sectarianism, racism, intolerance, etc., at work. Human nature has not changed much in the past 100,000 years, except now we have nuclear, chemical, and biological weapons to settle old scores.

However, once we make the transition to a Type I civilization, we will have many centuries to settle our differences. As we saw in earlier chapters, s.p.a.ce colonies will continue to be extremely expensive into the future, so it is unlikely that a significant fraction of the world's population will leave to colonize Mars or the asteroid belt. Until radically new rocket designs bring down the cost or until the s.p.a.ce elevator is built, s.p.a.ce travel will continue to be the province of governments and the wealthy. For the majority of the earth's population, this means that they will remain on the planet as we attain Type I status. This also means that we will have centuries to work out our differences as a Type I civilization.

THE SEARCH FOR WISDOM.