Armageddon Science (26 page)

The only way vril would later be remembered would be in the name of a popular British hot drink made from meat extract called Bovril, while Bulwer-Lytton is now best known as the author of the book that inspired cartoon character Snoopy’s fictional efforts. Bulwer-Lytton’s novel
Paul Clifford
is generally considered to have the worst opening passage of any book in history. It begins, “It was a dark and stormy night; the rain fell in torrents—except at occasional intervals, when it was checked by a violent gust of wind which swept up the streets (for it is London that our scene lies)…,” and Bulwer-Lytton’s name is now given to a contest for producing the worst opening line for a hypothetical novel.

The real death ray—or at least a beam of light that is capable of killing—emerged accidentally when a pair of Russian scientists were investigating the behavior of the pungent gas ammonia, in 1954. Some thirty-seven years earlier, Einstein had predicted that it would be possible to set off a kind of chain reaction producing light, which he described as stimulated emission.

According to Einstein’s theory, an electron in an atom can be pushed into a high-energy state when it is hit by a photon, leaving it like a bucket of water sitting over an open door. Another photon, hitting that electron, would not only be re-emitted itself, but would trigger the electron to release the stored-up energy as a second photon—as if the bucket was knocked off the door by the stream of water from a hose, resulting in a doubled downpour of water.

Nikolay Basov and Alexander Prokhorov found that photons of light of the right energy, in the nonvisible microwave region, triggered the release of further photons from ammonia. Generated in a sealed chamber, those photons could themselves stimulate yet more photons, a pyramid selling approach to producing light, not unlike a nuclear chain reaction. The result was something quite different from a conventional source of light. Because of the way they were stimulated, the light waves moved together, synchronized in their phase. It was the mechanism behind the device, amplifying the initial weak source of microwave photons, that led to its being described as microwave amplification by the stimulated emission of radiation—a “maser” for short.

By 1960, the American Theodore Harold Maiman had developed an equivalent device that worked with visible light. The concept had been the subject of a patent battle between American physicist Arthur Leonard Schawlow and another American, Gordon Gould. Gould was eventually recognized as the theoretical originator of the visible maser that Maiman was to build. Gould called his concept a laser, replacing the “microwave” in maser with “light.”

Unlike the ammonia in the maser, Maiman’s device contained a solid substance to produce the stimulated emission, a ruby, giving out a deep red light. The light was stimulated using a flash tube like a huge photographic flash unit. Inside the ruby, the light passed backward and forward, hitting mirrors at either end, each time stimulating more photons as the beam flashed back and forth. One mirror was only partly silvered, allowing part of the beam to escape while some remained in the system.

Because of the way that laser light is produced it is entirely different from the rays of the Sun or a lightbulb. The laser is a very powerful beam of light of a single color that is not easily scattered and dispersed as ordinary light is. A laser beam can be bounced off the Moon and will still return as a tight ray. And a beam of sufficient power can cut metal, bring down aircraft, and kill humans in good James Bond fashion.

While it’s true that a laser has the potential to be a death ray, the key phrase there is “sufficient power.” It takes a lot of energy to push out a laser that will do significant physical damage, so much so that we are unlikely ever to see vast lasers vaporizing whole cities. But with other unknown weapons they remain part of that classic sci-fi threat, the alien invasion. Is there any possibility this could become a reality? Could we be wiped out by UFOs?

For this to happen, we need to find some aliens—and that is a search that has proved surprisingly hard. It’s said that Enrico Fermi, whom we last met developing the first nuclear reactor in Chicago, was once seated in the canteen at Los Alamos in the 1950s with three other physicists. Talk turned to UFOs, or “flying saucers” as they had just become popularly known. Fermi suddenly said, after some thought, “Where is everybody?”

He was reflecting on the lack of alien visitors. It might seem from all that has been said and written about UFOs and alien abductions that this was a silly question, as the truth (as the
X-Files
has it) is out there. Yet all the evidence is that the vast bulk of reported alien visitations have been misunderstandings or pure fantasy. It’s telling that when the term “flying saucer” was first used, it was meant to describe how the craft moved (the way a saucer moves when it’s skipped across water), rather than the shape of the ship. All the sightings since of saucer-shaped spacecraft seem to have been imaginings based on this misunderstanding.

The reason scientists like Fermi are surprised by the lack of alien visitors landing on the White House lawn is not because of all the dubious UFO sightings, but rather because of the sheer number of stars in the universe. It seems very likely that a universe on the scale we know ours to be should have many planets supporting life, some of which, we would expect, would have civilizations more technologically advanced than ours. Theories for the lack of contact break down into three broad categories: the aliens aren’t there, they haven’t found us, or they have found us but choose not to be seen.

Each of these ideas has its appeal. It is certainly true that the circumstances for life on Earth are quite specific, and it may just be that there are very few planets where life has developed beyond the scale of bacteria—perhaps just one in our galaxy. (The scale of space is such that it’s quite possible for other galaxies to be teeming with life without anyone ever reaching us in the Milky Way.) But scientists are wary of anything that suggests a special place for the Earth, when there is no good reason for it to have that special treatment. Of course, if there were only one planet with life, then it would be bound, by definition, to be the planet on which the inhabitants were thinking “Why us?”—but it still seems unlikely.

The size of the universe suggests the second possibility. It could be that there is plenty of life out there, but there is so much space that with the fundamental physical limit of not being able to travel faster than light, the aliens just haven’t arrived yet. After all, there are plenty of parts of the oceans on the Earth that we haven’t got around to visiting, and by comparison with space, the oceans are tiny. Perhaps the majority of space will never be visited by living beings. The only problem with this idea is that in such a scenario, there could still be some alien races that had managed to build self-replicating probes.

These devices, rather like the nanobots in chapter 6, would be capable of duplicating themselves from the raw materials they found around them. A probe would travel to a planet, duplicate itself perhaps many times, and then the new probes would fly off to more planets, spreading through a galaxy below the speed of light, but still using the power of doubling to quickly take in more and more of the galaxy. However, the probes would have had to start out many thousands of years ago to have spread far across the galaxy, and it’s entirely possible that if one did visit the Earth, it wouldn’t arrive in the tiny window in the Earth’s lifetime when human beings would have been around to notice it.

The final possibility is that aliens know we’re here but don’t want us to be aware of them. Perhaps they have cloaking technology to be able to move among us unseen. Perhaps they have some kind of noninterference directive, or simply regard us as too unpleasant or inferior to mix with.

If either the second or the third case holds true, we could still at some point encounter aliens—and it’s possible that like the aliens of so many B movies, they will prove unfriendly and will want to exterminate us. Equally, they could have friendly intentions. But in either case, given the lack of evidence to date, I’m not holding my breath waiting for alien invaders.

Those imagined probes could themselves prove dangerous to the human race, if they carried some kind of interstellar plague, or destroyed life on Earth in the process of replicating themselves—and they aren’t the only kind of killer machines that science fiction has dreamed up.

Over the years we have increasingly put our day-to-day lives in the hands of machines, and a number of writers have considered what might happen if the machines decided it was time for them to run things. The movie series
Terminator
is based on this premise, one that has a noble lineage in written science fiction. In some stories it’s the computers that take over. If computers reach the stage that they are truly thinking devices and consider themselves superior to us, will they leave us here, or throw us away?

This is a rather different picture from the Singularity, where machines and men come together to form a new species. The “rule of the machines” idea is rather that our everyday devices, from cars to air-conditioning plants, are becoming more and more intelligent as we incorporate more computing power in them. All the machines around us could gradually come to regard the human race as an inconvenience, or as something that is best looked after by keeping it docile—turning human beings into something close to pets.

I don’t think we have a lot to worry about here yet. Just as was the case with robots and cyborgs, self-aware computers are probably further away than most technology enthusiasts predict, and we are generally quite good at building machines with sufficient built-in safety that they are unlikely to cause mass destruction, even if a few were to become rogues.

Other science-fiction disasters of the future have concentrated on the loss of vital resources. Water is one case of this. As we’ve seen in the chapter on climate change, we could face terrible water shortages in the future, but one science-fiction writer came up with a very different water-based threat to our survival. He imagined that we might lose our liquid water altogether. Liquid water is an essential for life, and the fact that it exists at all at the temperatures we need for life is due to a strange behavior of the water molecule. Water molecules are attracted to one another like little magnets, with the positively charged hydrogen being attracted to the negative oxygen in a different molecule. (This kind of attraction is called a hydrogen bond.)

The effect of this bond is that water molecules stick together more than you might expect. This makes water boil at a higher temperature than it would otherwise. Much higher. Water boils at 100 degrees Celsius (212 degrees Fahrenheit) at sea level. (The boiling point falls as air pressure drops, and it rises with higher pressure, which is how pressure cookers work. The increased pressure in a pressure cooker means the cooking takes place above 100 degrees Celsius.) If it weren’t for hydrogen bonding, the boiling point of water would be well below -70 degrees Celsius (-90 degrees Fahrenheit). Water just wouldn’t exist as a liquid on the Earth—and no water means no life.

The means Kurt Vonnegut devised to take away our water was to take something like hydrogen bonding even further. He imagined a special form of ice called Ice Nine that was so stable that it melted at only 45 degrees Celsius (114 degrees Fahrenheit). For most of the planet, water would be a permanent solid. Should a seed crystal of Ice Nine be dropped into a lake or an ocean it would spread uncontrollably from shore to shore, locking up the water supply and devastating the Earth.

Luckily, Ice Nine doesn’t exist (though it is a wonderful concept), although there is a type of ice that forms at very low temperatures with the intentionally similar name of Ice IX. This, however, isn’t stable at room temperatures, and presents no danger to our water supply or our survival.

However, ice has certainly put species at risk in the past. At one time, the Earth was largely tropical, but prior to the current spate of global warming, the general trend in temperatures on the planet had been downward for millions of years. The main influence for the underlying trend can be traced back to a geological event over 50 million years ago, when the tectonic plate supporting India ground its way into the Asian plate.

The result was a gradual change in the landscape as the Himalayan mountain range and the Tibetan plateau were brought into existence, thrusting higher and higher until they towered more than two miles above sea level. This is a big geological structure, covering the same area as about half of the United States. It was to have a major impact on the climate. The new structure interfered with the jet stream, the fast-flowing bands of air that circle the globe in the upper atmosphere.

Part of the impact was to change rainfall patterns, increasing the tendency to monsoon rains in the area. And, remarkably, the uplift of the Tibetan plateau also resulted in a kind of reverse of our current problems with climate change. Reactions of the rainfall on the rocks caused carbon dioxide to be taken out of the atmosphere. This reduced the greenhouse effect, lowering temperatures.

The overall trend of cooling that came from this vast geological event pushed the natural temperature cycles the world goes through below a freezing threshold. Over time, the Earth undergoes cyclical changes in its orbit, its rotation, and the degree to which it tilts. Bearing in mind just how much difference there is between winter and summer, brought on solely by the tilt of the Earth, it is hardly surprising that with the push downward in temperature caused by the geological changes, the temperature cycles could produce a terrifying result: the ice ages.

This isn’t a new phenomenon. There have been many ice ages when ice sheets covered a major proportion of the Earth, but the most recent one, which we are technically still in, lasting around 2.5 million years, is the one that we know most about. During the worst of these so-called glacial periods, of which there have been around eighty during this ice age, driven by those tilts and wobbles in the Earth’s path, sheets of ice have advanced to cover North America and Europe, making much of our present-day world uninhabitable.