Physics of the Future_ How Science Will Shape Human Destiny... Part 14

*Greenland's ice shelves shrank by twenty-four square miles in 2007. This figure jumped to seventy-one square miles in 2008. (If all the Greenland ice were somehow to melt, sea levels would rise about twenty feet around the world.) *Large chunks of Antarctica's ice, which have been stable for tens of thousands of years, are gradually breaking off. In 2000, a piece the size of Connecticut broke off, containing 4,200 square miles of ice. In 2002, a piece of ice the size of Rhode Island broke off the Thwaites Glacier. (If all Antarctica's ice were to melt, sea levels would rise about 180 feet around the world.) *For every vertical foot that the ocean rises, the horizontal spread of the ocean is about 100 feet. Already, sea levels have risen 8 inches in the past century, mainly caused by the expansion of seawater as it heats up. According to the United Nations, sea levels could rise by 7 to 23 inches by 2100. Some scientists have said that the UN report was too cautious in interpreting the data. According to scientists at the University of Colorado's Inst.i.tute of Arctic and Alpine Research, by 2100 sea levels could rise by 3 to 6 feet. So gradually the map of the earth's coastlines will change.

*Temperatures started to be reliably recorded in the late 1700s; 1995, 2005, and 2010 ranked among the hottest years ever recorded; 2000 to 2009 was the hottest decade. Likewise, levels of carbon dioxide are rising dramatically. They are at the highest levels in 100,000 years.

*As the earth heats up, tropical diseases are gradually migrating northward. The recent spread of the West Nile virus carried by mosquitoes may be a harbinger of things to come. UN officials are especially concerned about the spread of malaria northward. Usually, the eggs of many harmful insects die every winter when the soil freezes. But with the shortening of the winter season, it means the inexorable spread of dangerous insects northward.

CARBON DIOXIDE-GREENHOUSE GAS

According to the UN's Intergovernmental Panel on Climate Change, scientists have concluded with 90 percent confidence that global warming is driven by human activity, especially the production of carbon dioxide via the burning of oil and coal. Sunlight easily pa.s.ses through carbon dioxide. But as sunlight heats up the earth, it creates infrared radiation, which does not pa.s.s back through carbon dioxide so easily. The energy from sunlight cannot escape back into s.p.a.ce and is trapped.

We also see a somewhat similar effect in greenhouses or cars. The sunlight warms the air, which is prevented from escaping by the gla.s.s.

Ominously, the amount of carbon dioxide generated has grown explosively, especially in the last century. Before the Industrial Revolution, the carbon dioxide content of the air was 270 parts per million (ppm). Today, it has soared to 387 ppm. (In 1900, the world consumed 150 million barrels of oil. In 2000, it jumped to 28 billion barrels, a 185-fold jump. In 2008, 9.4 billion tons of carbon dioxide were sent into the air from fossil fuel burning and also deforestation, but only 5 billion tons were recycled into the oceans, soil, and vegetation. The remainder will stay in the air for decades to come, heating up the earth.) VISIT TO ICELAND.

The rise in temperature is not a fluke, as we can see by a.n.a.lyzing ice cores. By drilling deep into the ancient ice of the Arctic, scientists have been able to extract air bubbles that are thousands of years old. By chemically a.n.a.lyzing the air in these bubbles, scientists can reconstruct the temperature and carbon dioxide content of the atmosphere going back more than 600,000 years. Soon, they will be able to determine the weather conditions going back a million years.

I had a chance to see this firsthand. I once gave a lecture in Reykjavik, the capital of Iceland, and had the privilege of visiting the University of Iceland, where ice cores are being a.n.a.lyzed. When your airplane lands in Reykjavik, at first all you see is snow and jagged rock, resembling the bleak landscape of the moon. Although barren and forbidding, the terrain makes the Arctic an ideal place to a.n.a.lyze the climate of the earth hundreds of thousands of years ago.

When I visited their laboratory, which is kept at freezing temperatures, I had to pa.s.s through thick refrigerator doors. Once inside, I could see racks and racks containing long metal tubes, each about an inch and a half in diameter and about ten feet long. Each hollow tube had been drilled deep into the ice of a glacier. As the tube penetrated the ice, it captured samples from snows that had fallen thousands of years ago. When the tubes were removed, I could carefully examine the icy contents of each. At first, all I could see was a long column of white ice. But upon closer examination, I could see that the ice had stripes made of tiny bands of different colors.

Scientists have to use a variety of techniques to date them. Some of the ice layers contain markers indicating important events, such as the soot emitted from a volcanic eruption. Since the dates of these eruptions are known to great accuracy, one can use them to determine how old that layeris.

These ice cores were then cut in various slices so they could be examined. When I peered into one slice under a microscope, I saw tiny, microscopic bubbles. I shuddered to realize that I was seeing air bubbles that were deposited tens of thousands of years ago, even before the rise of human civilization.

The carbon dioxide content within each air bubble is easily measured. But calculating the temperature of the air when the ice was first deposited is more difficult. (To do this, scientists a.n.a.lyze the water in the bubble. Water molecules can contain different isotopes. As the temperature falls, heavier water isotopes condense faster than ordinary water molecules. Hence, by measuring the amount of the heavier isotopes, one can calculate the temperature at which the water molecule condensed.) Finally, after painfully a.n.a.lyzing the contents of thousands of ice cores, these scientists have come to some important conclusions. They found that temperature and carbon dioxide levels have oscillated in parallel, like two roller coasters moving together, in synchronization over many thousands of years. When one curve rises or falls, so does the other.

Most important, they found a sudden spike in temperature and carbon dioxide content happening just within the last century. This is highly unusual, since most fluctuations occur slowly over millennia. This unusual spike is not part of this natural heating process, scientists claim, but is a direct indicator of human activity.

There are other ways to show that this sudden spike is caused by human activity, and not natural cycles. Computer simulations are now so advanced that we can simulate the temperature of the earth with and without the presence of human activity. Without civilization producing carbon dioxide, we find a relatively flat temperature curve. But with the addition of human activity, we can show that there should be a sudden spike in both temperature and carbon dioxide. The predicted spike fits the actual spike perfectly.

Lastly, one can measure the amount of sunlight that lands on every square foot of the earth's surface. Scientists can also calculate the amount of heat that is reflected into outer s.p.a.ce from the earth. Normally, we expect these two amounts to be equal, with input equaling output. But in reality, we find the net amount of energy that is currently heating the earth. Then if we calculate the amount of energy being produced by human activity, we find a perfect match. Hence, human activity is causing the current heating of the earth.

Unfortunately, even if we were to suddenly stop producing any carbon dioxide, the gas that has already been released into the atmosphere is enough to continue global warming for decades to come.

As a result, by midcentury, the situation could be dire.

Scientists have created pictures of what our coastal cities will look like at midcentury and beyond if sea levels continue to rise. Coastal cities may disappear. Large parts of Manhattan may have to be evacuated, with Wall Street underwater. Governments will have to decide which of their great cities and capitals are worth saving and which are beyond hope. Some cities may be saved via a combination of sophisticated dikes and water gates. Other cities may be deemed hopeless and allowed to vanish under the ocean, creating ma.s.s migrations of people. Since most of the commercial and population centers of the world are next to the ocean, this could have a disastrous effect on the world economy.

Even if some cities can be salvaged, there is still the danger that large storms can send surges of water into a city, paralyzing its infrastructure. For example, in 1992 a huge storm surge flooded Manhattan, paralyzing the subway system and trains to New Jersey. With transportation flooded, the economy grinds to a halt.

FLOODING BANGLADESH AND VIETNAM.

A report by the Intergovernmental Panel on Climate Change isolated three hot spots for potential disaster: Bangladesh, the Mekong Delta of Vietnam, and the Nile Delta in Egypt.

The worst situation is that of Bangladesh, a country regularly flooded by storms even without global warming. Most of the country is flat and at sea level. Although it has made significant gains in the last few decades, it is still one of the poorest nations on earth, with one of the highest population densities. (It has a population of 161 million, comparable to that of Russia, but with 1/120 of the land area.) About 50 percent of the land area will be permanently flooded if sea levels rise by three feet. Natural calamities occur there almost every year, but in September 1998, the world witnessed in horror a preview of what may become commonplace. Ma.s.sive flooding submerged two-thirds of the nation, leaving 30 million people homeless almost overnight; 1,000 were killed, and 6,000 miles of roads were destroyed. This was one of the worst natural disasters in modern history.

Another country that would be devastated by a rise in sea level is Vietnam, where the Mekong Delta is particularly vulnerable. By midcentury, this country of 87 million people could face a collapse of its main food-growing area. Half the rice in Vietnam is grown in the Mekong Delta, home to 17 million people, and much of it will be flooded permanently by rising sea levels. According to the World Bank, 11 percent of the entire population would be displaced if sea levels rise by three feet by midcentury. The Mekong Delta will also be flooded with salt water, permanently destroying the fertile soil of the area. If millions are flooded out of their homes in Vietnam, many will flock to Ho Chi Minh City seeking refuge. But one-fourth of the city will also be underwater.

In 2003 the Pentagon commissioned a study, done by the Global Business Network, that showed that, in a worst-case scenario, chaos could spread around the world due to global warming. As millions of refugees cross national borders, governments could lose all authority and collapse, so countries could descend into the nightmare of looting, rioting, and chaos. In this desperate situation, nations, when faced with the prospect of the influx of millions of desperate people, may resort to nuclear weapons.

"Envision Pakistan, India, and China-all armed with nuclear weapons-skirmis.h.i.+ng at their borders over refugees, access to shared rivers, and arable land," the report said. Peter Schwartz, founder of the Global Business Network and a princ.i.p.al author of the Pentagon study, confided to me the details of this scenario. He told me that the biggest hot spot would be the border between India and Bangladesh. In a major crisis in Bangladesh, up to 160 million people could be driven out of their homes, sparking one of the greatest migrations in human history. Tensions could rapidly rise as borders collapse, local governments are paralyzed, and ma.s.s rioting breaks out. Schwartz sees that nations may use nuclear weapons as a last resort.

In a worst-case scenario, we could have a greenhouse effect that feeds on itself. For example, the melting of the tundra in the Arctic regions may release millions of tons of methane gas from rotting vegetation. Tundra covers nearly 9 million square miles of land in the Northern Hemisphere, containing vegetation frozen since the last Ice Age tens of thousands of years ago. This tundra contains more carbon dioxide and methane than the atmosphere, and this poses an enormous threat to the world's weather. Methane gas, moreover, is a much deadlier greenhouse gas than carbon dioxide. It does not stay in the atmosphere as long, but it causes much more damage than carbon dioxide. The release of so much methane gas from the melting tundra could cause temperatures to rapidly rise, which will cause even more methane gas to be released, causing a runaway cycle of global warming.

TECHNICAL FIXES.

The situation is dire, but we have not yet reached the point of no return. The problem of controlling greenhouse gases is actually largely economic and political, not technical. Carbon dioxide production coincides with economic activity, and hence wealth. For example, the United States generates roughly 25 percent of the world's carbon dioxide. This is because the United States has roughly 25 percent of the world's economic activity. And in 2009, China overtook the United States in creating greenhouse gases, mainly because of the explosive growth of its economy. This is the fundamental reason that nations are so reluctant to deal with global warming: it interferes with economic activity and prosperity.

Various schemes have been devised to deal with this global crisis, but ultimately, a quick fix may not be enough. Only a major s.h.i.+ft in the way we consume energy will solve the problem. Some technical measures have been advocated by serious scientists, but none has won wide acceptance. The proposals include: *Launching pollutants into the atmosphere. One proposal is to send rockets into the upper atmosphere, where they would release pollutants, such as sulfur dioxide, in order to reflect sunlight into s.p.a.ce, thereby cooling the earth. In fact, n.o.bel laureate Paul Crutzen has advocated shooting pollution into s.p.a.ce as a "doomsday device," providing one final escape route for humanity to stop global warming. This idea has its roots in 1991, when scientists carefully monitored the huge volcanic explosion of Mount Pinatubo in the Philippines, which lofted 10 billion metric tons of dirt and debris into the upper atmosphere. This darkened the skies and caused the average temperature around the earth to drop by 1 F. This made it possible to calculate how much pollutants would be necessary to reduce the world temperature. Although this is a serious proposal, some critics doubt that it can solve the problem by itself. Little is known about how a huge quant.i.ty of pollutants will affect the world temperature. Maybe the benefits will be short-lived, or the unintended side effects may be worse than the original problem. For example, there was a sudden drop in global precipitation after the Mount Pinatubo eruption; if the experiment goes awry, it could similarly cause ma.s.sive droughts. Cost estimates show that $100 million would be required to conduct field tests. Since the effect of the sulfate aerosols is temporary, it would cost a minimum of $8 billion per year to regularly inject ma.s.sive amounts of them into the atmosphere. One proposal is to send rockets into the upper atmosphere, where they would release pollutants, such as sulfur dioxide, in order to reflect sunlight into s.p.a.ce, thereby cooling the earth. In fact, n.o.bel laureate Paul Crutzen has advocated shooting pollution into s.p.a.ce as a "doomsday device," providing one final escape route for humanity to stop global warming. This idea has its roots in 1991, when scientists carefully monitored the huge volcanic explosion of Mount Pinatubo in the Philippines, which lofted 10 billion metric tons of dirt and debris into the upper atmosphere. This darkened the skies and caused the average temperature around the earth to drop by 1 F. This made it possible to calculate how much pollutants would be necessary to reduce the world temperature. Although this is a serious proposal, some critics doubt that it can solve the problem by itself. Little is known about how a huge quant.i.ty of pollutants will affect the world temperature. Maybe the benefits will be short-lived, or the unintended side effects may be worse than the original problem. For example, there was a sudden drop in global precipitation after the Mount Pinatubo eruption; if the experiment goes awry, it could similarly cause ma.s.sive droughts. Cost estimates show that $100 million would be required to conduct field tests. Since the effect of the sulfate aerosols is temporary, it would cost a minimum of $8 billion per year to regularly inject ma.s.sive amounts of them into the atmosphere.

*Creating algae blooms. Another suggestion is to dump iron-based chemicals into the oceans. These mineral nutrients will cause algae to thrive in the ocean, which in turn will increase the amount of carbon dioxide that is absorbed by the algae. However, after Planktos, a corporation based in California, announced that it would unilaterally begin a private effort to fertilize part of the South Atlantic with iron-hoping to deliberately sp.a.w.n plankton blooms that would absorb the carbon dioxide in the air-countries bound by the London Convention, which regulates dumping at sea, issued a "statement of concern" about this effort. Also, a United Nations group called for a temporary moratorium on such experiments. The experiment was ended when Planktos ran out of funds. Another suggestion is to dump iron-based chemicals into the oceans. These mineral nutrients will cause algae to thrive in the ocean, which in turn will increase the amount of carbon dioxide that is absorbed by the algae. However, after Planktos, a corporation based in California, announced that it would unilaterally begin a private effort to fertilize part of the South Atlantic with iron-hoping to deliberately sp.a.w.n plankton blooms that would absorb the carbon dioxide in the air-countries bound by the London Convention, which regulates dumping at sea, issued a "statement of concern" about this effort. Also, a United Nations group called for a temporary moratorium on such experiments. The experiment was ended when Planktos ran out of funds.

*Carbon sequestration. Yet another possibility is to use carbon sequestration, a process by which the carbon dioxide emitted from coal-burning power plants is liquefied and then separated from the environment, perhaps by being buried underground. Although this might work in principle, it is a very expensive process, and it cannot remove the carbon dioxide that has already been lofted into the atmosphere. In 2009, engineers were carefully monitoring the first major test of carbon sequestration. The huge Mountaineer power plant, built in 1980 in West Virginia, was retrofitted to separate carbon dioxide from the environment, making it the United States' first electricity-generating coal-burning plant to experiment with sequestration. The liquefied gas will be injected 7,800 feet underground, eventually into a layer of dolomite. The liquid will eventually form a ma.s.s thirty to forty feet high and hundreds of yards long. The plant's owner, American Electric Power, plans to inject 100,000 tons of carbon dioxide annually for two to five years. This is only 1.5 percent of the plant's yearly emission, but eventually the system could capture up to 90 percent. The initial costs are about $73 million. But if it's successful, then this model could rapidly be disseminated to other sites such as four nearby giant coal-burning plants generating 6 billion watts of energy (so much that this area is dubbed Megawatt Valley). There are large unknowns: it is not clear if the carbon dioxide will eventually migrate or if the gas will combine with water, perhaps creating carbonic acid that may poison groundwater. However, if the project is a success, it may very well be part of a mix of technologies used to deal with global warming. Yet another possibility is to use carbon sequestration, a process by which the carbon dioxide emitted from coal-burning power plants is liquefied and then separated from the environment, perhaps by being buried underground. Although this might work in principle, it is a very expensive process, and it cannot remove the carbon dioxide that has already been lofted into the atmosphere. In 2009, engineers were carefully monitoring the first major test of carbon sequestration. The huge Mountaineer power plant, built in 1980 in West Virginia, was retrofitted to separate carbon dioxide from the environment, making it the United States' first electricity-generating coal-burning plant to experiment with sequestration. The liquefied gas will be injected 7,800 feet underground, eventually into a layer of dolomite. The liquid will eventually form a ma.s.s thirty to forty feet high and hundreds of yards long. The plant's owner, American Electric Power, plans to inject 100,000 tons of carbon dioxide annually for two to five years. This is only 1.5 percent of the plant's yearly emission, but eventually the system could capture up to 90 percent. The initial costs are about $73 million. But if it's successful, then this model could rapidly be disseminated to other sites such as four nearby giant coal-burning plants generating 6 billion watts of energy (so much that this area is dubbed Megawatt Valley). There are large unknowns: it is not clear if the carbon dioxide will eventually migrate or if the gas will combine with water, perhaps creating carbonic acid that may poison groundwater. However, if the project is a success, it may very well be part of a mix of technologies used to deal with global warming.

*Genetic engineering. Another proposal is to use genetic engineering to specifically create life-forms that can absorb large quant.i.ties of carbon dioxide. One enthusiastic promoter of this approach is J. Craig Venter, who gained fame and fortune pioneering high-speed techniques that successfully led to sequencing the human genome years ahead of schedule. "We view the genome as the software, or even the operating system, of the cell," he says. His goal is to rewrite that software, so that microbes can be genetically modified, or even constructed almost from scratch, so that they absorb the carbon dioxide from coal-burning plants and convert it into useful substances, such as natural gas. He notes, "There are already thousands, perhaps millions, of organisms on our planet that know how to do this." The trick is to modify them so that they can increase their output and also flourish in a coal-fired plant. "We think this field has tremendous potential to replace the petrochemical industry, possibly within a decade," he said optimistically. Another proposal is to use genetic engineering to specifically create life-forms that can absorb large quant.i.ties of carbon dioxide. One enthusiastic promoter of this approach is J. Craig Venter, who gained fame and fortune pioneering high-speed techniques that successfully led to sequencing the human genome years ahead of schedule. "We view the genome as the software, or even the operating system, of the cell," he says. His goal is to rewrite that software, so that microbes can be genetically modified, or even constructed almost from scratch, so that they absorb the carbon dioxide from coal-burning plants and convert it into useful substances, such as natural gas. He notes, "There are already thousands, perhaps millions, of organisms on our planet that know how to do this." The trick is to modify them so that they can increase their output and also flourish in a coal-fired plant. "We think this field has tremendous potential to replace the petrochemical industry, possibly within a decade," he said optimistically.

Princeton physicist Freeman Dyson has advocated another variation, creating a genetically engineered variety of trees that would be adept at absorbing carbon dioxide. He has stated that perhaps a trillion such trees might be enough to control the carbon dioxide in the air. In his paper "Can We Control the Carbon Dioxide in the Atmosphere?" he advocated creating a "carbon bank" of "fast-growing trees" to regulate carbon dioxide levels.

However, as with any plan to use genetic engineering on a large scale, one must be careful about side effects. One cannot recall a life-form in the same way that we can recall a defective car. Once it is released into the environment, the genetically engineered life-form may have unintended consequences for other life-forms, especially if it displaces local species of plants and upsets the balance of the food chain.

Sadly, there has been a conspicuous lack of interest among politicians to fund any of these plans. However, one day, global warming will become so painful and disruptive that politicians will be forced to implement some of them.

The critical period will be the next few decades. By midcentury, we should be in the hydrogen age, where a combination of fusion, solar power, and renewables should give us an economy that is much less dependent on fossil fuel consumption. A combination of market forces and advances in hydrogen technology should give us a long-term solution to global warming. The danger period is now, before a hydrogen economy is in place. In the short term, fossil fuels are still the cheapest way to generate power, and hence global warming will pose a danger for decades to come.

FUSION POWER.

By midcentury, a new option arises that is a game changer: fusion. By that time, it should be the most viable of all technical fixes, perhaps giving us a permanent solution to the problem. While fission power relies on splitting the uranium atom, thereby creating energy (and a large amount of nuclear waste), fusion power relies on fusing hydrogen atoms with great heat, thereby releasing vastly more energy (with very little waste).

Unlike fission power, fusion power unleashes the nuclear energy of the sun. Buried deep inside the hydrogen atom is the energy source of the universe. Fusion power lights up the sun and the heavens. It is the secret of the stars. Anyone who can successfully master fusion power will have unleashed unlimited eternal energy. And the fuel for these fusion plants comes from ordinary seawater. Pound for pound, fusion releases 10 million times more energy than gasoline. An 8-ounce gla.s.s of water is equal to the energy content of 500,000 barrels of petroleum.

Fusion (not fission) is nature's preferred way to energize the universe. In star formation, a hydrogen-rich ball of gas is gradually compressed by gravity, until it starts to heat up to enormous temperatures. When the gas reaches around 50 million degrees or so (which varies depending on the specific conditions), the hydrogen nuclei inside the gas are slammed into one another, until they fuse to form helium. In the process, vast amounts of energy are released, which causes the gas to ignite. (More precisely, the compression must satisfy something called Lawson's criterion, which states that you have to compress hydrogen gas of a certain density to a certain temperature for a certain amount of time. If these three conditions involving density, temperature, and time are met, you have a fusion reaction, whether it is a hydrogen bomb, a star, or a fusion in a reactor.) So that is the key: heating and compressing hydrogen gas until the nuclei fuse, releasing cosmic amounts of energy.

But previous attempts to harness this cosmic power have failed. It is a fiendishly difficult task to heat hydrogen gas to tens of millions of degrees, until the protons fuse to form helium gas and release vast amounts of energy.

Moreover, the public is cynical about these claims, since every twenty years scientists claim that fusion power is twenty years away. But after decades of overoptimistic claims, physicists are increasingly convinced that fusion power is finally arriving, perhaps as early as 2030. Sometime by midcentury, we may see fusion plants dotting the countryside.

The public has a right to be skeptical about fusion, since there have been so many hoaxes, frauds, and failures in the past. Back in 1951, when the United States and the Soviet Union were gripped in Cold War frenzy and were feverishly developing the first hydrogen bomb, President Juan Peron of Argentina announced, with huge fanfare and a media blitz, that his country's scientists had made a breakthrough in controlling the power of the sun. The story sparked a firestorm of publicity. It seemed unbelievable, yet it made the front page of the New York Times. New York Times. Argentina, boasted Peron, had scored a major scientific breakthrough where the superpowers had failed. An unknown German-speaking scientist, Ronald Richter, had convinced Peron to fund his "thermotron," which promised unlimited energy and eternal glory for Argentina. Argentina, boasted Peron, had scored a major scientific breakthrough where the superpowers had failed. An unknown German-speaking scientist, Ronald Richter, had convinced Peron to fund his "thermotron," which promised unlimited energy and eternal glory for Argentina.

The American scientific community, which was still grappling with fusion in the fierce race with Russia to produce the H-bomb, declared that the claim was nonsense. Atomic scientist Ralph Lapp said, "I know what the other material is that the Argentines are using. It's baloney."

The press quickly dubbed it the Baloney Bomb. Atomic scientist David Lilienthal was asked if there was the "slightest chance" the Argentines could be correct. He shot back, "Less than that."

Under intense pressure, Peron simply dug in his heels, hinting that the superpowers were jealous that Argentina had scooped them. The moment of truth finally came the next year, when Peron's representatives visited Richter's lab. Under fire, Richter was acting increasingly erratic and bizarre. When inspectors arrived, he blew the laboratory door off using tanks of oxygen and then scribbled on a piece of paper the words "atomic energy." He ordered gunpowder to be injected into the reactor. The verdict was that he was probably insane. When inspectors placed a piece of radium next to Richter's "radiation counters," nothing happened, so clearly his equipment was fraudulent. Richter was later arrested.

But the most celebrated case was that of Stanley Pons and Martin Fleischmann, two well-respected chemists from the University of Utah who in 1989 claimed to have mastered "cold fusion," that is, fusion at room temperature. They claimed to have placed palladium metal in water, which then somehow magically compressed hydrogen atoms until they fused into helium, releasing the power of the sun on a tabletop.

The shock was immediate. Almost every newspaper in the world put this discovery on its front page. Overnight, journalists talked of ending the energy crisis and ushering in a new age of unlimited energy. A feeding frenzy hit the world media. The state of Utah immediately pa.s.sed a $5 million bill to create a National Inst.i.tute for Cold Fusion. Even j.a.panese car manufacturers began to donate millions of dollars to promote research in this hot new field. A cultlike following began to emerge based around cold fusion.

Unlike Richter, Pons and Fleischmann were well respected in the scientific community and were glad to share their results with others. They carefully laid out their equipment and their data for the world to see.

But then things got complicated. Since the apparatus was so simple, groups around the world tried to duplicate these astonis.h.i.+ng results. Unfortunately, most groups failed to find any net release of energy, declaring cold fusion a dead end. However, the story was kept alive because there were sporadic claims that certain groups had successfully duplicated the experiment.

Finally, the physics community weighed in. They a.n.a.lyzed Pons and Fleischmann's equations, and found them deficient. First, if their claims were correct, a blistering barrage of neutrons would have radiated from the gla.s.s of water, killing Pons and Fleischmann. (In a typical fusion reaction, two hydrogen nuclei are slammed together and fuse, creating energy, a helium nuclei, and also a neutron.) So the fact that Pons and Fleischmann were still alive meant the experiment hadn't worked. If their experiments had produced cold fusion, they would be dying of radiation burns. Second, more than likely Pons and Fleischmann had found a chemical reaction rather than a thermonuclear reaction. And last, the physicists concluded, palladium metal cannot bind hydrogen atoms closely enough to cause the hydrogen to fuse into helium. It would violate the laws of the quantum theory.

But the controversy has not died down, even today. There are still occasional claims that someone has achieved cold fusion. The problem is that no one has been able to reliably attain cold fusion on demand. After all, what is the point of making an automobile engine if it works only occasionally? Science is based on reproducible, testable, and falsifiable results that work every time.

HOT FUSION.

But the advantages of fusion power are so great that many scientists have heeded its siren call.

For example, fusion creates minimal pollution. It is relatively clean, and is nature's way of energizing the universe. One by-product of fusion is helium gas, which is actually commercially valuable. Another is the radioactive steel of the fusion chamber, which eventually has to be buried. It is mildly dangerous only for a few decades. But a fusion plant produces an insignificant amount of nuclear waste compared to a standard uranium fission plant (which produces thirty tons of high-level nuclear waste per year that lasts for thousands to tens of millions of years).

Also, fusion plants cannot suffer a catastrophic meltdown. Uranium fission plants, precisely because they contain tons of high-level nuclear waste in their core, produce volatile amounts of heat even after shutdown. It is this residual heat that can eventually melt the solid steel and enter the groundwater, creating a steam explosion and the nightmare of the China Syndrome accident.

Fusion plants are inherently safer. A "fusion meltdown" is a contradiction in terms. For example, if one were to shut down a fusion reactor's magnetic field, the hot plasma would hit the walls of the chamber and the fusion process would stop immediately. So a fusion plant, instead of undergoing a runaway chain reaction, spontaneously turns itself off in case of an accident.

"Even if the plant were flattened, the radiation level one kilometer outside the fence would be so small that evacuation would not be necessary," says Farrokh Najmabadi, who directs the Center for Energy Research at the University of California at San Diego.

Although commercial fusion power has all these marvelous advantages, there is still one small detail: it doesn't exist. No one has yet produced an operating fusion plant.

But physicists are cautiously optimistic. "A decade ago, some scientists questioned whether fusion was possible, even in the lab. We now know that fusion will work. The question is whether it is economically practical," says David E. Baldwin of General Atomics, who oversees one of the largest fusion reactors in the United States, the DIII-D.

NIF-FUSION BY LASER

All this could change rather dramatically in the next few years.

Several approaches are being tried simultaneously, and after decades of false starts, physicists are convinced that they will finally attain fusion. In France, there is the International Thermonuclear Experimental Reactor (ITER), backed by many European nations, the United States, j.a.pan, and others. And in the United States, there is the National Ignition Facility (NIF).

I had a chance to visit the NIF laser fusion machine, and it is a colossal sight. Because of the close connection with hydrogen bombs, the NIF reactor is based at the Lawrence Livermore National Laboratory, where the military designs hydrogen warheads. I had to pa.s.s through many layers of security to finally gain access.

But when I reached the reactor, it was a truly awesome experience. I am used to seeing lasers in university laboratories (in fact, one of the largest laser laboratories in New York State is directly beneath my office at the City University of New York), but seeing the NIF facility was overwhelming. It is housed in a ten-story building the size of three football fields, with 192 giant laser beams being fired down a long tunnel. It is the largest laser system in the world, delivering sixty times more energy than any previous one.

After these laser beams are fired down this long tunnel, they eventually hit an array of mirrors that focus each beam onto a tiny pinhead-size target, consisting of deuterium and tritium (two isotopes of hydrogen). Incredibly, 500 trillion watts of laser power are focused onto a tiny pellet that is barely visible to the naked eye, scorching it to 100 million degrees, much hotter than the center of the sun. (The energy of that colossal pulse is equivalent to the output of half a million nuclear power plants in a brief instant.) The surface of this microscopic pellet is quickly vaporized, which unleashes a shock wave that collapses the pellet and unleashes the power of fusion.

It was completed in 2009, and is currently undergoing tests. If all goes well, it may be the first machine to create as much energy as it consumes. Although this machine is not designed to produce commercial electrical power, it is designed to show that laser beams can be focused to heat hydrogen-rich materials and produce net energy.

I talked to one of the directors of the NIF facility, Edward Moses, about his hopes and dreams for his project. Wearing a hard hat, he looked more like a construction worker than a top nuclear physicist in charge of the largest laser lab in the world. He admitted to me that in the past there have been numerous false starts. But this, he believed, was the real thing: he and his team were about to realize an important achievement, one that will enter the history books, the first to peacefully capture the power of the sun on earth. Talking to him, you realize how projects like NIF are kept alive by the pa.s.sion and energy of their true believers. He savored the day, he told me, when he could invite the president of the United States to this laboratory to announce that history had just been made.

But from the beginning, NIF got off to a bad start. (Even strange things have happened, such as when the previous a.s.sociate director of NIF, E.Michael Campbell, was forced to resign in 1999 when it was revealed that he lied about completing a Ph.D. at Princeton.) Then the completion date, originally set for 2003, began to slip. Costs ballooned, from $1 billion to $4billion. It was finally finished in March 2009, six years late.

The devil, they say, is in the details. In laser fusion, for example, these 192 laser beams have to hit the surface of a tiny pellet with utmost precision, so that it implodes evenly. The beams must hit this tiny target to within 30 trillionths of a second of one another. The slightest misalignment of the laser beams or irregularity of the pellet means that the pellet will heat unsymmetrically, causing it to blow out to one side rather than implode spherically.

If the pellet is irregular by more than 50 nanometers (or about 150 atoms), the pellet will also fail to implode evenly. (That is like trying to throw a baseball within the strike zone from a distance of 350 miles.) So alignment of the laser beams and evenness of the pellet are the main problems facing laser fusion.

In addition to NIF, the European Union is backing its own version of laser fusion. The reactor will be built at the High Power Laser Energy Research Facility (HiPER), and it is smaller but perhaps more efficient than NIF. Construction for HiPER starts in 2011.

The hopes of many ride on NIF. However, if laser fusion does not work as expected, there is another, even more advanced proposal for controlled fusion: putting the sun in a bottle.

ITER-FUSION IN A MAGNETIC FIELD

Yet another design is being exploited in France. The International Thermonuclear Experimental Reactor (ITER) uses huge magnetic fields to contain hot hydrogen gas. Instead of using lasers to instantly collapse a tiny pellet of hydrogen-rich material, ITER uses a magnetic field to slowly compress hydrogen gas. The machine looks very much like a huge hollow doughnut made of steel, with magnetic coils surrounding the hole of the doughnut. The magnetic field keeps the hydrogen gas inside the doughnut-shaped chamber from escaping. Then an electrical current is sent surging through the gas, heating it. The combination of squeezing the gas with the magnetic field and sending a current surging through it causes the gas to heat up to many millions of degrees.

The idea of using a "magnetic bottle" to create fusion is not new. It goes back to the 1950s, in fact. But why has it taken so long, with so many delays, to commercialize fusion power?

The problem is that the magnetic field has to be precisely tuned so that the gas is compressed evenly without bulging or becoming irregular. Think of taking a balloon and trying to compress it with your hands so that the balloon is evenly compressed. You will find that the balloon bulges out from the gaps between your hands, making a uniform compression almost impossible. So the problem is instability and is not one of physics but of engineering.

This seems strange, because stars easily compress hydrogen gas, creating the trillions of stars we see in our universe. Nature, it seems, effortlessly creates stars in the heavens, so why can't we do it on earth? The answer speaks to a simple but profound difference between gravity and electromagnetism.

Gravity, as shown by Newton, is strictly attractive. So in a star, the gravity of the hydrogen gas compresses it evenly into a sphere. (That is why stars and planets are spherical and not cubical or triangular.) But electrical charges come in two types: positive and negative. If one collects a ball of negative charges, they repel each other and scatter in all directions. But if one brings a positive and negative charge together, you get what is called a "dipole," with a complicated set of electrical field lines resembling a spider web. Similarly, magnetic fields form a dipole; hence squeezing hot gas evenly inside a doughnut-shaped chamber is a fiendishly difficult task. It takes a supercomputer, in fact, to plot the magnetic and electric fields emanating from a simple configuration of electrons.