Physics of the Future: How Science Will Shape Human Destiny and Our Daily Lives by the Year 2100

beam that is extremely fine-tuned, you can knock out electrons from the shell of uranium 235 but not from that of uranium 238. Once the uranium 235 atoms are ionized, they can be easily separated from uranium 238 by an electric field.
    But the difference in energy between the two isotopes is so small that many nations have tried to exploit this fact and have failed. In the 1980s and 1990s, the United States, France, Britain, Germany, South Africa, and Japan attempted to master this difficult technology and were unsuccessful. In the United States, one attempt actually involved 500 scientists and $2 billion.
    But in 2006, Australian scientists announced that not only have they solved the problem, they intend to commercialize it. Since 30 percent of the cost of uranium fuel comes from the enrichment process, the Australian company Silex thinks there could be a market for this technology. Silex even signed a contract with General Electric to begin commercialization. Eventually, they hope to produce up to one-third of the world’s uranium using this method. In 2008, GE Hitachi Nuclear Energy announced plans to build the first commercial laser enrichment plant in Wilmington, North Carolina, by 2012. The plant will occupy 200 acres of a 1,600-acre site.
    For the nuclear power industry, this is good news, since it will drive down the cost of enriched uranium over the next few years. However, others are worried because it is only a matter of time before this technology proliferates into unstable regions of the world. In other words, we have a window of opportunity to sign treaties to restrict and regulate the flow of enriched uranium. Unless we control this technology, the bomb will continue to proliferate, perhaps even to terrorist groups.
    One of my acquaintances was the late Theodore Taylor, who had the rare distinction of designing some of the biggest and smallest nuclear warheads for the Pentagon. One of his designs was the Davy Crockett, weighing only fifty pounds, but capable of hurling a small atomic bomb at the enemy. Taylor was such a gung ho advocate of nuclear bombs that heworked on the Orion project, which was to use nuclear bombs to propel a spaceship to the nearby stars. He calculated that by successively dropping nuclear bombs out the end, the resulting shock wave would propel such a spacecraft to near the speed of light.
    I once asked him why he got disillusioned with designing nuclear bombs and switched to working on solar energy. He confided to me that he had a recurring nightmare. His work on nuclear weapons, he felt, was leading to one thing: producing third-generation atomic warheads. (First-generation warheads of the 1950s were huge and difficult to carry to their targets. Second-generation warheads of the 1970s were small, compact, and ten of them could fit into the nose cone of a missile. But third-generation bombs are “designer bombs,” specifically tailored to work in various environments, such as the forest, the desert, even outer space.) One of these third-generation bombs is a miniature atomic bomb, so small that a terrorist could carry it in a suitcase and use it to destroy an entire city. The idea that his life’s work could one day be used by a terrorist haunted him for the rest of his life.

MIDCENTURY (2030 TO 2070)
    GLOBAL WARMING
    By midcentury, the full impact of a fossil fuel economy should be in full swing: global warming. It is now indisputable that the earth is heating up. Within the last century, the earth’s temperature rose 1.3° F, and the pace is accelerating. The signs are unmistakable everywhere we look:
     
    • The thickness of Arctic ice has decreased by an astonishing 50 percent in just the past fifty years. Much of this Arctic ice is just below the freezing point, floating on water. Hence, it is acutely sensitive to small temperature variations of the oceans, acting as a canary in a mineshaft, an early warning system. Today, parts of the northern polar ice caps disappear during the summer months, and may disappear entirely during summer as early as 2015. The polar ice cap may vanish permanently by the end of the century, disrupting the world’s weather by altering the flow of ocean and air currents around the planet.
    • 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.)
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