Sun in a Bottle - Charles Seife [16]
Even as the United States used its fusion weapons to try to black-a mail China and assert its nuclear primacy, its advantage was slipping away once again. On November 22, 1955, the Soviet Union tested their own Mike: a 1.6-megaton hydrogen bomb. It, too, was a two-stage device. The Soviets had also unshackled the fury of the sun upon the inhabitants of the Earth.
CHAPTER 2
THE VALLEY OF IRON
... materials dark and crude,
Of spirituous and fiery spume, till, touched
With Heaven’s ray, and tempered, they shoot forth
So beauteous, opening to the ambient light?
These in their dark nativity the Deep
Shall yield us, pregnant with infernal flame
—JOHN MILTON, PARADISE LOST, VI, 478-83
Nearly a century before the quest for superweapons split the scientific community, fusion was at the center of another debate; physicists just didn’t realize it at the time. Decades before fusion was discovered, it was at the heart of an argument between physics and biology, between those who studied the fundamental laws that govern the universe and those who observed the processes of life on Earth. It was a battle between two of the leading scientific lights of the day: William Thomson (also known as Lord Kelvin), and Charles Darwin.
In 1862, Thomson, one of the brightest—and most famous—physicists in Britain, was absolutely certain: Darwin was wrong. The theory of evolution could not possibly be correct. He had ironclad proof. According to Thomson’s calculations, it was not possible for species to change form over millions and millions of years because the sun could not have been around that long. It was a physical fact, Thomson thought, and it would destroy the biologist’s pretty theory once and for all.
Thomson’s argument was far more ambitious than a mere attack on Darwin’s proposal. In fact, the physicist was trying to answer some of the biggest scientific questions of the day. Astronomers were just beginning to understand what the sun was made of, and they were suddenly faced with a new set of questions that once seemed unanswerable. Where did the sun come from? How old was it, really? Where did it get its energy?
When Thomson estimated the sun’s age, he calculated that it could only be a few tens of millions of years old, far fewer years than Darwin’s natural selection would take to generate the amazing diversity on Earth. It was a major puzzle; two branches of science were giving mutually contradictory answers. It would take decades before scientists uncovered the truth. The secret was fusion. Only when physicists could understand fusion could they understand the nature of the sun, much less create one for their own use.
Thomson’s calculations were extremely bad news for Darwin. The physicist argued that there was a fundamental problem with the theory of evolution, a problem that seemed to contradict a law of thermodynamics. If true, it would devastate Darwin’s theory. The laws of thermodynamics are among the most fundamental and sacrosanct laws of physics, and they brook no contradiction.
The field of thermodynamics studies the relationships among heat, work, and energy. Its first law has to do with energy: energy cannot be created out of nothing. Energy can be transferred from place to place. It can change form. For example, the energy of water spinning a wheel can light a lightbulb: the energy of motion is converted into electric energy then into light energy. However, energy always has to come from somewhere; it can’t be created or destroyed. Nature has a fixed amount of energy, and it is impossible to make more. This law is central to physics, yet Thomson believed Darwin’s theory fell afoul of it.
He based his argument on the energy flowing from the sun. When you go out on a bright summer day, you feel the warmth of the sun on your skin. The sun, shining continuously