Sun in a Bottle - Charles Seife [141]
44
Physicists use several terms when referring to the color of light: color, energy, frequency , and wavelength all essentially refer to the same thing. Visible light comes in a variety of colors: a whole spectrum stretching from red on through orange, yellow, green, blue, and indigo, to violet. It turns out that these colors correspond to light of higher and higher energy. Red has the lowest energy and violet has the highest. Frequency is proportional to energy, so red has the lowest frequency and violet the highest. Wavelength is inversely proportional to frequency, so red has the longest wavelength and violet has the shortest. It can get confusing, but the terms are all trying to describe the same phenomenon in different ways.
45
Hence the name “laser,” which is an acronym for light amplification by stimulated emission of radiation.
46
Thank Edward Teller for this last proposal. In the 1980s, he pushed hard to design a bomb-powered laser that could shoot down enemy missiles; the concept was a big part of Ronald Reagan’s “Star Wars” plan.
47
In practice, this usually means the latter rather than the former. In most modern inertial confinement fusion experiments, light heats up the outermost layers of a target capsule, causing them to evaporate. This pushes the rest of the capsule inward and ignites the fuel.
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Nuckolls had been involved in Project Plowshare. In the late 1950s, he designed a fusion power plant that heated steam by means of hydrogen bombs.
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Other labs, such as Los Alamos, had inertial confinement fusion programs, too. Livermore, however, came to dominate.
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Congress also took the opportunity to reorganize its entire portfolio of energy research. In 1974, it eliminated the Atomic Energy Commission and created the Energy Research and Development Administration to take on many of its functions. Just a few years later, ERDA, together with other federal agencies, would become the Department of Energy.
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Technically, doubling or tripling the frequency of the light.
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As with many of the stories surrounding cold fusion, there are a number of different versions of what happened. For example, some sources say the experimenters (or more precisely, Pons’s son) reduced the current rather than increased it. The nasty battle that erupted around the research turned the tale of cold fusion into a scientific version of Rashomon.
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Apparently, the prolific Andrei Sakharov had predicted this phenomenon in the 1940s.
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Most physicists who have studied the matter know that a great deal of helium- 3 was trapped in the Earth when it formed, and that a little bit is produced by cosmic rays and by the decay of tritium, not by subterranean fusion reactions.
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On an atomic scale, a million electron volts is a lot of energy; it is roughly what you would get if you were to take two electron-size particles and convert their mass entirely into energy. For comparison, the combustion of a molecule of TNT yields about 35 electron volts, meaning you would need to burn roughly 100,000 TNT molecules to get the equivalent energy of a single deuterium fusion.
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This is a consequence of the principle known as conservation of momentum, and it’s why a motorcyclist suffers so much more than the driver of a car when the two collide. The lighter object (the motorcycle) gets most of the energy of the collision, while the heavier object (the car) gets less. It is the same with subatomic particles. A helium-3 nucleus weighs almost exactly three times as much as the neutron, so the neutron gets three times the energy that the helium nucleus does.
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In fact, a 2.5 MeV gamma ray is obviously wrong. The gamma ray wouldn’t be more energetic than the 2.45 MeV particle that produced it.
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Peterson made the error of calling it an anonymous gift rather than admitting where the funds came from, and he was forced