Word: cesium
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...courier, claimed the material posed "no danger" and admitted it regularly used passenger trains to transport radioactive substances. In November a thief was arrested after carrying uranium-235 on the subway, and in December two men were arrested after riding with a stolen cache of potentially explosive cesium. Both materials can be deadly...
...reactors full of nuclear fuel, sank accidentally. The most dangerous, the world was reminded last week, may be the Komsomolets, which caught fire in April 1989 and went down in more than 4,500 ft. of water 310 miles off the coast of Norway. The wreck is already leaking cesium-137, a carcinogenic isotope. So far the leakage is considered too small to affect marine life or human health...
...have quietly moved back to their farm plots, where they consume contaminated animals and produce. "They would rather die here than live somewhere else," says Alexander Borovoi, a Russian nuclear physicist in charge of the sarcophagus. Some returned to find their homes pillaged of religious art. Although contaminated with cesium 137 and strontium 90, some of the icons have probably entered the world art market...
...principle behind all this precision comes from quantum physics. When an atom is bombarded with electromagnetic radiation -- in this case microwaves -- it shifts into a new energy state. Each type of atom responds most readily to a particular frequency. For the cesium-133 atoms in most atomic clocks, the frequency is 9,192,631,770 vibrations per second. When a microwave beam inside the clock is set to that frequency, the maximum number of atoms will undergo the energy switch, signaling the clock's internal computer that the device is correctly tuned. The vibrating microwaves keep time; the atoms just...
Theoretically, an atomic clock could keep perfect time; the actual performance, though, depends on the electronics and such engineering details as how the microwaves hit the cesium atoms. Hewlett-Packard will doubtless come up with other refinements, but for now losing a second every 1 1/2 million years will have...