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Uncle Tungsten
Here's a little unrelated bonus
Those of you who have been with me for a while have heard me comment on the annoying habits of crazy people living on our streets -- Foucault's Children, as I like to think of them. Coming home from the market this afternoon I discovered a completely naked man talking to himself at the entrance to my alley and trash strewn from one end of the alley to the other. Last I looked he was still going through his bags of stuff so I expect there will be more litter on the pavement later (I picked-up and put in our trash toters everything at my end of the alley). Just now there was shouting out there as well, which I haven't even bothered to investigate. I don't even know the name of the condition where people obsessively go through their belongings (and optionally change and re-change their clothes.) Would love to know.
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p255 Even though the rest of the scientific community had ignored the news of Becquerel’s rays, the Curies [also here] were galvanized by it: this was a phenomenon without precedent or parallel, the revelation of a new, mysterious source of energy; and nobody, apparently, was paying any attention to it. They wondered at once whether there were any substances besides uranium that emitted similar rays, and started on a systematic search (not confined, as Becquerel’s had been, to fluorescent substances) of everything they could lay their hands on, including samples of almost all the seventy known elements in some form or other. They found only one other substance besides uranium that emitted Becquerel’s rays, another element of very high atomic weight -- thorium. Testing a variety of pure uranium and thorium salts, they found the intensity of the radioactivity seemed to be related only to the amount of uranium or thorium present; thus one gram of metallic uranium or thorium was more radioactive than one gram of any of their salts.
p256 But when they extended their survey to some of the common minerals containing uranium and thorium, they found a curious anomaly, for some of these were actually more active than the element itself. Samples of pitchblende, for instance, might be up to four times as radioactive as pure uranium. Could this mean, they wondered, in an inspired leap, that another, as-yet-unknown element was also present in small amounts, one that was far more radioactive than uranium itself?
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... in July of 1898 they were able to make a bismuth extract [of pitchblende] four hundred times more radioactive than uranium...
...If the existence of this new metal is confirmed we propose to call it polonium...
They were convinced, moreover, that there must be still another radioactive element waiting to be discovered...
p257 They were unhurried... (They were unaware at the time that there was another eager and intense observer of Becquerel's rays, the brilliant young New Zealander Ernest Rutherford, [1st Baron Rutherford of Nelson] who had come to work in J. J. Thomson’s lab in Cambridge.) ... within six weeks they had a bismuth-free (and presumably polonium-free) barium chloride solution which was nearly a thousand times as radioactive as uranium. [Eugene] Demarcay’s [“the eminent rare-earth spectroscopist”] help was sought... and this time, to their pure joy, he found a spectral line (and later several lines: “two beautiful red bands, one line in the blue-green, and two faint lines in the violet”) belonging to no known element. Emboldened by this, the Curies claimed a second new element a few days before the close of 1898. They decided to call it radium, and since there was only a trace of it mixed in with the barium, they felt its radioactivity “must be enormous.”
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p259 The Curies had hoped they might isolate radium by 1900, but it was to take nearly four years from the time they announced its probably existence to obtain a pure radium salt, a decigram of radium chloride -- less than a ten-millionth part of the original... fighting (although they did not know it) against the insidious effects of radioactivity on their own bodies, the Curies finally triumphed and obtained a few grains of pure white crystalline radium chloride -- enough to calculate radium’s atomic weight (226), and to give it its rightful place, below barium, in the periodic table.
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...In 1903, Marie Curie summarized the work of the previous six years in her doctoral thesis, and in the same year she received (with Pierre Curie and Becquerel) the Nobel Prize in physics.
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p261 I was particularly moved by the description in Eve Curie’s book [their daughter] of how her parents, restless one evening and curious as to how the fractional crystallizations were going, returned to their shed late one night and saw in the darkness a magical glowing everywhere, from all the tubes and vessels and basins containing the radium concentrates, and realized for the first time that their element was spontaneously luminous. The luminosity of phosphorus required the presence of oxygen, but the luminosity of radium arose entirely from within, from its own radioactivity...
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p262 Uncle Abe still had some radium in his possession, left over from his work on luminous paint, and he would show me this, pulling out a vial with a few milligrams of radium bromide -- it appeared to be a grain of ordinary salt -- at the bottom. He had three little screens painted with platinocyanides -- lithium, sodium, and barium platinocyanide -- and as he waved the tube of radium (gripped in a pair of tongs) near the darkened screens, these lit up suddenly, becoming sheets of red, then yellow, then green fire, each fading suddenly as he moved the tube away again.
...”Radium decomposes the atoms of the air, and then they recombine in different forms -- so you smell ozone and nitrogen peroxide when you are around it. It affects glass -- it turns soft glasses blue, and hard glasses brown...” [That was Uncle Abe] Uncle Abe showed me a piece of fluorspar which he had exposed to radium for a few days. Its original color had been purple, he said, but now it was pale, charged with strange energy. He heated the fluorspar a little, far below red hot, and it suddenly gave off a brilliant flash, as if it were white-hot, and returned to its original purple.
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p263 I liked to watch Uncle Abe’s radium clock, which was basically a gold-leaf electroscope with a little radium inside. in a separate, thin-walled glass vessel. The radium, emitting negative particles, would gradually get positively charged, and the gold leaves would start to diverge -- until they hit the side of the vessel and got discharged: then the cycle would start all over again. This “clock” had been opening and closing its gold leaves, every three minutes, for more that thirty years, and it would go on doing so for a thousand years or more -- it was the closest thing, Uncle Abe said, to a perpetual motion machine.
Aside from, say, an atom of hydrogen.
With radiation of every other sort, going all the way from X-rays to radio waves, energy had to be provided by an external source, but radioactive elements, apparently, had their own power and could emit energy without decrement for months or years, and neither heat nor cold nor pressure nor magnetic fields nor irradiation [?] nor chemical reagents made the least difference to this.
p264 Where did this immense amount of energy come from? The firmest principles in the physical sciences were the principles of conservation -- that matter and energy could neither be created nor destroyed. There had never been any serious suggestion that these principles could ever be violated, and yet radium at first appeared to do exactly that -- to be a perpetuum mobile, a free lunch, a steady and inexhaustible source of energy.
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p266 With no plausible external source of energy, the Curies were forced to return to their original thought that the energy of radium had to have an internal origin, to be an “atomic property” -- although the basis for this was hardly imaginable. As early as 1898, Marie Curie added a bolder, even outrageous thought, that radioactivity might come from the disintegration of atoms, that it could be “an emission of matter accompanied by a loss of weight of the radioactive substances” [sic -- I would think this should read "an emission of energy..." but this is a quote and I will leave it as is.] -- a hypothesis even more bizarre, it might have seemed, than its alternatives, for it had been axiomatic in science, a fundamental assumption, that atoms were indestructible, immutable, unsplitable -- the whole of chemistry and classical physics was built on this faith. In Maxwell’s words:
p267 Though in the course of ages catastrophes have occurred and may yet occur in the heavens, though ancient systems may be dissolved and new systems evolved out of their ruin, the {atoms} out of which these systems are built -- the foundation stones of the material universe -- remain unbroken and unworn. They continue to this day as they were created -- perfect in number and measure and weight.
All scientific tradition, from Democritus to Dalton, from Lucretius to Maxwell, insisted upon this principle, and one can readily understand how, after her first bold thoughts about atomic disintegration, Marie Curie withdrew from the idea, and (using unusually poetic language) ended her thesis on radium by saying, “the cause of this spontaneous radiation remains a mystery . . . a profound and wonderful enigma.”
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