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Saturday, December 14, 2013

The butterfly effect on steroids

Writing before development of thermonuclear bombs, J.D. Stranathan gives this account of the discovery of deuterium :

G.H. Aston in 1927 obtained a value 1.00778 +- 0.00015 for the atomic weight of hydrogen, which differed from the accepted chemical value of 1.00777 +- 0.00002. The figures were so close that no isotope seemed necessary.

But, the discovery of the two heavier isotopes of oxygen forced a reconsideration because their existence meant that the physically derived and chemically derived scales of atomic weight were slightly, but importantly, different. This meant that Aston's value, when converted to the chemical scale, was 1.00750, and this was appreciably smaller than the chemically determined atomic weight. The alleged close agreement was adjudged to be false.

That discrepancy spurred Harold C. Urey, Ferdinand G. Brickwedde and George M. Murphy to hunt for deuterium, which they found and which became a key component in the development of the atomic bomb.

But, this discrepancy turned out to have been the result of a small experimental error. It was shown that the 1927 mass spectrograph value was slightly low, in spite of having been carefully confirmed by Kenneth T. Bainbridge. When the new spectrograph value of 1.0081 was converted to the chemical scale, there was no longer a substantive disagreement. Hence, there was no implication of the existence of deuterium.

Though the chemical and physical scales were revealed to have been slightly different, that revelation, without the 1927 error, would have yielded no reason to expend a great deal of effort searching for heavy hydrogen.

Had heavy water been unknown, would allied scientists have been fearful of German development of atomic fission weapons (British commandos wrecked Germany's heavy water production in occupied Norway) and have spurred the British and American governments into action?

Even had the Manhattan Project been inevitable, it is conceivable that, at the outset of World War II, the existence of heavy water would have remained unknown and might have remained unknown for years to come, thus obviating postwar fulfillment of Edward Teller's dream of a fusion bomb. By the time of deuterium's inevitable (?) discovery, the pressure for development of thermonuclear weapons might well have subsided.

That is, looking back, the alleged probability of the discovery of heavy water was miniscule, and one is tempted to wonder about some peculiar spiritual influence that fated humanity with this almost apocalyptic power.

At the least, we have the butterfly effect on steroids.

From The "Particles" of Modern Physics by J.D. Stranathan (Blakiston, 1942).

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