BOMBS AT BIKINI 



paper-thin, and at the same time must have the same 

 flexibility, elasticity, and plastic flow as the steel plates 

 on the transport ship. Model beams must be of paper- 

 thin material also. Even the rivets must be closely imi- 

 tated. The upshot is, of course, that no such thing as a 

 really comparable model exists; the model will show 

 damage from the model explosive charge, but nobody 

 will know what the damage means in terms of damage 

 to real ships. Determining the vulnerability of compli- 

 cated equipment such as ships' boilers by means of 

 models would, of course, be almost impossible. 



Third, no one — not even the scientists in the 

 Navy's Bureau of Ships or Bureau of Ordnance — 

 knew how to fully interpret model studies of water 

 waves, when the test to be imitated is the shallow- 

 underwater explosion of 20,000 tons of TNT, or its 

 modern equivalent, one atomic bomb. The crux of the 

 difficulty is: the weaves don't ''scale" as other phe- 

 nomena do. We can use a model fleet in a model lagoon, 

 and we will be rewarded by obtaining a very fine model 

 pressure wave. But the water waves will come out all 

 wrong ; they are much too high. They must be corrected 

 by some rather uncertain calculation. 



Fourth, we cannot imitate in a model test the sud- 

 den release of fission products and the sudden emission 

 of neutrons. 



Thus it appears to be a true paradox that to show 

 what the smallest of bodies — the atom — can do in 

 chain-reacting concert, we must use a testing ground 



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