Grad Talk- Self-Similarity and Dimensional Analysis Estimating the Yield of the “Trinity” Atomic Explosion from Photographs

Abstract: In 1950, sir Geoffrey Taylor published two papers, in which he attempted to estimate the yield of the first atomic explosion using some declassified pictures, that were marked with a scale and the time of each exposure after initiation. He came up with two estimates; 16.8 kt of T.N.T. and 23.7 kt of T.N.T. The actual value of the yield was about 22 kt of T.N.T. These surprisingly accurate values were based on an exact solution of the problem of the sudden release of energy on a single point in a uniform atmosphere, which was derived using dimensional methods. In this talk, a very brief introduction of the concepts of self-similarity and dimensional analysis will be provided, along with a discussion on how these can be used to tackle challenging physical problems, leading to an outline of Taylor’s work.