An estimate of the scale of the problems brought on by the 16 kt and 21 kt atomic bombings of Hiroshima and Nagasaki. The large temperatures and radiation bring about gas to maneuver outward radially in a skinny, dense shell named "the hydrodynamic entrance". The front functions like a piston https://stephenatgth.jasperwiki.com/6688585/helping_the_others_realize_the_advantages_of_scum_radiation_zone