Foe (unit) Foe (unit) A foe is a unit of energy equal to 10 joules or 10 ergs, used to express the large amount of energy released by a supernova. The word is an acronym derived from a part of the pronunciation "ten to the power of fifty-one ergs". It was coined by Gerald E. Brown of Stony Brook University in his work with Hans Bethe, because "it came up often enough in our work". A bethe (B) is equivalent to a "foe". The "bethe" is named after Hans Bethe. It was coined by Steven Weinberg. This unit of measure is convenient
Elastic energy of compressible fluids, and especially gases, demonstrates the essence of elastic energy with negligible complication. The simple thermodynamic formula: formula_2 where dU is an infinitesimal change in recoverable internal energy "U", "P" is the uniform pressure (a force per unit area) applied to the material sample of interest, and "dV" is the infinitesimal change in volume that corresponds to the change in internal energy. The minus sign appears because "dV" is negative under compression by a positive applied pressure which also increases the internal energy. Upon reversal, the work that is done "by" a system is the negative of the