The entropy of a weak shock is third order in its strength

The entropy rise across a normal shock against eps = M² − 1, over five decades. The measured exponent is 2.9989 and the leading constant 0.16216 against the closed form's 0.162037 — which is 2 gamma/3(gamma + 1)² per unit gas constant, and is the same expression divided by gamma − 1 that the books print per unit c_v.

2 essays call compressible-exact. The drawing above is what it returns with no arguments at all; every call below passes it something, because a placement that passes nothing draws whichever member of the family the generator happens to default to rather than the one its essay argues about.

It is also the blast radius. Changing compressible-exact changes every figure listed here at once, and on this site it may change what they assert as well as what they show — which is what has to be rebuilt and looked at before the change is believed.