Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Symmetry of Blast Waves   This article presents a brief historical review of G. I. Taylor's solution of
the point blast wave problem which was applied to the Trinity test of the first
atomic bomb. Lie group symmetry techniques are used to derive Taylor's famous
two-fifths law that relates the position of a blast wave to the time after the
explosion and the total energy released. The theory of exterior differential
systems is combined with the method of characteristics to demonstrate that the
solution of the blast wave problem is directly related to the basic
relationships that exist between the geometry (or symmetry) and the physics of
wave propagation through the equations of motion. The point blast wave model is
cast in terms of two exterior differential systems and both systems are shown
to be integrable with local solutions for the velocity, pressure, and density
along curves in space and time behind the blast wave.

11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph