Explosion implosion duality and the laboratory simulation of astrophysicalsystems

The Euler equations of ideal gas dynamics possess a remarkable nonlinear in volutional symmetry which allows one to factor out an arbitrary uniform exp ansion or contraction of the system. The nature of this symmetry (called by cosmologists the transformation to supercomoving variables) is discussed a nd its origin clarified. It is pointed out that this symmetry allows, one t o map an explosion problem to a dual implosion problem and vice versa. The application to laboratory simulations of supernova remnants is considered; in principle this duality allows the complete three-dimensional evolution o f highly structured explosion ejecta to be modeled using a static target in an implosion facility. (C) 2000 American Institute of Physics. [S1070-664X (00)02401-6].