Ethan Vishniac

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Ethan Tecumseh Vishniac is an American astrophysicist, son of Wolf V. Vishniac, and grandson of Roman Vishniac. He is the Editor-in-Chief of the Astrophysical Journal, Director of the Center for Astrophysical Sciences and a professor of Astronomy at McMaster University in Hamilton, Canada. His wife Ilene Busch-Vishniac, an ex-Dean of the Faculty of Engineering at Johns Hopkins, is the newly-appointed Vice-President of McMaster University (effective August, 2007).

[edit] Vishniac instability

His best known scientific work is the study of instabilities in expanding blast waves. In Vishniac (1983), he demonstrated that a blast wave expanding in a sufficiently compressible medium would be subject to a linear overstability growing as the square root of time. This is usually known as the Vishniac instability, and generally occurs in any thin enough slab bounded by a shock on one side and a contact discontinuity to a higher temperature region on the other. In Vishniac (1994) he then demonstrated that a thin-enough slab bounded by shocks on both sides is subject to a nonlinear instability, usually described as a nonlinear thin shell instability (NTSI). He has also worked with success in cosmology and the theory of astrophysical dynamos.