Magnetohydrodynamics: Waves and Shock Waves in Curved Space-Time

For seventy years, we have known that Einstein''s theory is essentially a theory of propagation of waves for the gravitational field. Confusion enters, however, through the fact that the word wave, in physics, implies sometimes repetition and sometimes not. This confusion is often increased by he use of Fourier transforms, by which a disturbanse which appears to be without repetition is resolved i...