Ernst Mach

Ernst Mach (February 18, 1838 – February 19, 1916) was an Austrian-Czech physicist and philosopher and is the namesake for the "Mach number" and the optical illusion known as Mach bands.

Physics

Most of his studies in the field of experimental physics were devoted to interference, diffraction, polarization and refraction of light in different media under external influences. These studies were soon followed by his important explorations in the field of supersonic velocity. Mach's paper on this subject was published in 1877 and correctly describes the sound effects observed during the supersonic motion of a projectile. Mach deduced and experimentally confirmed the existence of a shock wave which has the form of a cone with the projectile at the apex. The ratio of the speed of projectile to the speed of sound v/c is now called the Mach number. It plays a crucial role in aerodynamics and hydrodynamics. He also contributed to cosmology the hypothesis known as Mach's principle.

Related Topics:
Interference - Diffraction - Polarization - Refraction - Supersonic - 1877 - Shock wave - Speed of sound - Mach number - Mach's principle

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