Ernst Mach

PHYSICIST NAME: Ernst Mach
STUDENT NAME: Angela Mari Peralta

BIOGRAPHY

Ernst Mach was born in Chirlitz, in the Austrian empire.His father, who had graduated from Prague University, acted as tutor to the noble Brethon family in Zlín, eastern Moravia. Some sources give Mach's birthplace as Turas/Tuřany, the site of the Chirlitz registry-office.

Peregrin Weiss baptized Ernst Mach into the Roman Catholic Church in Turas/Tuřany.

Up to the age of 14 Mach received his education at home from his parents. He then entered a Gymnasium in Kremsier where he studied for three years. In 1855 became a student at the University of Vienna. There he studied physics and for one semester medical physiology, receiving his doctorate in physics in 1860 and his Habilitation the following year. His early work focused on the Doppler Effect in optics and acoustics.
In 1864 he took a job as Professor of Mathematics in Graz, having turned down the position of a chair in surgery at the University of Salzburg to do so, and in 1866 he was appointed as Professor of Physics. During that period Mach continued his work in psycho-physics and in sensory perception. In 1867 he took the chair of Professor of Experimental Physics at Charles-Ferdinand University, Prague, where he stayed for 28 years.

CONTRIBUTIONS

Mach's main contribution to physics involved his description and photographs of spark shock-waves and then ballistic shock-waves. He described how passing the sound barrier caused the compression of air in front of bullets and shells. Using a so-called "schlierenmethode" he and his son Ludwig were able to photograph the shadows of the invisible shock waves. During the early 1890s Ludwig was able to invent an interferometer which allowed for much clearer photographs. But Mach also made many contributions to psychology and physiology including his anticipation of gestalt phenomena, his discovery of Mach bands, an inhibition-influenced type of visual illusion, and especially his discovery of a non-acoustic function of the inner ear which helped control human balance.

Most of Mach's initial studies in the field of experimental physics concentrated on the interference, diffraction, polarization and refraction of light in different media under external influences. There followed 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 vp/vs 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.

OBJECT OF INTEREST

I chose Ernst Mach because I think he is a good physicist. In fact he was able to his task or work with his son Ludwig. And also I chose him because He became a good model to his son, that made his son a physicist like him too.
Secondly, I chose him because he had been related to our topic now in Physics.