Ernst Mach

Born in 1838 in what is now the Czech Republic and educated in Vienna, Ernst Mach became one of the most influential scientific thinkers of the late 19th century. He taught mathematics and physics at the University of Graz, then spent many years at the Charles-Ferdinand University in Prague, where he carried out important work in experimental physics.

Mach is widely remembered for his studies of motion at very high speeds and for the term behind the modern Mach number. He also investigated sensation and perception, including visual effects still associated with his name, and wrote major books on mechanics, scientific method, and the history of physics.

Beyond the laboratory, Mach was an important philosopher of science. He argued that science should stay close to observable experience and was skeptical of ideas that could not be directly tested. That outlook helped shape later debates in physics and philosophy, and his writings were read closely by figures including Albert Einstein.