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University of Vienna
Mach conducted numerous experiments related to sound using an empiricist approach to science. Some were conducted around the perception of the velocity of sound over distance. For example, using two electrical clockwork devices that ticked in unison at equal distance, but over an uneven distance would be perceived as ticking out of sync (Mach, 32-47). His approach using phenomenolism during experimentation was a driving force for his anti-metaphysical philosophy of science (Pojman). -
The Discovery of Mach Bands
Mach’s “On the Effect of the Spatial Distribution of the Light Stimulus on the Retina” describes visible dark bands on the outer edge of visual stimuli followed by lighter bands on the inner edge. Before this, variations such like these were seen as optical illusions, but Mach argued that it was due to how the body perceives stimuli (Britanica). (Picture of Mach Bands, Kingdom) -
The Sound of Inspiration
During a lecture given by Belgian artillerist Melsens, in Paris, Mach was inspired to test the theory that projectiles carry masses of compressed air in front of them when traveling at high speeds (Mach, 309-337). -
The First Shot
Mach conducted his first experiment using a target pistol and shot the bullet through a striate field, the small optical difference seen as a dark line from heat or explosions in bright light, creating an electric spark from a Leyden jar imposing the image of the projectile on a plate placed to capture the image. Mach captured images of the sound waves, but no compression of air in front of the bullet (Mach, 309-337). -
The Picture of Supersonic Sound
In the Summer of 1886 Mach began conducting tests with his son in the Adriatic seaport of Pola utilizing a cannon acquired for him from the Austrian Naval Department. These tests yielded promising results, but it was not until he returned to a laboratory and using an Austrian Mannlicher rifle did he attain the results he wanted (Mach, 309-337). (Picture of Bullet/Sound Waves, Paur) -
Analysis of Sensations
Mach’s 1886 " Contributions to the Analysis of Sensations", showed in full his theory on how knowledge is gained by experience and observation; not through mere contemplation. This being his truest work in anti-metaphysical philosophy and driving him on to his most known achievement, his work with supersonic sound (Pojman). -
The Principles of Supersonic Sound
Mach proposed the Principles of Supersonic Sound in his paper “Photographic Fixation of the Processes Initiated by Projectiles in the Air”. He also presented the first photographic evidence of shock waves created from a bullet traveling over the speed of sound. His use of empiricist thought mechanisms led him to inspire generations in scientific fields such as aerospace (Scott/Pojman). https://youtu.be/VlaGxYjnoPY (Khan Academy)
