Did you know that the Gillette MACH 3 razor is named after Ernst Mach, an Austrian physicist and philosopher? I didn’t, until I read Einstein’s 1930 statement in which he declared that Mach should be considered the precursor of the General Theory of relativity. This sparked my interest in Mach and led me to look again at the “Mach Principle,” the “Mach number,” and the “Mach Band.” My search revealed a wide spectrum of Mach’s intellectual endeavors and I delved a little deeper into his philosophy of science.
Why did Einstein sign his letters to Ernst Mach, “Your admiring student”?
Why do some brilliant physicists today call themselves “Neo-Machians”?
And why was Mach’s work so influential in physics, in psychology, physiology, mathematics, logic, biology, economics, sociology, jurisprudence, anthropology, architecture, education, and literature?
Ernst Mach was a complex thinker (despite his stress on simplicity) and I do not have time to write a three-hundred page theses on his interests and impact. Instead, I will attempt to describe his life and work as simply as I can and allow you to draw your own conclusions.
Ernst Waldfried Josef Wenzel Mach was born on February 18, 1838 in Chirlitz, in the Czech Republic, but then in the Austrian Empire. He was the first of three children in the family of Johann Mach and Josephine Lanhaus. His father, a graduate from Prague University, worked as a private tutor and tended his orchard on a farm near Vienna (the family settled on the farm when Ernst was two years old). His mother, an intelligent and artistic woman, instilled a love of poetry and music in her children.
Ernst was a fragile child with perceptual (mainly visual) problems which later led to his interest in the physiology of perception. He was home-schooled until the age of 14, but briefly attended the Benedictine Gymnasium in Seitenstetten. At the gymnasium he was deemed “unteachable and without talent” by the Benedictine Fathers…which seems to be a normal rite of passage for geniuses.
At fifteen, Ernst entered the sixth class of the public Piarist Gymnasium in Kremsier, and three years later continued his studies at the University of Vienna in physics, philosophy, and mathematics.
In his mid-twenties, Mach spent some time alone in a ruined monastery with his horse quartered in an adjacent room. This lifestyle gave him plenty of time to study his favorite philosophers of the Enlightenment era, and develop his own ideas about the philosophy of science.
But Mach wasn’t “all work and no play.” Upon his return to Vienna in the late 1850s, he developed a popular reputation as a superior boxer and the best fencer in the city, much to the surprise of people who knew him as a delicate child.
During his doctoral work at the University of Vienna, Mach focused on physics, the psychology of sensations, physiology, and psychophysics (a branch of psychology that deals with the relationship between physical stimuli and sensory response). His doctoral thesis “On electrical charge and induction” earned him his doctorate degree in 1860.
Mach’s studies in the field of experimental physics concentrated on the interference, diffraction, polarization, and refraction of light in different media. He also explored the Doppler Effect, optics, and acoustics. In 1861 he taught a course in physics for medical students at the university, from which he developed his first article on psychophysics and the relationship between tension in the eye muscles and the perception of form.
In 1865 Mach published “On the effect of the spatial distribution of the light stimulus on the retina”, which was the first of a series on what we know today as “Mach Bands”, the striping effect in graduating tones caused by an inhibition-influenced type of visual illusion.
He also conducted studies of kinesthetic sensation; this is the feeling associated with movement and acceleration, and discovered a non-acoustic function of the inner ear which helps control human balance.
By 1885, Mach had worked out the details of supersonic motion, developing high-speed photographic techniques along the way. In ballistics the “Mach Number” is the ratio of the speed of sound in the given medium to the speed of the projectile. An object moving at the speed of sound is at Mach 1 (the term MACH 3 was given to the Gillette razor to imply the triple speed of sound because of the triple blade razors).
In aerodynamics, a Mach number is used by those who fly at speeds approaching the speed of sound. The first time an aircraft flew faster than Mach 1.0 was in 1947. The current speed record for a piloted aircraft is Mach 6.7.
In 1867, Ernst Mach became professor of experimental physics at Prague University and later, in 1895, at the University of Vienna. Despite his immense popularity and prestige, Mach’s life wasn’t without tragedies. In 1898, he suffered a stroke and later retired from his professorship. His second son, Heinrich, committed suicide at the age of 20, soon after graduating from university in chemistry. In 1913, Mach moved to his oldest son’s home near Munich, and on February 19, 1916, he died just after his 78th birthday.
Ernst Mach was a freethinker, an active fighter against fanatical nationalism and anti-Semitism. He rejected the existence of God, as well as Isaac Newton’s concept of absolute time and space. As a relativist, he argued that no statement in science is admissible unless it is empirically verifiable. He rejected the assumption about the self-sufficiency of atomic particles and processes, which can never be directly observed but only inferred from direct observation.
For Mach, knowledge is provided entirely by the senses and instruments of direct observation. From this relativistic point of view, there can be no space, nor time, nor objects and their specific properties, but only their holistic relation to one another. This is the holistic interrelation between things we know as “Mach’s Principle”.
If you want to know more about today’s Neo-Machian movement and find out why they believe that if the world had accepted “Mach’s Principle” instead of Einstein’s theories, we would have been spared recently discovered anomalies, such as the “Pioneer Anomaly” and the “Missing Mass Anomaly”, search the web for “Extraordinary Physics” by Viv Pope and the “Pope-Osborne Angular Momentum Synthesis”.