Ernst Mach of experimental physics concentrated on the interference, diffraction, polarization and refraction of light in different media under external influences. From there followed important explorations in the field of supersonic fluid mechanics. Mach and physicist-photographer Peter Salcher presented their paper on this subject in 1887; it correctly describes the sound effects observed during the supersonic motion of a projectile. They deduced and experimentally confirmed the existence of a shock wave of conical shape, with the projectile at the apex. The ratio of the speed of a fluid to the local speed of sound "v"/"v" is now called the Mach number. It
Mach and Daddy artists in this genre. "Daily" and "Unforgettable" were the label's first releases. Mach and Daddy Peter "Mach" Machore and Martin "Daddy" Machore, better known as Mach and Daddy, are Panamanian duo brothers of Spanish reggae and reggaeton. The first single for which they were recognized, "La Botella" (""The Bottle""), charted throughout Latin America and hit #1 on the "Billboard" chart. Other popular singles included "La Juma" and "El Que Se Fue Pa Barranquilla". The duo's concerts attracted as many as fifty thousand people. They tour and perform throughout Latin America and the U.S. Peter Machore is "Mach" and Martin Machore