[ AdvancedImagingPro Shockwave Shadows in Extremely Sluggish Movement (Bullet Schlieren) Excessive Pace imaging at 28,000 frames per second of a bullet. Schlieren Imagery wikipedia.org/wiki/Schlieren Derek from Veritasium made a terrific video about Schlieren Mach Angle grc.nasa.gov/www/k-12/airplane/machang.html en.wikipedia.org/wiki/Transonic Indirect Shock grc.nasa.gov/www/k-12/airplane/indirect.html Credit: Dr. Kanistras uah.edu/eng/departments/mae/faculty-staff/konstantinos-kanistras

Schlieren Photo Technology This photo taken in the late 1960’s is a technique to visually observe ultrasound, a few years before medical ultrasound was developed.