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Shock waves are formed when a pressure front moves at supersonic speeds and pushes on the surrounding air. Recognized more than a century ago, these invisible phenomena are still relatively opaque to scientists. But they have been revealed as never before, thanks to some classical imaging techniques that have been updated with modern technology. Shadowgraphy and schlieren (German for "streaks") photography, developed by experts including H. E. "Doc" Edgerton (best remembered for his splashing milk drop), have been combined with high-speed video cameras and other innovations that allow the imaging of shock waves in natural conditions. The new images may advance forensics and the hardening of aircraft against terrorist attacks.