What If You Keep Slowing Down? (Quadrillion FPS Camera)

Scientists use innovative camera techniques, from high-speed strobe photography to quadrillion FPS X-ray pulses, to capture events at previously unimaginable timescales, revealing light propagation and electron dynamics.

• Harold Edgerton's strobe photography revolutionized capturing high-speed motion, revealing unseen details with bright, brief flashes.

• Single-pixel cameras can achieve a trillion frames per second to visualize light's propagation by stitching together numerous time-resolved measurements.

• X-ray free-electron lasers provide quadrillion FPS 'molecular movies' by probing electron density changes at attosecond timescales to understand fundamental chemical reactions.

Observing phenomena that occur too fast for the human eye, or even standard cameras, requires specialized techniques for 'stopping time.' Harold Edgerton pioneered strobe photography, freezing high-speed motion with brief, bright flashes, a method still effective today. Modern advancements include single-pixel cameras capable of a trillion frames per second to visualize light's actual movement, and X-ray free-electron lasers that achieve quadrillion FPS to image electron densities within molecules.

Edgerton's Strobe Photography

• 00:01:08 Harold 'Doc' Edgerton developed strobe photography in the 1920s to observe rapidly spinning electric motors, which were too fast for the human eye or contemporary cameras. He discovered that brief, intense flashes of light could 'freeze' moving parts, leading him to engineer a reliable xenon flash tube capable of 10-microsecond pulses. This innovation allowed for sharp photographs of high-speed events, initially to diagnose industrial motor issues, but quickly expanded to capture artistic and scientific phenomena like tennis balls hitting rackets or hummingbirds in flight.

Time-Lapse Strobe Applications

• 00:07:21 After demonstrating the power of strobe photography, Edgerton's technology attracted military attention. In 1939, Major George Goddard sought a strobe powerful enough for aerial night reconnaissance from high altitudes, a safer alternative to parachute flares. Edgerton developed a flash lamp releasing 60,000 joules in a millisecond, comparable to a large solar farm's output, which was crucial during World War II for missions like photographing Normandy before D-Day to confirm German troop positions. This showed the practical, high-stakes applications of his high-speed imaging.

Trillion FPS Single-Pixel Cameras

• 00:13:07 Modern single-pixel cameras achieve an astonishing trillion frames per second, allowing the visualization of light's actual travel and scattering. This technology, similar to LiDAR, uses a sensor sensitive enough to detect individual photons and counts them a trillion times a second, with each 'frame' lasting one picosecond. By repeatedly firing a laser pulse onto a single point and recording the faint signal at different camera positions across a grid, these cameras compile millions of measurements to reconstruct ultra-slow-motion videos of light propagating through a scene with virtually unlimited spatial resolution.

Quadrillion FPS Electron Imaging

• 00:19:04 Combining the principles of strobe photography with advanced particle accelerators, scientists can achieve imaging at a quadrillion frames per second to study electron movement around molecules. Facilities like SLAC use 3.2-kilometer electron accelerators to generate attosecond-long X-ray laser pulses. These pulses ionize specific atoms in molecules, and by measuring the kinetic energy of the ejected electrons at varying time delays, researchers can infer changes in electron density and create molecular movies, revealing fundamental processes of bond formation and breakage.