Particle detectors that utilize this effect can emit pulses with widths as low as 10-10 (read: 10 to the minus 10) seconds and can be used in time-of-flight measurements.  The angle of emission is related to the speed of light and the index of refraction of the medium, and measuring the angle can determine the particle's speed. Discovered by Frank 
Particle detectors that utilize this effect can emit pulses with widths as low as 10-10 (read: 10 to the minus 10) seconds and can be used in time-of-flight measurements.  The angle of emission is related to the speed of light and the index of refraction of the medium, and measuring the angle can determine the particle's speed. Discovered by Frank and Tamm and predicted by its namesake, FTP, identify this effect where a blue light is emitted from a particle when it passes into a medium at a speed greater than the speed of light in that medium.
Particle detectors that utilize this effect can emit pulses with widths as low as 10-10 (read: 10 to the minus 10) seconds and can be used in time-of-flight measurements.  
Cherenkov radiation