30 km per second 300 000 km per second 3 million km per second 30 000 km per second
Reflective Index Refractive Index Relational Index Dispersive Index
Diffusion Diffraction Dispersion Interference
Glass Perspex Diamond Water
Ultrafast Waves Ultrasonic Waves X-Rays Light Waves
5000 metres per second 330 metres per second 30 metres per second 1400 metres per second
20 km per second 200 000 km per second 2 million km per second 20 000 km per second