Thunder and lightning - HD 影片檔

Lightning strikes and their associated thunder. Sound travels at around 340 metres per second, with light essentially instantaneous, so every three seconds between the flash and the thunder indicates a distance of around one kilometres. In this case, the separation of some 13 seconds shows that the strike was about 4.3 kilometres away from the storm-chasing vehicle from which it was filmed. Filmed in South Dakota, USA.