Lightning and thunder - HD 影片檔

Lightning strike, followed towards the end of the clip by the thunder. The time taken between the bolt and the sound can be used to estimate the distance to the lightning strike. The speed of sound in air is around 340 metres per second, so the lightning is approximately one kilometre distant for every three seconds between flash and thunder. Filmed in Colorado, USA, in summer. Mastered from originals, frame size 1280x1080.