thunder

thunder, sound produced along a path of a lightning flash, caused by the rapid heating and expansion of the adjacent air; lightning can heat air to temperatures as much as five times hotter than those at the surface of the sun. Rolling thunder occurs either as a result of the time difference between sounds from the far and near end of a flash, or when mountains, layers of air, or other obstructions cause reverberations. Since sound travels about 1 mi in 5 sec, the distance between a lightning flash and an observer may be determined by counting the seconds between the flash and the thunder. Thunder as far distant as 10 to 15 mi (15 to 25 km) from an observer is usually not heard, even though lightning is often seen. See thunderstorm.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on thunder from Fact Monster:

  • Thunder Bay - Thunder Bay Thunder Bay, city (1991 pop. 113,946), SW Ont., Canada, on Thunder Bay inlet of Lake ...
  • Science Questions - Science Questions What causes a rainbow? Although light looks colorless, it’s made up of many ...
  • Fort William - Fort William: Fort William: see Thunder Bay, Ont., Canada.
  • Analogy Quiz - (What is an analogy?) LIGHTNING : STORM :: _____ : airplane Hint hood thunder wing Word Quiz ...
  • Lakehead University - Lakehead University Lakehead University, at Thunder Bay, Ont., Canada; founded 1946 as Lakehead ...

See more Encyclopedia articles on: Weather and Climate: Terms and Concepts