Friday, May 20, 2016
What is lightning?
Clouds may look fluffy and innocent, but they are actually active places. Water and ice move around inside the cloud; forced up by warm air currents, down by gravity, and compressed in the cloud. Just as rubbing a balloon can create static electricity, the particles in the cloud become charged. Charges separate in the cloud. Positive charges move up, and negatives move down.
Once a significant charge separation has built up, the positive and negative charges seek to reach each other an neutralise. ‘Streamers’ come up from the ground to form a pathway. Once a pathway is completed a spark forms, neutralizing the charge.
As the negative charge races down, the air surrounding it heats up.The spark is very hot at almost 20,000 degrees Celsius, and it rapidly heats the air to create a shock wave.
Considering light travels very fast – about 300 million metres per second, and that sound only travels at 300 metres per second; light is a million times faster than the sound produced. To find out how far away the storm is, you can count how long you hear the sound after the lightning. For every 4 seconds between the flash and the rumble, the thunderstorm is 1 mile away.
What causes lightning?:http://www.planet-science.com/categories/over-11s/natural-world/2012/06/what-causes-lightning.aspx