Fireworks of the Gods

Starting from Zeus (Greek mythology) to Indra (Hindu mythology), our forefathers have often personified and depicted various Gods to be the harbingers of lightning and thunder. Many anecdotes propose lightning strikes when a God is angry. We live in a modern world where many people will (and I don’t think rightfully, you are free to believe anything!) mock you if you told that anger of some God causes lightning. So, today’s quest is for science in this sea of mythology:

What Causes Lightning?

Lightning is a form of electric discharge (or current). To make lightning happen, we need a cloud.
When the ground heats up due to the energy from sunlight, it warms the air (and water vapour) above it. As the air rises, water vapour cools and it forms a cloud. When air continues to rise, the cloud grows and becomes bigger and bigger. After attaining a certain height, the top of the cloud starts forming ice particles due to the lower temperatures.

The little particles of ice bump into each other and exchange electrons. This creates charged particles in the cloud. The pieces that lose electrons become positively charged and lighter. The pieces that gain electrons become negatively charged and heavier. Thus, the negative charged particles are heavier and sink to the bottom of the cloud, and the positive charge rises up.

When the positive and negative charged grow large (larger than the breakdown voltage of air) enough, it leads to a large spark that we see as lightning. The crazy fact is, most of the lightning occurs either inside one cloud (from the bottom to top) or between the top and bottom portions of two different clouds.

Sometimes the ground below a cloud accumulates positive charge (including vertical structures like trees, buildings and even us, humans!). When this is the case, the lightning discharge makes its way down to the ground from the cloud and we go, Thunder, feel the thunder, Lightning and the Thunder. Cheers to the Imagine Dragons fans out there.

P.S. Lightning is around 27000 deg Celsius (six times hotter than the surface of the sun). I imagine the Gods to be pretty angry before sending a lightning bolt like that down at us.