Lightning is a form of electricity that is set free during a storm. Energy is suddenly released in a cloud when charges are built up. Although lightning is most common in tropical and subtropical regions, it can happen wherever hot air mixes with cold air. Thunderstorms produce about 8 million lightning bolts a day.
For a long time lightning was a big mystery. Ancient people thought that god was punishing people by sending a bolt of lightning down to Earth.
How lightning forms
Water droplets and ice crystals in a cloud have electric charges, positive and negative ones. Lightning happens when too many negative charges build up in a cloud and positive charges develop on the ground.
The particles want to meet and race towards each other. A flash of lightning is a sign of this meeting. Such a charge of light can be very hot, up to 20,000 degrees Celsius. It can be up to 5 km long. Large clouds produce more electric charges and eventually a very strong electrical current.
Lightning can also occur between two clouds or within a single cloud. In rare cases negative charges can form on the ground and lighting moves upwards, as is the case when a rocket starts.
Lightning strikes very quickly, several times within a second, but single bolts of lightning are impossible to see with a naked eye. A series of such bolts appear as a single flash.
Thunder accompanies lightning. It forms when electricity travels quickly through the air and starts vibrating. The hot air surrounding a bolt of lightning causes the air to expand, causing noise.
Lightning can do damage to buildings, cars or other objects when it hits. It can also kill or injure human beings. During a thunderstorm people should stay away from doors, windows and electrical devices. You should also stay away from phones and wires because lightning can travel through them. When you’re in the open do not try to protect yourself by hiding under a tree.
You can protect your house or other buildings surrounding your home by installing a lightning rod on the roof. It attracts the lighting that would otherwise hit the building and leads it to the surface.
Lightning can also have positive effects. It produces nitrates and other compounds when it is created in the air. These nutrients fall down to Earth and enrich the soil for good farming.
- accompany = go with; to happen together with
- although = while
- ancient = old
- attract = pull towards itself
- bolt =lightning that appears as a white line in the sky
- charge = here: small amount of electricity
- common = often seen
- damage = destroy
- develop = grow
- device = object, tool, machine
- droplet = small drop
- electrical current = flow of electricity
- enrich = to make better
- eventually = in the end
- expand = become larger
- flash = white burst
- human being = person
- injure = hurt
- install = put in, set up
- lightning rod = metal wire that is fixed to the top or side of a building and is used to protect the it from lightning
- nitrate = substance that has nitrogen and oxygen in it and is used to make plants grow better
- nutrient = chemical or food that gives plants what they need to grow
- occur = happen
- otherwise = or else
- punish = to make someone suffer because they have done something wrong
- race = move quickly
- rare = not very often
- release = set free
- series = one after the other
- several = many
- sign = signal
- soil = top layer of earth on which plants grow
- suddenly = unexpectedly, all of a sudden
- surface = the top part of something
- surrounding = around
- towards = in the direction of
- wire = thin cable of metal that can carry electricity