|Why does thunder make sound and lighting doesn't?|
|Question Date: 2017-08-31|
Lightning creates thunder. Lightning is an
electrical discharge that heats a channel in the
air to a plasma - about 11,000 degrees
Celsius. This super heated plasma then
explodes outward into the surrounding,
normal-temperature air with incredible force,
generating a shockwave. This shockwave is the
Because shockwaves tend to blur as they travel
great distances, the thunder has generally
turned into a low rumbling boom by the time it
reaches you and is no longer a shockwave, but
it is when the lightning strikes.
Sound also travels at a finite speed, about
1000 feet per second. The flash from the
lightning also travels at a finite speed, but it's
much faster, about 186,000 *miles* per
second. This means that you see the flash
before you hear the thunderclap, because the sound
waves haven't gotten to you yet when the light
Thunder and lightning are the very same
event, that is caused by massive and sudden
electric charge transfer inside clouds. This
event creates both sound and light, but because
light travels much much faster than sound,
we see light first (which we would call
lightning), and hear the sound later (which is
called a thunder).
The sound of thunder comes from lightning, and
you can’t have one without the other. During a
storm, electrical charge builds up in clouds,
with an opposite charge building up on the earth
below, like a huge battery. When the charge
gets high enough, the energy that has been built
up is released as a lightning bolt. As this
energy is released, the air around the lightning
bolt reaches a very high temperature and pressure.
The pressurized region travels outward from the
lightning bolt as a wave, reaches your ear, and
you hear the rumble of thunder.
Thunder is actually the sound that results
from lightning, which causes a sudden increase
in pressure and temperature in the air surrounding
and inside of the lightning bolt. This change in
temperature and pressure causes the air to
expand very quickly, producing vibrations of the
air molecules which are manifested as sound.
Thunder and lightning are both part of the
process when there's a huge electric spark in the
atmosphere. We see the light right away,
because light travels so fast - about 300 million
meters every second. Sound travels almost 1000
times slower, so it is slow to reach us.
Do you know that you can tell how far away
the lightning was by how long it takes to hear the
thunder? It takes the thunder 5 seconds to
go 1 mile, so you can count the seconds and that
tells you how many miles away the lightning was.
The huge spark in the atmosphere makes huge
amounts of air move, and that makes the thunder
Light is light, and sound is sound, so they're
different. Sometimes the same thing can cause
both light and sound, like the storms that cause
thunder and lightning.
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