And i dont mean "its lightning duh" i mean in a scientific manner please. I'm just curious as to what is causing that noise. Or if its an exothermic reaction and the noise thunder is just a byproduct. I'd like a scientific answer with a reputable source as well. Thanks.
2007-07-08 16:18:49 · 19 answers · asked by Confused Guy 2 in Science & Mathematics ➔ Weather
Lightning is, as you know, electricity rushing from cloud to cloud or from cloud to ground. A very large current momentarily rushes from a cloud to ground. (Actually, some physicists believe the lightning propagates from the ground up to a cloud. In any case, current flows, for a brief second.)
It's not easy to get current to flow across air, as you might guess--after all, you don't get shocked every time you walk by a light socket. So air has a high resistance. By Ohm's Law, V=IR, a large current across a high resistance requires an INSANE voltage. And by P = IV, it can be shown that the lightning generates a huge amount of power.
Not all of that power goes into the flash. The resistance provided by the air has to drop the lightning's voltage down near 0 by the time it gets to ground. So the power is absorbed by the resistance of the air, and is turned immediately into heat, in much the same way as 110V line power creates resistance heating in a toaster or hair dryer.
Treating air as an ideal gas (not a bad assumption in this case), you know that Pv=RT; temperature is proportional to pressure times volume. So if the temperature goes way up suddenly, and volume remains relatively stable, then pressure must go way up. This is precisely what happens. The air heats up and expands rapidly, creating a big, powerful pressure wave.
What is sound? Nothing but pressure waves.
In short: Lightning travels through air, air has a resistance to electrical current. The electrical power in lightning creates resistance heating in the air, which expands and creates an immense pressure wave, which our ears pick up and interpret as sound.
Clear enough?
2007-07-09 12:33:48 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Thunder IS caused by lightning, which is essentially a stream of electrons flowing between or within clouds, or between a cloud and the ground. The air surrounding the electron stream is heated to as hot as 50,000 degrees Farhenheit, which is three times hotter than the surface of the sun. As the superheated air cools it produces a resonating tube of partial vacuum surrounding the lightning's path. The nearby air rapidly expands and contracts. This causes the column to vibrate like a tubular drum head and produces a tremendous crack. As the vibrations gradually die out, the sound echoes and reverberates, generating the rumbling we call thunder. We can hear the thundering booms 10 miles or more distant from the lightning that caused it
2007-07-09 08:02:04 · answer #2 · answered by Michael N 6 · 1⤊ 0⤋
Lightning bolts are extremely hot, with temperatures of 30,000 to 50,000 degrees F. That's hotter than the surface of the sun! When the bolt suddenly heats the air around it to such an extreme, the air instantly expands, sending out a vibration or shock wave we hear as an explosion of sound. This is thunder. If you are near the stroke of lightning you’ll hear thunder as one sharp crack. When lightning is far away, thunder sounds more like a low rumble as the sound waves reflect and echo off hillsides, buildings and trees. Depending on wind direction and temperature, you may hear thunder for up to fifteen or twenty miles.
2007-07-08 17:50:42 · answer #3 · answered by margie a 1 · 0⤊ 0⤋
I don't have a source, but I was watching something on discovery or national geographic yesterday that said the same thing. Lightning is hotter than the surface of the sun. When you heat something, like air, it expands. It is heated so rapidly that the expansion occurs above the speed of sound, breaking the sound barrier and creating a sonic boom. The reason it sometimes rumbles is when the lightening is far away, it echos and reverberates off of the ground, buildings, etc. If lightening ever hits close by, it sounds like a shotgun going off next to your ear, with no echos or delay. The delay is simply caused by the speed of sound (roughly 700 mph) and the distance between you and the lightening strike itself.
2007-07-08 16:25:23 · answer #4 · answered by ajvpb 2 · 0⤊ 0⤋
Thunder is caused by lightning- right. The sound is made as the air around the lightning bolt heats & then cools. The air by a strike of lightning is heated at a high degrees.When the air cools down, it causes a shock wave to occur (aka) thunder.
2007-07-08 16:23:32 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Lightning only causes thunder.When a bomb explodes, air around expands very rapidly creating almost a vacuum near it.Immediately after the explosion, air suddenly contracts trying to occupy the empty space.In similar coditions shock waves are produced which create the noise.Similarly the lightning arc produces enormous heat which makes the nearby air expand suddenly and contract immediately after that creating the above mentioned shock waves resulting in a loud noise.
2007-07-08 17:32:17 · answer #6 · answered by Arasan 7 · 0⤊ 0⤋
The above nameless post is 100% correct. Thunder, in itself is nothing to be afraid of. However, when you hear it, it is a signal that you should move indoors if at all possible, and stay back from windows. Avoid contact with electrical appliances and telephone handsets that are connected by wire. Try to avoid contact with plumbing (yes, when you've "gotta' go" you've "gotta' go" but do so as quick as possible :) ). If you do not have your computer plugged in to surge protection, unplug it and disconnect the network cable (if you have a cable modem, disconnect the round cable going in to it that looks like a tv cable, and the power plug) to avoid damage. If you can't go indoors, a car is also an extremely safe place to ride out a thunderstorm (barring tornadoes).
2016-05-17 06:53:02 · answer #7 · answered by ? 3 · 0⤊ 0⤋
Thunder is caused by lightning. The sound is made as the air around the lightning bolt rapidly heats and cools. The air around a lightning strike is heated to 50,000 degrees Fahrenheit (27,500 C), as the air cools it causes a shock wave to occur known as thunder. The closer the lightning is, the louder the clap of thunder will be.
2007-07-08 16:22:37 · answer #8 · answered by Anonymous · 1⤊ 2⤋
A bolt of lightning will burn the air in a microsecond. Then the air has to rush back in to fill that space. That is what thunder is. The thunder is a byproduct of the electrical stroke.
2007-07-08 16:22:20 · answer #9 · answered by Dan S 7 · 0⤊ 2⤋
When a cold air front and a warm air front meet you get thunder. ...
Thunderstorms can occur just about any time of the year and any where. Severe thunderstorms usually will occur in the spring and fall because there are more cold and warm air fronts than at any other time of the year. Frontal thunderstorms happen when cold air is more dense than warm air. When a cold front reaches a warm air mass, it quickly makes the warm air rise, making the conditions for severe weather in the troposphere.This situation in the trosphere can cause winds of up to 58 miles per hour, large hail, and even tornadoes. A frontal thunderstorm looks like a thick line of thick cumulonimbus clouds.
http://library.thinkquest.org/CR0212082/tstormfore.htm
Had to go look it up just to be sure i was remembering correctly what I learned from science class.
2007-07-08 16:21:23 · answer #10 · answered by Anonymous · 2⤊ 2⤋