Strong thunder!!

[Samanta]

Thunder here in Surrey is so strong its making the windows shake It is not a long growling thunder like you usually get, its just one very sharp blast with very little echo, almost like an explosion...and yeah, its making the windows shake.

Does anyone know what the difference in thunder is caused by?

 

[gokuss4]

distance in lightning strikes. It echoes and rumbles when the lightning is further away because of the environment around. When lightning is close it is a sharp CRACK, and damn it's loud.

 

[mudlord]

distance in lightning strikes.

Which is related to the speed of sound, in relation to the proximity of the lightning bolt to the listener. This is used to measure the distance in how far a bolt occurs, by the volume and the timing of the thunder vs the lightning.

Basic science. :matrix:

 

[BlueFalcon7]

anyone know why thunder even makes a noise?

A bolt of lightning is supposedly 5 times hotter than the surface of the sun. That is sort of believable, because to spark something a few miles, it takes some massive amounts of energy. Massive amounts of energy means massive resistance, and massive heat.

So the air is superheated with this giant spark. If the 5 times hotter rule is true, that means that the air gets to over 10,000 degrees. If you remember PV=nRT from chemistry (even if you don't) you know when air gets heated up, it expands.

When air gets heated up a lot very quickly, the air expands a lot, and very quickly. (Explosions also expand air a lot, and very quickly.)

Sound is created by changes in air pressure. The Explosion effect from a lightning bolt is more than sufficient for us to hear it.

 

[mudlord]

A bolt of lightning is supposedly 5 times hotter than the surface of the sun. That is sort of believable, because to spark something a few miles, it takes some massive amounts of energy. Massive amounts of energy means massive resistance, and massive heat.

So the air is superheated with this giant spark. If the 5 times hotter rule is true, that means that the air gets to over 10,000 degrees. If you remember PV=nRT from chemistry (even if you don't) you know when air gets heated up, it expands.

Actually, its nearly 6 times hotter =] but the rest I can totally agree with.

Source: http://weathersavvy.com/Q-lightning1.html

 

[A.I.]

Did you know thunder was the WMD of the ancients? Aparently Thor could shoot thunderbolts outta his arse.

 

[gokuss4]

So what if someone was standing 50 feet away from a lightning strike? Would they feel the heat or is lightning too quick?

 

[Doomulation]

OF course, this is pure speculation, but well... maybe. Perhaps you can feel a shockwave as the air expands, and the insane amount of energy it has collected as the lightning sped its way past it towards its destination.

Again... just pure speculation. I've never done it nor have I heard of any such experiments...

 

[Cyberman]

Let me explain what happens.
Lightening is a plasma (IE similar to the gases in the sun), and caused by the dielectric break down of air. The potentials (IE think voltage) between two zones of charge was high enough to arc over several km. That's quite scarey if you think about it. The current is enormous as a consequence and the air becomes extremely hot and expands like an explosive going off. Plasma is the fourth state of matter, at a certain temperature ALL matter conducts electrical charge, thus it becomes a plasma.

Summary "thunder is caused by the plasma formation and the consequential super sonic expansion of air after a lightening discharge".

Sound level follows I/r^2 law IE the intensity is reduced by the square of the distance. If it strikes 1km away and is 90db... I don't want to be anywhere near that blast LOL. One is talking around 130db at 10 meters (enough to cause serious and permanent physical damage to a person).

Cyb