Wednesday, September 3, 2008

From the Sky to the Earth!!

Across the woods, two soldiers were walking down a road amidst all the shooting going on around during the World War II. Suddenly they heard a noise. The lieutenant heard that and got alerted and got into cover behind some bushes and was watching for the source of sound. They heard another sound and another. Then he realised that they were foot steps.

"Flash" said the lieutenant
"Thunder" was the reply...

Then the lieutenant relaxed understanding it was the ally...

That was keyword the US soldiers used to distinguish between friend and foe during the World War II. Obviously, the flash or lightning comes before the thunder. And many times they are very destructive. What may seem unbelievable was that about 3000 people died because the lightning struck the base of the church that contained gunpowder. But the most interesting is the fact that 31 cows died because of a single lightning strike... Whoa. There have been numerous air crashes resulting in a large amount of casualties.

Few years back I saw this small story in "Young World" published by "The Hindu". A soldier was struck by a lightning. He regained health. Again the lightning struck him. This time he quit the job. Then one day when he was going on his horse, the lightning again struck him leading to his death ultimately. Two years later, lightning struck his tomb and shattered it. Poor fellow!!!

At times the lightning causes air crashes. At times lightning could be caused by the launch of a satellite and volcano eruption

Many of us know that lightning is the electrical discharge and thunder is the sound produced when lightning is produced. But what marvels the scientists is what causes them. It’s obvious that the clouds should emit charged particles to produce a lightning. But the real question is what makes the cloud to emit the charges.
How lightning initially forms is still a matter of debate: Scientists have studied root causes ranging from atmospheric perturbations (wind, humidity, friction, and atmospheric pressure) to the impact of solar wind and accumulation of charged solar particles. Ice inside a cloud is thought to be a key element in lightning development, and may cause a forcible separation of positive and negative charges within the cloud, thus assisting in the formation of lightning.
Some may say that clouds of opposite charges collide to form a lightening. That is a good theory. But what makes the cloud to get ionised? Frankly I don't know the truth behind lightning. You can find a few theory and hypothesis. But nothing can give u conclusive evidence. It appears that we have really skipped an important aspect in electromagnetic. Typically a lightning reaches a temperature of about 30000ยบ C which is more than 3 times the temperature of the sun's surface!!! Thunder is produced when lightning occurs. Some people try to calculate the distance based on the time period between lightning and thunder

But as far the research can go no one can give a conclusive fact with evidence on the real cause of the lightning and thunder. What science can answer is how Lightning starts and not how clouds get ionised and what the weather and geography has to do with it etc. Typically when a cloud reaches a mountain or hill station it is called fog. If they acquire charge then why aren't hill stations affected by this phenomenon? And at times lightning goes towards the earth? what makes it to gotowards earth? is the earth's surface charged??? And how does ice crystals get charged up automatically? Though science can explain them, they cant provide conclusive evidence on all aspects surrounding lightning and the loud thunder!!!

The fear of thunder is known as astraphobia


Aslam said...

Well... according to my limited knowledge it is static electricity which causes this. Like when u run a comb through ur hair it gets charged up. And when u take it close to any small object it causes an attraction due to polarization. U might even be able to see small sparks flying.

When same thing is applied to large objects obviously they cant move. So what moves is a large amount of electrical energy or electrons. The transfer is initiated after a certain threshold point beyond which the charges cant be held.

And i had also read that it strikes from ground to sky. That is in the upward direction contrary the belief that it strikes from the sky to earth. The ground has -ve charges which are attracted by the +ve ones in the clouds. The visual display is caused as a result of the air getting heated up around the charges...

Visu said...

Ahem, As far as i have read, this is electrostatic induction between the positively charged clouds and the negatively charged earth's surface with air as a medium of discharge. And the airplanes struck by lightnings must be the 'Action of Points' funda. And yes, the visual thingy is because of the air particles getting heated up.

Well, you know, Science is more or less religion. You gotta believe some things as told by the pioneers as such with no further argument, that which when done may lead to chaos! ;)

"But the most interesting is the fact that 31 cows died because of a single lightning strike.."

Interesting?? Huh.

And hey, the young world thing you read must be a review of some Vijay movie. :P

And hey hey, astraphobia can be overcome by casting "Arjuna, Arjuna".. (Ofcourse you don't know this dude) :)

Visu said...

Ak, i don't quite agree with the earth to sky funda. Because you know, franklin dude experienced such a phenomenon when flying a kite. That makes sense that it could have come from the sky. :)

Aslam said...

Well... the earth is -vely charged and the clouds +vely... and the fact that the electrons are lighter implies that they wud hav to move towards the +vely charged particles... and not vice versa..!! ahh well.. i guess so..!

Philip Kingsley said...

well the earth to sky funda basically depends on certain factors da. for example when u r launching a satelite this type of lightning is caused. these are most probably caused by some artificial issues.