Thoughts And Trivia

I am afraid of the Lightning since childhood. I read a lot about lightning as a child out of curiosity. This has instilled a sense of panic in me when the clouds are angry - specially in the dark.
What I recall learning is:

1. The bolt of the lightning travels at a speed of 60,000 m/s ; temperature of 30,000^oC (five times hotter than surface of Sun)and carries a current of 40-120 kilo-amperes. A normal strike travels a distance of approx 1.3 Kms. Target is struck actually by 3-4 strikes 30-40 ms apart, due to repeated discharge of the charge in the cloud. The discharge channel in air is only 1 cm dia.


2. Lightning strikes the highest or the electrically the least resistive path to the earth. Be away from these high sites. Do not stand under a tree in an open space.


3. Its its search of least resistive paths that causes the cracking sound due to sudden changes in its paths. The thundering sound is due to the shock wave created by air in contact being suddenly heated to 10,000^oC.


4. In a structure it strikes the corners. Stay away from corner rooms or a corner in a room.


5. If standing in a row, it strikes the extremities. Stand in the middle of a line.


6. On striking or even before it may divide into a large number of splinter paths. If you are slightly afar from a target, even then you are vulnerable. People even 25 metres away may be vulnerable.


7. Rarely its has been seen to come as a balloon of bright light. Though lots of eye-witness reports are there, but there has never been a scientific confimtion of this.


8. More lightning is seen in rains after a particularly dry spell.


9. Mostly the lightning is negative charged. But rarely it is positively charged - which is more damaging - travels larger distances before striking. So even area not having clouds may get struck - really bolts from blue!


10. Lightning is the deadliest weather phenomenon, 24,000 people get killed and 2,40,000 are injured by it each year


11. Safest place is to be inside a strong house, but stay away from anything that can conduct electricity - phones, TV, Computer, plumbing, Metal doors/windows.


12. Car's tyres are ineffective as insulation. Its metal body of car that conducts away the charge that saves the ocuupants - if they are not touching any metallic part at that time.

No! No! I didn't want to infect you with my panic. Honest. Being forewarned isn't being forearmed always.

Posted by Girish Bhatnagar at Sunday, July 13, 2008