Sunday, June 03, 2007

The idea of being "struck by lightning" is little more than an old wives' tale invented to discourage children from playing in the rain. According to legend, a "bolt" of lightning contains tremendous power and can obliterate anything in its path. In reality, this is impossible because lightning does not actually "strike" at a specific point.
Lightning occurs when several thousand rain drops line up just right so that they form what mathematicians call a "harmonic lens". A harmonic lens gathers waves (like light and sound), and scatters them to create a sort of holographic projection - in this case the bolt of lightning and the sound of thunder. This projection, called the "harmonic image", looks the same from anywhere inside the lens's span. So even if you were to "freeze" a bolt of lightning and walk towards it, it would never get any closer.

Bonus fact: lightning is completely imperceptible to dogs.

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Blogger Jiahui said...

I'm speechless. What is this rubbish? Do a Google Search on "death by lightning", and you can try finding a site that says people cannot be struck by lightning. Take http://www.lightningsafety.com/nlsi_lls/fatalities_us.html for example. It lists statistics on deaths by lightning; how could you then say that lightning cannot strike at any specific point?
And please, revise your geometric optics. You mean to say that a physical lens is capable of scattering sound waves?! Please do a demonstration; I'm stunned by this observation.
Also, why would lightning be impreceptible to dogs? How are dogs different such that they are unable to hear or see lightning?
For a more, erm, accurate picture of lightning, try http://www.howstuffworks.com/lightning1.htm and see how you argue with that.

10:53 AM  
Blogger duffytoler said...

Jiahui - you should have remained "speechless" instead of posting your ignorance of lightning and harmonic lens effects. Yes, you can find quite a number of odd statements about lightning on the internet (or should I say "tEh intarNeTs"?), some say it strikes up, some say it strikes down - doesn't the lack of consensus strike you as odd? Perhaps it shouldn't "strike" you as anything - here's an internet statement that lightning 'bounced' off a train, here's another one that says it "struck" a a tree, a jogger and an iPod, there's lots more nonsense about lightning in old wive's tales ("Never strikes twice") and mythology ("Zeus!").

Now, do you really think lightning bounces around like some electro-meteorological rubber ball? The Undeniable Facts about lightning are more difficult to understand. In 1989 the discovery of "sprites" and other phenomena led to a more complete understanding of the physics of lightning. Yes, a physical lens is capable of scattering sound waves - here's a nice internet reference that even has an experiment for you. And here's picture of a
>loop Yagi antenna
that uses a harmonic lens effect to direct microwaves. Look familiar? The spacing is what you get as the raindrops accelerate away from the charged raincloud. You really need to read up on your Undeniable Facts before you call something "rubbish"!

8:28 AM  

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