Sunday, August 10, 2008


This has been all over the place for the last few days, but given that I recently posted on an article about lightning, I feel justified picking up the tail end of the virus. One note I read on it said that this was shot at 6000 frames per second. This is a fascinating video that allows you to see different phases in the development of a lightning bolt. First, as the charge difference between the cloud and the ground becomes too great, a diffuse "spray" of mini-bolts radiates from the cloud. When one of the little leaders comes in contact with the ground, it becomes the main conduit through which the current flows. Because of the "inertia" or "momentum" (I put those words in quotes because I'm not sure they're technically applicable to electricity, but the idea is similar), too much charge moves between the cloud and the ground. The charge again becomes unbalanced, so the lightning bolt, which has started to dim, but is still the conductive tube of plasma (ionized air), allows the charge to move back again. This process repeats until the charge is essentially equalized; this is the cause of the multiple pulses of brightness.

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