4 ms·

>Don't assume you're safe because you're not near a high point Yet again human intuition proves counter-intuitive. It's easier for us to visualize that being a

by sigkill 13y ago

>Don't assume you're safe because you're not near a high point Yet again human intuition proves counter-intuitive. It's easier for us to visualize that being at a high point is more dangerous than a lower place. If there were a method to use FFT and convert land from a height map to the resistance/conductivity domain, I'm sure there will be very very surprising results.

brazzy 13y ago
It has nothing to do with intuition, just with over-simplification. It is true that high points tend to attract lightning and that this can make you safe. The effect just isn't as strong as most people think. Basically, the "leader" that establishes the path through which the main discharge will happen moves randomly downwards, but will be strongly attracted towards grounded objects that it comes close enough to - and "close enough" is only about 50 meters. So if there is a high point within a sphere of 50m radius centered 50m above your head, you're indeed almost completely safe (or at least you won't be hit directly - what hit Marlin was apparently a part of the charge that was moving through his house.
- kposehn 13y ago
  Another note is that the stepped leader that comes down meets another coming up from the ground. The one which reaches the one from the cloud creates the main channel, no matter where it is coming up from.
- slacka 13y ago
  I grew up in an area that frequently had thunderstorms. I witnessed many strikes in my yard, including my house while I was in it, and investigated many in my neighborhood. Much of what the OP said was bullshit. If it were true, the lightning rods that attracted and diverted many strikes wouldn't need to be place high. The strikes always hit taller object like houses and trees and I never ever saw a strike or evidence of one in the middle of a field.
  - kposehn 13y ago
    Please don't generalize your experience across the entirety of all possible occurences. 1. http://www.youtube.com/watch?v=oqzjk1kp5Ug http://www.youtube.com/watch?v=oqzjk1kp5Ug - Notice in the shot how the lightning hits a small, low-in-the-water boat. 2. http://www.youtube.com/watch?v=keVm06H26ik http://www.youtube.com/watch?v=keVm06H26ik - In Boulder, with the mountains right next door, lightning strikes twice in the city proper, around 1,000 feet lower in elevation. 3. http://www.youtube.com/watch?v=YKw9kpD0rNc http://www.youtube.com/watch?v=YKw9kpD0rNc - Lightning strikes the water, less than a hundred feet away, instead of the palm trees the photographer is at. My point was that assuming lightning will strike the highest point is patently false; it doesn't meant that a valley isn't any safer than a mountain - just don't assume that being in a valley protects you.

by sigkill 13y ago

brazzy 13y ago

It has nothing to do with intuition, just with over-simplification. It is true that high points tend to attract lightning and that this can make you safe. The effect just isn't as strong as most people think. Basically, the "leader" that establishes the path through which the main discharge will happen moves randomly downwards, but will be strongly attracted towards grounded objects that it comes close enough to - and "close enough" is only about 50 meters. So if there is a high point within a sphere of 50m radius centered 50m above your head, you're indeed almost completely safe (or at least you won't be hit directly - what hit Marlin was apparently a part of the charge that was moving through his house.

kposehn 13y ago
Another note is that the stepped leader that comes down meets another coming up from the ground. The one which reaches the one from the cloud creates the main channel, no matter where it is coming up from.
slacka 13y ago
I grew up in an area that frequently had thunderstorms. I witnessed many strikes in my yard, including my house while I was in it, and investigated many in my neighborhood. Much of what the OP said was bullshit. If it were true, the lightning rods that attracted and diverted many strikes wouldn't need to be place high. The strikes always hit taller object like houses and trees and I never ever saw a strike or evidence of one in the middle of a field.
- kposehn 13y ago
  Please don't generalize your experience across the entirety of all possible occurences. 1. http://www.youtube.com/watch?v=oqzjk1kp5Ug http://www.youtube.com/watch?v=oqzjk1kp5Ug - Notice in the shot how the lightning hits a small, low-in-the-water boat. 2. http://www.youtube.com/watch?v=keVm06H26ik http://www.youtube.com/watch?v=keVm06H26ik - In Boulder, with the mountains right next door, lightning strikes twice in the city proper, around 1,000 feet lower in elevation. 3. http://www.youtube.com/watch?v=YKw9kpD0rNc http://www.youtube.com/watch?v=YKw9kpD0rNc - Lightning strikes the water, less than a hundred feet away, instead of the palm trees the photographer is at. My point was that assuming lightning will strike the highest point is patently false; it doesn't meant that a valley isn't any safer than a mountain - just don't assume that being in a valley protects you.