When Lightning Strikes 285
ctwxman writes "For most of the United States (sorry West Coast), this is the season for lightning. It is as powerful as it is spectacular to look at. It is destructive too - by itelf or through the hail, straight line winds and tornadoes that often accompany it. As someone who forecasts the weather, I'm often asked about lightning. As you might imagine, there's plenty to see about lightning on the Internet. The conditions necessary and a little bit of the physics behind lightning are explained by Jeff Haby, a meteorologist (one of my professors actually) at Mississippi State University. Once forecasters get a handle on what's going on, they put the word out through the Storm Prediction Center. Regular outlooks are issued by SPC for severe storms. Once those storms rear their ugly heads, they're followed with mesoscale discussions looking at the active areas. The Storm Prediction Center is also the place where Severe Thunderstorm and Tornado Watches are issued and storm related damage reports are compiled. Lots of hobbyists like to track lightning strikes on their own, and there's equipment available to do just that. Getting hit by lightning is never fun, though not always fatal. National Geographic chronicled an amazing story of a lightning strike, and rescue, on Grand Teton."
NLDN (Score:5, Informative)
better read (Score:5, Informative)
NMT LMS (Score:5, Informative)
It has some pretty neat images of their lightning mappings. You can see the lightning in 3D, and the precursors to lightning, etc.
Not much info, but there's been some really neat research going on out there. Maybe someone else knows more.
Re:Watching lightening...up close (Score:2, Informative)
Re:lightning.. (Score:4, Informative)
This is why people are discouraged from "seeking shelter" under large trees during a lightning storm. Not only is the taller object more likely to be struck by lightning, but also the radio waves emitted within a 10-15 ft radius can cause you to go into cardiac arrest. Dangerous stuffs if you're too close to the strike point.
Re:NLDN (Score:1, Informative)
The thing about it blasting him out of his car doesn't make any sense. A vehicle is a wonderful faraday cage. I've known of many people that have had their cars or airplanes struck by lightning. Not one of them was injured in any way.
Re:NLDN (Score:5, Informative)
Re:As someone who forecasts the weather... (Score:2, Informative)
Re:lightning.. (Score:5, Informative)
There is a great big electric field associated with a nearby channel, and field gradients can result in some really interestingly large voltages to appear across things like the ground.
However, to call these fields radio waves implies that they are oscillatory in nature, which is simply not accurate. I'm a lightning researcher, and in the course of my work I've studied lightning electric fields recorded during close lightning strikes. It's not my personal favorite area of interest, but I know enough to say that "radio waves" is a poor description.
The reason that you don't stand near trees during an electrical storm is because 1) the flash is likely to initiate a side channel which passes from the tree-trunk (radio tower, light pole, bus stop, etc) through you, making you very unhappy; and 2) because the HUGE injection of current into the ground causes the ground itself to "rise" from a nominal 0 volts to several kilo- or even mega-volts, and that voltage falls off as the square of the distance... so that if your two legs are 10 feet and 12 feet respectively from the channel termination point, you might experience a voltage of several kV (or more) between them. This causes a current to flow up one leg and down the other, and makes you (and your goodies, don't ya know) very unhappy. This is worse if you happen to have four legs which CAN'T be placed together, like if you're a cow or horse. Zap!
Chlorine pulled toward surface? (Score:1, Informative)
so it carries a charge. Prior to a lightening strike
or near-strike, you get weird effects on the target
from charges building up. If one half of the
chlorine compound (the + or - ion) got pulled to
the surface by this, you might well see some effects.
Re:Chlorine pulled toward surface? (Score:4, Informative)
I concure with this possability, it may not have been boiling (as per reaching an approx. temp. of 100 degrees C (220 F) but may have appeared to be boiling due to the movement described above.
This is similar to how microwaves work. [howstuffworks.com] Also Ionization is not just used for nuclear fusion, quick question for you...
Q: If nothing sticks to teflon, how do they get teflon to stick to the pan?
A: They ionize the pan with a positive (+) charge, and ionize the teflon with a negitive (-) charge and it will stick like the opposing ends of two magnets
"Physics class is now over, please read pages 121-320 by next class"
Clarification - from original poster (Score:4, Informative)
Re:oh let me count the lightning stories... (Score:3, Informative)
As far as the car thing goes, well I actually know someone firsthand who lost all four tires on the sawgrass expressway at speed when struck by lightening, car was totaled......so I'd have to say no it's not bullshit...
If you live in Florida and it's your time to go it will get you, one of my childhood friends lost his father to a lightening strike, a maint worker at my mothers work had all the clothing blown from his body and his head ruptured due to the strike, it's frequently on the news down here how someone died due to a strike, the details of what happens to people when struck are usually far to gory to put on tv, dead on strikes turn people inside out.
Re:NLDN (Score:3, Informative)
His surname is Romansch (Rhaeto-Romanic), from Switzerland. Grew up in a tight-knit Catholic family.
Re:NLDN (Score:1, Informative)
Sure, since lightning really is static electricity, as long as one doesn't touch part of the frame of the car, they'll probably be protected, w/o the tires, the electricity would stay on the outside of the car until it disappated through the air.
This explains why some cars with tires that replace enough of the carbon in the rubber with silica build up a good static charge on the outside of the vehicle, so one gets the shit shocked out of them when they close the door when exiting the car, for example. The tires are much less conductive, so the static charge on the outside of the car does not dissipate fast enough.
Airplanes and helicopters generate quite a large static field on them when flying through the air. Airplanes have little metal fingers that hang off the trailing edges of the wings, etc., that help the air "pull" off some of that energy so it does not build up too high as it is flying (remembering from basic electrodynamics class, E fields are concentrated at points, so the points of these protrubances can help dissipate the energy back into the air because the E field is high enough at the point).
Re:FffiiiiiZZZAP! (Score:2, Informative)
Microwave equipment has little trouble from the antenna itself. The culprits are mostly power cables and antenna feed lines, neither of which is a concern for a laptop running on batteries and using a built-in WiFi antenna. Anything close enough to hurt the laptop poses serious risks to you.