Posted on 06/22/2006 11:32:56 AM PDT by Mr. Brightside
Today: June 22, 2006 at 9:56:7 PDT
Lightning Strike Kills Colo. Motorcyclist
ASSOCIATED PRESS
WESTMINSTER, Colo. (AP) - A motorcyclist died after he was struck by lightning while riding in rush hour traffic between Denver and Boulder, police said.
Witnesses reported seeing a flash of light shortly before the motorcyclist struck the center divider on U.S. 36 Wednesday, police spokesman Tim Read said.
Gary Missi, 46, of Longmont was pronounced dead at the scene.
A coroner's investigation was under way to determine whether the lightning bolt, the collision or something else caused his death, Read said.
The lightning blasted a 4-inch-deep hole in the highway and sent chunks of asphalt hurtling across the highway.
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I missed where you quoted an article.
http://wvlightning.com/glossary.shtml
Corona Discharge- A slow, steady discharge streaming off of a point or edge of an object in the presence of high opposing electrical charge. Corona discharge is usually visible as a small, slightly glowing 'spray' extending out into the air. On a small scale, corona discharge can equalize opposing electrostatic charges before full electrical breakdown occurs and a spark jumps. On a thunderstorm-scale level, corona discharge can occur from objects on the ground underneath the cloud's charge region. However, this rate of 'current' leak is extremely miniscule or even nonexistent in comparison to the rate and magnitude that the gigantic storm cloud is generating the voltage. Therefore, corona discharge on the ground doesn't even in the slightest bit prevent a lightning strike from occuring.
There may be a slight occasional advantage to lying down, but for a herd of cows standing or flat a strike to the ground will kill a number of them. The ground current will go into their body, through the heart, and back into the ground. The only thing that would save a herd in an open field would be to attach a piece of wire from leg to leg all the way around the cow. (Probably a bit impractical!) Still, a direct hit would likely kill the target cow since it would usually be hit in the head.
I don't disagree with what you said. It's a far cry different and more explanatory than the original statement I said that I don't buy. That was equivalent to the "100 miles per" parameter or like saying "50,000 ohms is dangerous."
With the amount of voltage and amperage you're talking about in a lightning strike, the rubber tires, etc., would be next to useless. That kind of juice would arc to the frame of the bike so fast it would make your...well, you get the picture. Also, if I recall correctly, most of the highway between Denver and Boulder is concrete instead of blacktop, so there are literally tons of iron rebar all in a nice grid 6 or 8 inches below the surface of the road.
Sorry. Unsourced. Not the "new research" you teased us with. FACT: Hitachi has achieved nearly 100% lightning protection using corona discharge principles.
I used the term 'recent research'. The following was published by the National Lightning Safety Institute 2002. It references DAS, which, I believe, is the system Hitachi has invested in. The latest research listed is from 2000. There likely have been new developments since then. If so, can you point me to the research? I would be very interested.
http://www.lightningsafety.com/nlsi_lhm/Uman_Rakov.pdf
I have since checked out the possibilities of that happening, and low and behold, you can get zapped!
How's that saying go? ...
"I'd rather be lucky than good anytime".
Yeah ... that's it. ;)
Lucky is good, but I'd rather be blessed than lucky. In the case of electricity, I'd rather be grounded. :-)
The lab runs only test steady tip current, not the tip response, or compared response to any dE/dt. they also should have connected the tips directly to ground and measured current to ground. Also, a build with subsequent high dE/dt applied through a cap discharge arrangement.
The configuration is not really a presentation of ground through the tips as a lightning protection system would engineered to do. Several floating objects are presented above ground and the test determines which one(s) are more likely to be hit. Naturally one that simply ends up an induced dipole, with no space charge painted around it, will be hit first after the field of the leader is applied.
In design, the tips are placed to protect the objects. One that leaks charge will maintain a lower potential below it and provide a reservoir of charge. details in the outside experiment are sorely lacking. In one hit, however, a dull rod was placed between 2 sharp points. The lower potential provided by those sharp points is actually focusing the the field from the approaching leader on the dull rod, increasing it's induced dipole field. It's important to keep all objects below and within that lower potential and make sure any object that would respond as the dull points did, below that. Using dull rods keeps everything at a high potential and all objects "protected" by them are subject to the high dE/dt from the approaching leader.
Have you seen the umbrella shapes and brush shapes of some of the newer systems? One of them looks a bit like a thing Tesla made long ago. I think the drawing is on wikipedia under 'lightning rods'.
I would like to see actual head-to-head research setups of each of the major systems in the field to find out which is best and how they actually work. I don't think mixing types near each other is a good idea since their own fields are going to affect each other as you mentioned. One type on one building, another on a different one, not nearby. After 300 years of playing with lightning rods, it is about time someone writes the modern book on the topic. (Maybe the new systems have already done that. I would like to hear their detailed explanation of why theirs works better.)
This will eventually happen since the commercial rewards are great. The insurance companies are probably smelling the blood in the water and want to find out why they are paying out for lightning strikes if they can be avoided. This rate for this good system, that rate for that crummy system.
"Harleys suck. With as G_d is my witness, may he strike me down"
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