• Stormtrack's forum runs on Xenforo forum software, which will be undergoing a major update the evening of Wednesday, Feb 28th. The site may be down for a period while that update takes place.

Google photo find: more proof to debunk a lightning myth

Dan Robinson

Still believe that lightning myth? I just came upon this amazing photo during a Google search. Talk about lightning not hitting the highest point. This was shot by Kevin Ambrose in Washington DC.

http://www.weatherbook.com/images/monumentstruck_web.jpg

Notice the CG comes down alongside the Washington Monument, then abruptly jumps over horizontally to make contact about a third of the way down the side of the structure! An un-connected leader extends from the top.
 
Actually it probably shows how much it wants to hit the tallest object. It originates off to the left and yet still wants to find the shortest path. I think when it doesn't have any worth is when one is talking about powerpoles and some smaller trees. One can't expect a bolt to even notice those small differences when you look at the overall length. I imgaine the building gets hit more on average than a same square area on the ground in that area.
 
Yes, a very interesting image here Dan. Generally it is uncommon to see, this ..is it because it is a rare occurance, or perhaps not able to be photographed?
 
I think what your photograph demonstrates, Dan is that the highest object provided a return path from the ground to the sky (the brightest part of your image is in fact the return stroke after a conductive path was established from an initial leader downwards from the cloud) - it just happens that the path chosen from the monument upwards was from the side, probably following the path of an initial leader active just before your photograph was taken. It just happens that another leader was also in contact with the tip, but wasn't the most immediately available conductive path for the return stroke.
 
Here is another myth shattering image, I found via google. Generally, as I have noticed from friends and so on, people are staunchly under the belief that they're car can not be struck by a lightning bolt...I am not talking about having physical injury from it either...just it actually being able to be struck period..this myth runs rampantly under the roofs of many small communities.

car_bolt.jpg


I am going to assume this sort of occurance is rare, then? I highly doubt this event occurs with every thunderstorm, with some form of CG...and generally, would the car become diabled, or wouldn't the electric current, travel around - outside, the car thus grounding it?

Anyway, I know a lot of people think that the rubber from the tires contribute to the less dangerous environment a car, consequently inadvertantly provides for the driver, or the person seeking shelter.
 
Here is another myth shattering image, I found via google. Generally, as I have noticed from friends and so on, people are staunchly under the belief that they're car can not be struck by a lightning bolt...I am not talking about having physical injury from it either...just it actually being able to be struck period..this myth runs rampantly under the roofs of many small communities.

car_bolt.jpg


I am going to assume this sort of occurance is rare, then? I highly doubt this event occurs with every thunderstorm, with some form of CG...and generally, would the car become diabled, or wouldn't the electric current, travel around - outside, the car thus grounding it?

Anyway, I know a lot of people think that the rubber from the tires contribute to the less dangerous environment a car, consequently inadvertantly provides for the driver, or the person seeking shelter.
[/b]
That is one interesting pic!!
The metal in the car body acts as a Farraday cage channelling the majority of the electricity around the car, but the tires do not contain enough rubber to provide a ground. Considering also that the car will be touching water, that adds another component for the path of the bolt. Interesting to see the strike exiting at the rear tire...wonder how intact the tire was afterwards? Tires can be blown out as the electricity exits through them. If there is a direct strike to the car, the electronics are usually fried, and anyone in the car who is touching any metallic components in the car can possibly receive a nasty shock.
I know from experience that the car does not have to get a direct strike for the occupants to experience some effects from a lightning strike. Jo Radel and I were on a storm last June when a CG hit VERY close to my car as we were repositioning. I could feel the heat from the bolt through the window, my hands and arms tingled for a few hours from holding onto the steering wheel, and Jo had a earache and headache for a few hours.
 
In the case of the Washington Monument strike (again, I did not take this photo - it was shot by a photographer in DC), the CG is illustrating an instance where the stepped leader is descending close to the structure, then at the last few steps jumps horizontally to it. In other words, the lightning didn't 'see' the monument until its stepped leader was very close to the ground. The stepped leader was far enough away horizontally that the tip of the structure was further away by the time the lightning 'realized' the structure was there. In other words, the stepped leader came close enough to the structure to make the final jump only after it had descended to a point below the top.

This event of lightning striking the side of a structure is somewhat rare, but illustrates that lightning doesn't always strike the tallest object. It all depends on where the stepped leader is descending - and the stepped leader doesn't get influenced by objects on the ground until it is very close to the ground - in some cases less than 15 to 50 feet above ground. Here is a crop of a close strike I shot back in 1995:

groundhit.jpg


In this case the stepped leader never 'detected' the presence of the light pole that was 50 feet from its final connection point. Even no leader is visible off of the pole, which would suggest the pole was never even a condidate for a strike.

Evidence points to the concept that lightning will not get attracted to a conductive object that is further away than the object's biggest dimension. In other words, your tripod will only attract a strike that is already less than four feet from you. A chase car with tall ham antennas needs a strike to already be happening within 10 feet or so. In those cases, it's likely that you/your car would be hit anyway even without antennas. The lightning is initiated by large-scale cloud charging forces up inside the cloud rather than by anything small on the ground, and the lightning's stepped leader doesn't 'see' those things on the ground until it is making its final approach close to the surface.
 
What I find interesting about Andy's car strike picture is that it's obviously in close proximity to a high-voltage substation -- you can see the insulators in the background along with what looks to be some corona discharge off the top of the leftmost one.

The car may well have been the least resistance path for the strike which may have hit elevated electric structures above the frame. In otherwords, be careful parking near very high voltage electric structures. The lightning arrestor may just be you.

[ed., re. Faraday Cage] I posted this a few months ago.
The reason why you're quite safe inside a vehicle isn't technically because the metal of the body is a Faraday cage. Instead it's due to what's known as the "skin effect".

Lightning appears to a conductor as humongous power half-cycle RF to ground. The charge follows the outside "skin" of a conductor to ground; thus even touching metal inside a vehicle isn't reported to result in serious injury (though I guess the high voltages are enough to generate a Van de Graff-like tingle through charge leakage into free air). [/b]
I wouldn't bet my life on it, but a significant difference is you would probably survive a lightning strike to a Corvette (non-metallic) body, as the lightning would still course around the outside of the vehicle. I'll let some grad students do that experiment! :)
 
I believe the photo Andrew posted is the result of a test using an artificial lightning generator (a large Marx impulse generator) intentionally set up to hit the car. Lightning will usually blow out one or more of the tires on a car that is hit.

True, cars are not pure 100% safe lightning shelters, but they come pretty close. By far the best alternative if no substantial structural shelter is available.
 
I guess I take a pretty simple attitude about lightning…it will strike anything it wants, and no place, including a car, offers guaranteed protection. I’ve seen lightning do every possible zippy formation.

Here’s an example of at least a 10 mile reach-out...and for what reason...who knows...
Channel reaching out

And this is just a tiny segment of a bolt I would have to guess was more than 15 miles long (this is just about 1/3 of the bolt, I couldn’t get it all in).
Goes on forever
What was so attractive that the lightning shot clean out of a mountain range and into the desert for miles? A saguaro? A piece of yucca? It struck there because it felt like it =)

From what I've seen, lightning strikes whatever it darn well pleases, and therefore, that would include my car. So…I don’t talk on communications equip that is connected to anything, I keep windows rolled up when driving in storms and I don’t touch the chassis/door frames or anything else. Plus I take my antennas down during lightning. Still no guarantee but it is an effort toward a little bit more safety.
 
To add fuel to the point that lightning could strike anywhere it pleases, once when I was in Junior High, I saw lightning strike a man hole in the middle of the street in front of our house. There were lots of trees and houses around, but none were touched.

During one exciting storm intercept while I lived in NH, I watched lightning hit the ground just several feet from my car. It landed in the parking lot and shattered into many branches that slithered like snakes.
 
Here's more evidence in support of what Dan and Susan have said. This afternoon, I was out shooting some video of a garden variety storm over Choteau Island, between the Mississippi River and Chain of Rocks Canal in Madison Co., IL. I was hoping to get some CGs in my video; only got one but it was a close one:

[attachmentid=472]

Note that it struck in the middle of the field. Didn't hit the trees in the background; didn't hit the powerlines or poles along the road where I was parked. I have seen bolts hit in the middle of a field next to the road before when I was chasing, but this was the first time I managed to catch it on video.
 

Similar threads

Replies
0
Views
2K
Dan Robinson
Back
Top