Proof That Lightning is Totally Unpredictable...

Lighting takes the path of least resistance........... and the truck acted like a Faraday cage.

So you think that a truck on rubber tires (I know there's carbon black in them) with no galvanic connection to ground has less resistance than a properly grounded power pole?

the truck was only a path to ground. As far as the power pole being properly ground......... where did you read/see that?

You're right, there's no way to really "know" about any ground, but we can "assume" that the utility owning the pole doesn't want the liability issue of not conforming to safety codes in the event that the public somehow comes in contact with improperly grounded equipment and the lawyers get involved.

The step pulses actually do the work of ionizing the air,.....

So if your standing in a thunder storm, and suddenly your hair stands on end from static........ :O

Dive down and sideways.... I was given that advice a very long time ago. It's like getting out of the road when there is a truck coming.

I was told the same thing....... I always felt the reaction time to do so had to be awfully quick.

You have to only be as fast as lightning.

I haven't tried it but I was told that you do have time, the path takes time to set up.

I was told to curl yourself up into as smaller ball as possible with hands on your head, elbows tucked into the sides.

Another interesting thing is that many people have survived lightning strike, however a few times I have noted (from reports) that women who did not survive strikes actually had underwire bras on...........so, boys don't wear underwire bras in a thunderstorm!!!!!! Seriously though if you have metal in your pocket, particularly a shirt pocket get rid of it quickly...........because what it does evidently is concentrate an extremely high electrical charge around the heart area, if you are struck by lightning, and bang, one slightly stuffed heart???

As pointed out previously you do get a warning before the strike, e.g. hair standing up on end, etc.

Why not make sure both feet are firmly on the ground, therefor forming a voltage divider,shunting half the voltage through each leg?(HEH HEH HEH!)

I read that some villages in Africa put tires on their roof to prevent lightning strikes.

This makes more sense to them that putting a metal rod up in the air.

Again, a total myth. If lightning can travel through thousands of feet of air, a pile of tires is nothing.

Lightning rods work. If they didn't they would not be employed today and there would be tires on top of towers and buildings.

When was the last time you read a really good scientific paper coming out of Africa?

Nah, me neither.

More likely they put tires up there to keep the tin roof from blowing away in high winds.

And to breed mosquitoes.

Hmm! The last time I heard of anything was around 1967 or so, when the first heart transplant surgery was performed.

I didn't say the tires were scientifically based,I said it was customary;a relatively recent one by comparison to other tribal customs.

What about Jorrie?

He holds 4219.

Used to be, tires on mobile home roofs was very common. It kept the vibrations and noise from wind and rain down. The extra weight from the water in the tires seemed to hold the roof on a bit tighter, too.

This is from experience.

You can't fool a tornado.

true, true.

Here I am at home with my Laptop, reading your post has put my hair up on end!!

Am I about to be struck by lightning?

(My wife's middle name is lightning!!!)

Here I am at home with my Laptop, reading your post has put my hair up on end!!

Am I about to be struck by lightning?

(Oh by the way, my wife's middle name is lightning!!! But I have told her I am on strike!!)

This one would make your hair stand on end????
We grow 'em big in Australia!!!!
Note the taller trees that are quite close to the strike.........and they tell you not to stand under a tree.
Just goes to show the topic of this post "Proof that lightning is totally unpredictable"

The reason not to stand under a tree is not only that it makes a lightning rod, but the resulting shrapnel from the water in the wood turning to steam.

Had a neighbor's tree get a small strike and there were pieces of wood and branches easily exceeding a 300 foot radius.

............water in the wood turning to steam
.........and of course when water turns into steam it expands 1 700 times its volume........is it any wonder that the tree can virtually explode!!!!!

Quite the spectacle.

It's quite spectacular, we had (and still do) a beautiful maple tree that was across the road from our house, and a small lighting storm when through..........

To set up this story......

We had some friends over when the storm passed through and We were looking a large picture frame window......... (About 52 inches high by about 110 inches long)........ at this maple, and one of our guest mention, what would happen if lighting struck that tree, and the moment she said that, lighting did......, after the storm passed, we whe out there and there was spears 4-5 feet long 150 feet from this maple stuck in the ground like a javelin.......... As a 10 year old kid, I was impressed.

My mom got hit that way in the 1930's, as a little girl. It broke her arm, but no burns. Most of her neighbors insisted it couldn't have been lightning that did it, since there were no burns. But she swore all her life it was a lightning stroke that bounce off the tree. I always suspected it was the explosion of the tree when the sap and water in the tree's cells boiled so suddenly.

I suspect that is still true in many cases.....the lightning MAY strike the tree, but if you/someone are standing near to the trunk, it will maybe "come out" of the tree to pass though a human, as he/she has a lower resistance than a tree to ground.

That is what I was told many years ago....It is also supported by several web sites like this one:-

http://van.physics.illinois.edu/qa/listing.php?id=1342

I think in this case, the lightning found something "more attractive" than a tree......

Also, all the trees that I have seen that had been struck (I live 100 yards from a big forest! There are plenty to see), appear to have "exploded", I think probably due to water/sap being converted to steam almost instantly by the current flow.....

Why sideways? Lightning knows which direction you're facing?

The theory that was told to me was that path of the lightning, is actually connecting paths of the many particles that left ion trails in the atmosphere. Hence the jagged pattern.

"Interesting enough, most strikes start with a series of step pulses from the cloud toward the ground. You don't actually see these. The step pulses actually do the work of ionizing the air, which provides the pathway for the bolt to travel in the opposite direction from ground to sky."

Actually, from my work as a Lightning Mitigation Engineer for the US Air Force (and others), the majority of lightning strikes are cloud-to-cloud (roughly 60%) followed by cloud-to-ground (roughly 30%) and ending with the remaining 10% or so being from ground-to-cloud. The numbers are rough, and may be old, but are based on NOAA lightning research conducted up to about 1992.

The step pulses form a chain called the Stepped Leader, and the action of that formation and discharge accounts for the "ripping canvas" (my description) sound that is heard when one is within 75-100 feet of the actual stroke (I have been, numerous times). And that Stepped Leader actually starts at the earth, beginning creation of the plasma channel. Once the channel is sufficiently opened for the extremely high potential between the clouds and the ground to be breached, the main stroke drops from the clouds to finish the job.

I know, as did NOAA when I was reading their research, that this seems to mean the main stroke is "hole flow", but it appears that the actuality is that the earth potential which results in the stepped leader is a localized potential in the clouds, mirrored by a localized balancing potential rise in the earth, but that the greatest potential difference at that time is between the clouds. Thus the localized potentials are reversed (high negative in the earth, high positive in the clouds directly above), and both "localized" charges are counter-balanced by opposing charges in the clouds and earth surrounding the localized imbalances. Once the ionization path is completed, the entire charge is dumped across from the surrounding clouds to the central cloud, and across that gap to the earth, thus balancing all the potentials over a larger area.

The above chain of events seems to me to be a reasonable explanation for the higher propensity for cloud-to-cloud strokes than for either cloud-to-ground or ground-to-cloud, since it would seem MORE likely that a discharge from cloud-to-cloud would balance charges, than that the charges would be large enough to require the further gap-jump beyond cloud-to-cloud. Of course, that seems to mean that every stoke to or from earth must be accompanied by a stroke between clouds. But data wasn't available to verify that when I was studying the subject, and it is probably obvious why I wasn't able to verify it independently.

Interesting about those steps.

Why do you suppose lightning seems to follow stepwise path and not a smooth curve? Why does it go straight for (an average of) 10-15 m then suddenly change direction and follow another straight segment, then turn again, etc., sometimes forking, most times not? Ever wonder that?

Droplet spacing? It's as good a guess as anything.

The ionized trail is probably disrupted by wind and temperature variations at different elevations ,and a new path is found.

The forking is probably not exactly instantaneous,but alternate.

It always follows the path of least resistance,and it is constantly changing.

When they fire a rocket with a wire lead to attract lightning, it follows a straight line down the wire.

HTRK, RedFred, Europium:

According the reading I did back then, these are all contributors to the stepping, the jaggedness, the forking of the trail. In fact, it was also found that it was possible for a charged "particle" (more on this in a moment) to drag the path of the ionization channel with it, through the air. Small air currents are assumed to also be able to do so, but it was observed (photographed, video-taped, etc.) the strong winds aloft will definitely push the channel.

Back to those "particles", NASA flew an F-105 through the predicted path of a lightning storm in hopes of collecting strike data (I'm happy I don't fly, and that they didn't ask ME to fly that series of missions), and found, with recorded evidence, that the plane is actually capable of dragging the channel with it. Even more interesting is the fact that small dimples were found on the planes surfaces that showed the lightning bolt's entry and exit points, and that in at least one case, the entrance, on the outside of the fuselage AFT of the main wing, was matched to a pair of exit and entrance points inside the combustion chamber, further matched by an exit point on the side of the fuselage opposite the first entrance. But most interesting of all is that since the plane was traveling at high sub-mach speeds during that run, and thus the gases in the chamber and exhaust were at supersonic speeds, the entrance INTO the chamber, near the tail, was matched by an exit FROM the chamber, near the nose, leading NASA to the conclusion that the lightning bolt traveled UPSTREAM in the gas flow, contrary to expectations.

Unfortunately for me, since at this point in the article I was wide awake and fascinated by the findings, NASA offered no attempted explanation for the phenomenon.

makes sense to me... as fuel and air pass through the combustion chamber they are moving from a more reactive (and therefore the electrons are more mobile) to less reactive state, so it makes sense that the stroke, which I read elsewhere in this post is actually "hole flow" would move towards more mobile electrons.

As far as I know there is no special property of a car or truck that attracts or repels lightning.

The truck was simply at the right or wrong (depending on how you see it) time-space coordinates.

You would be guessing incorrectly. From Wikipedia: "...The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life..." It is unlikely that there are any commercial transportation tires that don't have carbon black in them, it's an essential ingredient.

btw- the "path of least resistance" is a red-herring that I put in the original post. I was curious how many readers would take the bait and run with it as you did. As AH points out, the stroke has traveled a few miles through air, the last few hundred feet mean absolutely nothing to it, if you're in or near the ionization path of the step-leader it is trying to reach, as was that truck, you're toast.

More importantly, carbon black will help dissipate static electricity buildup on the car.

Meaningless as far as lightning is concerned.

My point is the lack of a static discharge on the vehicle with high electrical resistance tires. Instead of just the charge induced by the storm onto all of the structures attached to earth, the static charge created on a moving vehicle with low electrical resistance tires can make it more likely to drive into an unstable field and be the trigger to discharge.

Really?

How much of a charge can a vehicle build up?

I would be surprised to see a static electrical arc exceeding 1/2" to 1" (about 5,000 to 10,000 Volts) on a car.

That's nothing compared to the voltage of a lightning bolt, which can be as much as a billion volts.

Additionally, how much of a deviation of surrounding natural electrical fields could a 5,000 - 10,000 Volt static build up make?

you presume the pole was properly grounded.... around here, meth heads have cut the ground wires off all the poles about 6 feet above ground for the copper.... AND since the rise time for lightning is so fast, the skin effect plays a very huge role in determining conductivity. thin sheet can be far more conductive than an equivalent circular crossection when rise times are taken into account.

All grounds would have to be cut all the way back to the generating station.The MGN is connected to every pole in the system on the crossarms.

Hence the term MGN: Multi Grounded Neutral.

If the ground was cut from the pole to the ground,the ground above the cut would still function effectively.However,you would not want to be in series with the broken ground during a fault condition.

I required my crews to visually inspect for broken ground wires and test with HV tester before climbing all poles.

If you place one hand above a cut ground, and one hand below the cut or break,and there is a fault condittion present,it could make you lose grip and fall.Not nescessarily fry you, but still enought to cause an injury.

Eh, mostly, but you start running into impedance issues due to skin effects that cause the effective impedance of the static wire running potentially several miles to the first intact ground wire exceeds the impedence of the ionized air nearer to the strike.

It does not have to travel to the next pole for ground.Ground is there at the top of the pole.The poles themselves contribute very little to the whole ground system,but each pole contributes a little.

Do a little research on MGN systems and it will become clearer.

if you mean the static line, then yes, but again how far must the very fast rise time voltage spike travel before it finally leads to earth ground? the pole itself is wood, but that isn't THAT conductive.

Sigh...

Dear HiTekRedNek.

In my limited experience/knowledge, the voltage on pylons is far higher than the end user actually requires, so it will be passed through a transformer before use at the end user!

Surely then, on the pylons is to say a minimum of two or more High voltage phases and a ground wire, no actual neutral at this point in time......

Neutral is "made/used" (in my understanding) to help protect the end user when failures occur with his equipment or installation to my mind .....not for transmission reasons.....

Even with normal 3 phase mains in a building, neutral is not actually needed (but will be available usually) where the 3 phases are used (on a motor for example), just a safety ground.

In my experience,neutral is simply a way to achieve a supply for single phase loads/Equipment, with some extra safety.

(I am simply ignoring the US type of 60Hz 220VAC supplied in housing for example, as that is really only a single phase with a midpoint neutral, bonded somewhere to ground....many do not fully understand that and talk of 2 phases....completely wrongly!)

So how can MGN systems (Multi Neutral Ground - whatever that is!) be applied at that point with pylons and high voltage transmission of power?

Surely it does not apply?

I will be really interested in a good answer. As its an area where I have little or no personal experience since my schooling. I am willing to learn.

I cannot understand either your statements or your theories. So please clear things up in a logical manner for us all here.

Remember, its the comment using that word "Neutral" that makes no sense to me.

Multi grounds are obvious to anyone I feel, no need to explain.

In the beginning,there was a generating station and in order to establish a good relationship with Mother Earth,giant copper plates were buried deep into her bosom,and connected to the generator as a reference point.
It was discovered that Mother Earth is not a willing participant in this man made scheme,and resists wherever possible,with varying degrees of success.
There was found to be significant difference in potential(voltage) between different areas of her bosom.
So, in order to harmonize the relationship between man and Earth,a decision was made to carry the initial reference wherever the power went.
Every pole,pylon,etc. would bonded,electrically, to every other pole,etc.
This would eventually establish millions of connections to Mother Earth.
This reference is sometimes used to carry unbalanced current from center tapped transformers, or fault grounds, but the Earth is not the main return path, but it does contribute somewhat to the overall system,being a parallel resistor of sorts in a massive parallel resistor network.
They could have called the system simply a multi-grounded system,but since it has other uses,such as a neutral when needed,and a safety ground for equipment,they chose MGN,Multiple-Grounded-Neutral system.Neutral is not always used, but it is there if needed.
Mother Earth is really not needed to carry any current whatsoever,but due to Earth's unwillingness to cooperate with man's schemes,there could exist a difference in potential on the surface of the earth,causing a hazard to anyone traveling on it.
The purpose in tieing all of the grounds together is to prevent this difference in potential.
There can be a potential difference in a swimming pool across a distance of one foot or less,which is why there are strict rules regarding swimming pool grounding and bonding.
There are cases where people have been electrocuted when stepping off of a curb onto a manhole cover,when a difference in potential existed,from say for instance, a street light not properly bonded to ground.
There can be non-grounded systems that do not bond the neutral and ground together,but there are special rules for these applications.
A typical industrial distribution would be 113,000 V to a step down transformer,to 13,200, then another step down to 7200,then another to 4160, down to the desired system voltage 600v,480,volt,etc.
A residential system would usually carry 13,200 primary,with a 240 center tapped transformer,to provide 240/120 volts for non commercial use.
At all of these points, the ground is carried continuously,although not needed everywhere,it prevents potential differences from occurring.
Remember, it takes a difference in potential to produce current flow.
The bird on the wire does not get shocked unless he accidentally touches ground at the same time such as near a transformer connection.
I saw this happen once,when a cockatoo escaped and got across a 13,200 Volt Feeder.
The feeder fed 10 parallel switches,and we bypassed the blown one and put the others back in service within 1 hour.
Had to special order an insulator from the factory to replace the one that exploded.This switch and connected department was down for 3 days.Had to charter a special flight to get the insulator from the factory.
I was surprised the bird was still in one piece, but there were absolutely no feathers or hair on the bird at all, and the skin was smoked black (A real "skin effect").Except for the head and beak, he looked like a chicken ready for the roaster.
He still had a tag on his leg, but no one claimed the bird.
Don't blame them, since it cost several million dollars in damages when it shut down a complete factory.
So,to summarize,the MGN system was created to reduce potential difference,but it is not always used as a neutral.
One great hazard often overlooked in a lightning strike is the EMF generated.
This can induce high voltages in wiring, conduit and equipment,which is another reason for bonding everything together.
A one ohm difference in resistance can result in thousands of volts potential when thousands of amps are involved.
Perhaps the system could have been named Multiple Ground AND /OR,Neutral system,to avoid confusion to the uninitiated.
I hope this does not muddy the water even more,and I am willing to go into more detail if needed.

That is simply the worst explanation I have ever seen for anything!!! It did not improve my knowledge in the slightest, but thanks for trying!!

By the way, I fully understand grounding and how it works. Or I might have been killed many years ago!!

But I still don't understand your explanation about Multiple-Grounded-Neutral system. It simply does not compute!!

It is now completely obvious that you do not understand fully yourself. Talk about the blind leading the blind!!

Look here and you will find a great explanation of how it REALLY works:-

neutral-single-earthed-or-multi-earthed

or here:-

Three-phase_electric_power

There were several others, similar.....I hope this helps, it certainly helped me.....I should have looked on the web first and saved you a lot of typing....

What were you drinking last night? I want some too.......

Andy I have not actually heard the term MGN.............would I be correct in assuming that this is the same as the MEN (Multiple Earthed Neutral). I kknow they use this system as one of the approved electrical systems in ships, but the preferred system is the insulated return, no earth, and this is applied in ELV systems and low voltage, e.g. 240v single phase and 415v 3 phase systems. One of the ways to achieve 240v from 3 phase is to run a neutral and connect either red, white or blue phases to neutral.

Yes, Ground = Earth

Grounded = Earthed

Grounding = Earthing

It's a lot like labeling building floors, in the US, the main entrance is the first floor, while in the UK (and I'm guessing Australia because it was populated mainly by Britons) it's the Ground floor. So what you call the first floor, we call the second floor, but that's another stor(e)y.

Thanks for that............and it is Australia.

Firstly, I had never heard of it before yesterday.

I had to research it myself online...

Secondly, it appears to be used ONLY in some areas of the USA.

It is totally banned in all of Europe as being too dangerous.....

It is thought to be the reason for many unexplained electrocutions in the USA....

It is (it appears) only to be used AFTER the last transformer, no matter what the voltage is....

Usually not on pylons (I could not find a verifiable usage on pylons), only in ground(ed) shielded cables - but fully prepared to be wrong.....

Look at the two links I posted in my previous post.

Here is a link that explains it far better than I could .

Lots of useful info.

Be sure to go to the Mike Holt Video.

It is long,but worth it.

It applies only in the USA,and there are better systems in other countries.

http://www.dslreports.com/forum/remark,28114500

Meanwhile, John Dewar's Black Label and I have some serious things to talk about.

That shows major differences between the "John Dewars" version and reality......

Only the state of California uses phase-to phase (double bushing) transformers

to prevent neutral inbalance from creating potential problems.

The MGN system was established before the hazards were fully understood,but by

that time,there was too much infrastructure to change out.So they continue down the

same path originally chosen.

I do not know which country the lightning strike shown was in, but the wiring does

not look familiar to me in the USA.

Six missing feet of ground wire makes one iota of difference to lightning that has travelled *miles* to reach this point? Miles through air - a notoriously lousy conductor - and would it suddenly balk at six *feet* of missing ground wire, or at skin effect? Lightning doesn't care if there's a ground wire or not. It doesn't need a ground wire. If it can't find a way, it makes one.

You wrote, "- and would it suddenly balk at six *feet* of missing ground wire..."

Of course! Lightning would simply stop, turn around, and go back home. Happens all the time.

LOL!!!

I believe you are correct. The pole and van are not that close together. It just appears that way from the direction the picture was taken.

It looks like it actually struck the ground next to the truck...ga

I like the holes that the lighting left in the tarmac.

Lucky escape for the couple too!

Didn't I read somewhere that the actual strike is from the ground upwards under certain conditions?

Maybe the strike was from the ground under the truck and it grounded back on the electric pylon...? The truck sort of got in the way......or the Pylon was badly earthed or something...

I really don't know, but it was a strange picture....thanks for posting!

My friend and his wife got struck just like that driving down the highway in Pennsylvania.

I don't think it was quite as intense, but it did fry the truck electronics and the AM/FM antenna was a withered and twisted stalk of stainless steel.

"That's a joke,son, a joke."

" A good kid, I say,but he has no sense of humor"

---Foghorn Leghorn

Likewise Andy...........I guess it is to do with where the positive and negative charges are in relation to the earth and the clouds

I think it most cases it is from the cloud (negative charge) to the earth (positive charge), but sometimes it does reverse (when the charges are reversed)

Had a friend that use to repair car stereos had a female customer brought her Mercedes in because the radio did not work. He took the radio out of the dash and immediately smelled burnt electronics he thought it had just popped a cap or some such until he got inside it and found nothing to repair as everything was melted into a pool on the board. He then called the customer and asked her when the radio quit working. She told him just the other day, during the thunderstorm that she had been driving home from work and heard a loud pop from the radio and it just quit. And also a foul smell in the air enough to make her roll down the electric windows that no longer worked as well and had to open the door to clear the smoke and smell. In the end the car was totaled as the cost of repair was more then the car was worth. The lightning had hit the antenna and taken out every electrical circuit in the car, and the first thing she wants to fix is the radio and did not wonder why the car did not start. women and cars are not meant for each other. He did not say but I believe she was blond

Why won't lightning strike my Bonneville?

Cavaliers first, not that anybody would notice.

"...explain why the power pole didn't shield the truck."

Because the universe is stochastic, not deterministic, in nature?

Not entirely stochastic. If a tornado's involved, it HAS to hit the trailer park first. It only gets stochastic when there's more than one trailer park.

Sometimes the dice are loaded.