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Was that really St. Elmo's Fire?

I have a possible explanation from personal experience. I had a similar thing happen to me while riding a motorcycle, and it was quite a startle! I was riding to work at about 30mph when something yellow and thumb sized hit me just below my goggles. I felt pain quite similar to an electric shock. Later that day when my eye swelled up I realized I had gotten stung by a wasp at 30mph. This explains her description of yellowish, the erratic flight path, the golf ball(ish) size, and I believe she even used the word “Sting” to describe the shock. Wasps also make a buzzing noise not unlike an electric arc. If a wasp hits you stinger first and bounces off, I figure it does not have enough time to inject a full dose of venom, which would mean any swelling would quickly subside. Wasps can also sting through thin clothing. If the wasp had hit me in the eye proper, it could easily have caused me to crash. I would recommend everyone wear sunglasses when driving with the top down, they will protect your eyes should this happen to you, and they make you look quite glamorous in a convertible.

I like the Bug Theory. While driving the one that hits you(don’t ask me how I know) Appears to float in mid air growing larger and if it doesn’t hit your eye it appears to veer off at the last instant. Good old “steady bearing, decreasing range.” Defines a collision course and that’s what i thought of when I heard the story

( On the show which aired Saturday AM on WUOM, a woman caller described
a ball of electricity which ran up the side of her convertible & hit
her in the shoulder, shocking her.)

There’s a possibility that she’d hit/run over a fallen/falling live wire
which was arcing, flipping it up the side of the car. If persuaded to return
to the scene, she might have seen the wire to one side of the road.

I registered on this forum expressly to give my .02 on this. I believe it was, as lifers stated above, a bug. Maybe a yellowjacket, I’m guessing a firefly, which, when coming into your car from out of nowhere at road speed, probably looks like a big electric spark. As a motorcycle rider, I can tell you, when a big bug smacks into you as you go down the road, it can surprise you with what might feel like an electric shock. Those little suckers can be as hard as rocks!

I am a newbie on this site. I heard this question asked three times while driving across the state and the answer was wrong each time. What amazes me are the number of “truthers” that inhabit this forum.

What I took away was it was a brand new car and one of the first times she drove with the top down.

Being a Moo U grad (as opposed to MIT geniuses) I immediately thought of a Van de Graff generator and carbon black.

Obviously what is going on here is that this sleek vehicle is moving through the air generating a static charge, as all vehicles do. Normally, we do not detect the static charge because it dissipates to ground through the tires. Remember several years ago when there was a rash of complaints associated with certain models of cars using certain tires from a certain manufacturer? It was chased down to the fact that the manufacturer was reducing the the amount of carbon black in the compound to improve tire life. They had reached the point where the tires were not conducting the static away from the car.

Because the car is so new, I suspect that there is some hi tech stuff in the car and tires that is creating static to high levels and not allowing it to dissipate. It could also be a function of the drivers clothing. Cotton versus wool versus synthetic. Remember, an electrostatic discharge happens so fast that it is impossilbe to tell which way it travels.

In conclusion I will bet this is not the first time this will happen to BMW 128i convertible owners and it will not be the last.

Now go ahead and tell me how stupid my answer is, I am ready

I have owned many convertibles in the last 14 years and I have been hit by all manner of things while driving top and windows down.

Ice cubes, bugs, cigs, rocks, batteries, coins, bird poo, rain, hail, and more.

I have been riding motorcycles on the street for over 36 years and have really been pelted by various items.

Never any St Elmo’s Fire or ball lightning in either case, though.

I would suggest Christi was hit by something more common and was just surprised and “shocked” more in the figurative sense than the literal sense.

I married a pyromaniac—and consequently gave birth to two pyromaniac sons.
Christy in DC drove over an unexploded firecracker or “cherry bomb”

A friend of mine has a Toyota Yaris that will give you the shock of your life if you touch it immediately upon getting out after a decently long drive on a dry day, so I don’t doubt that a great charge can build up on the body of a car.

What puzzles me is that the voltage necessary to make it arc from car to driver would be immense. As a rough approximation I used Paschen’s law which gives us breakdown voltage as a function of air pressure and arc distance - for the arc to be just one centimeter at 1 atm you need upwards of 50,000 volts. Or you could just assume air has a breakdown voltage of 30 kV/cm at 1 atm (as I read on wikipedia). Either way you’re talking about hundreds of thousands of volts, which you’re right, is pretty much what you’d expect with a Van de Graaff generator - but a car? maybe?

Also, all that ignores a potential difference from car to driver as you mentioned with the clothes and maybe there was a thunderstorm coming in and the air pressure was lower and maybe some conducting debris got kicked from the road that could help bridge the gap - all this would lower the required voltage.

So, it is distinctly possible that under the right circumstances it was static charge on the car.

I think it was a bug.

I think the cause of the "lighting strike"
in the BMW convertible was that someone
dropped a golf ball off the bridge, it
bounced off the road, struck her in the
shoulder. I do not believe you would see
a “st elmo’s fire” ball in the circumstances
she described.

I have had patients in the emergency department with side-splash lightning. Whether this was ball lightning or just a “normal” discharge is beyond me, but you can get hit by lightning from 10 miles away on a seemingly cloudless day. Side-splash is what you call it when the lightning strikes very near. I had a patient once with persistent arm numbness after side-splash when his truck window was down and his elbow was out the window. She is a lucky lady. Look at the emergency medicine books - it’s there and common. She could have perceived the strike in her peripheral vision as a “ball,” or maybe it really was ball lightning.

Ball Lightning is very likely if no bug or debris mark remained as the caller indicated. Ball lightning will roll around, bounce, appear out of “nowhere”, often caused by lightning several miles away.

You neglected to ask Christy some important questions. Was her shoulder bare and did the phenomenon leave a mark? There are two clues in her story that lead me to believe that it was not St Elmo’s Fire, but a formerly common event that has become less common in recent years. Clue one is that she was in Virginia and clue two is that she had never experienced an electric shock before. I think that Christy got hit in the should by the cherry (the burning tip) of someone’s cigarette that was tossed from another car on the overpass. The cigarette hit the ground, came apart and the cherry burned her shoulder slightly, it would have disintegrated at that point and left virtually no evidence behind. I think that her description of a shock was due more to the brief pain and then the accompanying adreneline rush.

Obiviously this was a capacitor from an old satallite which had a previous collusion in space(space junk). The capacitor was falling thru space and did not copletely vaporize during high altitude reentry. The capacitor case finally vaporized when the capacitor was about 100 ft above the ground. All that was left then was the charge inside the capacitor, which immediately discharged causing the electrical charge. As we know from elementary physics, this would be positively charged and when it came close to the ground it attracted some small metallilc scrap on the ground (negative charge) which was immediately attracted to the charge and discharged in one event just above the ground. Simple huh. If the normal explanations don’t work - go to the next most obivious.

Ball lightning is a magnetohydrodynamic ring vortex. An electric doughnut or smoke ring. It is a combined electric and magnetic field system with a toroidal form, one field in a ring and the other at right angles through the hole and around. Like a smoke ring, it persists until the energy has dissipated, which depends on how big it is. Any sudden interruption of current with enough energy can create one. Lightning, circuit breakers, electrical accidents. The rapidly decaying magnetic field causes it to levitate, repelled by any conductive surface by an induced virtual image. In a metal container like a submarine, they can be pretty exciting. Any electric current creates a magnetic field, and when the current quits, the field collapses. The field around a wire is like a rotating tube. As a magnetic field collapses it creates an electric field around it, and if there is an ionized arc in that field, it can bend around into a circle or torus and remain intact until the magnetic field has collapsed, which can take several seconds if it is strong enough. It happens. Not common, but not to be dismissed.