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Mobile Phones and Lightning a Lethal Mix
An anonymous reader writes "In a letter to the British Medical Journal, doctors wrote that people should not use mobile phones outdoors during thunderstorms because of the risk of being struck by lightning. Usually 'when someone is struck by lightning, the high resistance of the skin conducts the flash over the body in what is known as a flashover, but if a metal object, such as a phone, is in contact with the skin it disrupts the flashover and increases the odds of internal injuries and death.'"
What does the BMJ have to say about body piercings, such as multiple earrings/studs?
The only metal-bodied phones I've seen are the boutique ones like a Motorola V3. Everything else is firmly plastic, although most seem to have some kind of metal shielding inside when you open them up.
Does it have to be metal in contact with the skin?
When I am king, you will be first against the wall.
Hey, look at how many golfers and fishermen get struck by lightning every year even though they should know better.
A few lightning facts that need to be stated:
1. Lightning strikes can occur on any day, even in the absence of clouds.
2. Lightning can strike 10 miles away from a thunderstorm.
3. If you can hear thunder, you are in range to be struck by lightning.
4. Contrary to popular notion, there is no 'safe' location outdoors to take shelter from lightning, although your car will offer some protection (read: its a crude faraday cage) provided that you do not come in contact with any metal object.
5. If you are on your cell phone talking to your friends and lightning strikes in the general area, causing you to scream like a little girl and soil yourself, and your friends hear it, they will not let you live that down for quite awhile. Doubly so if it is captured on video.
Navicula hydraulica plena anguilarum est. Omnes castelli tuus nostri sunt. Ed elli avea del cul fatto trombetta.
...I know, I know, I really shouldn't be doing this. But hey...
Is it just me that finds the 'flashover' principle slightly improbable? Now, I'm not a physics PhD (but then again neither were the *doctors* who wrote the letter to the BMJ, presumably!) but this was a notion first suggested by Nikolai Tesla. He hypothesised that he was able to pass the enormous voltages of his Tesla Coil across himself without feeling pain because it was so fast it 'crawled across his skin'. It has since been shown by far greater physicists than I that this was little more than a theory; it has no basis in Physical fact.
In actual fact, the reason he felt no pain was that the potential difference across his body and the floor (voltage to thee and me) was so high, and of such high frequency, that the AC current was oscillating faster than the nerves can respond - in much the same way as we like our CRTs to refresh at a faster rate than our eyes can, we just don't see it happening. As a result, his nerves never responded to the high frequency arc of electricity. If it was sustained, he would certainly feel his skin burn, and death would ensue (as continued high current has a nasty nasty tendency to do!)
In case it wasn't obvious...the arcs of electricity produced by a Tesla Coil are almost identical to lightning, in that they require a high enough potential difference to ionise the air to arc. He essentially shot (small) bolts of lightning across himself in the process of demonstrating his new-fangled AC.
So what am I saying? Well, I don't really feel the 'flashover' idea holds its own weight. Finally, who wouldn't expect a lightning strike to demobilise a person? If you ask me, she's frightfully lucky to be alive at all...
It seems that you know what you are talking about, i remember that day... all the local news suddenly becomes, "experts on electrical storms". They give a lot of recommendations (do not wear cell phones, leave rings and metal things at home, etc.)
I was surprised because the metal piece has the size of a memory stick (imagine that). I don't know about lightning storms... but i imagine that at this particular case the sea is more important than wear something metallic or not.
Rock and Roll
When I was a student, I used to know someone who loved windsurfing during thunderstorms. He also liked to sit on the (flat, copper) roof of the (steel framed) halls of residence during thunderstorms. He didn't see anything wrong with this, despite the fact he was studying physics.
Sometimes I wonder if he is still alive.
You're arguing that tales of mobiles interfering with devices etc is an old wives tale. You counter with...wait for it...another old wives tale.
Way to go.
I'm sitting here next to a commercial ECG telemetry system. By taking a call with my cell phone and walking around near the telemetry transmitters, I can *see* the interference on the monitor screen. I can also *see* the interference as I walk near clinical trials subjects with holter ECG recorders on. I'm doing it now: the disturbances are also present in the electronic data captured from those ECG machines.
If I were to go to our sister site and make a call within earshot of the coronary care unit, I'd get punched for using one because it *visibly and demonstrably* fucks up the readings and traces which are used for live, safety-critical monitoring.
Sure, there are areas of hospitals where it won't affect anything, but there are areas where it will, and it's safer and easier to ban the use over a wider area rather than trying to enforce a policy of allowing it in one room but not the one next to it.
Banning mobile phones in certain areas is just common sense - it's all about whether you can prove, beyond all doubt, that it *doesn't* interfere. If there's any doubt, or you just can't prove it, don't do it.
1. Lightning strikes can occur on any day, even in the absence of clouds.
2. Lightning can strike 10 miles away from a thunderstorm.
If lightning can strike even in the absence of clouds, why should there be a 10 mile limit?
Or is it wrong of me to confabulate thunderstorms and clouds? Perhaps you're suggesting that thunderstorms can take place in the absence of clouds, too.
Also, can somebody handy with Google please quantify for us the number of clear sky strikes versus "traditional" storm-associated strikes? As a corollary, how many of the people struck in clear sky conditions immediately prior to the strike invited some form of higher power to immolate them lest they be lying? (For example, "If I'm not telling the truth may Zeus strike me down on this very spot!")
Inquiring minds knead to no.
I am from a small, grease-loving country in the north called Ca-na-da.
Lightning is a very fast pulse. Therefore, it is actually a form of RF energy.- December/040019.html_ techniques/skin_effect.html
https://ewhdbks.mugu.navy.mil/wavelet.pdf
http://lists.contesting.com/pipermail/tentec/2003
RF would much rather travel on the surface of an object than internally.
http://www.conestogac.on.ca/eet/courses/microwave
So, yes, the skin effect applies.
I think it is a good assumption that Lightning + Almost Anything Else = Lethal Mix. I saw a CNN article with video yesterday where a guy was hit by lightning on a motorcycle. Being the "Almost Anything Else" part of the equation did prove lethal to him. They showed gouges in the asphalt where the lightning had hit it!
I haven't seen that specific episode, but I have first hand experience of the interference potential of using a GSM phone in a Cessna 406 used for aerial work purposes. It did cause erratic behaviour of a number of radio navigation aids onboard, although I can't recall which ones.
;-(
Our workaround was for the pilot to fly using Visual Flight Rules (VFR) during cell phone calls and to prohibit the use of the cell phone (which was, in any case, legally prohibited by the UK CAA) when operating under Instrument Flight Rules (i.e. in cloud, fog, etc).
FYI, the worst case of airborne RFI I've ever experienced was when we flew very close, at about 400ft altitude, to the 'hot end' of the BBC Russian Service's antenna array. The instruments freaked out, Russian voices came through the intercom, plasma screens threw wobblies (before the computer driving them crashed) and a 1.5 amp fuse popped in the power feed to a sensor towed on a 100m cable.
Being a Slashdot reader, I've not yet discovered whether or not this intense RF exposure has left me sterile. The whole thing was quite amusing though. We had some 'interesting' times on that contract
In theory, theory and practice are the same. In practice, they're not.
I've been hiking in subalpine areas a number of times when I've been warned about incipient electrical activity because the zipper on my pants has started buzzing. REAL hikers apparently keep some aluminum foil on top of their backpacks so they can hear it well before zippers start arcing.
(head downhill, fast, get your pack off your back, and if/when you stop huddle down and keep your feet together, since even a close strike will have enough voltage drop across the ground to go up one leg and down the other if you're standing straddling something.)
Nostalgia's not what it used to be.
Shouldn't that be:
3. If you can hear thunder, Thor missed you. This time.
The lightning that hits you, you won't hear. They're like the mob that way.