Would the wetness have actually helped? Why go through all that higher resistance human flesh when the current can go straight to ground via the electrolyte solution that's around you instead?
Skin is also hydrophobic. You're unlikely to have a complete circuit with no breaks on the outside of your body, unless you're currently standing in the shower.
I've had a similar experience, where (at the age of about 10) I touched an exposed 120v AC wire on a running water pump, while standing in a muddy field, and I only got a mild vibrating feeling from it.
Depends on how it is wired. Sometimes lights are wired so that the switch comes before the fixture, sometimes after. One of several reasons you should always turn power off at the breaker when fiddling with the wiring, instead of assuming it won't be hot if the switch is off.
[hot wire]---[switch]---[load]---.
|
[neutral wire]-------------------+
|
[person]
|
[ground]
Edit: Or this one...
[neutral wire]---[load]---[switch]---.
|
[hot wire]---------------------------+
|
[person]
|
[ground]
the parallel resistance is lower
And once you've turned the power off, test wit with a non-contact voltage detector. A brand name one that's actually been built to UL/CE standards and is subject to actual recalls/etc is under $30. It's a straightforward, pretty much foolproof way to make sure you don't get yourself shocked.
A multimeter is, in theory, a fine alternative but in practice is not. The non-contact detector detects the presence of the fluctuating magnetic field from A/C. A multimeter measures the difference in potential between two points. If you were to, say, have 120V on from same phase on both hot and neutral in an outlet, it would read 0V. If, say, the ground were also not connected then you'd also get 0V testing either against ground. By all accounts there is no voltage in the plug. If, say, each side of the plug were on a different breaker you might think you'd killed the power while it's still live. (Yes, this is based on a true story.) The only way to avoid this is to make sure you have a known good ground to test against. Whereas a non-contact voltage detector immediately lights up like a christmas tree telling you this situation is all sorts of fucked up.
commonly the neutral wire has something like 20vac rms on it for a variety of reasons
if you are ungrounded (due to rubber boots or whatever) your body is in series with your capacitance to ground, and that will commonly give you just a mild vibrating feeling or nothing at all
this 'path of least resistance' thing can be pretty misleading, because if you have two resistors in parallel, the least resistance is always the parallel resistance (i.e. current through both resistors in inverse proportion to their resistances) and not just one resistor or the other
Electricity doesn't take the path of least resistance. It takes all paths. Think of it as a resistor network:
(+)---[R1]----[R2]-----(-)
\--[R3]--/
If R1 is sufficiently high, e.g. the light was off but the switch interrupted the neutral side, and you touched the neutral side (i.e. the lamp was between mains and you), then the "path of least resistance" matters: R1 and the parallel set of R2/R3 form a voltage divider, and the smaller the combined resistance of the right part is, the lower the voltage across you.
That voltage is all that matters. If R1 is small enough to be insignificant, e.g. because you're touching mains and R3 isn't a short to ground, the voltage across you will be mains voltage.
My guess would be not enough of the main current was passing across your heart to kill you? I didn't think mains electricity was necessary powerful enough to kill people in most scenarios, just that it is powerful enough to do it in an unlucky few. I'd also imagine the floor wasn't really conducting to earth.
My guess is that it went only through the one hand, and the sensation in the arm is just a side effect.
And that came from the "ground" pin of an outlet! Except that the building (in a third-world country that I'll leave unnamed here) hadn't been wired correctly, as I learned the hard way.
Though if there's one thing we've learned from the article, there will be plenty of people waiting in the wings of the Intenet to sputter "Karma!" and "Darwin!" when you do.
Aside, if you ever feel like saying that sort of thing, take an idea, principal, or religious icon that has a deep meaning to you, or in the latter case, someone whose work you think was influential and great. Fix that image in your mind, think "serves you right, asshole", and scream the word or the name out at the top of your lungs. Then reflect on how fucking stupid that was.
Uh...
That's fucking stupid because I presumably picked an idea or person that's completely unrelated to the concept of "play stupid games, win stupid prizes". Also because I'm at the top of my lungs. If I called out something like "Midgley'd!" it wouldn't share those reasons for being fucking stupid at all.
I've had a few mains shocks before as well, a fair few years ago, and what saved me was live and neutral touched the same hand. I now have an inductance tester I use first, then follow up with multimeter and only THEN do I start whatever I'm doing.
I was fine. The driver was some kid that stole their parents car. The kid seemed uninjured. The parents were I guess chasing them in another car as they arrived only a few seconds after the wreck.
Allow me to even further your disbelief. Nearly the same thing happened to me again years later. Except the second time was a motorcycle. I narrowly sidestepped a motorcycle on a mountain road that had taken the turn too fast while I was looking over a marked "scenic viewpoint". The driver in this case though I do not know if they lived. As they did go over the side of the ravine into very rough rocks and ground. They were alive when Ambulance took them away though.
He saw a car barreling towards him as he was walking on the street, instinctually jumped up, rolled over the windshield and roof and landed safely, albeit not on his feet.
The lesson here is this: lightning strikes twice (frustratingly, the usual idiom is as wrong as can be). In other words, if you observe an outcome and have no other data whatsoever about the conditions that produced that outcome, it is safe to assume that the conditions continue to exist to allow the outcome to happen again.
In this case, the existence of a car that has spun out around a curve is the clue that cars will continue to spin out along that curve.
Whatever caused the accident is just as likely to cause another car to go in, ie oil or coolant on track, or even debris from the current incident.
Same applies on the roads I guess, especially in poor conditions.
Also, in confrontations where you are outnumbered, keep one of the suspects between you and the rest. Discourages anybody taking a shot at you when their friend/accomplice is in the line of fire.
https://www.theweathernetwork.com/ca/amp/news/article/can-li...
> Believe it or not, this long-held myth is far from the truth. While the odds of being struck by lightning are low, the chances of lightning striking the same place twice are high. Lightning can, and often will, hit the same spot multiple times.
That is, seeing the strike shows that things are primed at the moment. Seeing a singed tree is not. (That make sense?)
That said, I can see how that still fits the idea.
If you observe an extremely unlikely event, you should update your Bayesian prior about how likely that event is.
Close in thought to each other, but still different things. Granted, I think your point still fully holds. There is a decay function for the likelihood of repeating events. And if you don't have evidence that what you are looking at is old, much safer to assume it is not and that the circumstances are still primed for it to happen again.
Lightning will not strike a TREE again because usually it destroys the tree in some way, changing it's height. But for many other things (buildings, mountains, etc), lightning will happily strike it over and over again.
Is the car in a ditch for a truly unlikely reason, or there a hidden lightning rod there? Perhaps you shouldn't assume a seemingly unlikely event won't happen again.
I was out on pescadero creek road and saw a guy had wrapped his 911 turbo around a tree. This particular bend would send you off a hillside if not for the trees. I slowed not just to gawk at the loss of a great car or to have sympathy for a man who just lost a valuable asset but cause I was wondering, “how did he manage that? Is something wrong with the road?” Didn’t notice anything wrong with the road but I took it slow anyway.
He probably just took the corner too hot. Waved a happy wave to him as I finished the turn slowly then revved back up to the usual fun speeds to enjoy the remaining 150 bends.
In a lab, sure. In reality you need a lot of amps going into the body to get enough amps across the heart to screw with it. Defibrillators wouldn't be chock full of capacitors if that wasn't the case.
Constantly repeating these sorts of misleading DARE-esque talking points is why nobody takes what the safety preachers have to say seriously.
People find out through life experience that smoking while filling gas, a couple amps from arm to arm, working under suspended loads, side rolling big cylinders long distances, using ladders on less than perfect surfaces and other little stuff like that isn't the instant death and dismemberment that they were told it was supposed to be and that throws doubt at everything else.
You can't lie to people 50% of the time even if it's "for their own good" and expect them to believe the other 50% of stuff you say.
I said mains voltage won't kill you every time but it definitely can. We wouldn't put it in residential settings if it was instant death. The problem is that the conditions that can lead to a deadly accident don't trigger any of our ape-brain fear response. Like any risk it should be approached with knowledge and care.
If you think any of the things you listed are fine and safe just because they don't result in "instant death" then I would say we have very different ideas about risk management.
I don't appreciate you calling me a liar for presenting facts and urging caution.
>The problem is that the conditions that can lead to a deadly accident don't trigger any of our ape-brain fear response.
No. The problem here is that you are peddling fear to get the reaction you want out of people. Potential energy, electric or otherwise is potentially dangerous. Pretending like it's more dangerous than it is to scare people straight is bad. Just because reality doesn't scare people into behaving how you like doesn't entitle you to be dishonest.
>If you think any of the things you listed are fine and safe just because they don't result in "instant death" then I would say we have very different ideas about risk management.
If you think it's ok to just lie to people because you think the end goal is noble I don't care what your ideas are.
The former puts the information into the hands of individuals, and let's them draw the appropriate conclusions. With the latter, you risk someone saying "I played Russian roulette and it was fine, this whole safety thing is BS”
This risk is even bigger if millions of people have tried and survived the purportedly deadly activity, such as home wiring shocks.
Yes, pretty much. 400 people are electrocuted in the US every year, usually in industrial situations. Thousands of people will get shocked today. The odds of a heart problem are low enough that suggesting people should be terrified of light sockets because it may stop their heart is just fearmongering, and reduces the effectiveness of other safety-related communication. This is like California proudly proclaiming that everything causes cancer. Counterproductive.
> Thousands of people will get shocked today
Before I come to any conclusions.
According to [0], “There are also at least 30,000 shock incidents per year that are non-fatal” and “ In the United States, there are approximately 1000 deaths per year, as a result of electrical injuries”
So about 1 in 30(ish) if we assume they accounted for nonreporting. If we assume they underreported by 10x, 1/300 is still pretty bad odds
They said that you can die if you're shocked. If you have a substantial chance of death doing something it's common sense to avoid that thing, especially when it's trivial to do so. If you want to be a manly man who don't need no safety, go for it, but you're setting up a straw man in OP's post and safety awareness in general that isn't there.
Oh please, Officer Do Good who's doing his guest lecture doesn't tell the class that most of those people who's overdose he responded to probably wouldn't have been saved if they eschewed pot. Presenting the edge case as worst case as though it's the common case is lying. Gating it with verbiage designed to make it not provably lying doesn't change that. There's a reason I compared it to DARE. The dishonest messaging is common to both contexts and does more harm than good to the core messaging.
Getting people worried about low voltage or low amperage serves no useful purpose in any context. It is pure manipulative fear peddling of the same level as making people think pot and alcohol are likely to lead to hard drugs.
I'm not saying electricity can't be dangerous. I'm not saying to be cavalier about stuff in general. I'm saying people engaging in dishonest messaging are doing harm by casting shade upon all the people who are preaching similar messages but with honesty.
Disrupting the heart's rhythm is way easier than restoring it. Especially if the disrupting current punctured the skin (which the defibrillator is not allowed to do)
> a couple amps from arm to arm
This is incredibly bad advice. A couple amps at 220VAC is devastating if actually delivered inside your body. The reason people routinely survive mains shocks is dry skin, no path across their body, or no path to ground, which is totally a matter of luck.
But that's what a defib does. It disrupts your heart's rhythm. And then you hope it goes back to normal.
If you through further education come to possess a more nuanced view of risk analysis this doesn't invalidate the simpler process it just adds value to your understanding. For instance YOU don't seem to have concluded that there is zero risk through your more nuanced understanding. Why are you assuming everyone is is dumber?
I think that’s because most accidental contact doesn’t produce much current across your heart. Touching the two wires of mains electricity with one hand? Not a good idea, but unlikely to kill you. Touching one with your left and one with your right hand? Way more risky. Grabbing one with your left and one with your right hand? Even more risky.
And of course, modern circuitry often has circuit breakers that in many cases rapidly stop the current from flowing.
https://en.wikipedia.org/wiki/Residual-current_device#Purpos...:
“To reduce the risk of electrocution, RCDs should operate within 25–40 milliseconds with any leakage currents[clarification needed] (through a person) of greater than 30 mA, before electric shock can drive the heart into ventricular fibrillation, the most common cause of death through electric shock. By contrast, conventional circuit breakers or fuses only break the circuit when the total current is excessive (which may be thousands of times the leakage current an RCD responds to). A small leakage current, such as through a person, can be a very serious fault, but would probably not increase the total current enough for a fuse or overload circuit breaker to isolate the circuit, and not fast enough to save a life.”
There was also a stainless fryer on the counter, but insulated with plastic legs, so I did some experimenting by completing the circuit a few ways:
- Counter to rail: weak shock
- Counter to fryer: stronger shock
- Fryer to rail: nothing
I reasoned that the rail and fryer were both grounded, the fryer more so because the metal exterior was wired directly to the ground pin in a 3-prong electrical plug. The problem was the counter.
I was pretty stoked: as a lowly ski lodge porter / custodian I'd diagnosed an electrical fault in the cafeteria! Everyone working there was way above my pay grade, but I got the manager's attention and excitedly explained my three experiments. The manager looked annoyed, confirmed that touching the counter and fryer gave a shock, and then unplugged the fryer (thus removing the ground) and went on with the day. As far as I know the counter remained electrified for the rest of the season, or longer.
I'm amazed more people don't get electrocuted.
Usually it's good for one little light zap and then nothing for minutes/hours.
The shock from the fryer was stronger because it was bonded to ground by an equipment grounding conductor that is connected to grounding conductor of the electrical circuit, while the railing was (likely) bolted to the floor, resulting in a less optimal path to ground as it didn’t have a path back to the ground rods/grounding loop of the building’s electrical distribution system.
It’s about the closest I’ve come to a head on collision. With my whole family in the car, there was utter silence for the next several minutes.
Pretty sure I nearly died three days ago.
(Then again, feel free to ignore the unsolicited advice of an internet stranger, but if you say you nearly died, then you’re likely in shock to a degree. Maybe this sounds excessive, but consider professional support.)
I used to commute in London for many years on a motorcyle and also raced them for a few years. I've had my share of near misses and ended up in hospital once. That was all somehow different - it was only me in danger usually and at least when racing I was always hyper aware that things can go bad fast.
This was a totally different experience. Completely innocuous one might think, on a road regularly traveled, at legal speeds. I think having my family with me made a big difference to my reaction. It wasn't just me in danger any more.
All I can say is that it took me a long time to regain the appetite for calculated risk. My companion in the scenario seemingly shrugged it right off, but only through keeping talking did I know otherwise.
*(/s)
That v² in there also means that, if enough people follow your advice, we'll eventually start seeing SUVs equipped with reactive armor.
That's far different from proclaiming either that there is no problem or that outcomes are to be measured blindly.
Suddenly [1] isn't so ridiculous anymore...
I can relate to the shock story. In a school lab I managed to lean on a exposed 220V cable. I remember my arm shaking and hearing a low hum but couldn’t figure out what’s going on. It felt like an eternity until I pulled my arm away but I bet in reality it was just a second.
That kind of thinking makes people resist taking reasonable safety precautions. The reality is that risk varies a lot; while there's no such thing as perfectly safe, there are things you can do that substantially reduce your risk of dying young, such as driving less.
A light fixture generally won't create enough current to kill you. Usually. Probably not worth testing excessively though.
With as resistive as skin is to electricity, 110 isn't usually enough to overcome it and push power through the heart.
Keyword: usually
Modern circuit breakers and outlets have GFCI/AFCI electronics that detect abnormal current leaks to ground and abnormal waveforms, and shut off the circuit. These actually stand a chance of saving you in a scenario like this.
If you're earthed/grounded through your feet though, that's a problem, likewise if it's live on one hand and neutral on the other.
A breaker may provide some protection against electric shock (assuming it's an RCD or RCBO), but I wouldn't like to rely on it.
Portugal is 230V. Not sure what breaker the lighting would be on but in the UK it's not uncommon for a 6A lighting circuit to not be on an RCD at all.
I guess there is a asterisk here if you're also shorting something much more conductive than yourself, since the breaker might cut power before you'd naturally let go and break yourself from the circuit. But that seems like a pretty unlikely situation for most home shocks.
My speculation: most of the power went through the light and only a part of it shocked the OP.
Calling the whole thing nonsense, without elaboration, is confusing at best.
I've lived near two such blind curves in my life, and at each I've seen minor issues like a flat tire turn into catastrophic accidents when the driver parks and someone else comes along and hits them.
The immediate answer might be turn of the circuit breaker, but what if we're in a giant office building? Or I don't have access or know where the circuit breaker is?
Grab them with rubber gloves?
If someone is being shocked, live, then it all depends on the circumstances, but the most generic standard suggestion in various first aid courses seems to be using a non-conductive stick (e.g. broomhandle) to push them away from the source of power or vice versa. They have probably grabbed the thing with their hand and are unable to release it as the hand is cramped, so that may be difficult.
Finding a circuit breaker may be too long. My intuitive guess (though that's not something I have seen recommended) is that intentionally causing a short-circit and trip the breaker might be faster.
Alternatively, throw a scarf or other garment as a loop in between the victim and the source of the shock and use it to pull them away from it from behind them - the garment not being conductive means you'll be safe.
[1] e.g. https://www.amazon.com/100-500V-Electrical-Screwdriver-Detec...
What kills people is current, not voltage. With AC having your heart beat 50 times a second can also cause you to die hours or even days after receiving a shock, but even that requires enough current to flow and cross your skin resistance. Go to ghe hospital even if you are alive and feel well after an electrical shock! Your heart may have suffered from this.
That being said, there can be many things at play here. E.g. there could have been contact resistance between the live wire and the fixture, which would mean the current that could have flown through your body was limited by that resistance. The reason why you can touch an insulated wire is because there are megaohms of resistance between your hand and the wire. Lower that resistance gradually and there will be a point where you feel the electricity slightly, lower ot more and there is the shock. The most hurtful thing would piercing a wire through the skin, because then the skin resistance is gone.
Aside from contact resistance it could also be that the bath the current took through your body was good (so more on the surface, not across the heart, but down one side of the body and so on).
That being said, your description of the shock does not sound like a fully fledged 230V 50Hz shock to me (certified electical engineer). In my experience you will definitely notice it right away, e.g. because you suddenly just see black and a sharp pain including with extreme vibrations that feel like pure energy is hitting you with a brick in the face. Feeling the vibration like you described it and then making the decision to let go sounds like only a very small current was flowing.
Can you point to any source for this? I have not been able to find any report of someone suddenly dying from cardiac problems days after an electric shock. It sounds kinda plausible, but I wonder if it is an urban legend.
People lose limbs or die from severe electric burns, and people can die from cardiac arrest immediately after being shocked, but are there really cases where people have cardiac arrest days after an electric shock?
I've heard this idea before, that you can die hours or days after an electric shock without realizing anything is wrong, but I think it is very rare.
An electrical injury can certainly trigger an abnormal heart rhythm, but you would probably notice most of those and, hopefully, go get a cardiogram.
If you felt normal, but had a serious electrical injury to the heart that would later lead to fibrillation, one would have to postulate some sort of abnormal re-entrant (sort-of circular) depolarization current in the heart muscle that was very regular, say 60 beats per minute, but that was prone to deteriorate into fibrillation over time.
That is what I recall about the matter, off the top of my head.
Do they use 230V in Portugal?
In NZ I'd never seen a pull cord until I moved to the UK. All of our electrics in bathrooms are certified for use around water there, including proper breakers/multiple RCDs etc.
I think modernised UK homes that are now up to date often forgo the pull cords.
Just a moment of shock, then pain, followed by lots of cursing and then gratitude it wasn't worse.
From an engineer here, let's not continue this dangerous trope.
High voltage breaks down resistance and allows current to flow. Current can only flow in the presence of voltage.
Proof:
A 1V 1000A power supply won't kill any one and won't give a shock. A 2000V .001A power supply might give quite a shock on the other hand, and depending upon any capacitance in the supply might just as well prove fatal.
It very well could if the frequency is high enough. The skin is like a capacitor which acts like a short circuit at high frequency. DC is much less dangerous than AC at the same current/voltage for this reason.
What does the capacitor supply, that the PSU can't? Could it be discharge current?
Before you accuse me of repeating dangerous tropes, please consider making sure to discuss it with the folks at VDE, because this is what it says in their (and the equivalent european) product norms and norms for electrical installations.
When touching the positive pole of a 1V 1000A PSU (I assume DC) you won't have 1000A flowing through your body. It is not the rating current of the PSU that kills you, but the actual current going through your body. And how well that current will flow through your body depends on many things, including voltage, frequency (if we are talking AC), contact resistances, skin resistance, the internal resistance of your body, how big you are, your ground connection resistance, the duration of the current flow, etc.
There is a reason we use high AC voltage for transportation of currents for long distances.
All else equal, twice the voltage yields twice the current (and 4x the power).
So while yes, it's the current that kills you, in the majority of circumstances high voltage = high current. Outside of explicitly current-limited setups (e.g. a Van de Graaff generator or a desktop ionizer), most higher voltage devices will kill you more easily.
And so the "voltage doesn't kill" meme more often than not (IMO) gives laymen an undue sense of safety when working with higher voltages, at the benefit of appealing to the more electrically-inclined crowds sense of "being precisely correct".
Just look at the dozens deaths a year from people messing with microwave transformers, trying to make some pretty wood lightning art, for an example of this.
I = V/R
It's as simple as that. A high enough voltage will find a current path ionizing the air or whatever is in it's way. A high current doesn't doesn't do that by itself.
That's why you see warning signs for "HIGH VOLTAGE" but not "HIGH CURRENT".
I assume that's because it doesn't form a complete circuit with the electrical substation your power is coming from -- though some power is delivered, perhaps does due to capacitance between the ground and the distribution lines.
Note it would be completely different if your power service used single-wire earth return (SWER)[0].
Years ago, I heard of someone feeding their pets cooked, bone-in chicken. Eating cooked chicken bones is very dangerous, but you can do it for years before that one day that it suddenly isn't safe.
Why is that?
> If anyone would like to explain why that didn't kill me I'm all ears.
I once got jolted while grabbing an electric transformer. I've researched this a bit, but I'm not a doctor so take my hypothesizing here with a grain of salt:
From what I've read, it seems like most deaths are caused by 1) disruption of the human body's electrical systems or 2) severe burns where electricity enters/exits the body.
It's a bit unclear to me what exactly causes burns--it seems that arcs, especially longer, sustained arcs, are related, but not necessarily. This seems to happen more with high-current situations. If you didn't experience burns, it's probably because the current wasn't high enough to cause that.
The more common thing seems to be disruption of the body's electrical systems, which can occur with much weaker currents than cause burns. The most common thing seems to be that electricity across the heart can disrupt the nerves that regulate heartbeat, but electricity across blood vessels can also cause constriction that causes stroke, and electricity across the brain can cause seizures, disruption of breathing/pulse, etc. It really does seem like the vast majority of deaths are caused by electricity across the heart though. If you don't see cardiac symptoms shortly after a shock, you're unlikely to see them, which is probably because the electricity didn't primarily go across your heart.
I'm not sure what the configuration of your grabbing this light fixture was, but a right-handed person grabbing a light fixture with their right hand, would likely see a current traveling through their right arm and then down through their right leg and, to a lesser extent, through their left leg, to the floor (once the current hits your torso there's more "bandwidth" on the way to the floor and the current spreads out more which is why you experienced "vibrating" in your hand and arm, but not your torso). This path doesn't take the current over your heart or any of the parts of the brain that regulate heartbeat or breathing, so that's my best guess as to why you didn't die.
There are several mountains in North America, Central America, South America, Spain, the Philippines, and probably other countries w/ Spanish language influence named "the Sierra <something>s" or "the <something> Sierras".
As I was about to cross the highway a car come sliding around the bend more or less sideways. I stopped and watched it slide past. I could tell it was going to miss me by 10 feet or more, but afterward I couldn't stop thinking: What if it had been headed towards me? Could I have gotten out of the way in time? What if I'd slipped? I couldn't believe how close I might have come to dying without even thinking about it. I'll never get out of the car in a storm again, at least not without thinking very carefully about the situation first.
My other near miss experience was staying at a bread-and-breakfast farmhouse in Portugal. I had taken a shower, and was standing in front of the bathroom mirror, when I noticed the light above the mirror was crooked. It was one of those swiveling can fixtures, so I reached up to adjust it. I knew it wouldn't be hot since I'd just turned it on, so I grabbed it firmly and then asked myself why it was vibrating. And for that matter why was my whole arm vibrating? When I realized I was being shocked I was able to let go and spent 20 minutes pacing around my room making sure I wasn't dead. You really can't do worse than standing barefoot, soaking wet, on a stone floor, and grabbing a live fixture, can you?
If anyone would like to explain why that didn't kill me I'm all ears.