[intrepidhero]

It only takes 80ma across your heart to stop it. Mains voltage, in both the US and the rest of the world, can easily develop that kind of current, especially if there is moisture involved. And yet plenty of folks have accidental contact without lasting effects. Electricity is fickle that way. The difference between, no problem and totally dead can be subtle, random and not obvious. It all depends on the path the current takes. Show it respect.

[Someone]

> It only takes 80ma across your heart to stop it. Mains voltage, in both the US and the rest of the world, can easily develop that kind of current, especially if there is moisture involved. And yet plenty of folks have accidental contact without lasting effects.

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.”

[dsfyu404ed]

>It only takes 80ma across your heart to stop it

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. Electricity and many other things are sufficiently dangerous that you shouldn't need to lie.

[intrepidhero]

Defibrillators are full of capacitors to boost the voltage, not current. They also use carefully located electrodes, and come with a razor to remove body hair to create the ideal conditions to affect the heart because they need to work every time. That has nothing to do with whether residential power is dangerous or not.

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.

[OkayPhysicist]

Volts and amps are not independent values if you're applying them to the same resistance (you), and you cannot "boost voltage" using capacitors. A capacitor can only charge to the voltage that it is charged with.

[martyvis]

Yes, a single capacitor will only hold the voltage applied to it. But after charging each one and cleverly arranging them in series you can hold very high voltages with a bank of them. This is what occurs in a voltage multiplier circuit.

[dsfyu404ed]

Portraying the 80ma number as anything other than what can happen in a freak accident is misleading and dishonest and is counterproductive if the goal is to get people to respect electricity because it is in contradiction to the lived experience of basically everybody.

>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.

[idiotsecant]

This is a really silly take. Parent post didn't say YOU WILL DIE IF YOU EVER GET SHOCKED, FULL STOP.

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.

[ak217]

> Defibrillators wouldn't be chock full of capacitors if that wasn't the case

Disrupting the heart's rhythm is way easier than restoring it. Especially if the disrupting current got in through punctured skin (which the defibrillator is not allowed to do)

> a couple amps from arm to arm

This is very bad advice. A couple amps at 220VAC is devastating if actually delivered inside your body. The reason people routinely survive mains shocks is the current doesn't actually get through due to intact dry skin, pure (poorly conducting) water, no path across their body, or no path to ground, which is all a matter of luck.

[Dylan16807]

> Disrupting the heart's rhythm is way easier than restoring it. Especially if the disrupting current got in through punctured skin (which the defibrillator is not allowed to do)

But that's what a defib does. It disrupts your heart's rhythm. And then you hope it goes back to normal.

[MayeulC]

Hmm, I didn't experiment much with that, but most houses are wired with 30 mA differential circuit breakers. If there is a difference of more than 30 mA between phase and neutral, it means there is a leak to ground somewhere, so the breaker trips. Well below 80 mA (though not instantly).

If you're wet though, your impedance is lower, so a lot more current can flow through you. That makes it much more dangerous to touch electrical stuff. Same with being barefoot.

Our bodies also have capacitance (complex impedance), which makes us more sensitive to AC than DC.

What I don't get is why do we still use differential circuit breakers while connecting neutral with ground instead of monitoring line impedance a thousand times a second. You'd trip the circuit breaker when connecting (including touching) neutral or phase to ground, without endangering the user (currently we only detect a user touching phase via the current flowing through them).

Have the circuit self-test multiple times a second, and use 10kV (like livestock fences) with very low capacity to measure impedance: give a serious jolt to the person touching a wire, with no danger.

[nerdponx]

Wait, what? This is like advocating for playing Russian roulette because it's not guaranteed to kill you.

[gameman144]

I read it more like saying that we should teach "Russian roulette has a 1/6 chance to kill you, which increases every round", rather than "Russian roulette will definitely kill you."

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.

[rootusrootus]

There's a pretty big difference in the odds of a house mains electrical shock stopping your heart compared to the 1 in 6 chance of the bullet being in the chamber that lands in alignment with the barrel.

[nerdponx]

How big? Big enough to disregard?

Humans are notoriously bad at evaluating probabilities and expected outcomes in probabilistic scenarios, especially in when one possible outcome is catastrophic with low probability. Otherwise you wouldn't see so many reckless distracted drivers on the road.

You are advocating for a public communication strategy that only makes sense in some kind of rationalist fantasy world, but not in the real world.

It's not some conspiracy to infantilize the public, it's just good sense to not do dangerous stuff and tempt fate.

[rootusrootus]

> How big? Big enough to disregard?

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.

[californical]

I appreciate the point you’re making, but I’d like a source for

> 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

[0] https://www.ncbi.nlm.nih.gov/books/NBK448087/

[michaelmrose]

<INSERT DUMB THING> can potentially kill you so always take precautions is about the size of the message that fits in people's brains and everyday decision making process thus it is the reasonably actionable thing to communicate.

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?

[antipotoad]

Exactly why I believe telling the public anything but the whole truth in a pandemic is a terrible idea (not that I really wish to open that can of worms).