You can’t be zapped by low voltage and high amperage. A wrench can be, but you’re not a wrench.
Others have answered the OP pretty well, but a couple of points:
It’s pretty difficult to generate a billion volts. Lightning is up in the 100 million or so volt range. Surviving a lightning strike is definitely not guaranteed (lightning kills about 50 people per year IIRC), but some folks have survived direct lightning strikes with little to no damage to their bodies. So while a lot of luck is involved, people can survive voltages up around 100 million volts.
I’m having a hard time picturing how you’ll get 50 amps to flow through a person at low voltage. As Chronos said, you’re not a wrench.
The human body isn’t a simple resistor. For safety standards and such, the human body is often modeled as a resistor in series with a resistor and capacitor in parallel, and even that seems way too oversimplified to me. The thing is, even with that model, the values for the components changes based on the voltage being applied.
At lower voltages, the resistance of the human body is quite high. As the voltage goes up, the resistance generally drops, but even at its best, the values never drop much below about 1,000 ohms or so. 50 amps through 1,000 ohms means you have a voltage up around 50,000 volts, which I wouldn’t consider to be a low voltage.
Agree.
It’s just about impossible to come up with an accurate electrical model of the human body. This is because the mobile charges are not (the relatively simple) electrons like you find in a copper wire, but mobile ions.
Researchers have been studying the electrical conductivity of saltwater for over 100 years, and they still don’t fully understand it. And that’s what your body is… a big ol’ bag of saltwater.
Take small wire feed mig welder
Clamp the ground to persons toe, take welding tip (we will have to assume moron) and pull trigger, injecting the welding wire into some part of said morons flesh.
16VDC@50AMP or more, depending on welders heat setting.
I can not say how much of that a persons body will resist, but that scenario should give a pretty good connection?
“mig?”
Just to be clear–I think :)–people who die by being zapped by lightning do not die from the electrical interference with the human system per se, as is generally being talked about here, but by being fried first by the ionized air.
Yes?
MIG
Metallic Inert Gas
TIG
Tungsten Inert Gas
Mig feeds a spool of wire, that is connected to + or - depending on what you are welding
the wire comes out a copper nozzle where mig gas is ejected.
The gas creates a shield to keep impurities out of the weld
Tig works kind of the same, but the wire is hand fed, and the electrode is a a fixed piece that is not consumed in the welding process.
It also welds at a lower temperature
Both methods make for an inherently clean weld with no slag
I would say it all depends on how the lightning hits you, and what part of it hits you.
The right bolt is definitely hot enough to cook you.
Huh?
ETA: Also, thnx.
I swear to God I heard this as hyperbole, and I hope to God not as a news report, but I’ve heard the words “I’ll spot weld your asshole” (as in “get medieval on your ass”).
[Just me?]
NOAA keeps track of death by lightning strikes (averages out to 51 per year in the US, Chronos had it almost spot-on) but doesn’t differentiate between direct and indirect strikes or secondary factors like dying in a fire caused by lightning or a car/plane crash caused by a strike. So we don’t have good stats to know for sure (or I can’t find them).
A direct strike can kill you through internal heat (cooked from the inside) and/or damage to internal organs and the nervous system. You can be shocked by touching something electrified by the strike. You can be shocked if the lightning strike “splashes” from the initial strike and hits you. Or the concussive blast can knock you through the air and/or rupture your eardrums.
An indirect strike can cause an EMP that could short out a pacemaker or other essential life-sustaining device which can lead to death. But supposedly the most common way lightning kills is when the step potential causes a charge along to rush along the ground toward the flash channel as the strike discharges which can have a widespread effect, see this article where hundreds of reindeer were believed to have been killed this way in a lightning storm: Reindeer killed in Norway lightning storm - BBC News
Unfortunately since you are a better conductor than the earth you stand on, the charge rushes through you toward the flash channel instead of continuing along the ground. So although you’re not hit by the lightning you’re killed by a secondary effect.
While ground lightning is devastating to livestock, it usually isn’t too big a deal for humans. The key is that deer, cows, and such usually stand with legs very far separated, while humans usually stand with our legs very close together. So there’s a large voltage difference between the cow’s legs, but only a small voltage difference between ours.
No.
Electricity tends to kill you in typically one of two ways. Either it screws up your heartbeat or it literally cooks you to death. Fairly small currents across the heart can cause fibrillation, and our hearts have a weird design in that the fibrillation state is stable, meaning the heart won’t come out of it on its own. Instead of pumping blood, the heart just sits there and shakes, and since your blood isn’t circulating you pass out from the lack of oxygen to your brain and die shortly thereafter. The “safe” level of current (at least according to a lot of safety standards) is 5 mA (0.005 amps). Anything above that can cause fibrillation.
Electricity through pretty much anything other than a superconductor generates heat. Once you get into the range of a few amps, the current can start to cook your tissues and damage you that way. Your typical lightning bolt is a few hundred million volts with a current of a few tens of thousands of amps. That massive current is what heats the air, and the current alone is several thousand times higher than the minimum needed to cause burn damage to your body. You don’t need to be heated by the ionized air. The lightning bolt itself will cook you plenty.
Here’s a video of lightning hitting a telephone pole. All of that current causes water inside the wood to flash into steam, and the sudden steam pressure makes the pole explode.
Like say for example you get zapped directly by the core of a big fat bolt of lightning.
School bus width bolt
(which i dont think actually ever hits the ground actually?)
200M volts, 50,000° F
Serve with buttered carrots and gravy, cause you are cooked.
But what comes down to the ground varies a lot, and some times you see it have lots of varying sized runners, which are something like an inch or less?
I assume that how much whoop-ass is in them is going to vary a lot?
The main branch carrying more bang than some little millimeter wide creeper?
Not that any of it would feel good, but being hit in the toe by a little creeper seems more survivable than taking the main bolt to the head?
For all your SerenDipitous[sup]TM[/sup] needs:
Chinese scientist passes 71,000 volts through his own body
Researcher puts himself through ordeal to test human threshold for static electricity and to test meter measuring charge in tissue, state media report
South China Morning Post, May 5 2017
What kind of carpet and for how long would you have to walk on it in wool socks to get to that amount of static electricity?
[Also, since we’re on about it: Why is electricity static? All the other electricity is “dynamic?”]
Static vs. “dynamic” …
All this flows from really crappy naming conventions established by the early researchers before they understood what’s really going on. In simple terms, the vocabulary problem is that the 1700s guys chose the same word for “presence of water” and for “flow of water”. If one avoids ever using the noun “electricity” and instead speaks of “electrical charge” = presence and “electrical current” = flow things are much clearer.
Consider a lake behind a dam. The water “wants” to go downriver but is held back (impeded) by the dam in the way. Consider an identical river with no dam there. The water is unimpeded and flows freely.
“Static” electricity is a buildup of charge in a hunk of material (or liquid or gas) that’s not big/strong enough to force itself through the obstructive impedance of the surrounding material. Once the buildup is big enough compared to that impedance, the “static” electricity will flow through/around it just fine.
In something like a piece of copper, the impedance is so very close to zero that even a negligible amount of charge will flow freely. In something like a vacuum or even air, the impedance is high enough that a sizeable charge can “back up behind the dam” before it pushes over/around/through the dam.
Charge also behaves a bit like water behind a dam in that once the water overtops the dam it often progressively destroys the dam unleashing an exponentially increasing avalanche of water until the water is drained. Charge buildup in air eventually exceeds the impedance of air. Once that happens and the electricity begins to flow, it locally “destroys” the air by heating & ionizing it. Which greatly reduces the air’s impedance. So the electrical flow increases exponentially in a positive feedback loop until the charge supply is drained.
This is what drives lightning, the thrilling arcs we see in youtube vids of power substation malfunctions, and in static shocks from your finger to a doorknob. The charge built up over time until barely it broke through the “dam” then quickly and progressively destroyed the rest of the dam by its flow. The big difference is the air “self-heals” in a few seconds and becomes non-conductive again, whereas a destroyed dam stays destroyed until we rebuild it.
Back to what can hurt you for a moment.
Fully charges 6V car battery of back yonder years.
Prick left hand so as to get blood running, do same to the right hand, put one hand on each terminal of the battery = you are prolly gonna be Daisy food.
Most human resistance to electrical flow in a human is dry skin.
As said above the rest is a bag of salt water, especially the blood.
That battery can provide a lot of current.
One hand to the other kinda puts the heart in the middle of things. ( BAD )
Be very careful around batteries when you have rings or cuts especially with blood present at the cut.
Do NOT try this at home. Just be aware of the danger.
One of the reasons so many people are confused about electricity is because we (and the media in this case) screw up the terminology.
A voltage doesn’t “pass through” something. A voltage is an energy potential that exists between two points. A voltage is placed across a load. If you get a shock, it means a voltage was present between two points on your body.
By the same token, a current exists through something.
Thus when you receives shock, there is a current through you due to a voltage across you.