Heat From Lightning Bolts

[IRG CommandoJoe]

Doing a quick Google search, I read on several sites that lightning bolts heat up the air it passes through to tens of thousands of degrees Fahrenheit. However, when people are struck by them their bodies don't immediately burn up, but their clothes do. Why is that? How hot is it several feet from where the lightning bolt hits?

I ask this because yesterday I was outside with Person A and Person Bduring a thunderstorm. Lightning struck very close by, scaring the shit out of me. I didn't catch sight of it, but Person A said that Person B nearly got hit by the bolt. I don't believe that for one second because Person B was standing right next to me. I'm sure I would have felt a tingling sensation, heat, or some sort of thud in my chest from the shock wave. But I experienced none of that.

So if a lightning bolt struck several feet away from someone, what would happen to that person?

[DPDarkPrimus]

Lighting can and does cause burns on those that it strikes. Like this rather painful case...

From what I've found from some sites from a quick Google, lightning can vary in intensity.

Lightning bolts do not create shockwaves along their entire path, so you wouldn't have felt anything unless there was a shockwave created by the actual impact of the bolt.

As for feeling a "tingling" sensation, that would only happen if your body were interacting with some sort of electrical current. Based on how lightning actually occurs, I would guess that there wouldn't be any ambient current in the area, because all the charged particles in the relative area were focused where the strike occurred.

[Surlethe]

Doing a quick Google search, I read on several sites that lightning bolts heat up the air it passes through to tens of thousands of degrees Fahrenheit. However, when people are struck by them their bodies don't immediately burn up, but their clothes do. Why is that?

This probably has to do with the specific heats of air, clothes, and flesh. Lightning is over very quickly, and that may be enough time to raise the temperature of clothes to combustion point, but not the temperature of skin.

[IRG CommandoJoe]

Hmm...so then a lightning bolt could hit two feet away from a person and that person might not feel a thing?

[metavac]

Hmm...so then a lightning bolt could hit two feet away from a person and that person might not feel a thing?

Yep. Resistivity and duration matter.

[General Trelane (Retired)]

Hmm...so then a lightning bolt could hit two feet away from a person and that person might not feel a thing?

Don't count on it. Lightning has this annoying habit of arcing unpredictably. Chances are, if it strikes two feet away from you, you are going to get hit too. It's not as if there is only one path for this lightning to take. It's a common misconception that standing under a tree is a safe place to be during a lightning storm (the assumption is that the tree will act like a lightning rod and safely ground any strikes). Just a few weeks ago, some people in Alberta found out the hard way that lightning hitting a tree will also arc to anything nearby (see here).

It's not the heat of the air through which the lightning travels that's dangerous to people. It's the fucking current in that lightning! It generates heat as a function of its current and the electrical resistance of the conducting medium.

But yes, if the lightning strikes very near and doesn't actually strike you too, you're not likely to get crispy fried. It's not an experiment that I'd recommend though.

As for feeling a "tingling" sensation, that would only happen if your body were interacting with some sort of electrical current. Based on how lightning actually occurs, I would guess that there wouldn't be any ambient current in the area, because all the charged particles in the relative area were focused where the strike occurred.

That's. . .hilarious!

Yes, you could feel a "tingling" sensation if your body interacts with some sort of electrical current like, say, lightning! What do you think happens during lightning?

For the record, thunderheads build up positive charges at high altitudes and negative charges at low altitude. The low-altitude negative charge repels electrons at ground level (that includes you!), which causes an "ambient" current as electrons get the hell away. Lightning groundstrikes are caused by the negative charge arcing to the now-positive ground, which results in a new ambient current as the displaced electrons are dispersed around the strike site (this also includes you).

If you feel a tingle, it may simply be the hairs on your arms or neck standing up. Remember, you're part of ground, which means you'll be positively charged during a lightning storm, and if your hairs are positively charged, they will, in fact, repel each other and tend to lift. That could be described as a tingling sensation even though you're not actually conducting current.

More extreme, if lightning strikes nearby, there's a good chance that you actually do conduct some of that current. If it's a small current, that might result in a tingling sensation. If it's large, you'll experience something much worse.

[DPDarkPrimus]

Man I said I was guessing.

[weemadando]

I've had lightning hit only a few metres from me, the only heat I felt was from the small transformer on the powerline it hit exploding.

[Shrykull]

I remember once hearing from our teacher in 7th grade science class that lightning is many times hotter than the sun's core. If this is true, then shouldn't the person being struck be vaporized?

I don't know if it's that hot, but it is plasma.

[Alerik the Fortunate]

I hadn't heard it was that hot, but there's a big difference between temperature and heat. A fine filament like column of air can be heated to obscene temperatures, yet the mass involved may be so miniscule that there is insufficient energy to appreciably heat a big water based mass like a person.

[Napoleon the Clown]

It's five times the surface temprature of the sun, not the core. The core is millions of degrees farenheit.

Air heats and cools pretty quickly, so while thee lightning bolt makes it very hot it only exists for a few moments so there's not time for it to massively change the temprature of something that has a lot of water, such as a human body.