Science Questions

If you skydive through a thunderstorm, could you be struck?

Sun, 20th Nov 2011

Listen Now    Download as mp3 Part 1,2 from the show Is Technology Altering Your Brain?

Question

Andrew Roberts asked:

Chris,

 

Great show, been listening from NY, CT, Brazil & MD for years! Awesome!

 

If you skydived through a large cumulonimbus/active storm cloud with lightning, would you be struck? What would happen if you happen to pass through the cloud and 'intercepted' a lightening strike?

 

Thank you so much! I would tremendously appreciate a notice if you intend on answering the questions - wouldn't miss it!!!†

 

Best Regards,

 

Andrew

Answer

Andrew -   Well, I was wondering.  If you were to sky dive through an active storm cloud, assuming that lightning strikes were occurring, are you at particular risk of getting struck? And if you were to be struck, would the result be the same as if you were standing on the ground?

Chris -   Do you partake in such dangerous pursuits, Andrew?

Andrew -   I do not.  Especially not through storm clouds.

Dave -   Itís probably very wise.  If you're in a storm cloud, then essentially you're in something which isn't a very good conductor, itís mostly air, although you also get a bit of water in there with raindrops. 

If you're there, especially if you've got a wet parachute above your head, then you're actually acting there a bit like a big long wire which means that if a lightning bolt is going to occur somewhere in that broad area, itís probably going to find a shortcut, essentially down your parachute through the ropes, down through you and out your feet. 

Certainly, planes get hit by lightning quite a lot, but they are made out of aluminium.  That's a very good conductor - acts a bit like a lightning conductor.  But I think skydiving, you would probably have similar effects as if you've been hit on the ground, possibly slightly less intense but I think it would be pretty messy.

Chris -   Ouch!  Dave, can I ask you a question which has occurred to me and thanks for the question, Andrew.  It was very good.  If you're in a lake and itís freshwater, because you're a bag of salt as a living being, and you're therefore a better conductor than poorly ionised freshwater, are you more likely to come off worse if the lightning hits the lake than if you were doing sort of swimming around in the sea?

Dave -   Yes, very definitely.  Certainly, there's lots of instructions if you live in a place with a lot of lightning strikes.  As soon there's any possibility of lightning, get out of the water because lightning will hit the water and then that current is going to spread out from the lightning and if you're anywhere near that, that current is going to go through you rather than through the water, and you'll get a fairly serious shock. If you were in salt water you would get a shock, but  the current wouldn't concentrate through you as salt water is a better conductor than you are.

Multimedia

Subscribe Free

Related Content

Comments

Make a comment

I would expect it possible, after all, aircraft's get struck by lightning now and then and the human body containing around 65% salt water is a good conductor.
=

As for it being dangerous? There's no 'ground' to it so I don't think so myself?

"during a 1980s lightning research project, NASA flew an F-106B jet into 1,400 thunderstorms and lightning hit it at least 700 times. The lightning didn't damage the airplane, but the data the jet collected showed that lighting could induce relatively small electrical currents that could damage electronic systems." yor_on, Sun, 20th Nov 2011

A lightning strike consists of a column of ionised air thru which a high electrical current is passing (10,000 - 100,000 Amps).
This posses little danger to a metal aircraft due to the low resistance of the path so that little power is dissipated.
The story is quite different if a human body got in the way considerable power would be dissipated and the results would be catastrophic. syhprum, Mon, 21st Nov 2011

Would it really be any different than the effect when you are standing on the ground?

The arc current would still flow through and/or over parts of your body. It would be less likely to flow along the length of your body, but 10,000A is still 10,000A. Geezer, Mon, 21st Nov 2011

I'm not sure, but I was thinking of those guys that repair high power transmission lines by helicopter as a example, incredible stuff (BBC) where they work with live feeds using a helicopter as their 'platform'. But I can't find anything about any sky diver hit directly by lightning (airborne) so it has to be rare, if existing. yor_on, Mon, 21st Nov 2011

If the AmpŤres don't kill the skydiver, the temperature will. The air heats up to 20.000 deg Celcius around a lightning column...

This rapid heat expansion of the air is what produces the sound of thunder btw.. Nizzle, Tue, 22nd Nov 2011

Nizzle, you're forgetting something there. People survive lightning strikes every year, while grounded. But it would surely be interesting to know how much difference it would make to be hit while high up in the atmosphere. yor_on, Tue, 22nd Nov 2011

Being struck by lightning while connected to the earth is a problem.
Also, the nature of the connection isn't that important.
A mile long channel of ionised air will do just fine.
If you get hit by a cloud to earth bolt, it's because, from the lightning's point of view, you were grounded.

If being hauled perhaps 20Km into the air doesn't kill you with cold or asphyxia then perhaps this  would.
http://en.wikipedia.org/wiki/Downburst
It's probably best to avoid skydiving in thunderstorms.

Bored chemist, Tue, 22nd Nov 2011



Not to be picky or anything, but shouldn't that really be an "earth to cloud" bolt? Geezer, Tue, 22nd Nov 2011

Not really.
electrons travel one way. Conventional current travels the other way and, in fact nothing apart from a field travels the whole distance anyway. Bored chemist, Tue, 22nd Nov 2011



I seem to remember that lightning bolts actually start on Earth, but I may have it wrong. Geezer, Tue, 22nd Nov 2011

Here we go.

"Then, when the stepped leader is pretty close to the object or ground, a traveling spark is emitted from the object up to the stepped leader.  There is still no lightning yet, but watch out!  When the stepped leader and the traveling spark meet, huge amounts of electrons travel towards the ground. Then, the actual lightning travels upward toward the cloud, following the path used by the stepped leader to reach near the object.  This is called the lightning stroke."

http://weathersavvy.com/Lightning.html Geezer, Tue, 22nd Nov 2011

See the whole discussion | Make a comment

Not working please enable javascript
EPSRC
Powered by UKfast
STFC
Genetics Society
ipDTL