death by lightning

[Kingaroo]

If someone were to leap from a great height with intent to kill himself, but on the way down was hit by lightning, would he be dead when he hit the ground?
(This seems like a great premise for one of those forensic police dramas -- the insurance will pay off  because he hadn't finished committing suicide....)
But really, what I wanted to know was: can someone suspended in air be electrocuted or does one have to be grounded?

[Hamish]

You have to have electrical contact with the ground. I guess if you happened to get caught in a salty rainstorm and water was running off you onto the ground, possibly. Not sure how long you would take to die, and therefore how far off the ground you would have to be.

[mr. piper]

A "Salty Rainstorm" sounds rude to me!

[Chapel]

what if they succeeded in killing themselves, then got hit by lightning, and it jumpstarted their heart?

Sickener or what?

[fo3nix]

also note: when people just from very high buildings, many of them die of a heart attack (i.e. due to the shock of falling to your death), before hitting the ground.

[kempie]

fo3nix - that sounds like urban myth material to me.

How can choosing to jump from a tall building be in any way a shock to the jumper? "I didn't know I was going to jump!"

An accidental fall; well that's another matter... but I would still not expect the resultant anxiety to cause a heart attack.

[Hippy]

Kempie: in the same way as when you go on a roller coaster you know full well that you are going on a roller coaster, but it still causes fear, adrenaline, fear & flight, etc etc. Just thinking about it makes me want t..... AHHHHH...ooooargh eeeee!

Jumpers land on the earth with a bang and blood vessels rupture. However, the flow of blood is hardly ever more than a dribble because at the point of impact the heart was not operating. Medics in family have confirmed this for many years.

ORIGNAL Q:

The insurance would not pay out because the lightning death would not have happened without the suicide jump, and therefore was a result of the leap. Thus, whilst not the intended death method it was the intended result.

[Quizmonster]

I'm with you on that, Kempie. What kills one after a long fall is almost invariably "terminal deceleration trauma"!! I suppose one might faint from fear, but a fatal heart attack is no more likely in these circumstances than in any other frighening situation...ie just a vague possibility.
(Apologies for our hijacking your thread, King.)

[kempie]

Hippy - Freefall is nothing like the changes in G-force associated with a rollercoaster; also skydivers fall considerably further before deploying their parachutes and yet many seem to land with cardiac functions intact.

If you contend that it is the adrenaline which causes death "in transit" how come so many people survive your rollercoaster analogy. A typical rollercoaster ride lasts 90 seconds, whereas falling 22 storeys (~250 feet) would take 4 seconds - enough time to provoke cardiac arrest?  I think not.

As you say, upon impact blood vessels rupture. I cannot see that this proves a heart had failed prior to the impact. When a working heart instantaneously ruptures it would be unable to pump and so, of course, all of the blood would pool and leak out slowly.

[gen2]

I dispute Hamish's answer to Kingaroo's question about being electrocuted in mid air.  It is not necessary to be in contact with the ground to be electrocuted, your body only has to form part of the conductive route to ground.  The voltages involved are so great that the air molecules ionise and form a conductive path between -ve and +ve.  The human body offers less resistance to the flow of electricity than the air and electricity will flow through the body rather than around it.  Conversely, if you are sitting in an aeroplane at the time, the metal of the aircraft offers the lowest resistance and the current will flow through that rather than through the occupants.  In both cases, (the falling body and the aeroplane), the lightning does not terminate where it strikes - it will enter at one point and leave at another.

[Hamish]

Yep gen2 you are right. I had forgotten about aeroplane strikes.

[theren_911]

Just curious.. where does the electric go once it "goes to ground" is it just absorbed, so to speak, or what?

[gen2]

theren_911,  Objects are naturally neutral having equal quantities of +ve and �ve charges.  If you separate these charges into an area with more +ve charge and an area with more �ve charge then you create an electrical potential difference (voltage) between them.  When electricity flows (current) between these areas the +ve and �ve charges cancel out and the normal neutral state is restored.

So, the electicity that flows from lightning dissipates through the ground, neutralising an imbalance of charge.  It wouldn't have struck in the first place unless there had been an imbalance.

It is a bit like you and your partner getting back together again after a period of enforced separation.

By the way, not all lightning strikes are to ground.  Many are cloud to cloud between +ve and -ve regions.

[Kingaroo]

Gen2 -- This whole question came about from explaining to my kids that birds on the utility wires aren't electrocuted because they aren't touching the ground (never mind the insulation).

I confess this is the answer that was always given to me and never made sense to me. If a bird flew into a live uninsulated wire, wouldn't it be electrocuted despite not touching the ground?

If a bird was sitting on an insulated wire and touching the ground with a looooong stick it was holding in its tiny little beak , then what? I can't imagine it would go through the bird and stick to the ground and cut off power to everyone past that point?

And what happens to the electricity in an airplane strike? After buzzing around the metal skin of the plane, does it dissipate in the air, even though the air is less conductive than the metal?

Thanks -- Kingaroo

[gen2]

Kingaroo
You are correct when you say that birds sitting on power lines are not electrocuted because they are not touching ground, but it is more accurate to say that they are not electrocuted because their body is not forming part of an electric curcuit.  Flying into the cable, standing on it or swinging from it by its beak, it makes no difference

Think of it this way:
The electricity supply lines are part of an existing circuit so the current is already flowing from A to B and the bird is just an incidental object attached to the side. No current will pass through its body.  However, if the cable were to break exactly between the feet of a perching bird, then (this is hypothetical so ignore the possibility of arcing) the only route the current can take from A to B would then be through the bird�s body and it would be electrocuted.

Although I stated that the electricity is flowing from A to B, it would equally easily flow from A to the ground to complete the circuit.  This is because the neutral wire is grounded at the power station end.  If the electricity could find a route to the ground then a large current would flow.  Air is a very good insulator and the voltages involved are not high enough to break down that insulation over the distances involved.  Anything greatly reducing that distance (such as a fisherman with a carbon fibre rod) could risk electrocution if the electricity can arc across the remaining gap.  The shortest distance between the conductors and an earthed object is at the pylon.  Large birds have been electrocuted - not because they flew into the live cable, but because they provided a conductive path to the metal of the pylon.  Children climbing a pylon run the same risk.

continued . . .

[gen2]

Your other question about the lightning striking a plane was answered above but to explain more, the lightning strike does not end at the plane.  The plane just forms one part of the circuit as the lightning passes from cloud to cloud or cloud to ground.  That is much the same as a light switch forming a link for the electricity to pass through on the way to a lamp.

A final note for any pedants reading this. There will in fact be a minute current through a bird on a live wire because there is a finite but very small resistance to the short segment of conductor between the bird's feet.  That means there will be a minute potential difference between each foot.  The resistance of the bird's body will be high in comparison so the current flowing through the bird will be so small as to be undetectable by the bird.

[Kingaroo]

Thank you gen2, that is all very clear.