[pct-l] Lightening risks using external frame pack?

[Ben Crowell]

>I use to use an external frame pack and got nervous about wearing it during thunderstorms.
>Anyone know if there is any research showing if you are more likely to git hit/killed with a big
>lightening rod array - er, external frame pack - tied to your back?

Lightning rods work because they have a pointy tip. Whenever you have a conductor with a tip or
a knife-edge, the electric field around the apex or corner is greatly increased. This is likely
to cause an electric discharge to start in the air right near the tip. If your aluminum tubing
in your pack doesn't have pointy tips on it, this won't happen.

The frame might conceivably even have some protective value.

For comparison, if you're caught in an electrical storm, one of the smartest things you can
do  is to get inside a car. Even if the area around the car is struck directly by
lightning, you are likely to survive, because the volume inside the metal framework is
shielded from electric fields. This is similar to why you can't get a cell phone signal
inside a building that has a lot of metal in its building materials. It's called a
Faraday cage.

With an aluminum external frame pack, I would expect the only effect of the frame to be
to act as a Faraday cage and protect your gear in case you're hit by lightning. Maybe
that would be nice, because it would make it easier for the cops to identify your charred
remains and notify your relatives. If you're hiking the PCT with your beloved pet ferret,
stuff the little guy inside your pack when the thunderbolts start falling, and maybe
he'll survive to inherit your estate.

  Ben