How plausible is a "Lightning Amentum"

Question

I have a race of mountain giants (who stand roughly 10-15 feet tall) and have long worship the storms and more importantly the lightning that is cast from them. Long have they sought after a way to "create" lightning of their own.

Their current idea is a Amentum that a warrior would spin at great speed before releasing causing the javelin to discharge lightning at their foes as it flies into their ranks.

This question has two main parts: Is there any material that can build up enough static electricity through kinetic force to cause lethal damage to humans and secondly would muscle mass alone be enough to wield this weapon?

Note: The giants are pretty strong roughly 3 times the 'average' human and a Amentum can be wound up like a sling before release (which can break the sound barrier in the right hands) no clue if this information helps.

Answer 1

I imagine that the amentum wraps round the javelin. The force of the throw causes the javelin to spin and the triboelectric effect causes the javelin to become charged. When the javelin reaches its target, it discharges, causing death by heart failure.

There is no real world way to do this by creating static charge from the triboelectric effect.

You can't put sufficient charge on a javelin that it could ever do any damage. Electric machines used the triboelectric effect (ie rubbing) to separate charges. The voltage that can be obtained this way is quite high, but the actual amount of charge, and hence the amount of current that can be achieved is very low.

We can't achieve sufficient charge using any kind of rubbing. If we want deadly levels of electricity we either need Tesla coils or an AC generator (and an electric chair).

If you did somehow manage to charge the javelin up, it would rapidly discharge out the pointed end before it reached any hostiles.

We can't create anything that approaches a lightning bolt, even with our most power generators and tesla coils. The powers required are beyond us. If you want death from lightning, first give your giants weather control skills.

What we can make is an electric "cattle prod" and the tech to make these is fairly low: a battery, some transformers a few wires. It has been suggested that the Ancient Greeks used a very simple electrical cell in some temples, so it is not inconceivable that your giants could have developed "cattle prods", and it is only a short step from a cattle prod to a taser.

Answer 2

The closest we can come to controlling lightning today is to send a sounding rocket into a thunder cell trailing a copper wire. This creates a conductive path for the lightning to flow (essentially creating a massive lightning rod). Even without trailing a wire, the action of the rocket and plume can create "Triggered Lightning", which is dangerous to the rocket as a minimum.

Lightning travelling down the copper wire

For premodern tech, Benjamin Franklin famously conducted an experiment where he flew a kite into a storm, and electricity from the cloud flowed down the kite string to a key tied to the string, confirming that lightning was, in fact, electricity. I will note this experiment is extremely dangerous, Benjamin Franklin was amazingly lucky, and modern day Franklins tempted to try this might not get away so easily.....

So the method is actually the reverse of what we might normally think. Using a catapult or other mechanism to accelerate the javelin, you fire upwards into the cloud to start the "triggered lightning" effect and direct it with a string attached to the base of the projectile. You might have to create an odd looking weapon looking like two steel crossbows back to back, one to fire the "triggering bolt" into the clouds and a second one to fire a "target bolt" at the target, with a bobbin of string between the two projectiles. A large device on mountain tops could easily be used to direct lightning strikes at forces advancing in the valley below.