Set in an alternate universe we have homo electricus instead of homo sapient, they evolved organs similar to electric eel and they are capable of discharging deadly amount of electricity up to 1.5m away. I was wondering how would the homo electricus fight in the medieval warfare? How can they utilise such ability to inflict damage over a long distances?
Impossible to use bioelectricty as a deadly weapon between closely matched opponents. If it is deadly for a recipient similar to you, it is deadly for you, as the source, too. The same current needs to pass through you (as the source) as through the destination - being similar to you, his body has a resistance (or impedance) in the same range as you. If that current make him boil, the same current will make you boil too.
Even worse, you must use your body as the source of power, but he can shunt the current with a long light chainmail to the ground. The result: you boil or explode, he gets a slightly warmer chainmail - thank you very much, the weather this morning was a bit cold.
How can they utilise such ability to inflict damage over a long distances?
Keeping into account the best we could do in terms of individual electrical weapons is a stun gun, I'm skeptical it would make any difference.
At best, with advances in technology, one may think of a bio-electrically powered railgun. But keeping into account the immense currents involved, each projectile fired will probably destroy the 100+ humans acting as a battery.
Personally, I'd rather use some diesel motors with a generator charging a supercapacitor bank, but then, it's just me.
The consideration above may not apply as such if the "attack vector" is not involving the source once launched - something on the line of "bolt; form it, launch it and forget it".
But this is physically even harder than a "lightning strike" (which connects the source with the target during the attack). The "bolt" acceleration is the easy part, the formation of a stable bolt will require energies at least one order of magnitude higher. Bioelectrical sources for those currents are going to be more than toasted to a crisp, highly likely their final state will be the same as the formed bolt - a hot plasma.
For reference Rail gun - plasma and Plasma railgun
in a plasma railgun, the armature and ejected projectile consists of plasma, or hot, ionized, gas-like particles, instead of a solid slug of material. Scientific plasma railguns are typically operated in vacuum and not at air pressure...
After armature formation, the plasmoid is then accelerated down the length of the railgun by a current pulse driven through one electrode, through the armature, and out the other electrode, creating a large magnetic field behind the armature.
There Would Be Nothing Medieval About It
All of human history and behavior would be so radically changed by the ubiquitous ability to shoot lightning that warfare is the least of the changes.
Take fire for example. We had to invent bow drills, flint and steel, matches and lighters to start fires. But if you can just zap things there’s absolutely no reason to innovate.
Why would man ever become a highly social tool user if he was instead a supremely deadly predator without any tools or cooperation? There’s a reason a naked ape created the internet and not a tiger.
Why would anyone ever make a sword or even a club if you can just zap people?
But if you did get to the point where humans have formed complex states and a system resembling feudalism, the warfare wouldn’t look like our Middle Ages at all.
Projectile weapons would absolutely dominate the battlefield. Why get close to an enemy that can zap you? Even though you can zap each other it’s way more reasonable to keep your distance and force them to get into your zapping range.
You’d have to be insane to use metal melee weapons, and non throwing spears might be very questionable to use if they’re at all conductive.
The only metal tool that would be useful would be faraday armor. Imagine a faraday cage fit over the human body. It doesn’t currently exist but you’d be damn sure that’d be an innovation that would occur if we all could zap people.
Assuming that this ability was not a big deal prior to the Middle Ages, for simplicity's sake, we'd have some pretty radical changes rather quickly:
- Blocking electric attacks will be done. Faraday Cage type armor would be work to develop, but it would happen. A metal pole with an insulated handle or gloves for positioning would make an excellent shield.
- Chemistry and metallurgy would benefit from ready access to electricity. Expect batteries to be invented earlier, and certain materials to be more readily available. (Would this affect aluminum production? Would electrolysis allow early oxygen isolation?)
- There are many ways to weaponize electric shocks other than attacking one's enemies directly. Set things on fire, mess with the integrity of certain materials, etc. If you want a semi-direct attack, don't zap the enemy at close range; invent a copper lasso, and use that to give yourself more range.
As it was pointed out, the ability to generate electricity implies that one has a means of not being fried by one's own attacks. This suggests that other people with this ability will naturally be more resilient to it than random, non-electrogenic critters (did this ability take off as a means of frying disease-carrying insects, maybe? Now I want this power just to repel mosquitos.). Therefore, more indirect applications will likely dominate.
Oh, and here's an idea I have not run the numbers on: primitive rail-cannon? Or possibly an electrolysis cannon? I remember someone designing a cannon to use saltwater and electricity in a DnD based setting, but I'm not sure how well that would work in real life, or with the particulars of this type of electrogenesis.