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Science of Spellcasting: Lightning

  1. Aug 9, 2014 #1
    I hope it's not too brazen to make my first post my first thread, as well.

    I was tasked with developing a system of magic for a fantasy RPG I'm involved with. I wanted to step away from the traditional schools, and look at the magic in terms of what's happening. I won't elaborate, for sake of keeping some things under wraps, but I'll talk a little about "casting" lightning, and how it sort of works.

    My understanding of electrostatic discharges is limited. If I'm doing my reading right, what's essentially going on is that if a strong negative charge and strong positive charge are within a certain proximity, and their charge (or charge difference? I can't recall) is strong enough, than it causes a discharge, which has a visible spark, even through such a poor conductor as air.

    In looking up lightning strikes, there seems to be a phenomenon called a "leader", which in most of the illustrations and other graphical representations I've seen, is something like a series of "feelers", that search for a source of positive energy, and upon making contact, the discharge occurs.

    With this as a basis, the way I've thought of casting lightning is that the spellcaster has the ability to draw "negative energy" (electrons) from the air, or around a source (most specifically, their target) and store the energy, to some extent. The breaking point is either when the fields that they've created (by absorbing a lot of negative energy from a source, presumably that source becomes very positively charged) either exceeds the "dielectric field strength" of air (thanks, wikipedia), or the caster may be able to "release" the energies, or otherwise induce their own leader without necessarily building up that much charge, if they so choose.

    Of course, please correct me where I'm mistaken, but I'll ask the following questions based on the assumption this is accurate:

    1. I'm also aware of "positive" lightning, which is often much more powerful and dangerous. Is this simply due to the greater distance it has to travel, as it often comes from higher altitude clouds? If so, is the strength of an electrostatic discharge correlated, or at least can be extrapolated in some fashion, from the distance it has/had to travel?

    2. What may be some complications of this method of "casting"? My understanding is the human body does not really store electricity, but ignoring that, and presuming the caster is not in danger of electrocuting themselves, via some defense mechanism, are they in danger of discharging into the ground around them? Should they wear insulating or conductive footwear, if so? Are the mechanics of the leader well enough understood that it shouldn't be so straightfoward as "the caster makes their own" (basically; should the leader be a phenomenon outside the caster's abilities)?

    I appreciate any and all productive input. If more information about the system is necessary to answer the question, I may be able to divulge some of it.

    Thanks in advance,

    -Cav.
     
  2. jcsd
  3. Aug 10, 2014 #2

    Simon Bridge

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    This is quite a way out. You can look up the physics of sparks online quite easily.
    Basically if there is a potential difference between two objects, then free charges from one object may flow to the other object. In the case of lightning this happens when there is a considerable buildup of charges between two places. The "visible spark" is the heat from the charges travelling from one place to another through air.

    electrons have positive energy...
    but OK - the spellcaster somehow accumulates a large negative charge someplace.

    Concentrate on the problem you are trying to solve - getting a lot of charge on the caster is not that hard, it's the magic equivalent of a tesla coil or van-der-graaf generator. The problem here is how to direct the discharge at a specific target.

    The specific method chosen would create the "flavor" of the magic system.

    i.e. the mage could throw a charged object at the target, which provides an ionized pathway that the rest of the lightning (mostly) follows. This restricts lighting to how far the mage can throw, shoot a crossbow or whatever. OTOH: the mage could just generate the electricity very close to the target if you prefer non-material action at a distance.

    You need more energy to go further - the initial feelers make an ion trail in the air, the bigger the store, the further the initial trail can go. Basically, the gradient of the potential energy has to be steep enough for the resulting force to pull the air molecules apart.

    The caster gets the same size shock as the target ;)
     
  4. Aug 10, 2014 #3
    See, now I'm imagining a sorcerer giving an archer an enchanted arrow which when shot acts as the lead. Maybe in a universe where magic is low-power (a la Lord of the Rings) he gives a second arrow to a second archer who shoots it into a thunderhead to gather the lightning.
     
  5. Aug 10, 2014 #4
    I know, I know, electrical stuff isn't actually my strong suit, I'm more involved in human kinetics. I did a bit of this stuff, but more than anything I was seeing if I could clarify that what I'm reading is more or less right.

    Aye, charge. The "negative energy" isn't meant in the physics sense of the word, but more so the philosophical sense, I suppose. Yin and Yang, and whatnot. Have you seen Avatar: the Last Airbender? One of the characters, Iroh, describes how "firebenders" (people who can create fire and heat, and control it to an extent) can make lightning by "separating the positive and negative energies, and then letting them crash down." or something to that nature. That's not an exact quote.

    But I still should've clarified that. The spellcaster accumulates a large negative charge, yes.

    Mm. I suppose that if the caster could just "create a lead" he could just "cast lightning", making the complications of the process moot, ah? So would the act of pulling the electrons from the target not create the field that the lead would automatically gravitate to? I know leads act in semi-random "steps" of a certain distance (50 meters for lightning, I think, but I imagine that's not the base distance, so much as the distance of the steps is related to the strength of the charge. Though I don't know for sure).

    I figured if the source was positively charged (from having their electrons pulled away) and the caster was negatively charged, the lead would just kinda go in that direction. Is the discharge more prone to just going into the ground, as apposed to the target (due to the fact that the ground may be closer in proximity)?

    I kind of like your idea of throwing an ionized object at the target, though I just feel in my gut that the lightning should be able to be cast at a distance without a physical device or object...

    Mmkay, so if I understand correctly, positive lightning isn't more powerful by the fact it's positive, but by the condition that if positive lightning is striking the ground, because the clouds are so far away, the energy had to be pretty huge to occur anyhow. I was wondering if the caster making some sort of "positive lightning" would be any more significant, basically.

    Mm. This is why the casters have to train first to immunize themselves to electric shock, and if they attack another electric caster, there's little to no effect (though I suppose the heat of the shock would also need to be something to work against, aye?). That said, it's theoretically possible for a caster to create lightning without training their bodies for the shock: I suppose that would be painful, if not fatal.

    But is there any danger of the discharge going into the ground before the caster fires it off, or is that a sort of non-issue (it's assumed the caster has a degree of control over the electrons, and can either store them in their body, or in the air around them)?
     
    Last edited by a moderator: Aug 10, 2014
  6. Aug 10, 2014 #5
    That's kinda neat. What's going on in this is that there's spellcasting, and then there's theurgy (rituals and practices for people who can't or don't wish to cast spells). That sort of thing could certainly work as a sort of theurgy: in fact, it'd be pretty powerful for it's simplicity, I think.
     
  7. Aug 11, 2014 #6

    Simon Bridge

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    The reading was correct but your interpretation of it left quite a bit to be desired.

    OTOH: you may need to parse what I say on the understanding that I am answering in "science" while you are speaking in "arts".

    Yeah - the description was devoid of meaning. It's like reversing the polarity of something in Star Trek.

    "gravitate" is not right either - but now I'm being nit-picky :)

    The problem is that the leader would arc to the nearest handy place ... watch Tesla coils in action sometime. The target would look good though - they'd be like the other part of a capacitor.
    The effect would be that the hair on the target would stand up and they'd feel tingley - then lots of sparks jump from the caster (maybe the caster's staff-knob) to land all over the target, preferring the pointy bits and the metal bits.

    You don't need a full strength lightning bolt to kill with this BTW.
    And even just a stun can be quite devastating.

    The ground near the caster also becomes positively charged - just like the ground under a thunderhead.

    ... well sure.
    There are other approaches - i.e. you could create bolt lightning and give it a definite momentum vector. Then it may even chase the target.

    you can get used to the pain I suppose, but you cannot get less resistant to the shock. It's more likely to be why lighting wizards carry staffs with a copper knob on the end (and wear rubber-soled boots).

    Have you never had a play with a van-der-Graaf generator in school?

    You also want to look up "electric shock" effects to add to your knowledge of lighting.
    Lightening is actually very extreme.

    Technically the caster could just draw charges from the ground if there's control so it may not be an issue if you don't want it to be. Or it may be that it takes an effort to maintain the charge - so that lightning mages would routinely wear rubber soled shoes and maybe touch the charge source with their hand (or staff) to charge themselves up. The insulation stops them from discharging too fast without needing so much concentration.

    Even so - if they have enough charge for a lighting-sized spark - then there is a strong danger of the lighting just arcing to the ground.
     
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