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  • Antvasima
    Antvasima closed this thread because:
    07:43, October 16, 2017

    Okay, so its about time we got around to making a rule for the speed of electricity. It was mostly agreed on here and here that electricity with AP comparable to that of natural lightning should be treated as moving at a comparable speed as per this formula:

    Electricalenergyformula

    As well as the Drift Velocity of electrons being proportionate to the voltage and the fact that electrons traveling through air go much swifter than the ones traveling through much denser materials such as metals

    So how exactly should this rule be worded?

    Also sorry if this is a bit awkward, ive never had to make a staff thread before.

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    • Well, not just that formula.

      According to what I skimmed in Wikipedia, it also seems like the drift velocity of electrons is proportionate to the voltage, although the formula in the page below is for metallic ohm conductors:

      https://en.wikipedia.org/wiki/Drift_velocity

      I also noticed that electrons travelling through air go much swifter than the ones travelling through much denser materials such as metals, but I may have misunderstood:

      https://en.wikipedia.org/wiki/Speed_of_electricity

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    • Oh, that too, sorry Ant, i'll add that to the OP

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    • Anyway, the ideal solution would be if somebody could find the formula for drift velocity through air. I have been unable to do so.

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    • It is preferrable when dealing with feats regarding electricity to refer to this formula if possible. The speed of electricity may be derived from such formula.

      IDK about electrical feats, but I assume somehting like that ^ would be fine.

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    • @WeeklyBattles

      No problem.

      Regardless, the issue here is that it seems like the drift velocity of electrons is proportionate to the voltage, which in turn is proportionate to the energy of a current.

      This is an oversimplification, as the drift velocity also depends on other variables, but we cannot overcomplicate the issue too much.

      For practical purposes we have to consider electric discharges of equal or higher energy than natural lightning, that also travel through air, as having at least comparable speed as well.

      However, we need somebody who is skilled with math and physics to write down a practical rule for this convenience.

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    • Perhaps you could notify all of our calc group members about this thread, and ask them to help out with making this convenience work for us.

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    • Ive already done so

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    • Thank you for the help.

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    • I guess that formula is OK.

      Drift Velocity is a subject about electricity that I don't really like to deal with when it comes to speed calcs. That's the one that's relativistic, right?

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    • Drift velocity is the speed for a current of electrons through a medium. It is generally far slower than an individual electrons can travel (which is close to the speed of light, if I remember correctly).

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    • Antvasima wrote:
      Drift velocity is the speed for a current of electrons through a medium. It is generally far slower than an individual electrons can travel (which is close to the speed of light, if I remember correctly).

      Well I mean, yeah.Electrons are just bits of ordinary matter.Any form of regular matter is potentially capable of reaching relativistic speeds.

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    • I think it seems fine.

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    • Nice. Might finally be able to give real, concrete speed ratings to a bunch of characters now.

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    • Wait, so, how do we handle electricy which voltage/energy is unknown?

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    • Also what about weird exceptions like ball lightning? It says here: Direct measurements of natural ball lightning. that it moves at 8.6 m/s nowhere near even normal lightning speeds not even touching electricity speed.

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    • AidenBrooks999 wrote: Wait, so, how do we handle electricy which voltage/energy is unknown?

      Then it would be rated as unknown unless it has AP comparablto lightning

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    • I sent DontTalk (who used to be our likely most mathematically knowledgeable staff member) a message asking him to analyse this.

      He was kind enough to take the time to do so.

      Here is his reply:

      I have no definite answer for the problem either. A lot of really complicated things are involved, like for example the fact that the lightning we see is actually the glowing air as it's heated up and that follows rules of plasma science I have no idea about.

      I can make some guesses on the issue, but that's all. So take anything I write here with a grain of salt.

      First the thread already linked to this page, which is a good place to start.

      https://en.wikipedia.org/wiki/Speed_of_electricity

      Now drift velocity is probably not which you want to use here. As that article mentions drift velocity of electrons in a wire is something in the millimeter per hour.

      Using it would imply that if one holds a wire and someone lets electricity flow through it one would be absolutely fine for days, until the electricity does one damage.

      Instead the value interesting would be the speed at which the energy flows through the cable. That energy is what makes the damage after all.

      As the pages states the energy is transmitted through electromagnetical waves. Such waves, as the article states, are very fast with 50%-99% of the speed of light. The transmition to air is even noted to be particularly fast and judging by its refractive index I would guess around 99% the speed of light.

      https://en.wikipedia.org/wiki/Refractive_index

      Now we at first have a problem: Doesn't our article from harvard state lightning is only 440000 m/s fast on average? That is much less than 99% of the speed of light.

      Now what they in detail found is "The average speed of the leader tip". The word "average" is important here. As it turns out lightning doesn't flow at one constant speed, but while a lightning strikes it changes the speed constantly.

      Look at this page of the NOAA.

      http://www.srh.noaa.gov/jetstream/lightning/lightning_max.html

      “Between each step there is a pause of about 50 microseconds, during which the stepped leader "looks" around for an object to strike. If none is "seen", it takes another step, and repeats the process until it "finds" a target."

      “Studies of individual strikes have shown that a single leader can be comprised of more than 10,000 steps!"

      Essentially a lightning takes a lot of very short breaks while moving. This breaks are so short and under circumstances so many that one wouldn't be able to see any of them usually. For us it would just look as if the lightning is moving at a continuous speed.

      Given that my guess on why the theoretical close to lightspeed energy transmission of lightning (which I would assume coincides with the visible lightning speed, albeit the visible phenomenon likely lacks behind by some amount due to the time necessary to heat up the air) is in practice only on average 440000 m/s is that the movement with close to lightspeed and the breaks average out to just about 440000 m/s.

      So with that is my guess on why lightning is as fast as it is. What does that mean for electricity now?

      Well, for electricity flowing through air (and possibly other insulating materials) I would assume that its speed it determined through the same close to lightspeed with breaks average. In that case what determines the speed in the end would be how many breaks there are and how long this breaks are.

      For that one really has to know what even causes them in the first place, which isn't mentioned. My personal guess is that after a step the potential difference drops a bit and the lightning needs a bit to build it up to the point of reaching the breakdown voltage of the next step again. That is only an unintellectual guess, though.

      https://en.wikipedia.org/wiki/Breakdown_voltage

      If we were to assume something in that direction, though, the main factor for electricity through air to reach lightning speed would be to have a comparable or higher voltage which would be 100 million to 1 billion volt.

      Since for electricity Power = Voltage * Amperage, one can probably do a generous approximation by saying that electricity, that in power is comparable to real lightning, can be assumed to flow equally fast through air.

      I assume for electricity in conductors the velocity factor gives that correct value.

      https://en.wikipedia.org/wiki/Velocity_factor#Typical_velocity_factors

      So this is my hypothesis on the matter at hand. As said, take it with a grain of salt.

      In any case I think electricity flowing through air that has similar power to lightning (and fulfills the general requirements in regards to realistic lightning) should have properties similar enough to lightning to have the lightning speed value applied to it, however it works in detail. Whether or not the source is a cloud shouldn't be what makes the difference after all.

      So essentially I agree with the conclusions you guys seemed to have reached, albeit due to different reasoning.

      Or was it specifically the writing of some rule that you wanted help with? In that case I would simply suggest adding "Additionally, since lightning speed could change depending in various factors, it is required to show that the electricity carries an energy of around 5 billion joules or more, or has a voltage of around 100 million volt or more" to the second bullet point of the "What is a real Lightning?" section on the lightning dodging feats page.

      The 5 billion and 100 million volt figures come from here:

      https://en.wikipedia.org/wiki/Harvesting_lightning_energy

      http://www.srh.noaa.gov/jetstream/lightning/positive.html

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    • So basically he agrees and the rule will be:

      Since lightning speed can change due to a variety of factors, it is required to show that the electricity carries an energy of around 5 billion joules or more, or has a voltage of around 100 million volts or more.

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    • Yes, that seems to be the case.

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    • We should also preferably insert the last two links as evidence for that these are the typical properties of lightning.

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    • Okay, so how about:

      "Concerning attacks that are electricity-based, if said attack displays the properties of and power comparable to that of natural lightning, it fulfills the requirements to be considered moving at a comparable speed. However, Since lightning speed can change due to a variety of factors, it is required to show that the electricity carries an energy of around 5 billion joules or more, or has a voltage of around 100 million volts or more."

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    • I modified the text a bit. Is this acceptable?

      "Lightning speed can change due to a variety of factors, but for practical purposes, concerning attacks that are electricity-based, if they display power comparable to that of natural lightning, and fulfill the other requirements listen within this page, they should be considered to move at a comparable speed. It is required to show that the electricity carries an energy of at least 5 billion joules or a voltage of around 100 million volts in order to qualify."

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    • Sounds good, what do you guys think?

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    • As DontTalk said, the text should be added to the second bullet point of the "What is real lightning?" section in the Lightning Dodging Feats page.

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    • So this can be added? Should a link to this thread be included as well?

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    • Yes, I think that we can add the text.

      I suppose that a link to this thread can be added in a footnote.

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    • So, should we lock this thread?

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    • We've already got everything squared away so unless anyone has anything to add i think we can close this

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    • Okay.

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