Since there is a voltage difference between the ground and sky, shouldn't I theoretically be able to light a bulb by connecting one terminal to the ground and raising the other one to the sky (via a very, very long wire)?


1 Answer 1


You'd need a very big electrode, and you'd need extreme power conversion. The voltage is typically 100 kV per km altitude, but only 2 pA current per square meter. Way too much voltage, and way, way too little current to light a bulb.


  • $\begingroup$ Doesn't lightning have a lot more current than that? Also, my understanding is that P=IV, so if there is ton of voltage, shouldn't there be a proportionally high amount of current? Unless the resistance between the ground and the sky is that much. $\endgroup$
    – Undefined
    May 10 at 1:21
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    $\begingroup$ Is that current through the atmosphere? Why woild it be relevant to the current through a wire? $\endgroup$
    – WillO
    May 10 at 2:28
  • $\begingroup$ If you search up the current in a lightning strike, you get 30,000 A. If that much current can build up during this strike, why not through a wire? $\endgroup$
    – Undefined
    May 10 at 4:39
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    $\begingroup$ @Undefined because lighting only occurs when clouds (or in rare cases blobs of unusual atmosphere) collect a shitton of charge. That is nothing like the normal atmospheric situation JDoty presented here. $\endgroup$ May 10 at 12:55
  • $\begingroup$ However, when you get near a high-tension power line, both E-field strength and available current are large enough to light a bulb -- "fun experiment" :-) $\endgroup$ May 10 at 12:56

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