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Hardware Science

Working On Man Made Lightning 67

Posted by Soulskill
from the i'll-order-a-dozen dept.
New submitter PerlJedi writes "There is a very cool write up on the Make blog about an effort to build the world's largest tesla coils. Quoting: '"Somehow lightning can generate huge discharges with only about a fifth of the voltage per foot that lab discharges require," Leyh explains. "The part that especially fascinates me is that this mysterious ability kicks in around 200' in length, which is right at the edge of what we can produce with a practical machine." Leyh wants to see if humans can replicate this voltage economy effect, and has launched a Kickstarter campaign to fund the building of two 10-story Tesla Coil towers (obviously superseding his current coil-size world record).'"
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Working On Man Made Lightning

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  • by jellomizer (103300) on Thursday November 17, 2011 @12:30PM (#38086880)

    I feel sorry for that house in the middle. It looks like a nice one too. But to be placed under massive Tesla coils will greatly reduce resell property. Perhaps it is one of those older houses where the ghetto was built around it.

  • I'm absolutely electrified to see the results of this experiment! I would be shocked if he doesn't get enough funding to try it.

    Kidding aside, I too am curious about why lightning can exist at lower voltages. Do longer distances allow for more pathways in the air, where enough variances in humidity etc, to allow lower dielectric breakdown on average?

    • by Moryath (553296)

      It's a good working theory. I wonder if we'd also see a measurable difference in pristine air as opposed to polluted air, similar to the dielectric difference between pure and impure (read: soapy, salty, etc) water?

    • I had always understood that lightning exists in two stages. an initial pop that causes an ionized channel in the atmosphere, and the second, 'real' lightning strike, that follows the ionized path to the ground. I would assume that the ionization is responsible in some way for the reduced voltage requirement.
      http://www.youtube.com/watch?v=dukkO7c2eUE&feature=related [youtube.com]
      this video was shown in the article, but sort of shows what i'm talking about. when one of those initial charges finally grounds, th
  • Man-made (Score:1, Funny)

    by Anonymous Coward

    "Man made lightning" and "Man-made lightning" mean two different things.

    • by Anonymous Coward

      Hyphen, bitches! Learn it, know it, use it!!

      • by Anonymous Coward

        Hyphen-bitches! Know 'em, use 'em, slap 'em!

  • In soviet Russia... (Score:5, Interesting)

    by TheBlackMan (1458563) on Thursday November 17, 2011 @12:36PM (#38086956)
    In soviet Russia they actually have some of these already:

    darkroastedblend.com/2007/07/creepy-high-voltage-installations.html
    • Those are fantastic; Straight out of 1950's sci-fi. I note the maximum arc is 150 meters.
    • Harry Diamond Labs used to have a place down near Albuquerque that they used for zapping things with lightning and other big electromagnetic pulses. If you needed to simulate what happened to an airplane, radio system, or telephone switch near a nuclear explosion, that was the place to go. I don't know if it's still operational - Wikipedia indicates that HDL got absorbed into the Army Research Labs in the 90s, but at least the equipment should be in better shape in dry New Mexico than in Russian climates.

    • HNNNGGG NERDGASM!

  • by Oswald McWeany (2428506) on Thursday November 17, 2011 @12:38PM (#38086976)

    Completely misread the title as

    "Man made lighting" - I was getting all excited thinking they would soon be able to add photo-luminescent genes into people.

    You know at the bars all the men are going to want to hit on the girl whose buttocks glow like a fire fly.

    • by thelexx (237096)

      I was personally hoping the phrase 'piss lightning and crap thunder' had gained new relevance...

    • by necro81 (917438)
      At first I thought they were seeking to allow people to throw lightning bolts. Dark side of the force, anyone?
  • by Sez Zero (586611) on Thursday November 17, 2011 @12:45PM (#38087076) Journal

    I don't care if it works or not, I just want a pic of me in front of two 10-story tall Tesla Coil towers wearing my xkcd [xkcd.com] shirt.

    And perhaps a white lab coat, monocle and puffy white wig.

    And pants, yes pants as well.

  • Command & conquer Red Alert

  • AC vs DC? (Score:5, Insightful)

    by Artraze (600366) on Thursday November 17, 2011 @12:57PM (#38087316)

    What confuses me is that there seems to be a disconnect regarding this project vs. lightning... Tesla coils operate on relatively high frequency AC whereas lightning is a very slow DC process. If I were to hazard a guess, I'd say the lightning can get away with lower voltages because the charge buildup allows for partial ionization at charge concentration points (e.g. a lightning rod) which can create ion streams and render the atmosphere partially conductive thus reducing the required potential. That may not be quite right, but still I find it odd that one would try to replicate lightning using such a fundamentally different design; a marx generator seems far more appropriate. Does anyone know if they're planning on rectifying the output? I guess it's theoretically possible...

    Also, Tesla coils generate a _huge_ amount of broadband RF interference (not to mention sound). It seems to me that building this thing would be far less difficult than simply being allowed to build it (and for good reason!). Do they have a location picked out and have they talked to local government and the FCC?

    • Rectifying a signal that is able to jump over 200' of air?! Have they started to gather funds for the wold's largest pair of diodes?

      Theoretically, you could do that with 250V diodes... I'd put them on a serial/parallel mesh for dealing with some of them burning, but putting diodes in paralel isn't that easy.

    • by Stoutlimb (143245)

      Considering that physicists suspect that lightning is triggered by vertical ionized trails in the atmosphere caused by cosmic rays, the experimenters may have to also use a portable cosmic ray generator to get their machine to work.

    • by mark_reh (2015546)

      Yeah, I don't get the point of this project except that it's going to make big sparks. AC vs DC arc physics are quite different, as is the energy contained in the discharge of lightning vs the spark from a Tesla coil. Lightning can produce thousands if not millions of amps (the source of thunder) whereas a Tesla coil might come close to matching the voltages involved, it can't produce anywhere near the same current. I think this whole thing is just some hobbyist's wet-dream Tesla coil project and he's tr

    • Burn it down (Score:4, Informative)

      by wsanders (114993) on Thursday November 17, 2011 @02:13PM (#38088390) Homepage

      It may be cool, but I'm a ham radio operator and if you build this thing anywhere within 10 miles of my house, I will come over and burn it down.

      This is just a toy for rich techies. There are plenty of places where lightning is frequent enough that if you build a structure to attract it, you will get lots of hits from the real thing:

      http://www.lightningsafety.noaa.gov/images/map.jpg [noaa.gov]

      • by treeves (963993)

        From the looks of that map, I'd swear lightning is attracted to low IQ.
        Flame away!

    • by drinkypoo (153816)

      Correct me if I'm wrong, but don't many types of lightning involve a return stroke? Isn't that AC in a way, just with only one wave?

    • I put in my guess as to 'why'.

      Lightning causes the 'starting' bolt up in the air to ionize and creates some plasma. Now, lightning is electrons which, when moving, create magnetic fields. Even straight copper lines can cause RF interference when voltage oscillates because of this effect. The thin 'coating' of plasma around the lightning could be creating an electromagnetic field of it's own due to induction that only becomes strong enough when enough plasma is created -- 200 ft or more. Thus, the lightning

  • Resistance is divided by the area of the resistor. For instance, to resistors in parallel have R 1/(1/R1 +1/R2), which makes the R drop mighty fast for many resistors. When I learned as a teen that lightning is in the 10's to 100's of millions of volts, I thought that sounded really low for spanning such distances. But the resistor (sky) is obviously really big, so it made sense, I thought.

    So basically what I'm trying to say is that I never considered it a mystery, but I guess that was just my ignorance.
    • It's not that simple. Yeah, some electricity will run through the insulating air, but not a lightining. Lightininh only happens when the potential becomes so big that part of the air ionizes, and starts conducting better. And theoretically, the ionization will happen in the volume between the charges, it doesn't matter what is around it. The size of the sky isn't really relevant, or at least shouldn't be.

      • by surd1618 (1878068)
        The bulk of the conduction goes through the lowest-resistance path, which is also going to be the first one to connect (more conduction = more ionization = faster-growing path). Also, it need not be the shortest path. Therefore, the greater the volume, the lower the resistance. I think you misunderstood my initial post.
        • The bulk of the current pass through the shortest path because the elctrical field there is strong, and you need strong fields to get ionization. After some ionization, there is very little resistence, so the current passes there. Stronger field = more ionization = less resistence = more current (and current negatively feeds that cycle, so the lightining stops). You can't do calculations with constant resistivity when the resistivity is changing by several orders of magnitude.

          At least, that is what theory s

  • I would have thought all it took was 1.21 gigawatts.
  • I read lighting rather than lightning and wondered why slashdot was posting a story a century late
  • Oh, you silly Tesla. Only you would want to build a giant coil of self-naming.

  • ...when you can wear one as a personal MIDI player...

    http://www.youtube.com/watch?v=aEgaI6WouQ0 [youtube.com]

    • I've got to admit that when I read that they were looking to build the world's largest Tesla Coils, I was wondering how loud the music they would be playing on them would be.

      The show from playing the Dr. Who theme with Tesla coils [youtube.com] that huge would be unbelievable.

      And like earlier commenters, I think they're missing out on too many variables as to how lightning accomplishes what they're trying to duplicate in order for this endeavor to be of any practical use or gain any substantial further useful knowledge.

  • Gimme!

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