The sight of a sandworm of Arrakis (Shai-Hulud) breaching the surface is usually accompanied by lightning. Is there any explanation given for this phenomenon?

Is it supposed to be due to accumulation of electric charge from the friction between the moving sandworm and the sand (like a Van de Graaff generator)? Or is it caused by some other feature of the sandworm, the environment of Arrakis, or even the spice?

Furthermore, a high electric potential between two separate regions must exist for a lightning discharge. If the sandworm is one of these regions, what is the other region? For example, does the desert planet Arrakis have suitable clouds for lightning discharges between a cloud and a charged sandworm that breaches the surface of the isolating sand?

  • 3
    Are you referring to the book, the film or the mini-series?
    – Valorum
    Jun 3, 2016 at 22:26
  • 2
    @Valorum just about to ask the same thing afaik the book has 0 lightning
    – Himarm
    Jun 3, 2016 at 22:27
  • Possibly referring to the film; youtu.be/ld2DMsyy0go?t=4m45s You can see lightning in the clip above
    – Valorum
    Jun 3, 2016 at 22:29
  • 2
    @Valorum I am mainly asking about the 1984 movie. However, the book mentions "… a wide hole emerged from the sand. Sunlight flashed from glistening white spokes within it."
    – user35609
    Jun 3, 2016 at 22:35
  • 6
    @Loong - I believe those are reflections from the sandworms' teeth. The krisknives are described as being quite shiny later on.
    – Valorum
    Jun 3, 2016 at 22:39

1 Answer 1


I always assumed it was a similar effect to that seen in sandstorms in the real world, where saltation of the sand particles (in this case produced by the motion of the sandworm breaching the surface rather than by wind) produces static electricity.

As the force of wind passing over loosely held particles increases, particles of sand first start to vibrate, then to saltate ("leaps"). As they repeatedly strike the ground, they loosen and break off smaller particles of dust which then begin to travel in suspension. At wind speeds above that which causes the smallest to suspend, there will be a population of dust grains moving by a range of mechanisms: suspension, saltation and creep.

A recent study finds that the initial saltation of sand particles induces a static electric field by friction. Saltating sand acquires a negative charge relative to the ground which in turn loosens more sand particles which then begin saltating. This process has been found to double the number of particles predicted by previous theories.

(src: dust storm)

  • 2
    This is the coolest thing I learned all week.
    – zahbaz
    Jun 4, 2016 at 0:36
  • 3
    @zahbaz Yeah, but it needs a soundtrack and Morgan Freeman.
    – Marakai
    Jun 4, 2016 at 0:57
  • 1
    I don't understand why people like Morgan Freeman as a narrator so much. He just doesn't cut it for me. Don't get me wrong, I quite enjoy films he's in, but in scientific programs... No. For one thing, he pronounces cosmos as cows moss.
    – Mr Lister
    Jun 4, 2016 at 7:24
  • @MrLister I'm pretty sure it comes from Shawshank being so awesome that the better aspects of it (e.g., narration by Freeman) are seen as awesome by themselves. Now, if you've seen Shawshank and don't get why people think it's awesome... you might want to keep that to yourself. ;-) Jun 4, 2016 at 11:21

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