what is the film-technique called, where phosporus? is dropped onto a

['ataturkt]

camera below to mimic a sci-fi explosion?

it is obviously filmed in ultra slow motion, and it looks like a gigantic explosion. i presume its similar material to that used for flares.
this pic gives you an idea of what i mean:

http://www.shutterstock.com/pic-40727026/stock-photo-blue-light-burst-with-stars.html

 

[JamPie]

Pyrotechnics may be what you are referring to. Although, that is not a film technique. That is simply the art of making or displaying fireworks. But on film, the explosion could be manipulated.