[AGuyNamedMike]

Man, that's pretty dang cool! [/geeking out]

I used to do PC support for Mike Davidson, king of photomicrographywebsite, out at the Maglab, so I grok the significance.

 

[AGuyNamedMike]

I know the answer to that!

They would set off smoke pots to send a nice clear straight column of smoke straight up or fired rockets that produced smoke trails prior to the test. That way they could see the shape of the shockwave as it disturbed the smoke columns.