Phenomena

Seeing Blast Waves

Featured Video Play Icon

With a large enough explosion, it’s actually possible to see shock waves. This high-speed camera footage shows the detonation of a car packed with explosives. After the initial flash, you can see the thin membrane of the blast wave expanding outward. This shock wave is a traveling discontinuity in the air’s properties–temperature, pressure, and density all change suddenly over an incredibly small distance. It’s this last variable–density–that enables us to see the effect. Density has a significant impact on air’s index of refraction (which also explains heat mirages). In this case, the shift in refractive index is large enough that we see the difference relative to the background, enabling our eyes to follow an otherwise invisible effect.  (Video credit: Mythbusters/Discovery Channel; via Gizmodo)

If you enjoy FYFD, please help support me by becoming a patron!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: