Where there's smoke, there's fire

[HorsePunchKid]

I've mentioned this BFG project that I worked on last spring; basically a game built by students for class credit to show off the new computer science building at UIUC. Well, we're at it again this semester, only this time we're doing a Firefighting Simulator for the UIUC Fire Service Institute. One thing we did recently was sit in a burning building. Here are a few photos from that experience. These are mostly ISO 1600, 1/45" or so, f/4, ~25mm, and not exactly great quality, but still worth a look perhaps...

It was amazing how clearly defined the boundary was between smoke and clean air. You can see the layer in that last photo and how the smoke colors the top half of the doorway in the second photo.

 

[Rooster]

Much like a thermalcline under water. Hot and cold seperated into two defined layers. It's often clearer once you decend below the thermalcline.

 

[HorsePunchKid]

Much like a thermalcline under water. Hot and cold seperated into two defined layers. It's often clearer once you decend below the thermalcline.

Interesting. There's definitely a temperature transition in the smoke-filled room, too. You can see people reaching up into the smoke to feel how the heat suddenly increases from practically ambient temperature to too-hot-to-stand within about a foot or two. If I had stood up in that room, I'd probably have hurt my lungs pretty badly. The clarity is also very analogous. One of the things that we learned is very important is to not disturb the layers by dumping lots of water on the fire; it just mixes the air, eliminating that safe zone from the floor up to about four feet.

 

[Rooster]

Maybe the smoke filled, hotter air is dryer, causing it to be less dense. And the air on bottom has more moisture making it more dense, thus settling on the bottom.