Burn baby burn

Growing up I had a love-hate relationship with fire. I loved it for smores and Helena's cool fire trucks. I hated forest fires because I thought they were very scary. When the Elkhorn Mountain and the Gates of the Mountains burned in 1989, I'd wake up every morning and check to make sure those wild fires were not coming to get me.

On a recent camping trip I realized fire still intrigues me. While trying to start the
campfire with damp wood, I was reminded that I've often thought it would be sweet if wood
could spontaneously combust. That will never happen though, because a wood fire needs to
have three things for it to be "successful": fuel, oxygen, and an ignition source. Once these three
requirements are met, we can break out the sticks and marshmallows.

There is much more to the science of fire than the three requirements. For that stack of camp wood to become fire, the woody material needs to ignite and decompose. It decomposes in a variety of forms but to keep it simple, think smoke, charcoal, and ash. Charcoal, by the way, is almost pure carbon and some is simply wood that's been heated to remove the volatile gases that create smoke. This is why the hot charcoal in your barbeque grill cooks without smoke.

While looking at our campfire, it occurred to me I really didn't know much about the flames of the fire. I tried to decipher its properties in my head but the flame possessed none of the common properties of solids, liquids or gases. A little quick research revealed a simple explanation.

A flame is neither a solid, a liquid, nor a gas. A flame is plasma, a substance in which some of the particles are free to move rather than be contained.  These moving particles are the rising carbon atoms and emit the incandescent light we see.  If you watch a fire, you might notice the color of the light varies as the flames seem to dance of the logs.

The flames can range in color from blue at the hottest spot to a yellowish/orange at their coolest location.  The "dancing" of the flames we see is the product of gravity.  If we could have a small campfire in the Space Shuttle, the fire would be a sphere, about the size and shape of a basketball!

When it is time to go to bed, we always put the fire out so it does not get away and start a forest fire.  There are a number of ways to do this; we usually pour water on the fire.  This disrupts the combustion process by rapidly cooling the fire down.

I hope this helps in your campfire endeavors for the rest of the summer. Remember to pay attention to warnings in your area to make sure it's safe to build your campfire. I don't want to keep an eye peeled on wild fires coming to get me!