September 9, 2013 | 3
A candle is more illuminating after it has been blown out.
In 2009, aspiring science photographer Grover Schrayer took a series of photos documenting candle smoke–something that most people have seen before, but never looked close enough at. As his incredible shots revealed, there is so much more to a candle once you blow it out.
Once you extinguish a candle, the light is gone, and a plume of smoke replaces it. The smoke is a grey veil apparently solid enough to twist into the air like a piece of silk. But look closer, as Schrayer did, and you will see something amazing.
A typical wax candle works by drawing melted paraffin up the wick to be combusted. It works well enough to light a room, but the process isn’t completely efficient. Along with the flame comes a mist of innumerable wax droplets.
Up close the mist looks almost like how water vaporizes at the bottom of a waterfall. Indeed, the wax droplets are enough like water that they reflect and refract light to create a very special sight; I call it a waxbow.
A rainbow is the product of physics working for your appreciation of beauty. When the Sun is behind you and a mist of water ahead, light first enters the droplets, is refracted—bent by passing through the water—and then reflected off the back of the droplet like a mirror. Before meeting your eyes, the light is again refracted as it escapes from the oxygen and hydrogen sphere. With light hitting the droplets in front of you at different distances, each curtain of droplets projects a differently colored disk of light towards you. Slightly offset, only at the edges of these disks can you see their differences in refracted light—the colors and shape of the rainbow. (The stacking of offset “disks” of light is also why the inside of a rainbow is usually brighter than the outside. Where the light disks stack up, they recombine into white light, making the inside brighter.)
The same optics and physics that combine to produce a rainbow produce a waxbow in these amazing images. Vaporized wax droplets in fact make up what looks like solid smoke—they are the mist after a rainstorm. A billion floating waxen spheres refracting, reflecting, and again refracting light emanating from behind the camera produce in wax miniature what is so spectacular crossing the sky in water-based macro.
Carl Sagan used to say that science is a candle in the dark. But once the candle is extinguished, science can still be just as illuminating.