Don't tell the Double-Rainbow guy, but all those beautiful colors really can have a deeper meaning. That's because different chemicals reflect and absorb different wavelengths of light, leaving tell-tale patterns in the rainbow. If you know what colors specific chemicals absorb, you can look at the light reflected off a sample and use the rainbow to figure out what you've got. That's basically what a spectrometer does. And blogger Charles Soeder made his own.
The light source is an LED flashlight. The light shines through the sample (in this case a vial of chlorophyll) and gets broken up by a diffraction grating. This produces a spectrum which gets projected onto the photosensor. I pulled the sensor out of an automatic night light. It is mounted on a stand, which is taped to a TI89 which is taped to the table- so I can slide the sensor back and forth along the spectrum to get readings at different frequencies. I measured the frequency of light hitting the detector by noting where its shadow falls on the ruler in the background. The resistance of the sensor changes depending on how much light falls on it (which is an indication of how much light gets absorbed by the sample); I measure this with a multimeter.
There's more photos of all the different parts in his set-up. My favorite features the helpful caption, "This is where the rainbow goes."
(Thanks to Kevin Zelnio!)
Yes, that is actually Space.com’s brilliant headline on this story about a new discovery from data collected in 1986 by NASA’s intrepid spacecraft. When the probe neared Uranus (heh heh), it measured the planet’s surrounding magnetic field. Recently, NASA scientists Gina DiBraccio and Daniel Gershman analyzing Voyager’s old data found a “wobble” in Uranus’s magnetosphere […]
Watch Quick test! from atinyworld on www.twitch.tv What the world needs now are tardigrades, sweet tardigrades. ‘A tiny world’ is a fun little internet window into the microscope with Julie Laurin, who lives in Ottowa, Ontario.
Cocaine, as they say, is one hell of a drug. In fact, it was recently shown in a study published in the Proceedings of the National Academy of Science to have greatly helped the re-wilding a good chunk of Columbia. How you might ask? Pablo Escobar’s hippos, which are still hanging around breeding in Columbia […]
You probably have a lot of items in your home that you’d hate to lose to theft or damage. While certainly no one ever hopes to fall victim to a natural disaster or home invasion, you need to be prepared just in case it does happen. When it comes to choosing a reliable renters insurance, […]
Stuck at home? Us too. And all anyone can think about is food. Stuffing your face for hours on end is definitely not a good way to stay healthy right now, but if you’re going to do it anyway (let’s be real—your original stash is already gone), why not improve what you’re snacking on? No, […]
With the world in the midst of unprecedented upheaval, there’s plenty to be concerned about out there. But while there are obviously far weightier issues facing us all right now, a true golfer will admit that being cooped up inside and missing the fairways and greens is its own little personal tragedy. To help soothe […]