You know those orangish street lights? They're low pressure sodium discharge lamps.
Q. What's a pickle?
A. Sodium in pickled cucumber form.

Here's how it goes:
First off, I take no responsibility if you hurt yourself, others, or property. This requires electricity, bare wires, and heat... Do it at your own risk, if you're not sure, dont do it.

You will need:

You do this:
1. Nail the nails through the back of the board, space them about 3" apart, and leave a tiny bit sticking out the back to attach the wires.

2. Solder one end of the first wire to the first nail, one end of the second wire to the second nail. If you're confident in your soldering job, you can pound the nails in flush to the back of the board.

3. Attach the other ends of the wires into the appropriate terminals of the circuit breaker. Wire up the electrical cord to the other appropriate terminals of the circuit breaker.

4. Open the pickle and skewer it on the nails so that there's one nail near each end of the pickle.

5. Put on safty glasses, plug in, and within a few seconds the pickle should light up and glow very faintly with a slight yellow/orange color.

This is always a fun geek project to impress geek dates, friends, and middle school science fair officials. I would caution you however: This will heat the pickle, causing it to dry out, once it's dry it'll go out and start to smoke and stink. Use the switch on the breaker to control it.

Final notes:
This idea came to me via the Penn and Teller's "how to play with your food" book. The process by which it works is known as Sodium Vapor Discharge. What happens is electrical current passes through the pickle breaking up the sodium molicules and ionizing it. Once it reaches this point it vaporizes and burns up (sodium reacts violently to oxygen). In low pressure sodium vapor lights there's a containment system to keep the sodium from escaping. Because it takes very little sodium to put off a fair amount of light these lights can be very efficient and last a very long time. The down side of course is the limited spectrum of light output. This is countered by upping the pressure in the chamber and using diffrent elements like mercury and nickle halides, but that's another node for another day.


Here's a cheap ASCII diagram:



         N1                     N2 
         /\                     /\        
         ||                     ||   
         ||                     ||
         ||                     ||
  _______||_____________________||_________
  |      ||                     ||        |
  |      ||     BOARD           ||        |
  |______||_____________________||________|
         ||                     ||
         /\---|             |---/\
              |             |        
              |             |
              |   _______   |
              |   |     |   |
              |---| C/B |---|
                  |_____|
                    ||
                    ||     PLUG
                    ||       _
                    ||      / |__
                    \\=====<  |__
                            \_|

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