Glowing Pickle

WARNING: The voltage used in this demonstration is potentially lethal! Perform this demonstration with extreme caution!

Equipment: A pickle, a plate, two forks, a power cord with two alligator clips and a variac.

What it does: The variac is connected to the pickle and a large voltage is applied. The pickle begins to sizzle and steam. After a short time, the pickle glows.

Concepts Demonstrated: Atomic excitation and emission.

Classroom assembly:

1. Place a pickle on the plate.
2. Insert a fork into each end of the pickle.
3. Attach the alligator clips to each fork.
4. Plug the power cord with alligator clips into the variac.
5. Plug in the variac.
6. Turn on the variac.
7. Increase the variac voltage to about 120 V.
8. Hold your microphone near the pickle (taking extreme care not to touch it!) to demonstrate that the pickle is sizzling.
9. Wait for the pickle to glow. Let it glow for a few moments before turning off the variac.

• The pickle glows at one electrode only.
• This demonstration smells strongly. Do not allow the pickle to glow for a long period of time in a small lecture room.

• The sodium D line can be seen fairly clearly using a handheld spectroscope. Spectroscopes can be distributed in a small class.

WARNING: The voltage used in this demonstration is potentially lethal! Do not touch the pickle when it it connected to the variac.

Setup Time: Short.

Difficulty: Straightforward.

Visibility: Medium. The light from the pickle can be seen in large lecture halls but not the details of the setup. A video camera is often used in large lecture halls.

Related demonstrations: Cooking a hotdog.

References:

• PIRA 5D30.30 (also 5E30.30 and 5F15.20)
• Video Encyclopedia 18-15
• J.R. Appling, F.J. Yonke, R.A. Edgington and S. Jacobs, "Sodium D Line Emission from Pickles", J. Chem. Ed., 70 (3), 250, (March 1993) - shows a comparison of the spectrum from a pickle with the sodium spectrum, no lines other than the D lines were observed.
• P.M. Weimer and R. Battino,"The Incredible "Glowing" Pickle and Onion and Potato and...", J. Chem. Ed., 73 (5), 456-457, (May 1996) - i) made a hole slightly larger than the electrode at one end, this end invariably glowed; ii) suggests cutting pickle in half and looking at discharges in gaps around seeds; iii) other veggies marinated in a 15% brine solution.
• P. Scharlin, A.A. Cleveland, R. Battino, and M.E. Thomas, "Glowing Veggies", J. Chem. Ed., 73 (5), 457-459, (May 1996)
• Penn and Teller mention "The Incredibly Dangerous Glowing Pickle Machine" in "How to Play With Your Food", Villard Books, New York, 1992:

  "When a regular old dill pickle is skewered on two metal pins and 110 ac, regular old U.S. of A. house current is run through the pins, the pickle glows a ghostly yellow. It's the most beautifully goofy science thing you will ever see." They point out that Mr Wizard demonstrated the pickle on The Tonight Show, January 24, 1990 and that the pickle was described in Scot Morris' Games column in Omni magazine, December, 1990.

Original Construction: The plug with alligator clips was made from a standard 2' long power cord. Each lead of the cord was soldered to an alligator clip. All other equipment was purchased.