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Science project: Pennies aren't dissolving in Coke and Dr. Pepper!

Dear Sir:

Science project is not doing well. My mom and I have done a experiment for my science fair. We put pennies in Coke, Dr. Pepper, 7 up. After the second week the Coke and Dr Pepper penny don't look bad like we thought they would. Is there anything I can do to speed up the process? My project is due in 4 days? Sorry to bother you; can you give me some advice?

Clint E. [surname deleted for privacy by Editor]
- Lapalma, California, USA
2003

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Clint: No junk science! No cargo cult science! Your science project is doing well!

Junk science can roughly be defined as juryrigging or redesigning an experiment as wacky as you need to until you get the results you wanted. It involves subtly discounting and pooh-poohing contrary observations, and talking yourself into "seeing" things you didn't actually see. It is preparation for life as a lobbyist rather than as a scientist. You didn't see the extensive corrosion your "research" had prepared you to expect, and the Coke and Dr. Pepper didn't corrode the pennies ... end of story.

Cargo cult science involves believing that you are following "the scientific method" when you are instead misreading the situation and believing in causal relationships that don't exist. Nobel prize winning scientist Richard Feynmann coined the term, explaining that, during WW2, Japanese and American planes landed on air strips in the pacific islands carrying cargo of food, clothing, etc. When the war ended, the native islanders cut away vegetation and laid down wood and leaves and sticks in the pattern of an airstrip. They built little shacks at the end of the strips, and erected tall shoots of bamboo sticking out the top of the shacks to look like radio antennas; they stationed a tribesman round the clock in the shack with a pair of half coconut shells over his ears like headphones. Does it surprise you that the planes with their cargo didn't come despite the fact that they did their best to emulate the necessary conditions?

Your job now is to explain the results you got, not to corrupt the process by trying to get different results. And here's a hint for your teacher: you're the one who didn't drink the Kool-aid -- Coke and Dr. Pepper don't dissolve pennies. Try to figure out where you heard that they do, before you learned for yourself that they don't -- and take a lesson about the lack of reliability of that source :-)

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003