Sunday, January 5, 2014

A Demonstration Fail Tale

In a recent blog post titled Public Speaking-(Using Props)-A Mississippi Mess Jonathan Sprinkles described a mealtime demonstration he tried that didn’t work. He started by showing that an egg sank to the bottom of a clear glass vase filled with water.

Then he added table salt, which was supposed to dissolve and make the egg float. (His point was that how things work can be different when you make just one change to your environment). But, even after he poured in a whole salt shaker worth the egg still sank.   

Jonathan said that:

“One of the people at the head table happened to be a science teacher. He discreetly leaned over to me when I sat back down and said, ‘Hey, it happened to me my first time, too. Next time, use warm water.’ ”

He warned:

“Don’t ever try something for the first time on stage, especially when you are getting paid. I got big-headed and forgot the importance of testing before I go live. No matter how well you think you know a part of your talk, practice it in the car, in your hotel room, over the phone, wherever. Don’t risk your rebooking on what you think you know.”

What else might be wrong? Maybe just not enough salt. A web page about Floating Eggs in Salt Water suggests using six tablespoons of salt per cup of water.  What else could go wrong? Use a hard boiled egg, not a raw one. You might crack a raw egg if you stir the water with a table knife to make the salt dissolve. 

More complicated demonstrations have even more possible glitches. A common one is in products with rechargeable batteries, which can drain via self-discharge. (That’s why I have a spare battery pack for my electric drill). Check first, and bring along a charger and a spare.  

The egg image came from Wikimedia Commons.

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