Jumpy Monitor

This story didn't age well, as most modern computers have LCD monitors, which don't display the behavior here at all

This is a story within a story...

Part one happened to a friend and former co-worker.

Steve was one of the several great technicians we had working for us at the store, he was both very capable, and very good with the customers, a rare combination of skills which we managed to get more than our fair share of at the store (we had several absolutely fantastic techs -- Pete, Steve and Richard, all of which were legendary with the customers for their abilities to both fix computers and please customers).

One day, he got a call from a customer complaining about a "jumpy monitor", where the picture would jump around while she was trying to use it.

There are two very common situations which generate this complaint. The first of course is where the monitor is broke. The second is where the monitor is just fine, but it is being influenced by an external magnetic field, such as that of a transformer, a flourecent light, a clock radio, etc. Neither is particularly uncommon. Steve had her look for things like this, but she denied that any were around her desk, so Steve has her bring the monitor in.

She does, Steve puts it on the bench, and leaves it there for a day, and never sees the sligtest jump from the display. He calls the customer, and says he can't reproduce the problem. So, she comes back and picks it up. Sure enough, within an hour, she calls and says it is "doing it".

Steve, being the nice guy he is, makes a trip out to the customer's office to see for himself. He's pretty sure there is something generating a magnetic field near by. He gets there, the monitor is sitting on the desk, operating perfectly. He says, "Figures, not doing it".
    She looks back at the monitor and says "Yes, it is!"
    Steve looks closer, "I don't see anything wrong..."
    The customer grabs some of her co-workers, "See, my monitor is jumping!"
    They didn't see anything wrong, either.
    Steve looked at the woman, and noticed she was chewing gum.
    "Stop chewing your gum for a moment" Steve requested.
    "Hey! It quit jumping!"

(Explaination: When you tap your teeth together, when chewing gum or otherwise, the vibration in your skull will cause your eyes to jump. Because of how old CRT monitors draw on the screen, it makes a wierd "jump". If you are working with a more modern, high speed refresh CRT monitor, the effect may not be clear unless you are sitting across the room from the monitor. Modern LCD monitors don't display this behavior at all)

End part one.
Begin part 2:

I told this story to a client of mine. He thought it was pretty funny, and was curious about seeing the effect. He looked over at his co-worker's computer, and tapped his teeth, and said "Wow, that's cool!" Then, he called to his co-worker, "Hey, Denise! Check this out!" and he began tapping his teeth

Then he thought about it a moment...

We all got a pretty big laugh, except for his co-worker, who really didn't have any idea what was going on.