This isn't entirely an invention, so I'm happy for it to be MFDd, unless it counts as an invented way to amuse onself slightly.
I have just noticed a strange and curious effect on the LCD screen of my MacBook Pro (an old one), and thought it might interest or puzzle others.
If you press (firmly but not too hard) on the screen with a fingertip, and then suddenly remove your fingertip (from the screen, not from your finger), you get a sort of ripple effect. This is not the interesting part. The "ripple" is caused, I presume, by the slight compression and distortion of the LCD screen.
Now the interesting part. This works best if the screen is showing white (like the blank space on this page). Press the screen at two points, an inch or two apart, then suddenly remove one fingertip. What happens (at least on my screen) is that a little shadow zips across the screen from the place you just removed your finger from, to the other (still pressing) finger.
No idea if it works on other screens. But it amused me.-- MaxwellBuchanan, Jul 04 2012 // it amused me //
You need to get out more.-- 8th of 7, Jul 04 2012 Wait - the alien hegemonising steam-engine enthusiast is telling me I need to get out more?-- MaxwellBuchanan, Jul 04 2012 Yes, we are. You should be worried. Very worried.-- 8th of 7, Jul 04 2012 True. But I bet you've tried the thing with the fingers and the screen.-- MaxwellBuchanan, Jul 04 2012 I've tried and it wasn't terribly successful. There was a little sort of ripple thing but not much. It was on a resistive touchscreen, with a white background.-- nineteenthly, Jul 05 2012 No, it works better on a non-touchscreen LCD monitor ... oops.-- 8th of 7, Jul 05 2012 random, halfbakery