Hacker News Reader

Comment by ddlatham | Hacker News Reader

I have a very low voice and enjoy singing or humming along with the bass line in music some times. While I was singing along with a song, all of a sudden my monitor started to go a bit nuts and wave. When I stopped singing (or changed notes) it stopped.

I turned to my roommate, "Can you see that?"

"Nope."

It turned out that if I sang a note at the same frequency as my monitor's refresh rate, the image on the screen would start to modulate up and down in a wavy sort of way. But to my eyes alone. Must have been something with the motion of my eyes or my head matching the refreshing of the screen.

View on HN

I think that's exactly right. Try chewing crackers or chips (the crunchier the better) while looking at an LED clock (like a microwave). Most work, depends on refresh rate. There's a good chance you'll see the same sort of waviness.

blowing a raspberry achieves the same effect.

Or using an electric toothbrush.

And now my screen has tiny specs of spit on it.

Well played sir, well played.

it really does work with things like alarm clocks.

Yeah, it does. Tried it with my alarm clock and got it to work. Just thought I'd remind people to think before trying it on their computers. ;)

This is actually a museum exhibit.

http://www.exploratorium.edu/exhibits/bronx_cheer/Bronx_Chee...

It works with our oven's alarm clock if I hum, regardless of frequency, I seem to recall.

Many times at notting hill carnival I have stood in front of a 20 foot tall wall of speakers and had my vision go blurry due to the 30Hz bass tone at 125db making my eyeballs oscillate in my skull.

Ahhh, notting hill...

You head is a resonating structure. If you make it resonate at a frequency that has an interesting relationship to your monitor it will shake your eyes (being part of your head) so that you can see the refresh. (Or at least that's my theory.)

This is easy to try, incidentally. Just hum a very low note, then gradually increase the pitch until you can see the CRT start to look weird.

You'd still need to have a pretty low voice for anything under 100 Hz, though.

Yep. It's called the "Dorito effect", after what happens when you crunch Doritos while looking at a microwave's fluorescent display.

A well-documented phenomena of the wikiality.

If you have an electric toothbrush and a digital clock, it makes the numbers dance while brushing your teeth. Humming could work too

Reply on news.ycombinator.com