# Can a human sized object vibrate so fast it appears invisible to the human eye? [duplicate]

my brother and I are working on a story in which a being's atoms vibrate back and forth so rapidly that it appears invisible, like a plucked guitar string or a plane's propellor. Is that theoretically possible?

Thanks for any help!

• Can you see how your bits and pieces are vibrating? Sure... with the right equipment. Is a novel about Brownian motion and molecular spectroscopy in the far infrared exciting? I wouldn't be so sure about that. :-) Aug 14, 2016 at 20:16
• Guitar strings and plane propellors are not invisible when vibrating. Their image is just more spread out. If you're writing science fiction, who cares whether it is theoretically possible or not? Aug 14, 2016 at 20:20
• Anything is theoretically possible, given enough assumptions. H.G. Wells wrote about the same idea, The Invisible Man, although he never explained the trick behind it.
– user108787
Aug 14, 2016 at 20:32
• Since we are at it... in Star Trek the "cloaking device" is a constantly used theatrical device. Moreover, all you ever need in the Star Trek universe is to reverse the polarity on the dilithium matrix and something magical is guaranteed to happen... you just wonder why the didn't design the reversal switches into all the ships... since one seems to need them all the time. Anyway, whenever such things happen on the show, we know that the second rate writers had control of the script that week. :-) Aug 14, 2016 at 20:44
• @count_to_10: Sounds about right. I think they had a better process on the later shows, though, as there is some real character development... Aug 14, 2016 at 22:15

I guess in principle you could reduce a "being's" visibility by vibrating it fast enough to confuse the eye. Some problems with this:

-You'd have to vibrate the whole object coherently, not the "atoms" individually. Basically you're just shaking the person really hard. Which would probably kill them.

-The necessary vibration rate is in the sonic range. So it would be very noisy.

-Even to the human eye, the object wouldn't be completely invisible, just blurred (same goes for a propeller).

-The reduction in visibility is because the human eye samples information at a finite rate. Video cameras, etc, wouldn't necessarily have this problem.

• Video cameras sample at a finite rate also, each pixel at 60 or 120 Hz or multiples. Even film goes at certain, certainly, frames per sec. There would still be a reduction in visibility. Aug 15, 2016 at 1:17
• Yeah, but it would be a different reduction is all I'm saying
– AGML
Aug 15, 2016 at 3:26