Tuesday, April 28, 2009

senses revelations

yesterday i made a connection between knowledge acquired from work and a long known and previously little understood childhood phenomena. when someone is nearsighted as a kid, they often try to put off getting glasses by making a telescopic lens with the fingers - you put your fingers together to make a tiny hole, and looking through that allows you to focus on objects farther than before.

well, i've been wearing these backup glasses that are a bit uncomfortable, so yesterday on the bus i took them off and was staring out into the great blurry beyond, when i thought how nice it would be if my eyes could focus mechanically like the lenses we have in our lab. then i took my hands and made that hole and looked through it to improve the focus. then i realized that eyes are exactly like lenses. in my case, because the focus mechanism was broken, the only way was to decrease the aperture, and when you have a small aperture, the depth of focus increases. so essentially by looking through my fingers, i have a smaller aperture, which allows my lens, set permanently to a focus of about 1 foot, to now have a range of focus from 1 foot to several meters.

understanding the human body only after understanding a mechanical system designed after a natural system is fun.

the other thing is, this morning and for many mornings in the past, i always get awakened on the bus by the last person getting off, because i have earphones on and couldn't hear when the bus stops and people start to shuffle as they're getting off. i guess that means my sense of the location of the bus is based purely on hearing and not on other things, like an internal clock or the motion of the bus (maybe some unique combination of turns and stopping that happens only at the end.) that also means even when i'm sleeping, the sense of hearing must be half awake, kind of like dolphins who sleep with one eye open all the time.

No comments: