The smallest movement detectable?

[YT2095]

Ever watched an ordinary clock, the sort with hands on?

you can see the second hand moveing quite easily, MAYBE sometimes the minutes hand if they`re long enough, but certainly not the Hour hand, and yet it clearly DOES move

 

I was wondering, what is the smallest movement that the eye (or brain) can detect and what factors govorn it?

 

I use the term "smallest" but slowest may apply too.

[Skye]

http://people.brandeis.edu/~sekuler/papers/SWBchapterJune2001.pdf

[YT2095]

Damn .pdf files... still can`t get em to work

[Skye]

http://216.239.57.104/search?q=cache:5en18ppguAgJ:people.brandeis.edu/~sekuler/papers/SWBchapterJune2001.pdf+minarc+definition&hl=en&ie=UTF-8

That's a HTML version, so you miss out on the pictures

 

By the way, it's forty-odd pages long, that's why I didn't even try to give a short answer.

[YT2095]

Thnx, I`ll take a peek when I have a free hour

meantime if anyone else wants to share ideas, Shoot

[Kedas]

- I would take the 1/'viewfrequenty' about 1/20sec ?

(freq when a wheel seems to rotate backward, I think)

-And the distance of the smallest noticable resolution.

 

speed=disctance*20 (v=ds/dt)

 

BTW there are no pics in the PDF, but I'm to lazy to read it though.

[YT2095]

well I know such things as visual accuity apply, I guess it`s more like RATE of movement perhaps?

because when there`s an ant crawling alont the floor at say 1 foot every 2 seconds I can see it move when I stand above it, but if I were to see it from maybe 100 foot high, it would seem to maybe not even move, a bit like white peak waves in the ocean as seen from an aircraft, so a standard would need to be set I should imagine?

based upon certain constants, and then experimented with, I dunno, it just something that was bugging me while watching a clock I`de made

[Kedas]

You do the testing for one distance later when you have al the data you can easely recalculate for further or closer.

[YT2095]

well I`m also part wondering if EYES work on a basis similar to Pixels (obviously on an analogue level).

but then one must also take into acount body to head to eyes movement as the heart beats and we breathe etc...

if we move, then the brain has to try and remember the last position the slow moving item was at, and that in itself can be tricky! :?

[fafalone]

I can imagine a way to to calculate it based on the distance and diameter of photorecptive pigments in the eye and wavelength of light and the angle it comes through the cornea and the focal distance... but I've got no definite numbers, but if a small object was an inch away from your eye you should be able to detect movement of around 0.22mm/s

[aman]

Now that we are on the level of quantum science everything you see happened a long time span before it reached your eye. We have mechanical and biological which in this case are more efficient limits. Soon we should be able to build super eyes through electronics.

Just aman

[YT2095]

erm ok,,, thats nice dear ... errr

 

 

YT2095 smiles at Aman and backs away slowly

[iglak]

well, if i look for minute hand movement on an analogue watch, i can see it up to about half a foot away, so i'd say fafalone is right, and maybe even less than that.