small riddle

[hopper]

you go a movie, the screen is blank half the time yet everyone enjoys it and some even watch it again, why?

[alexandgruntz]

The screen is blank because the projector broke down. :P

[tnl2k7]

It's a horror film and it's dark maybe? I don't know =P

-Luke.

[dhz4u]

The screen is blank half the time cause when its half the running time there is an intermission and the screen goes blank.
And people watch it again after the intermission.

[hopper]

actually it was a trick question ;)
the above is true of ANY movie you see in the movie theater
how so you may ask? the answer lies in how movie projectors work
the film moves past the lense in an intermittent fassion (start/stop) as a claw jerks the next frame into place a bow tie shaped shutter covers the lens, the screen goes blank inbetwen frames, if this did not happen we would see the film moving and the picture would look like a blur
this happens 24 times each second, but our retina's are slow so the previous frame lingers in our eyes long enough for the next frame to be projected onto the screen, thus creating the illusion that the screen is constantly illuminated when in reality it flickers like a strobe
this effect interestingly is also responsible for why wagon wheels appear to spin backwards in old westerns

[tnl2k7]

actually it was a trick question ;)
the above is true of ANY movie you see in the movie theater
how so you may ask? the answer lies in how movie projectors work
the film moves past the lense in an intermittent fassion (start/stop) as a claw jerks the next frame into place a bow tie shaped shutter covers the lens, the screen goes blank inbetwen frames, if this did not happen we would see the film moving and the picture would look like a blur
this happens 24 times each second, but our retina's are slow so the previous frame lingers in our eyes long enough for the next frame to be projected onto the screen, thus creating the illusion that the screen is constantly illuminated when in reality it flickers like a strobe
this effect interestingly is also responsible for why wagon wheels appear to spin backwards in old westerns

Well, you got me with that one, I must say. I still like my answer though lol ;)

-Luke.

[kkenny]

Very nice. I didn't understand the answer but it sure gave me a headache thinking about it.