why does the night sky not look like a long exposure camera shot if the earth is spinning and the light from distant stars takes so long to get here?
In: Planetary Science
The same reason a laser pointer doesn’t leave a big line on the wall when you turn it slowly in your hand. The photons are moving at light speed one by one. By the time the star has moved in the sky there are no photons coming from the old spot anymore.
It takes a long time to get here, but the light is still moving fast. By the time the stars appreciably move in the sky, the light from their old position appears to come from the new position. A long exposure shot shows those streaks because there’s no light being generated, only what was recorded in the shot.
Our eyes work similar to animation. We are seeing one frame at a time at a rate of around 30 frames per second. In everyday life, things move fast enough that those individual still frames in rapid succession appear to us as movement.
When shooting a long exposure on a camera, it is one frame that lasts anywhere from minutes to hours. It would be similar to taking all the frames of a movie and showing them simultaneously. It would just look like a blur.
We can’t set our eyes to long exposure mode like you would a camera. Our eyes don’t collect and store light like a camera would, they transmit it to the brain in real time. We can’t just “pause” our vision the way a camera can hold its shutter open for different lengths.
if your eye had a shutter speed its not slow enough to capture that movement. the camera stays open for a few seconds to capture that image.
your eyes are a whole different beast. they are really good at some things but, get blown away by a camera with others. our brains are the ones processing the image and they are doing a lot of movie magic behind the scenes. colors take time to “recharge” before the get activated again. if a protein didn’t help it along it would take millions of years to fold on its own. even with the protein it might take some time so, the brain is like that was blue 1/2 a second ago its probably blue now too.
[https://www.youtube.com/watch?v=QK-9abhGexQ](https://www.youtube.com/watch?v=QK-9abhGexQ)
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