If I stand in front of a mirror, the light takes a finite, albeit small, amount of time to reach my eye.
So I am seeing myself as I looked some small fraction of time in the past.
Now if I stand with a second mirror behind me, I can see an infinite number of images of myself, each slightly older.
If I had my arm raised, and then I lowered it, can I still see an image of myself with raised arm?
yes you will see an image of yourself with a raised arm, but only for a small fraction of a second, so small in fact that your brain won't have enough time to process it apart from the current image of yourself with arm lowered.
they do it with mirrors
