Thread: optics's questions

1. Why the screen made of the white of linen and not made of the plane mirror in cinema?
2. I surprise the next phenomenon. I shut the left eye and I look at the point beside the small black circle on the sheet of paper. When I approach the head to sheet that the small black circle disappear. Why it's happened?
I ask pardon for the grammatical mistakes.

The white linen scatters the light in all directions so that anyone in the room can see that light coming from that point on the screen. If a mirror was used the projected light would be reflected in one diretion only and even if you were in the right part of the theater the image may not be the right size because it would be like looking back at the tiny picture on the film itself.

The first question is easy. I had published its for limbering-up. You answer right! But I answer for second answer. A thick nerve go penetrate into a retina where beam of light penetration through cornea and point there are is don't work a brain. I have explained easily?