I own a PC with a flat monitor (not LCD). One thing I'm feeling odd about it is that when I place something in front of the screen (when there's not much radiation), I see double reflection, of different size.
Why?

U will have to explain it a bit better I think..........!

I assume you have a flat-face CRT screen and when you place something on front of a dark area on the screen, you see a double-reflection, right?

This is because a CTR has a vacuum inside, and in order to withstand the atmospheric pressure, your screen is made of very thick glass. A curved screen is more resistant to pressure, so in order to make a flat screen, they have to make it nearly an inch thick! That is also the reason they are so d*mn heavy.

So when you hold something in front of the thick glass, you get two reflections, one from the surface facing you and another from the rear side. The latter will be smaller, because it is more distant.

(The pressure of the air on a 22" screen totals about 1.5 tons)

Hans

Oh, I bet that explains it, thanks
True, I have a flat CRT screen (since mine is not LCD screen...), but since you said that, does it mean that there are other types of flat monitors other than LCD and flat-CRT?

Just trying to be very precise, since my explanation was specific for CRT. Well, there is actually a number of different different technologies for "real" flat screens (non-CRT).

Hans