ThirdTwin---My sister decided to go from retail, into nursing, and became an RN at 37.
O.K., I have more info on the glass. I stacked the 6 pieces of glass this morning = 1 1/8 inches. The illusion of raised appears to be 7/16 in heigth off the paper.
There is no distortion.
Refraction is only 1/16 inch (through all that thickness of glass!) out at the edges of the 4 inch square stack.
If you raise the stack straight off the table (let's say up one foot...close to your eye), the raised illusionary effect is still off the table by 7/16. It is not 'in' the glass. So, no matter if the glass is on the table, or raised off the table, the letters, writing, or whatever, appears higher than the paper by 7/16.
This holds true whether or not you have nearsighted glasses on.
If you have a straight line drawn on the paper and you stagger each piece of glass, over the line, like you are making stairs...the line 'curves' up in the air, off the paper. (neat visual)
If you take the whole pile of stacked glass and rock it from side to side (or front and back), then you definitely observe a lot of refraction.
But what's odd to me, is that when this tall stack of glass is laying flat on the print, the refraction of the letters is about only 1/16 inch when you look through the glass near the edges (which would be about 2 inches out from straight down.) But the illusionary image of letters is higher than this, at about 7/16 inch.
Near where I live is one of the world's tallest towers. It is 2000 feet tall. (the Sears tower is ONLY about 1450, to give you an idea). If you stand right under the tower, the tower looks like it might be only 100 feet tall. As you back away, the tower appears taller and taller and taller. Till you finally say, "No WAY would they get ME up there to change those light bulbs!!!"
There is some effect where distance becomes compressed when you are right at the base of a tower. I think the same effect is going on looking through the glass.
If instead of laying the glass on the table...suppose you held it up, with the paper ontop of the glass, and you looked at it from below, you would get the same affect of compression, as mentioned above.
Try THIS once: Take a piece of paper. Draw 2 heavy dots on it. Put one dot real near the edge of the paper, and another dot about 1 1/2 inches inward from it. Now hold it level with your eye. You can cock the paper so that the 2 dots appear to touch. Weird. Now listen to my way of saying this, to make it sound really weird.: If you have the paper on the table directly below your eyes. each dot is the same distance from your eye...and that is when you perceive the 1 1/2 inch distance. Yet...when you hold the paper level with your eye...when the farthest dot truly IS 1 1/2 inches farther from your eye than the leading edge dot...then you don't see them as 1 1/2 inches apart! Weird, eh? Try to explain this affect of why distance becomes bunched up.
)
I was caught in the crossfire, while I lived in Sarasota, Florida in the 70's, when the police ran down a bank robber and they had a 'shootout' with tons of cops and this dude. I was on a construction site and bullets were hitting the building and even made a car tire go flat. A cop later came over, after the riddled the robber to death and had to account for where all the bullets went. I was out front, landscaping and was 'in the line of fire. Another time when I lived in Texas about 6 years later, I thought I was being shot at and I ended up running and clotheslining myself at full speed. Got up and continued running through rattlesnake infested grass.