For our next trick, we are going to make one million rupees appear from nowhere! Sorry, we are mistaken. Due to tax laws, we won’t be able to work with such a large sum of money. We will, however, make a hidden coin magically reappear.
Things Required:
Opaque soup bowl or mug
Water-filled cup
Coin
Directions:
Place a coin in the bottom of an opaque soup bowl or mug. Position yourself off to the side. Slowly lower your viewing angle until the coin can no longer be seen. What happened to the coin? Did it disappear?
Suppose light rays didn’t travel in straight lines. How might a curved ray affect your observations? While keeping your viewing angle, slowly add water from the cup into the bowl.
As the level of water rises, you may be surprised to observe your “lost” coin. What caused the coin to reappear?
This Is What Happens:
Although light rays travel straight paths yet these paths change direction as light moves from one substance to another. The border (scientists often call this an interface) between the surface of the water and the surrounding air causes light rays to bend. So when you look at the surface fo the water, you don’t see objects that are in a direct line-of-sight. Instead, you see things that are submerged and out of a direct line-of-sight.
