Science Projects And Inventions

YOU  NEED:

• The jack of spades or the jack of hearts from a deck of cards
• Glass of water
• Transparent glass or plastic rod
• Paper and pencil

Did you know that the jack on a playing card can do an about turn mysteriously while a rod meant for stirring can change the meaning of a sentence. A deck of cards has two one-eyed jacks — the jack of spades and the jack of hearts. Just hold either one behind a glass of water. If you press the jack against the side of the glass and look at him through the water, he will face in the direction he was facing just like it is on the card. Try to move the card slowly, away from the glass, and lo the jack will turn around and face in the opposite direction. Pick up a transparent glass or plastic rod or what is called a clear swizzle stick. Now, hold it slightly above the short sentence "bob KICKED pop," and you will see what "pop" did next. He kicked bob.

HOW  DOES  IT WORK?

Actually, a glass stick functions like a cylindrical lens. It reverses or turns around what is being seen through it. The transparent rod is also a cylindrical lens. When the rod is held horizontally over a printed line, it turns the letters upside down. The letters "KICKED" remain the same when upside down or in reverse. This is also true of "O." However, the letter "p" becomes a "b" when turned around. Again a "b" changes into a "p."