This Week's Experiment - #218 Spoon ReversalsThese experiments are from Robert Krampf - The Happy Scientist
Thinking up experiments while on the road is not always easy. Even though I try to use experiments which use items commonly found around the house, the average hotel room is much more limited in materials. This week's experiment came from all of the meals that I wind up eating in restaurants. It is also a question that several list members have asked. You will need:
a metal spoon
Hold up the spoon and look at your reflection inside the bowl of the spoon. You should notice something. You are upside down! How can the spoon turn your reflection upside down?
To understand, stand in front of a mirror with your flashlight. Turn on the flashlight and shine it directly into the mirror. The beam of light reflects from the mirror and comes directly back to you. Now, still facing the mirror, take four steps to your right. Again, shine the flashlight on the mirror. Does the light reflect back to you this time?
No. Instead, the light reflects off the mirror towards the other side of the room. If the beam of light comes in from the right, it bounces off towards the left. If it comes in from the left, it bounces off to the right. What if you used two mirrors? Standing to one side, you could shine the light on the first mirror and then arrange the second mirror so that it would reflect the beam back to you. Try it and see if it works.
Yes, if you put the two mirrors close together, at the proper angle, you can shine the light into one mirror and have it reflected back by the other. You may have to adjust the angle to find the right position. What does that have to do with the spoon? Look at the mirrors. Just as the beam of light was reflected back to you, so is your own image. Your image is hitting one mirror, bouncing to the other and then back to you. Look carefully at that image. Wave your right hand. Which hand does the image in the mirror wave? Now, lean over sideways and look at your reflection. You are upside down, just as you are in the spoon. The sides of the spoon work just like the two mirrors, to reverse the image.
Your two mirrors only reverse the image from side to side. The bowl shape of the spoon reverses it from side to side and from top to bottom. No matter how you turn the spoon, you will still be upside down. When you get tired of that, turn the spoon over and see if you can figure out why you look the way you do in the bottom of the spoon.
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