This Week's Experiment - #218 Spoon Reversals
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
2 mirrors
a flashlight
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.
From Robert Krampf's Science Education Company
PO Box 60982
Jacksonville, FL 32236-0982
904-388-6381
krampf@aol.com
To start receiving the Experiment of the Week, just
send a blank E-mail to: krampf-subscribe@topica.com
|
