This week's experiment was inspired by my walks on the beach. When I
was young, I was told that if you held a sea shell up to your ear, you
could hear the ocean in it. At that time, I had never been to the
ocean, but the distant roaring sound from the shell sure sounded like
an ocean. Now I live at the beach and listening to a sea shell still
sounds much like the ocean. You can try this too, and you don't even
need a sea shell. Instead, you will need:
* a drinking glass
Hold the opening of the glass against your ear, as if you were
listening to something that was inside the glass. What do you hear?
Sort of a static/roar sound. Wait a minute. Supposedly, the shells come
from the ocean and that is why you can still hear it inside. That glass
probably did not come from the ocean. Maybe you are hearing the sound
of the dishwasher?
To find out about the sound, you want everything to be VERY quiet. Wait
for a time when nothing is going on. Turn off the TV. Go ahead. Turn it
off. Nothing horrible will happen. Once you have the room very quiet,
listen to the glass again. The ocean sound is very dim, and if you have
things quiet enough, it may be gone. Now, you want some noise. Turn the
TV back on.
(See, I told you it would be OK.) Turn on some other noisy things. Once
the place is good and loud, listen to the glass again. Now the ocean
roar is very loud.
What is going on? Our experiment gives us the information we need. The
sound you are hearing is related to the sound in the room you are in.
As the sound waves hit the glass, it vibrates. This causes the air
inside the glass to vibrate, which causes the "ocean" sound. The louder
the room, the louder the sound in the glass. Try listening to different
things. Does a glass make a different sound from a shoe? What do you
say when you hear the sound of a shoe? Geshunteit, of course.
Back
to Krampf Index Including permission to post
these
experiments on my web site.
