Physics of Echolocation :: physics echo echolocation

While visiting the Grand Canyons, you couldn’t honestly tell me that you didn’t scream into the canyon just to hear your echo come back to you. Don’t be ashamed, we all do it. Many kinds of animals actually use their echo to find out where they are in a closed area or to find out if there are any other animals close by. One classic example is the bat. To understand what an echo is, you first have to understand what sound is. In Webster’s Fourth Edition College Dictionary, sound is â€Å"vibrations in air, water, etc. that stimulate the auditory nerves and produce the sensation of hearing.† Vibrations through the air can be thought of as oscillation of molecules. As the molecules oscillate, they pass energy on to surrounding molecules, and those molecules pass energy on to other surrounding molecules. This is how sound travels, and the oscillation of the molecules is often referred to as sound waves. An echo happens when the sound waves reach a surface, bounce off of it and travel in the opposite direction. For optimum echoes, the surface should be perpendicular to the waves, and as frictionless as possible. In places like the Grand Canyons, you can hear many echoes because the sound waves bounce off of surfaces, then others bounce off of other surfaces, and some will bounce back to you, but at different times. In echolocation, bats send out short pulses that have a high frequency. The short pulses that the bats send out have such a high frequency that the average human cannot hear them. The waves that the bats send ripple out from them circularly and will bounce off of anything that is in the bat’s way, and will also go back to the bat in the form of an echo. By instinctively examining the echoes that they receive, the bats will be able to tell the direction that the object is coming or going from, how fast it is going that way and how far away it is from the bat. Some bats can even tell how big the object is that is in their way. If bats didn’t have the use of echolocation, they’d need some other way to stay alive, because echolocation is the bat’s way of life. It is the primary reason that it is able to live in its environment.