Thursday, January 7, 2010

How is damping saving our lives?

Have you ever believed that, one of the reasons that you are alive is because of Damping?

If 1, my thoughts are same as yours.
If 0, you may agree after reading this blog.

Damping is any effect that tends to reduce the amplitude of Simple Harmonic Motion or any oscillation.

Take a sinusoid (which is a smooth repetitive oscillation) for instance (this can also be thought of as cosine, with a phase difference), the waveform looks like this:

The same waveform, when damped looks like this:

According to Fourier series, complicated periodic functions are written as the sum of simple waves mathematically represented by sines and cosines.

So, almost all the signals in the nature can be approximated to Fourier series.

How is damping saving our lives?
A natural signal, speech. When any person speaks, the speech (which can be represented by Fourier Series) damps after some time. This can be seen from the following speech wave form:

This is the same reason,
  • why we cannot hear a person speaking at some long distance. 
  • why when a word is uttered, we could hear the word. 
If there's no damping, all the signals of each word will overlap and and we won't be able to hear anything. Apart from this, if the whole signal doesn't damp, then we could hear the speech of the whole world speaking and all the words uttered from the past will never die out.
The end result, it will be an overlap of all the signals from the past, till date.

Apart from this, each speech signal is sample. It is different from the previous one(you can take samples of uttering the same word for life time and it will be different each time). If this doesn't happen, it will be like in some of the lifts, when you open the door, there will be a recorded voice sample saying, "Please close the door!". It becomes irritating on hearing for a long time.

Nature is designed well for the existence, which is very hard to replicate.


  1. i am still wondering thats so true "damping saves our lives" cant imagine still listening to Alexander the great's shouting to his army 'attack' ...
    but still thinking if there were no damping and we were made in a way to listen to all the sounds then it would be so easy recollecting history .. i would hav got some betters marks then ;)

  2. I don't always believe in science(sinusoid wave), because lot of concepts are only assumptions and differs from reality(my view only)...

    I go with '1', because your explanation is right...