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Cycle by Cycle



Frequency in Hz / GHz              =                      Cycles   x  sec.

Speed of Sound  (20°C)             =               343,4  Mt.   x  sec.
Speed of Light                             =     299.792,458 Km  x  sec.

 

It should be emphasized that to pass from one NOTE to the next octave of the same NOTE is enough to double the frequency in Hz. Theoretically, if we double the frequency of the INFRARED we will get ULTRAVIOLET frequency.

 

In music, the vibration of sound waves propagating through the air is perceived by the human ear's eardrum, which distinguishes them based on pitch. To be clearer, if we double the vibration of A at 440 Hz, we get 880 Hz, which still corresponds to A but in the next octave interval. Therefore, if we double the frequency in Hz of each individual tone in the chromatic scale, the vibration of its sound wave always produces the same sound but at a frequency twice as fast, reaching the threshold of ultrasonics because beyond this threshold, our ear can no longer perceive it.

Continuing to double the frequency of the tones in the chromatic scale, their sound waves progressively transform into ultrasonics, and then their frequency reaches radio waves, microwaves, the zone of light, X-rays, gamma rays, and so on.

 

With that said, if we measure by the spectrometer the frequency of the wave emitted by the microwave oven in our kitchen, we find that the appliance operates at 2.45 GHz. Therefore, the food is heated with the tone of D because the frequency of D in the chromatic scale is 587Hz, and when multiplied by 2^22, it reaches the frequency of the microwave oven, which is 2.462 GHz.

In turn, if we continue to multiply the frequency of D at 587Hz by 2^40, we reach the visible zone at 645 THz, so in the electromagnetic spectrum, D corresponds to the color blue.

 

To recap, unlike sounds where we perceive about 10 octaves, the visible spectrum for the human eye has only one octave. In fact, the F# at 369 Hz, multiplied by 2^40, corresponds to the border of INFRARED (406 THz), and multiplied by 2^41, it corresponds to the border between visible light and Ultraviolet (813 THz).

 

So, the frequency generated by the sound wave of each of the 12 tones of the chromatic scale in the visible zone corresponds to the following colors:

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The Hertz is equivalent to cycles per second.



In defining the second, the CIPM declared that "the standard to be employed is the transition between the hyperfine levels F = 4, M =  0 and F = 3, M = 0 of the ground state 2S1/2 of the cesium 133 atom, unperturbed by external fields, and that the frequency of this transition is assigned the value 9 192 631 770 hertz" thereby effectively defining the hertz and the second simultaneously.

As an SI unit, Hz can be prefixed; commonly used multiples are kHz , MHz, GHz  and THz . 

One hertz simply means "one cycle per second" (typically that which is being counted is a complete cycle); 100 Hz means "one hundred cycles per second", and so on. The unit may be applied to any periodic event—for example, a clock might be said to tick at 1 Hz, or a human heart might be said to beat at 1.2 Hz.  x

References:  http://en.wikipedia.org/wiki/Hertzp:/