RADIO SIGNALS TO EXTRATERRESTRIALS

Alexander L. Zaitsev
IRE RAS, Vedensky Square 1, 141120 Friazino, Russia


Spectral approach is a universal tool of both astronomical observations 
and SETI. Besides, it has a clear physical meaning - spectrometer finds 
the energy distribution of photons, in human sensing it is color and 
pitch. Under the hypothesis on identity of physical laws in our part of 
Universe, it may be proposed that spectrometry also are used by those 
aliens, who know radio and lead theirs own SETI, too. Also, in order They 
will be able easier to conceive our spectral information, the better if 
it will represent the single-valued function of time. The second 
argument for such function is a fact of transmitter's energy concentration 
inside one band, which will lighten to aliens to solve their SETI 
Problem. Further, there are three thinkable types of single-valued function - 
continuous, discrete and constant.

The transmission of constant, extremely narrow spectral line may be 
used for information about "unknown" knowledge. In other words, if we 
shall transmit the signal with slow frequency drift, which accounts the 
Earth's rotation and moving around Sun, in order to imitate the radio 
emission from the Sun's center, They definitely understand it and try to 
extract from such signal the useful astrophysical information about 
secular change of radial velocity and propagation effects in interstellar 
medium. Such method, also called radio sounding, now widely used in Solar 
System space research. And here is suggested to extend it on radio 
probing of Galaxy.

The second function, or transmission the spectral line, which is 
coherently jumping among few discrete positions is a well-known way to 
transmit the logical messages.

The third type of our spectral behavior is a show of continuous 
function at the alien's SETI indicator. It may be proposed that this function 
might be used for information about our emotional world. The most well 
known and easy way to express our emotional condition is music. 

Further, there are two main types of musical sources. The first type produces 
the damped oscillations, it's a piano, guitar, tam-tam, etc, and the 
second one produces the self-oscillation, it's a violin, organ, singing, 
theremin, etc. You see the second type is an adequate to a process of 
implementation of continuous radio signals. And the theremin is the most 
preferable source of space music, because it produces a 
quasi-sinusoidal signal with smooth frequency and continuous phase under performance, 
and so is better detectable across interstellar distances.

To resume, it may say that radio signal with constant frequency and so, 
with zero initial information uses the "language of nature" to report 
Them some useful astrophysical data, discrete variation is a tool of 
"language of logic", and continuous one may be used as an instrument of 
"language of emotions" in order to inform extraterrestrials about our 
unique inward experiences.