Arecibo Proposal No. Zaitsev000704074140 on July 04, 2000.

Corrected by Dr. Ellen Howell, NAIC.



Alexander L. Zaitsev,

Institute of Radio Engineering and Electronics

Vedensky Square 1, 141120 Fryazino, Russia




Both previous radio messages for aliens, Arecibo 1974 and Evpatoria 1999 (see for details) were the logical ones and represented the binary stream of FM information, which should be arranged into two-dimensional forms to perceive by eye-like sense-organ. And I guess the primary one-dimensional message is more understandable by unfamiliar aliens and the music is the most universal expression of intellectual activity by means of one-channel ear-like radio link. Further, the Theremin instrument is the most preferable for interstellar transmission since Theremin produces quasi-sinusoidal narrow-band signals with continuous phase under performance, which are more easy for extraction from noise. So, I suggest to implement the 1st Theremin Concert for Aliens from Arecibo or Evpatoria Radar facility. The Theremin virtuoso Lidia Kavina agrees to give such Concert with appropriate classic and cosmic repertoire either in on-line mode at observatory's concert-hall or off-line Concert in audio studio. The Theremin's signal lies at about (0-10) kHz, and it should be shifted by SSB mixer to radar band and transmitted into space toward any star cluster or Sun-like star.




Giordano Bruno, whose theories of the infinite universe and the multiplicity of worlds anticipated modern science, was brought to the Campo de' Fiori, his tongue in a gag, and burned alive. The modern gag is the Item 8 of IAA Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence: "No response to a signal or other evidence of extraterrestrial intelligence should be sent until appropriate international consultations have taken place". But this IAA document forbids the future response as a reaction on definite detection and I suggest the present broadcast for proposed aliens before hypothetical message is received.


There were four Messages from Earth to proposed aliens -- two material (Pioneer Plaque and Voyager Record) and two ethereal (Arecibo-1974 and Evpatoria-1999). Both Arecibo and Evpatoria messages were the logical ones and represented the radiosignals, frequency manipulated by binary stream of information, which could be understandable after error-free extraction of this binary stream in whole, conjecture that it is the production of two prime numbers, and an ability to conceive two-dimensional images. However I propose not a discrete two-tone radio signal but a more native continuous one, in which smooth frequency variations directly transfer one-dimensional emotional information. I am talking about music, which is more universally comprehensible than language, and about theremin, which is an electronic non-contact musical instrument.


Theremin consists of a box with analog ICs producing oscillations at two sound-wave frequencies above the range of hearing (100-500 kHz); together, they produce a lower audible frequency equal to the difference in their rates of vibration. Pitch is controlled by smoothly moving the hand toward or away from an antenna at the right side of the box. Theremin produces a quasi-sinusoidal signal with smooth frequency variations without phase breaking, therefore such signals have the high delectability across interstellar distances. To transmit, the theremin's signals should be up-shifted by SSB (single side band) mixer without any additional modulation or manipulation into radar S-band and directed toward the selected target star cluster or Sun-like star with its own planetary system.


The theremin approach for constructing messages for aliens provides direct implementation and does not need any postulates in order to create a sophisticated and disputably cosmic language to inform Them about our emotional world. It is clear, the theremin has a moderate emotional impact and it is not a symphonic orchestra, but the Arecibo picture with 1679 black-and-white squares is not a color oil-painting, either.


The theremin was invented 80 years ago, in 1920 by Leon Theremin. Theremin's daughter Natalia Theremin and grand-niece Lidia Kavina are well-known theremin performers (you may visit The Theremin Word Home Page at for further information). Natalia and (or) Lidia are ready to visit Arecibo or Evpatoria and give an on-line theremin concert for aliens. Also, off-line Concert in studio and audio cassette with its tape recorder are acceptable. Of course, any American or European theremin virtuoso are welcome, too. The concert playbill would include both classical and cosmic repertoire, as well as the specially composed music. Appropriately, this instrument was used in the soundtracks of several science fiction films. And before this concerto I would make the presentation "The Logical and Emotional Messages from Earth".




The observing time needed to carry out the program depends on tracking duration of selected target by fixed Arecibo antenna. Anyway this time is equal or less than 2.5 hours. The user-provided special equipment which would be brought to the Observatory is the theremin.


The auxiliary Observatory equipment needed for the project are the special real-time hardware and software which should periodically (I guess, not faster than each 0.1 sec) determine the theremin's current frequency and replace it on stable continuous signal from DDS (direct digital synthesizer) in order to provide the coherent radar transmission, which would be easily detectable across interstellar distances.