When I was a kid, I liked to imagine one day I'd build a device to receive the alien communication in the universe. Because, without doubt, if there's aliens somewhere they would send messages all through space. It occurred to me later they probably wouldn't broadcast all through the universe and the earth being in the line of their signal seemed rather unlikely.
Anyway, there are other ways one can imagine how alien civilizations could leave messages, possibly especially for less advanced civilizations - like us - to provide hints for boosting technological development and hopefully scientific insights. Jaron Lanier e.g. speculates that aliens might rearrange the stars, so we should probably go look for unusual star constellations. Hsu and Zee go one step further to suggest the creator of the universe himself could have left a message in the CMB. (We already found it.) The most recent contribution on this matter is
- The Cepheid Galactic Internet
By John G. Learned, R-P. Kudritzki, Sandip Pakvasa, and A. Zee
In this paper the authors suggest that alien civilizations would use modulation of Cepheid variable stars to encode their message. Chepheid variable stars are well known for a fairly tight correlation between their period of variability and their absolute luminosity, which makes them ideal candidates to determine distances. Cepheids are giant yellow stars with a luminosity about a thousand times that of the sun and are easily observed. The authors thus “expect that any civilization undertaking astronomy would soon discover them.”
They further speculate that a modulation could be achieved by injecting a pulse of neutrinos into the stellar core where the deposit of additional energy would affect the exact period of oscillation. Such a modification of single periods however, they go on to explain, would likely go unnoticed in the commonly made Fourier analysis of the measured spectrum. Therefore, they suggest to reinvestigate the luminosity oscillations using a different analysis method that would allow to discover the alien message over the periodic signal (and possible noise).
They close with saying
“We propose that there may well be signatures of [extraterrestrial intelligence] communication available in data already recorded, and that a search of Cepheid [...] records may reveal an entre into the galactic internet!
It may be a long shot, but should it be correct, the payoff would be immeasurable for humanity. The beauty of this suggestion seems to be simply that the data already exists, and we need only look at the data in a new way.”
A long shot indeed. Science fiction, fantasy? But isn't it nice to imagine the answer to our questions might be in the stars quite literally?
A nice weekend to all of you!