Advanced extraterrestrial civilisations may be sending signals through space by 鈥渢ickling鈥� stars, new research suggests. The signalling would be the galactic equivalent of the internet.
鈥淚f it exists, it might be revealed by an analysis of already-existing stellar data,鈥� says John Learned of the University of Hawaii in Honolulu.
Learned and his colleagues have focused their attention on stars that vary regularly in brightness. Crucially, these 鈥淐epheid variables鈥� are so luminous they can be seen as far away as 60 million light years.
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Jolting the star with a kick of energy 鈥� possibly by shooting it with a beam of high-energy particles called neutrinos 鈥� could advance the pulsation by causing its core to heat up and expand, they say.
That could shorten its brightness cycle 鈥� just as an electric stimulus to a human heart at the right time can advance a heartbeat. The normal and shortened cycles could be used to encode binary 鈥�0鈥漵 and 鈥�1鈥漵.
The team says information could thus be shuttled around our galaxy鈥檚 network of 500 or so Cepheids 鈥� and out as far as the Virgo cluster of galaxies.
鈥淭he beauty of the idea is that we have over a century of data on Cepheid variability so it is necessary only to look at it a new way to spot the signature of ET tampering,鈥� Learned told New 杏吧原创.
Seth Shostak of the SETI Institute in Mountain View, California, thinks it is a 鈥渘ice suggestion鈥�.
鈥淏ut I鈥檓 inclined to think that positing the Cepheid scheme is like someone in Marconi鈥榮 time predicting future radio broadcasters will use giant spark-gap transmitters to reach audiences in large cities,鈥� he says. 鈥淏etter technology means higher efficiency, so using an entire star as the 鈥榗arrier鈥� seems unlikely to me.鈥�
