COULD aliens be 鈥渢ickling鈥� stars to communicate via a galaxy-spanning internet?
John Learned at the University of Hawaii, Honolulu, and colleagues reckon unstable yellow giant stars called 鈥渃epheid variables鈥� could, in principle, be tweaked to send signals across vast distances.
Cepheids are so luminous they can be seen as far away as 60 million light years. They also pulse like clockwork. The researchers say that an energy kick at a crucial instant could advance the star鈥檚 pulsation, and so shorten the cycle, just as an electric shock to a human heart can advance a heartbeat. This kick could take the form of a pulse of energy dumped into the heart of the star, such as an intense burst of 1-teraelectronvolt neutrinos.
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The normal and shortened cycles could be used to encode binary 0s and 1s. There are over 500 cepheids in the Milky Way, and countless more in nearby galaxies, so data could be shuttled around as in a computer network.
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 says ().
It is a 鈥渘ice suggestion鈥�, says Seth Shostak of the SETI Institute in Mountain View, California. 鈥淏ut it is like someone in Marconi鈥檚 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鈥� seems unlikely to me.鈥�
Astrobiology 鈥� Learn more in our out-of-this-world .
