Although we haven't found aliens yet, we have established the fact that communicating successfully with extraterrestrial beings is a difficult job. The number of solar systems present in the universe and the vast distance between them makes it extremely tricky to comprehend where to start and how. However, the most important question is what if the methods we are employing are not even comprehensible to them?
If intelligent extraterrestrial civilizations exist out there in the universe and if they are trying to reach out to us, there are multiple ways of communication that they might be using. For example, it can be visible lights; if they are technologically more advanced they could use the ultraviolet light and X-rays or it is also possible for them to make use of a completely different wavelength along the electromagnetic spectrum.
Recently, a Breakthrough Listen project surveyed around 700 stars in the universe and found out only 11 signals, which could be alien. However, finally, all of them were revealed to be false positives.
"In order for us to discover a distant transmitter, they'd have to ping us in just the right time window," said an astrophysicist at the Max Planck Institute for Solar System Research, Rene Heller. Add to that they would also have to make use of the same frequency of the radio signal that we are listening in, Heller said, reported Wired.
An independent astronomy researcher Michael Hippke believes that "radio is an immature and inefficient way to communicate over interstellar distance. He conducted a comparison among all the potential ways of communication between the solar systems. "If we'd have an outpost at the nearest star next year, we'd certainly not use radio signals to communicate. Instead, current technology would favour optical or UV lasers. Better technology would use even higher frequency communication, like X-rays," said Hippke.
In his new paper, which was published on the arXiv server, Michael Hippke discovered that if we use the photons while trying to establish communicating across solar systems, we need to send them at wavelengths of about one nanometer, whereas, the wavelengths of the radio waves that we are sending currently range from 1mm to 10 km. It would then place those waves in the X-ray part of the electromagnetic spectrum. Photons are the primary particles, which create visible light. "Radio might be used by some civilizations over a short period of time before they abandon this wasteful childish technology," Hippke said.
Other than photons and lights, there are other means of communication as well. For example, there is neutrino and also the very ambitious megastructure method.
While on Earth we have already achieved communication with neutrinos, it is going to be really difficult to send them off to the galaxies further than Earth and Pluto's distance, according to Hippke. Among all the possible methods, the most preferred route would be to send a probe inscribed with something, he said. We had tried this one earlier with the Golden Record vinyl aboard NASA's Voyager 2 spacecraft. It was launched in 1977 and a copy of it is now available for people to purchase.