The aliens are coming!

Before the 20th century, some philosophers considered the possibility of the existence of intelligent aliens, from outside the Earth. We can cite Lucretius (De Rerum Natura, book II, 1st century BC), Nicholas of Cusa (15th century), and Giordano Bruno (16th century). The idea was happily adopted by science fiction writers, such as Lucian of Samosata (Vera Historia, 2nd century) and Cyrano de Bergerac (Comic History of the States and Empires of the Moon, 1656), of whom I spoke in another post.

During the 19th century, public attention focused on possible intelligent inhabitants of other bodies in the solar system, especially the moon and Mars. In 1835, The Sun newspaper published in New York six false reports declaring that flying men had been discovered on the moon. It is said that nine out of ten Americans believed it. In fact, The Sun had published a science fiction novel as though if it were real news, making reference to existing people, such as the astronomer Sir John Herschel. Near the end of the century, The War of the Worlds by H.G. Wells (1898) raised the possible existence of Martians, at the time of the scientific controversy over the canals of Mars, which was not finally solved until 1965.

The eerie silence

A little over half a century ago, saw the beginning of project Ozma (named for the princess ruling the fictional country of Oz), which continued with the SETI program (Search for ExtraTerrestrial Intelligence). Assuming that there must be many cases of extraterrestrial intelligence, most of which will undoubtedly have reached a technology capable of communicating by means of electromagnetic waves, surely some of them are sending messages that perhaps we can detect and answer. Initially it was thought that we could take the initiative, sending messages to stars that might harbor planets with life similar to ours, but this was soon considered too expensive, so all efforts were allotted to intercept messages, not necessarily addressed to us. After half a century of efforts, nothing has been achieved. There have been a few false alarms, but none that has been confirmed.

In a previous article I mentioned the Fermi paradox, which holds that we must be alone in the galaxy, because otherwise any extraterrestrial intelligence with several million years advantage would by now be here, because it would not take long to colonize the whole galaxy, even at the interstellar speeds we will reach in the next few centuries.