Fermi, the quantum physicist, was not the first scientist to ask about aliens.
Konstantin Tsiolkovsky in an unpublished 1933 manuscript had written:
people deny the presence of intelligent beings on the planets of the universe because if such beings exist they would have visited Earth, and if such civilizations existed then they would have given us some sign of their existence.
This has not prevented many of us fantasising about aliens in science fiction and about “them” having given us signs such as the pyramids and some cave drawings. Some people have even suggested that our “junk DNA is the remnant of alien-life code, which is useless on this planet…