Extra-terrestial life

Fermi Paradox

Is the conflict between the lack of clear, obvious evidence for extraterrestrial life and various high estimates for their existence. As a 2015 article put it, "If life is so easy, someone from somewhere must have come calling by now."

Italian-American physicist Enrico Fermi's name is associated with the paradox because of a casual conversation in the summer of 1950 with fellow physicists Edward Teller, Herbert York and Emil Konopinski. While walking to lunch, the men discussed recent UFO reports and the possibility of faster-than-light travel.

There have been many attempts to explain the Fermi paradox, primarily suggesting that intelligent extraterrestrial beings are extremely rare, that the lifetime of such civilizations is short. This suggests that at universe time and space scales, two intelligent civilizations would be unlikely ever to meet, even if many developed during the life of the universe.

The Great Filter prevents "dead matter" from giving rise, in time, to expanding, lasting life according to the Kardashev scale The most commonly agreed-upon low probability event is abiogenesis: a gradual process of increasing complexity of the first self-replicating molecules by a randomly occurring chemical process. Other proposed great filters are the emergence of eukaryotic cells or of meiosis or some of the steps involved in the evolution of a brain capable of complex logical deductions.

Radio waves

To find possible extra terrestial life \

SETI are scientific searches using electromagnetic radiation for signs of transmissions

Recently proposed quantum communications as a way to try communications with aliens.

Technosignatures

If alien life is advanced enough, we would find mega structures, acting as a lighthouse

Seager Equation

Developed by Dr Sara Seager, rework of Drake Equation

Focus more on biosignatures.