via HACKADAY: Frank Drake’s Legacy, Or: Are We All Alone In The Universe?

When Frank Drake began his astronomy career in the late 1950s, this was an incredibly exciting time for the field. Humanity was beginning to unlock the secrets of the Universe using ever more powerful radio frequency and optical telescopes, including the tantalizing prospect of space-based telescopes. Amidst the ramping up Space Race between the US and USSR, there was an ever-growing excitement about humankind’s future among the stars.

As concrete plans for landings and colonies on the Moon, Venus and Mars were proposed and put into action, it also brought to the forefront many existing and new questions about humanity’s place in the Universe. During Frank Drake’s 92 years on planet Earth – until his passing on September 2nd of this year – he was one of the driving forces behind the search for extraterrestrial intelligence (SETI), along with other legends like Carl Sagan.

Although to the average person the acronym SETI is most likely to bring to mind popcorn movies about little grey – or green – men, Drake’s Project Ozma, as well as the SETI Institution and the ongoing Breakthrough Listen project are just some of the attempts made by Drake and his colleagues over the decades to answer that one question that may affect the very course of humankind’s future: are we alone in the Universe?

INTELLIGENT LIFE AS A FLUKE
In a Universe that contains billions upon billions of stars and planets, what is the chance that life will form on any of these planets? Of this life, what percentage will possess a level of intelligence that enables complex societies in which scientific inquiry and technological development can be sustained? Out of these societies, how many will acquire the means to reach out beyond the limits of their planet?

Although the speculation about extraterrestrial life has been around for hundreds, if not thousands of years, it hasn’t been until the development of more advanced means of observation that humanity has gained the ability to put these speculations to the test. As commonplace as we consider lifeforms – whether intelligent or not – to exist within the Earth’s biosphere, we know at this point in time that of all planets and moons in our Solar System, only the Earth is capable of supporting life, never mind an advanced society.

In the 1930s, rocket scientist Konstantin Tsiolkovsky mentioned his doubts about alien intelligent life in an unpublished work, with physicist Enrico Fermi becoming associated in the 1950s with a formal definition of these doubts, commonly referred to as Fermi’s Paradox. Essentially this paradox entails the conflict between the likelihood of a significant number of alien civilizations, and the clear absence of these civilizations.