10 Principles That Govern Our Understanding Of Extraterrestrial Life

Many people, at some point, have looked up at the vastness of a summer night’s sky and wondered, “Is anybody out there?” There are over 200 billion stars in the Milky Way galaxy, which is just one of maybe 100 billion galaxies in the known universe. Our understanding of space changes daily, and our perception of the cosmos changes with it. If you’ve ever thought about what’s going on in the night sky, there are teams of cosmologists, astronomers, and physicists committed to finding out.

This list drills down into the terms scientists and layman alike use in discussing the probability of extraterrestrial life. From theories explaining why we have yet to come across alien life to the terms used by scientists who are actively searching for it, this list can be your go-to guide for an introductory look at our ageless pursuit for extraterrestrial life.

Fermi Paradox

earth science space science science earth science space science science earth science space science science

Enrico Fermi was an Italian-American scientist, born in Rome at the turn of the 20th century. A noted “architect of the nuclear age,” Fermi’s brilliance can’t be overstated. At 28, he was elected to the Royal Academy of Italy, the youngest inductee in its history. He went on to win the 1938 Nobel Prize in physics for his contributions to the discovery of induced radioactivity and was a core contributor to the Manhattan Project. Yet, among the accolades his name can be associated with, it’s his quandary regarding extraterrestrial life that stuck.

The Fermi paradox is a relatively basic concept which asks if it’s easy, or even possible, for intelligent extraterrestrial life to develop, then why haven’t we come in contact with it? His comment, made at lunch with coworkers, went on to underscore fundamental notions about extraterrestrial life. Our galaxy has many stars similar to our Sun, and many are billions of years older. At least some of these stars likely have planets suitable for life orbiting them. Further, with the development of life comes the evolution of intelligent life and interstellar travel.

Fermi believed that any intelligent civilization with adequate propulsion and even a modest thirst for conquest should have made itself known in the Milky Way by now.So why hasn’t it? Our data about the observable universe suggests the presence of life should be noticed; that it isn’t has become one of the great paradoxes dictating our understanding of space.

Drake Equation

earth science space science science earth science space science science earth science space science science

Frank Drake is an American astronomer and astrophysicist who developed a formula with quantifiable variables determining the presence of extraterrestrial life. Drake’s development of what came to be known as the Drake equation was mostly accidental. He was spearheading a meeting of like-minded astronomers at the National Radio Astronomy Observatory in Green Bank, West Virginia, in 1961 and lacked a structured agenda. A day before the conference, Drake shorthanded a formula for determining the possibility of intelligent life in our galaxy.

This formula is N = R x fp x ne x fl x fi x fc x L, where:

N = the number of civilizations in our galaxy capable of communication
R = average rate of star formation
fp = proportion of those stars with planets
ne = average number of habitable planets per star
fl = fraction of habitable planets that go on to develop life
fi = proportion of planets with life that develop intelligent life
fc = intelligent life bearing planets where life develops detectable communication
L = duration of time a civilization’s communication is detectable

The Drake equation relies on multiple unknown variables, but it gave astronomers a concrete starting gate for deducing the presence of intelligent life throughout our galaxy. For more than 50 years, scientists have used Drake’s equation as their foundation for extrapolating the existence of intelligent extraterrestrial life.

Zoo Hypothesis

earth science space science science earth science space science science earth science space science science
Star Trek fans recognize the Prime Directive as one of the core ethical tenets of the cosmos. Simply put, the Prime Directive forbids Starfleet communication with, or interference in, the development of fledgling civilizations across the universe. This means civilizations in their early years are left to develop undisturbed by outside forces.

This conception of alien life, and why we haven’t encountered any, was suggested in 1973 by MIT radio astronomer John Ball as the zoo hypothesis. Ball’s hypothesis asserts that alien civilizations may be observing a pact or treaty in which they actively avoid underdeveloped civilizations, like ours on Earth, which have not yet reached a level of interplanetary communication. There are several proposed reasons behind this avoidance, chiefly that it is to our benefit, or the benefit of other civilizations, that we be allowed to organically grow as a civilization. Simply put, the zoo hypothesis views humanity as part of a galactic sanctuary, off-limits to more advanced beings.

Prev1 of 3Next

Leave a Reply

Your email address will not be published. Required fields are marked *