The Fermi Paradox and the Search for Extraterrestrial Life

Is there intelligent life out there? If so, where and what is it? These were the questions asked by renowned atomic physicist, Enrico Fermi, a few years after World War II. Fermi, one of the scientists who took part in the famed Manhattan Project, was an Italian physicist who won the 1938 Nobel Prize in Physics for his work on induced radioactivity.

Regarded one of the top scientists of the 20th century, Fermi was a contributor in the fields of quantum theory and nuclear physics, among others. He also famously posed the question about whether we share the universe with life forms other than those on Earth.

The Fermi Paradox Defined
If there is life out there, Fermi wanted to know, why haven’t we seen it? This has become known as The Fermi Paradox

While it may seem rather cheeky to assume that galactic life doesn’t exist merely because we haven’t seen it firsthand, Fermi raised a good point. Our galaxy has been around for more than 10 billion years. Doesn’t it seem likely that some race in that time would have figured out intergalactic travel? After all, think of how far we humans have come in just a few thousands years.

Fermi’s paradox lies in the contradiction between the high probability of extraterrestrial (ET) existence and lack of evidence of such. We’re here, many ET believers say, so it stands to reason that, in the incredible vastness, there are others.

However, according to Fermi, with the extreme age of the galaxy, if other life did exist, even the slowest space vessel would have found Earth by now.

Fermi Paradox Theories
One of the theories that ET believers put forth to debunk The Fermi Paradox is that non-Earth life is simply hiding. Perhaps they are afraid of us or prefer not to let themselves be known. Here are some other theories believers have come up with to answer the Fermi Paradox:

  • ETs are communicating with us, but we’re just not advanced enough to realize it.
  • ETs exist but have not communicated with us yet.
  • Humans are descendants of an alien civilization and we can no longer recall our origins.
  • Other life forms exist but have no desire to communicate with us.
  • Other life forms were here and left or remain and keep us in a rather elaborate zoo.

Other theories stemming from the Fermi Paradox only seem to complicate things. The Drake Equation, for example, is an attempt at a systematic means of evaluating the probability of alien life. Dr. Francis Drake worked out a set of criteria used to determine whether other planets in the galaxy hold life. However, his equation wasn’t useful because it contained factors that we couldn’t know for sure.

Consequently, the equation’s inexactness can lead to wildly different estimates. While Carl Sagan has used it to estimate there are as many as one million communicating civilizations in the Milky Way, other scientists have come up with there being less than one.

Making Contact
Most experts agree that the only way to settle the matter is to find evidence of other civilizations. At our current level of technology, a probe to the required distance would take about 40,000 years, leaving it an unrealistic option.

Radio astronomy, the use of electromagnetic waves for intercepting a message sent to us, is a more realistic option for confirming the existence of ETs. These waves move at the speed of light, allowing them to get very far very fast. It is considered our best bet for finding out just how unique or alone the human race is in this galaxy.

SETI – The Search for Extra-Terrestrial Intelligence
In 1985 the SETI Institute began operations under CEO Thomas Pierson and SETI scientist Jill Tarter. Today over 100 scientists are part of the SETI Institute and the search for intelligent life in our galaxy and the observable universe.