In 1950, when the Italian physicist Enrico Fermi (1901-1950) was living in the USA, the subject of aliens came up one day while he was having lunch with his fellow scientists, and he asked the question, “Where is everybody?”
Indeed. If, as many alien believers think, there are advanced alien civilizations in the galaxy, why is there no sign of them? In the 75 years since Fermi’s question, technology has advanced dramatically, but even today there is no evidence of alien spaceships, unmanned spaceships (probes) or any sign of alien communication. There are even projects like SETI (Search for Extraterrestrial Intelligence), which monitor the skies for signals coming from outer space, but without any success.
Fermi’s question soon became known as Fermi’s paradox. It is not actually a paradox, because it is not a logical contradiction. Instead, it should be more accurately called a dilemma.
This article is based in a large part on the book “If the Universe is Teeming with Aliens… Where Is Everybody?” by the physicist Stephen Webb, published in 2002.
No alien ships
There are no alien spaceships anywhere to be found. Yes, sometimes there are blurry dots in the sky, called “UFOs”, but there is no tangible evidence of any alien ship anywhere.
Those who believe in extraterrestrials generally also believe that there are extraterrestrials whose technology is advanced enough to travel to Earth in spaceships. Many of them believe that in the decades since the Roswell incident in 1947, UFOs have been flying in the sky, many of them have crashing.
Still, there is no concrete, tangible proof of any alien spacecraft on Earth. Alien believers promote a variety of solutions to this dilemma.
One solution is the “interdict scenario”. Here, the aliens do not visit Earth, because humans have not yet reached a certain level of development. This idea is best known to the general public as the “Prime Directive” in Star Trek, which prohibits the Federation from making contact with any civilization which hasn’t invented warp drives. Another similar idea is that the Earth is never visited by anyone, because it is the galactic equivalent of a national park, and the aliens don’t want to violate the ecosystem and its “primitive” inhabitants.
Thinking about it logically, one of the main problems with many of the solutions is that they assume that all aliens have the same intentions. But more importantly, the solutions do not explain why humans haven’t picked up any alien communications.
Webb observes: “There is something unsatisfying about an approach in which, no matter how hard we look, no matter how thoroughly we search, the absence of ETCs [aliens] is explained simply by saying they do not want us to see them.” (p. 48)
If faster-than-light travel is truly impossible, then “first contact” with any alien race becomes even more unlikely. This topic is outside the scope of this article. One should just take a look at the best-selling book “Physics of the Impossible” (2008) by the theoretical physicist Michio Kaku to see that interstellar travel relies on extremely far-fetched ideas, like “negative energy” or wormholes.
If one assumes that faster-than-light space travel is impossible, and the universe is billions of years old, as assumed by those who believe in evolution, a civilization could still colonize slowly. Webb uses a simplified example: if space travel at one-tenth of the speed of light (0.1c) is possible and each established colony waits as much time as the journey itself took to launch new ships, then a “colonization wavefront” would move through the galaxy at 0.05c.
There are more sophisticated theories. For example, one explanation uses a scientific idea known as “percolation theory”. “Percolation” is a Latin word meaning “to flow through”. (p. 74)
The proponents of this idea make the following assumptions: space travel is possible but difficult; colonized planets gain their independence; invasion of an already colonized world is impossible; and each alien civilization will either have a drive to colonize other planets or not. They propose a sort-of line of colonization, where neighboring planets are inhabited.
In other words, there is a cluster of inhabited planets in the galaxy and Earth just happens to be in one of the holes of this cluster. Again, this would not explain why there is no sign of alien communication.
No unmanned alien ships (probes)
As Webb points out, an advanced civilization doesn’t have to send manned spaceships. Using self-replicating robots is much safer and cost-effective than sending living beings on interstellar journeys.
A self-replicating probe was first theorized by John von Neumann, who is considered by many to be the inventor of the computer. He called it a “self-reproducing automaton”. The Australian professor Ronald Bracewell was the first person to propose such probes for interstellar travel, so this idea is also known as a Bracewell probe.
Where are the remnants of such probes?
No alien communication
The fact that there are no signs of alien communication hits even harder than the fact that we haven’t seen any spaceships. Even if interstellar travel is impossible, there should still be some form of alien communication reaching Earth, since electromagnetic waves travel with the speed of light. Since physics is the same everywhere, all alien civilizations would figure out that using waves in the electromagnetic spectrum are the best way to communicate.
Radio signals need to be narrowband signals, since broadband signals can be easily confused for background noise. Since radio waves are between 3 kHz and 3 THz in the electromagnetic spectrum, the search is hard but there are dedicated alien believers who took up the task. Another possible communication method are gamma rays, which have a higher frequency.
In the last seventy years, there have been a few projects searching the skies for alien signals. The best-known of these projects is SETI (Search for Extraterrestrial Intelligence). However, there has been no signal detected as of yet.
Some people object that aliens may have no desire to communicate. In other words, “everyone is listening, no one is transmitting”.
The engineer and Catholic author Daniel O’Connor points out that ever since the first radio transmission was made by Guglielmo Marconi in 1897, countless communications via electromagnetic waves have been made, which continue on into space. “Your conversation with your sister about favorite recipes, while holding your 1990s Nokia phone? It is now slamming into the planets of Gamma Pavonis—in the constellation of Pavo, visible in the night sky—having already passed innumerable other solar systems. The crickets remain. In the year 1934 (long before SETI), Cincinnati, Ohio’s WLW radio station began belting out 500,000 watts of transmissions. These immense signals have been hurtling through space now for almost a century, likewise inundating thousands of solar systems with news from planet earth. And even this is dwarfed by the signals earth began emitting thereafter. Assuredly, any ‘ET civilization’ like those envisioned by today’s Ufologists would have abilities to decipher—and respond to—such signals at massive distances. Even the head of SETI himself, Dr. Seth Shostak, admits as much. In 2003, he noted that we have, for decades, already been ‘irrevocably signaling our existence to other star systems.’” (The First and Last Deception, p. 43) He also points out that HAM radio operators are able to bounce a radio signal off the surface of the moon and reach somebody far away on the Earth. This technique is called “Earth-Moon-Earth” (EME) communication or “moonbounce”.
It is completely logical to assume that the aliens, after they have reached a certain level of development would similarly communicate via electromagnetic waves and send out space probes, which they can’t retract either.
Other solutions
There are some other solutions to the Fermi paradox, which are thankfully less dangerous to our faith, but are nevertheless adventurous.
Some people suggest that there are alien civilizations out there, but since space has been expanding since the (imaginary) “Big Bang”, all of them are outside our particle horizon, so we can’t see them.
Others claim that all civilizations are wiped out before they reach a certain stage of development due to nuclear war or a rogue AI.
The obvious solution
Webb writes towards the end of his book: “The only resolution of the Fermi paradox that makes sense to me—is that we are alone”.
The obvious solution is that there are no aliens and that the entire physical universe was made by God for us humans. The same God, who sent His only Son to die for us on the cross. He loved us so much – not some aliens He never told us about. Never even hinted at.