Are human beings alone in the universe? The question has plagued people for centuries. Scientists have used all the modern resources at their disposal in the search for extraterrestrials. NASA and other space agencies have innovated space exploration technology to study the cosmos. Even independent organizations such as the SETI (Search for Extraterrestrial Intelligence) Institute scan the skies in the hopes of making first contact. With all the efforts to find signs of life among the stars, why haven’t we found aliens in space yet? The answers are as limitless as the stars themselves.
The Fermi Paradox
In the early 1950s, Enrico Fermi first tackled the question of why human beings had not yet contacted extraterrestrial life. His arguments, detailed along with astrophysicist Michael Hart, explain the paradoxical nature of the aliens and the universe.
- Billions of stars similar to our Sun exist in the universe. Many of them could be older by the Earth by billions of years.
- There is a high probability that some of these stars support planets similar to Earth. They may develop intelligent life if the Earth follows a typical model.
- Advanced civilizations might develop interstellar travel.
- Even using the slow pace of current interstellar travel, it takes a few million years to traverse the Milky Way Galaxy.
Given these arguments, Fermi and Hart reasoned that Earth should have already welcomed extraterrestrial life. Many have suggested that intelligent life in the universe is exceedingly rare. Others have concluded other lifeforms see no reason to contact humanity.
Where is Everybody?
In light of his paradox and without any evidence to suggest a visit from a cosmic explorer, Fermi famously asked, “Where is everybody?” There are between 100 and 400 billion stars in the Milky Way alone. Multiply that by the number of galaxies in the observable universe. Data from the Hubble Space Telescope puts that estimate at about 2 trillion. Keep in mind that figure is for the observable universe. The sheer size of the universe makes it difficult to comprehend how many stars with unique solar systems are out there. Small wonder then that extraterrestrials have yet to contact Earth, let alone find it.
Scientists argue for various hypothesis. They claim humanity has not contacted extraterrestrial life because no other advanced species have arisen. Microbes, bacteria, flora, and fauna may very well thrive on planets far beyond the borders of the Milky Way. Organic life may exist but it has not reached a point where it is capable of contacting civilizations on other planets. To build upon that hypothesis, some experts believe there is a cap on evolution that makes intelligent life rare.
Others postulate that advanced civilizations are prone to destruction. As technology evolves, so do the ways in which a society can destroy itself. War, resource depletion, environmental contamination, and climate change all stand to annihilate any intelligent life. Species destroy others, too. There is the possibility of civilizations overcoming the urge to destroy themselves. Removing this self-destructive tendency may mean that aliens view less advanced species as a threat to peace. In that case, their best option is to destroy others. They may also require more resources for survival. There is no room for another species.
More far-fetched hypotheses include the “zoo hypothesis.” This scenario states that Earth, and by extension human beings, acts as an experiment or zoo for other civilizations to observe. They refuse to communicate for fear of influencing the natural development of the species. Experts say that a highly advanced civilization would have to govern this possibility through force or as a universal norm. Others think that extraterrestrials have already made contact. People think that aliens pilot UFOs. Certain portions of the population believe governments keep contact secret to avoid causing a panic. Some go so far as to say that intelligent life forms from distant worlds control governments across the globe.
Maybe extraterrestrial life advanced beyond little green men in flying saucers. Hypotheses centered on a digital existence have gained traction in recent years. Experts point to developments made by humanity itself. As a species, human beings have made incredible technological strides in their short history. They enjoy a level of sophistication and convenience unimaginable to previous generations. Civilizations existing for millions of years would have improved upon or perfected those innovations. They may have gone so far as to forego organic existence altogether.
Advancing beyond biology seems like a strange concept. It makes sense in terms of preserving a highly advanced species, though. Uploading consciousness to a computer allows for survival no matter the environment. With this method, extraterrestrials could inhabit the harshest conditions the universe has to offer. That assumes their computing systems can work as efficiently as possible. Technology of that power needs frigid environments. Even the vacuum of space, with a temperature just three degrees kelvin above absolute zero, proves too hot for them. If there is any intelligent life existing digitally, they can look forward to a cooling universe. The echoes of the big bang gone, the background radiation no longer keeps things balmy in space.
If intelligent life has advanced to the point where it no longer needs a physical body, human beings might not even know if they’ve come into contact with it. Advanced lifeforms may have developed beyond the need for a planet. Gravity is an essential element in the growth of organic life. Without a need for bodies, digital life may thrive at galactic energy sources. Called “the singularity” by futurists, this existence allows for the continued dominance of artificial, inorganic intelligence.
What are the real reasons we haven’t found aliens? There are too many to even begin to consider. Scientists hold out hope, though. At the current rate of technological advancement, many say humanity is only a few decades away from answering the question, “Are we alone in the universe?” International and independent efforts at space exploration continue to seek answers for years to come. The bigger question is, “Does whatever might wait for us beyond the stars want to hear from us?” Are intelligent species asking the same questions? Only time, and the future, can tell.