Ever since we began exploring the stars, humanity has pondered on whether we are alone in this universe. The universe is potentially infinite, ever expanding, we know this due to having witnessed galaxies moving away from us and each other. It is due to this vastness of the universe that we can speculate that there must be intelligent life, other than ours, in either this galaxy or another. If the universe contains billions of galaxies, and if each galaxy contains billions of stars, and if a fraction of those stars have earth-like planets, then the chances of alien life existing must be pretty high, right? In 1995, astronomers located the first planets outside our solar system. Since then, they’ve detected nearly 300 more. Most of these planets are large hot planets, much like Jupiter, but some are small earth-like planets. Could these planets already have intelligent civilisations?
If only there was a mathematical equation to determine this for us. In fact, there is. In 1961, astronomer Frank Drake presented a formula, now known as the Drake Equation, that estimates the number of intelligent civilisations in our galaxy. The formula generated much controversy, due to it generating widely variable results, but still remains as our best way to quantify just how many extraterrestrials there could be. The formula goes like this:
N = RfpneflfifcL
In this equation, N is the number of detectable civilizations in our galaxy. The other variables are described below:
- R is the rate of star formation in the galaxy
- fp is the fraction of stars that form planets
- ne is the number of planets hospitable to life (i.e., Earth-like planets)
- fl is the fraction of these planets on which life actually emerges
- fi is the fraction of these planets on which intelligent life arises
- fc is the fraction of these planets with intelligent beings capable of interstellar communication
- L is the length of time such a civilization remains detectable
As you can see from the equation, there are many variables that we can only speculate on, however, this has been done. Drakes original calculation predicted that there are 10,000 undiscovered intelligent civilizations in the Milky way alone.
Harvard physicist Paul Horowitz stated in a 1996 interview “Intelligent life in the universe? Guaranteed. Intelligent life in our galaxy? So overwhelmingly likely that I’d give you almost any odds you’d like.” However, this was swiftly countered by the Fermi Paradox. This paradox, first articulated by nuclear physicist Enrico Fermi in 1950, asks the following questions: If extraterrestrials are so common, why haven’t they visited? Why haven’t they communicated with us? Or, finally, why haven’t they left behind some residue of their existence, such as heat or light?
I must agree with the questions raised by the Fermi paradox, however, maybe we can speculate the whys of this argument. It is only being assumed that they have not visited, maybe they are here already. We have all heard of the popular theories of reptilian aliens being in major places of power and the alien structures under the sea. Unfortunately, there is no hard evidence on this, but anything is possible and the speculation must come from somewhere. Maybe they are watching us right now, deciding when the time is right to make contact. Crop circles, UFO sighting and abductions all point to this. There have been literally thousands of such cases, can so many people be wrong? Maybe, they are out there, but they haven’t reached us yet. The problem is distance, even if we manage harness travelling at the speed of light, our galaxy itself would still take 25,000 years to span. That’s 1/8 of our entire existence on this earth! However, it is impossible to know the full potential of technology. Our own technology is forever advancing, and what we can do now, when compared with 6,000 years ago, is astounding. A species that has survived much longer than ours could have unlimited technological potential, maybe even more so than our minds can fathom.
In conclusion to this, the chances of alien life existing is exceptionally high. We may not see any hard evidence of this for many years to come, or we might be shaking hands with extraterrestrials tomorrow. We can only speculate and calculate using what we are still discovering about the universe and our own existence. What extraterrestrials will do when they discover us or how they will act when they decide to unveil themselves, is a different matter altogether, and a topic for another post. I personally believe that, with the facts that I have uncovered, we are not alone in this universe, and I hope that we will discover evidence of that within my lifetime. Keep watching the stars, and know that someone, somewhere, might be watching back.