Everyone has at one point or another pondered the age old question: are the living beings that inhabit Earth the only organisms in the entire universe? Since everything that occurs in the universe is entirely up to the will of natural physics and is therefore extremely random, extraordinarily diverse types of planets exist everywhere; no two are the same. Some planets are too hot for life, some too small, some rotate too fast, some are not even solid structures, etc. Habitable planets, that is, planets that at least have the potential for life, are seemingly very rare throughout the universe. This detail is very important in the debate over whether or not extraterrestrial life exists, however the size of the universe is a slightly more essential fact to consider. Of an estimated 400 billion stars in our galaxy (also keep in mind that our galaxy is only one of hundreds of billions in the universe), how could only one contain an orbiting planet with life? No matter how difficult it is for life to arise from non-life (which is, of course, how life on Earth began), the scale of the universe is magnificent enough that it seems almost silly to say that we on Earth really and truly are unique.
This debate over the existence of aliens seems even more one-sided when you look at the chemical composition of Earth, which was obviously, in its infancy, one of the few planets actually capable of creating life. Since Earth was an eventual result of the big bang, as was everything else that exists in the universe, let’s take it back to the beginning to consider how we came to be.
At first, there was nothing, except for an infinitely dense spot that held all of the mass in the universe. Then, in an instant that we refer to as the big bang, this spot started to expand, forming the universe (which, of course, is still expanding).
The universe is infinitely expanding at an accelerated rate, so galaxies get further and further away from each other as time goes on.
The big bang got everything started by creating Hydrogen and Helium (and traces of Lithium). The Hydrogen and Helium went on to become parts of stars around the universe, which conducted nuclear fusion in their cores to create heavier elements. But, since stars have lifespans just as everything else does, they were ripped apart at the end of their lives by massive explosions starting in their cores known as supernovas. These supernovas scattered all of the elements created by the star’s nuclear fusion into the universe. Solar systems then formed from the enormous clouds of gas (with abundances of various elements within) that were left after the supernovas. Several billion years pass, and now people are studying the elements that were, in the very beginning, the reason for their existence.
Now that it is clear that everything in the universe had the same beginning, the following fact should be even more incredible – at our very core, we are made up of billions and billions of tiny carbon-based structures, without which we could not function effectively and live. This is such a shocking detail because even though life does not seem to be widespread throughout the universe, carbon, the element that allows us to exist, is just about everywhere. How could the main ingredient for life exist everywhere, while life itself is currently only known to exist in one place? It is this pondering that leads most scientists to believe that it is not that life does not exist somewhere out there in the cosmos, but instead that it is just extremely rare and difficult to find. The scale of the universe and adverse environment of deep space makes our search even more tough, and it is likely that the only thing holding us back from discovering a plethora of extraterrestrial species is current technology. Once we develop a way to travel through space much quicker and are able to sustain life on a spacecraft for extended periods of time, I can almost guarantee that we will find life.
