Are we alone in the Universe? (Fermi Paradox part 1) April 3, 2014Posted by oktyabr in personal.
We are the evidence of life in the universe because we exist. Is the universe conducive to life? Yes, absolutely, or we wouldn’t be here. As an example of “intelligent” life found in this current universe I do a lot of thinking, usually over my morning cup(s) of coffee. For the last few years I’ve done a lot of pondering… and debating… about a subject known as “The Fermi Paradox”. This is the first of several posts I’ll share here… my thoughts on this topic.
In the entire universe is there anything we can identify that is required to harbor life, that is unique, makes it stand out alone, as THE single example… about our Milky Way galaxy? No. There are hundreds of billions (at least) of other galaxies besides our own. While they all have a somewhat unique appearance and may exhibit any of a range of other characteristics we know that our galaxy is nothing special. Observations of our nearest galactic neighbors reveal that they too contain stars and that those stars are representative of the same sort of stellar formation we find here, at “home”.
About our particular star? No. Our star, “Sol”, is a relatively common “G” type, main sequence star, called “main” because they are the most prevalent (anyone else remember “Oh Be A Fine Girl/Guy, Kiss Me”?) A “G2V” to be precise. Like the temperate or “Goldilocks” zone there is a stellar zone of star types too, that are prime for planetary formation and long-lived enough to have experienced a similar timeline of geological and biological evolution (generally the larger the star the faster it burns it’s fuel, the shorter it’s life span.) Similar planetary systems are likely to be found not just around G type stars but also a whole range of K and F types as well, etc.
About our particular solar system? No, not really. While we haven’t studied enough star systems, closely enough or long enough (yet) to have established trending patterns we DO know that planets form around other stars and that some stars definitely have more than one planet. An important rule to examine is the Titius-Bode law, which was first used in the 1700’s to predict the orbit of the planets in our own solar system. Counting Ceres (or the entire asteroid belt) as the fifth orbit this set of mathematical calculations were found to be surprisingly accurate. While this specific formula may or may not apply to other star systems it is very likely that planetary formation (in their orbits) will be found to comply with a similar, algorithmic, exponential equation. i.e, planets aren’t just scattered around a star willy-nilly.
About our planet Earth? No. While we have yet to reveal a planet that could truly be thought of as “Earth like” we know that planets of a similar size and composition have been found around similar stars and at a similar distance from them.
Hydrogen gas is by far the most abundant molecule in space and oxygen isn’t exactly rare either. Atomically bonded together to form H20, water, is a common result in this universe.
Even more amazing is that we know that complex organic molecules have formed beyond our own star system! To me, one of the most interesting is the discovery of glycolaldehyde, in a distant star system early last year. Biochemists believe that this substance is needed to form RNA. The raw materials of proteins and DNA itself too have been found away from our own, cozy little corner of the universe, in the form of poly-aromatic hydrocarbons (PAHs), just last year.
We have no reason to believe we are somehow a special case. Our planet, our solar system, our star, our galaxy, are all fine examples of components found in a life-bearing universe.