Since the earliest days of mankind, when we roamed the Savannah’s of Africa we have pondered while looking up at the night sky, the question are we alone? Until quite recently there was no way of addressing this, however quite recently before my lifetime a vigorous search by some of the most brilliant minds ever for an answer.
First of all the most difficult challenge they face is; what is life? This question has eluded the definitions of philosophers since time immemorial. Even though they thought they had an answer but on closer examination they were most often incorrect. For they often turned to religion in search for our origins and the nature of life. However I shall not indulge in such idle banter for this post. Fundamentally life is nothing but aggregates of molecules arranged in such a manner that they are able to repair themselves against the ravaging hold of the second law (of thermodynamics which as I have previously explained as:” Moreover energy flows from a region of higher concentration to lower concentration i.e. entropy increases in a system reducing differences in temperature, pressure, density, and chemical potential that may exist in a system”) so what these atoms tend to do is that they form an “open” system i.e. a system which is not isolated from the surroundings they take in molecules and using reactions, which may fall in any category, they gain energy which they use to create negative entropy. Please note that entropy can not decrease in an isolated system where heat can not enter nor leave, thus such a decrease is in accordance with the second law.
So life is in simple terms nothing but a system of molecules (or atoms in our imagined earlier form) which is able to gain energy and repair itself {or should I say himself/herself ;)}. Now due to evolution this system overtime will definitely under go change and perhaps mechanisms will arise to transfer information from one generation to another and better methods of reproduction will arise. This is all probabilistic there is not guarantee that life will survive the crucible of it’s creation. Hence to search for life one needs to find cases of reverse entropy-find that and you have found life.
It has been proven that simple organic molecules could have been created by a younger earth by the now famous Stanley Miller and Harold Urey but remember this the substances that came out of that experiment were ,as Carl Sagan said, “the stuff of life” but not life itself. How did life evolve from a simple naked chemical system to an information carrying behemoth? How did it happen? Well this is partly the reason why we are looking elsewhere in a hope to explain our own origins or we could always invent a time machine which goes back in time and send instruments back to observe the primordial life on the adolescent earth (imagine a time probe: sounds impressive doesn’t it?). Well the first greatest challenge life had to face is how will it reproduce? For it is essential for survival, by physical forces or chemical forces like some reactant in the environment breaking the system down into smaller one’s without destroying it or by simply due to the fact that networks grew so large that they simply broke apart each dying to give birth to new one’s? One can only speculate and hope that someday experiment or observation will show the right path.
So now lets just assume that there was a molecule capable of reproducing and it somehow arose, now let’s call this little molecule the Replicator (I am following Richard Dawkins tradition over here) and now the question arises what is this Replicator is it DNA? Which is the vehicle of heredity in majority of organisms today? No, there are some recent developments to suggest that this cannot be so, let me explain why you see it carries the information with which proteins are to be built but it also needs some infrastructure to decode it namely with the help of proteins. So the question arises which came first the protein or DNA? Now tear your hair out over this one as much as you want and it will lead you nowhere. Thus let’s abandon this DNA-first model and now lets look at something more simple RNA, which has emerged as a possible entry in the contest for creating life. As Walter Gilbert put it “One can contemplate an RNA world, containing only RNA molecules that serve to catalyze the synthesis of themselves & The first step of evolution proceeds then by RNA molecules performing the catalytic activities necessary to assemble themselves from a nucleotide soup.” ( I am quoting this from sciam) . However this theory again has to face the execution block of why and it does seem to on the surface at least escape unscathed.
Hence I hope the above briefing has been illuminating and I shall write about in detail in the near future but to divulge further would take us out of the scope of this post. However, if you have read my briefing then you will realize that reverse entropy is essential for life but that requires us to send probes to places and test for it. So how should we test for it, well there is always indirect observation we can always look for certain conditions but yet again we might be too prejudiced in doing so but we have to try.
Through spectroscopy or other such techniques (I am not so sure if others exist, if yes then please enlighten me) we are trying to search for essential things that we think might be required to create our naked system. Thus taking earth as a successful criteria and other possible combinations we look for them using telescope and analyze them through spectroscopy if the results are interesting then we investigate further. The second logical thing to look for will be a star near the age and size of our star (I still somehow find the Idea comical that mankind has tried claim it, due to lack of other competitors it seems that we won the case). As a star too young wouldn’t have time to let life evolve and red giants are out of question, hence we try to find the star which is just right (reminds one of Goldilocks doesn’t it?). Then we will check for the temperature of the planet and try to calculate it’s surface temperature on the basis of the electromagnetic radiation we receive(the surface temperature will be different for planets with atmospheres due to factors like the greenhouse effect). I am sure that life can’t exist in 400 degrees centigrade but then life may find a way. Then liquids are also searched for as liquids offer a good medium for ionic exchanges to occur. So on and so forth they look for a host of variables in order to search for life in the universe.
Another hope is that a civilization has evolved on a planet and that they have proceeded to develop radio, why are we assuming this? As utilizing a radio is surely one of the easiest ways in which a civilization can communicate, no matter how brief the period is before they move on to other, possibly better form of communication. This assumption may be due to our own current inadequacy to find a more efficient means of communications over really long distances. However, I still think that it’s reasonable to assume that a civilization will advertise it’s presence on the electromagnetic spectrum.
Hence more for the sake of trying than the remote probability of contact we should keep our ears open for possible contact. In order to search for radio signals in the sky an international effort is required do a systematic search of the visible cosmos. However that’s clearly not being done, SETI is hardly succeeding at all in it’s initial objectives despite finding the WOW signal funding has been scarce and several parts of the sky are not being monitored. Now, the sad thing is that the search for extraterrestrial intelligence is probably the most important search we humans as a species will undertake. Isn’t it sad that we can’t devote a few millions a year for such an important enterprise, I guess it’s due to the fact that we spend it on preparation of war, now that’s important.
I would like to end this post by saying no matter how subjective, we are in our definitions of life. It’s imperative that we continue to question and search till we find it. For no matter how remote the odds may seem we have to try, it’s not a matter of choice. For think deeply and you will realize, as i have previously said, it’s a search for ourselves. The final answer of this question is so intrinsically tied to the very fabric of human reality that it’s a compulsion not a choice. Imagine the psychological consequences of an answer to the question “are we alone”? It will shake humanity down to it’s core, suddenly the chauvinism’s several of us indulge in, will look foolish in the face of all the vastness. We will be finally forced to accept the oneness of our species. Imagine how much good will come from it, but yet caution will have to be maintained and pray (I mean this metaphorically) that Hollywood wasn’t right…..
PS: I haven’t touched upon several topics relating to his matter, I have decided to write about them later…