What is Life?

A very fascinating question!

This is also a very important question which leading thinkers and scientists are trying to answer. Advances in space research (search for life), robotics, computing, biology, etc. have now reached those frontiers where it is becoming necessary to be able to define life. See some current approaches to understanding of life here.

Does life has to be like that of humans? Does it have to be intelligent (What's intelligence?)? Does it have to have feelings (What are feelings?)? Does it have to have DNA? Does it have to be based on carbon or organic chemistry?

As you answer surely or tentatively 'No' to these questions, you slowly start becoming uncomfortable and ask, then what is life at its core?

While no one knows for sure how to define life, everyone can recognise life when they see it. It is easy to see that a single cell bacterium is live but a complex computer chip is dead. All known living beings are made up of carbon and have DNA (again, made of carbon) but there is a realisation that life doesn't have to be based on carbon. Could it be silicon? If yes, could some computer chip some day be taken as live? Here is my definition of life that I think is helpful.

Life is a phenomenon within the context of an environment. A unique characteristic of this phenomenon is that it simply strives to continue (or you may say, survive and sustain). It derives sustenance from environment and the same environment threatens its continuity in different ways. In turn, by virtue of its characteristic of continuity, the phenomenon adapts its "implementation" (the living beings) or manifestation to give it newer forms and survival tactics. Another distinguishing characteristic of this phenomenon (to distinguish from other non-life continuing phenomena) is that it moves from the state of disorder to order over time in its local environment.

An important pre-condition that I may add here is that the environment must be natural, i.e., an environment with pre-set rules (like laws of physics which do not change for life to sustain) and randomness, not a controlled environment (like a man-made environment where humans can interfere and change conditions). It's not natural in the sense that humans can't create it but it must meet above criteria.

At first sight this definition might appear too simplistic and even silly to many but in next few posts I will build more arguments around this and will hopefully show this definition as an underlying thread behind all life we know, including ourselves. For the time being, the take home from here is that the purpose of life is just to sustain itself. In the meantime, do some reading on evolutionary biology...