• Why Astrobiology?

    Earlier this month, I was invited to deliver lectures at INFN (Italian Nuclear Agency) in a summer school entitled “Terrestrial atmosphere and cosmic rays” held at the LNGS campus (Gran Sasso Naional Lab) in L’Aquila, Italy. Aside from talking about the atmosphere and cosmic rays, I had a lot to talk about Astrobiology as well. It was the first occasion when I will be lecturing an audience of high-energy physicists. Although, I have given talks to such an audience, but never in the lecture format, which requires much more preparation on my part than a typical talk.

    At the time of preparation, it got me thinking that why would a typical high-energy physicist care about astrobiology? Well, they (we) study the interaction of high energy particles and develop models to explain why the matter behaves in the way it does. Finding the higgs boson particle is at the forefront of research and finding it will complete the standard model particle physics. One would be able to explain most observed phenomena using this model and universe will become a relatively boring place. Astrobiology, on the other hand deals with the study of life in the Universe, which seems to be completely different from high energy physics.

    In fact, physicists like Stephen Hawking are working towards a “Theory of Everything” (TOE), which will explain everything in the Universe from fundamental principles. Quantum physics explains the laws of the universe at very small scales on one hand, and the general theory of relativity explains phenomena on large scales, but these theories are incompatible and TOE will explain everything!

    But, are we missing something here?

    One thing physicists never take into account in such discussions is this unique form of matter called life. We don’t know how it originated (from dead things) but we do understand how it evolves. It is very similar to the Big Bang Theory (BBT) which can take us back to 13.7 billion years up till the time when our universe was just 10^-43 seconds old! But we have no clue what happened before that. We can trace the evolution of the universe but we don’t know how it originated. BBT is not the theory of the origin of the universe as advertised, but it is the theory of its evolution.

    We need to connect these two seemingly unrelated fields, and it needs inputs from experts in different disciplines. And this is the reason why I study Astrobiology, and why people should care about it.

    During the talk, I also spoke about the role of astrophysical events on the history of life on Earth. But, I’ll talk about that some other time.

    Now, if you are an astrobiologist, my question to you is — Why do you study astrobiology?