Life in the Universe

Khagol Mandal is arranging free lecture series which is free to all and on last Wednesday Prof. M.N. Vahia came to deliver the third lecture in the series. Prof. Vahia is working in TIFR in the Department of Astronomy and Astrophysics. The lecture was on the topic “Life in the Universe”.

He started the lecture by saying the basic requirements to sustain the life formation. The basic molecule in any organism is DNA and RNA which store all the basic information about the organism and which is capable to replicate that is it has the capacity to produce the exact copy of itself. The DNA or RNA is the complicated molecule which is formed by the long chains of carbon atoms and other elements combined to them. Such long chins of atoms can be made by only tetravalent elements like carbon, silicon, germanium, etc. But in these all elements only carbon is the abundant element in the universe. So life forms must be carbon based. Hence we have to see the conditions where these molecules can sustain without braking and hence only certain small zone known as habitable zone around any star can give rise to the life formation.

After we fix our problem to a little zone around the star we will have to see other requirements like the gravity, temperature, water (this is the most necessary thing other than carbon), oxygen, ozone (UV rays can break the long carbon chain), etc. This is formulated by Drake and he gave the famous ‘Drakes Equation’ which gives the probability of occurrence of the life form in the universe. But unfortunately we cannot solve the equation as some values are unknown till date. But it seems from the equation that it is easy to prove that we (i.e. life) do not exist in the universe than to prove the existence of life outside Earth.

Prof. Vahia gave very useful and simple examples like spilling of milk, etc to explain the complicated things. The lecture was very exiting and everyone enjoyed the lecture and some of the comic sentences made by the Prof. to keep the lecture interesting throughout. Around 45-50 people attended the lecture. The next lecture in the series is on 17 Oct and is on the topic “Astronomy for Beginners”. It will be delivered by Pradeep Nayak, Director, Khagol Academy. For more details visit www.khagolmandal.com