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From DNA to Cosmology: Science Club Lecture Series Spans a Wide Spectrum

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The IISER Pune students’ Science Club began 2015 with a series of talks by eminent scientists from varied fields. In this series organized for the students and by the students, distinguished speakers are invited to give popular lectures on their areas of research.

The first talk of the season was given by Dr. Yamuna Krishnan from University of Chicago who spoke about “DNA nanotechnology and novel uses of DNA”. Dr. Krishnan, who was visiting IISER for the International Symposium on Bioorganic Chemistry, started with the basic properties of DNA molecules. She explained how its programmability, complementary base pairing and relative strength as a double strand make DNA a suitable material for supramolecular chemistry and nanotechnology.  Speaking informally she connected instantly with her audience, giving them a broad overview of the field of DNA nanotechnology. She concluded with a description of structure and uses of the DNA icosahedron made in her lab.

Renowned theoretical physicist and proponent of string theory, Dr. Ashoke Sen from the Harish Chandra Research Institute, Allahabad was the second speaker of the series. In his talk, Dr. Sen attempted to bridge the gap between two domains of physics that operate at vastly different scales: on one hand, string theory that deals with physical laws operating at very minute scales and on the other, cosmology which studies objects on the scale of the universe. Dr. Sen first explained how quantum mechanics has limitations when applied to scales where gravity exerts significant effects. He then went on to describe the basic postulate of string theory, that the most fundamental objects in nature are one dimensional vibrating objects called “strings”, which can exist in various vibrational states. The salient feature of this theory is that it incorporates gravity – something that quantum mechanics struggles to account for. Dr. Sen also illustrated data collected from varied sources which are consistent with String Theory hypotheses.

Next, Prof. R. Ramesh, a paleoclimatologist from Physics Research Laboratories, Ahmedabad spoke about “Decoding information from natural archives using stable isotopes”. Prof. Ramesh described how measurement of certain rare but stable isotopes of common elements can be used as a window to the events of the past. The relative proportion of various isotopes of certain elements is fixed under a given set of conditions. Thus, the levels of these isotopes in ancient deposits can be used to predict the atmospheric conditions of that point in time. Citing diverse examples such as tree rings, marine sediments, ice cores, and calcareous deposits in stalactites and stalagmites, Prof. Ramesh demonstrated how this technique is used to track physical, chemical and biological process. This data is then used for reconstructing the climatic conditions like temperature, monsoon, etc. in the geological past.

Each lecture was followed by a discussion session where the scientists encouraged students to come forth with questions and comments. The talks were well-attended and saw enthusiastic participation of the audience. The Science Club plans to continue this series throughout the semester and also has other interesting activities like visits and workshops on their cards.

-  Reported by Apurva Barve with inputs from Siddhartha Sohoni, Vikram Ravindranath and Karthik Prabhu (BS-MS students, IISER Pune)