Dr. Mather discussed The 'Big Bang' theory explicitly, from the scratch. He sent slides, which were being presented simultaneously as he was delivering his lecture.
It was the story of formation of the universe. How the small concentrated mass of a size of about 10 cm across exploded n expanded into the universe, as we know it today. Much of the world we know today comprises of matter, however 90 percent of the universe comprises of matter and energy, which does not interact with light. It is the presence of force fields of such matter which provides us with the evidence that it exists, scientists also used the term 'Dark' to classify this matter and energy, however, not much is known about it till date.
The speaker then briefed the audience about his work with NASA on project of an observatory on a satellite station and plans of NASA to collaborate with ESA (European Space Agency) and send a New Telescope to be stationed in outer space which would be a much improved version of the Hubble Telescope which is already in space and has served valuable information of the universe.
The lecture concluded with Dr. Mather offering a live interaction with the students in a question-answer session in which interesting questions raised. One example of which was a question as simple as-"What is universe?" and the speakers closing statement went something like-"Sorry i could not answer all the questions properly but that is the beauty of science".
The crowd appreciated the effort put up by IIT Guwahati community and also Dr. Mather for a highly enjoyable and learning experience.