Sonia Gandhi watches Manmohan Singh greet Rahul Gandhi after Mr Gandhi was appointed vice-president of the Congress—PTI

Sonia Gandhi watches Manmohan Singh greet Rahul Gandhi after Mr Gandhi was appointed vice-president of the Congress—PTI

Sonia Gandhi watches Manmohan Singh greet Rahul Gandhi after Mr Gandhi was appointed vice-president of the Congress—PTI

On the first day of American President Barack Obama’s visit to India, the two most commonly used words were chemistry and optics.

January 27, 2015, was an eventful day. A few events took place almost simultaneously on this day that are likely to impact the future of India’s security and economy.