Switzerland's Roger Federer waves to the crowd after his fourth round win over Canada's Milos Raonic at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 21

Roger Federer waves to the crowd after his fourth round win over Canada's Milos Raonic at the Australian Open - AP

Roger Federer waves to the crowd after his fourth round win over Canada's Milos Raonic at the Australian Open - AP

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.