Sadhus arrive for “Bhumi Pujan” on the banks of Yamuna river ahead of the Maha Kumbh festival in Allahabad on Wednesday

Sadhus arrive for “Bhumi Pujan” on the banks of Yamuna river ahead of the Maha Kumbh festival in Allahabad on Wednesday - PTI

Sadhus arrive for “Bhumi Pujan” on the banks of Yamuna river ahead of the Maha Kumbh festival in Allahabad on Wednesday - PTI

Sadhus arrive for “Bhumi Pujan” on the banks of Yamuna river ahead of the Maha Kumbh festival in Allahabad on Wednesday - PTI

Sadhus arrive for “Bhumi Pujan” on the banks of Yamuna river ahead of the Maha Kumbh festival in Allahabad on Wednesday - 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.