When light travelling through the core deviates from its course and hits the cladding, the boundary between the two acts as a mirror, and the errant light is reflected back into the core.

ECONOMIST: New-age crystals

Before the summit, India had floated the idea of opening extra border crossings between the two countries, and optimists had speculated about an agreement to build an oil pipeline from Iran to India, through Pakistan.

ECONOMIST: Aggravation in Agra | The