Seeing is believing? Not always

We tend to rely on our eyes as reliable witnesses of events taking place before us. In contrast to the information conveyed by other senses like ear or nose, we trust what we see. There are glitches in this reasoning, of course. The curved mirrors in the hall of mirrors of a fair present us with our distorted images, which we know to be far from reality. Travellers across hot deserts see illusions of water reservoirs reflecting images of trees. These mirages are caused by the bending of light as it travels down from the source towards the sandy base, the bending being caused by refraction of light travelling through successively hotter, and hence less dense, layers of air. This bending ultimately leads to reflection of light and hence to the illusory presence of water.

Chasing an elusive particle

When one year ends and another begins, that is an occasion to take stock of a field in order to see where we are and which way are we headed. In mid-December last year, I attended an international conference on gravitation and cosmology held in the pleasant surroundings of Mobor beach, Goa. It is perhaps a testimony to the interesting subject that the conference rooms were well filled despite the lure of the beach.

Who is faster: You or light?

There wasa young lady named Miss Bright, who travelled much faster than light. She departed one day, in an Einsteinian way, and came back the previous night.

This limerick by Arthur Buller, published in Punch in 1923, reflects the interest of the man had in time travel when the concepts behind Einstein’s theory of relativity began to percolate down to the lay world.

Taxila aglow, but Nalanda in shadow

A few years ago, a regional conference in Islamabad gave some of us Indian scientists an opportunity of a visit across the border.