Indian physicists have finally got a laboratory deep underground--
almost half-a-kilometre below the earth's surface - to hunt for "dark matter", the elusive glue that holds galaxies together. A form of energy and matter, it has evaded detection so far. To search for dark matter, scientists need to dive deep underground, so their experiments are shielded from intruders like cosmic rays and other radiations. The rock overhead is expected to absorb these unwelcome rays that interfere with the experiments.