Apparently peeved at India's May 11 nuclear tests that caught it completely by surprise, the US decided to keep out Chidambaram perhaps under the belief that exchanges at such fora help Indian scientists to hone their skill in forbidden areas: atomic energy, for example.

Chidambaram himself only laughed at the suggestion. Confirming that he was refused the visa, he told The Indian Express: ``I had applied for visa for attending the annual meeting of the International Union of Crystallography and it was rejected.

``It is not a scientific conference and has nothing to do with atomic energy or related research. It is a routine yearly meeting. I used to attend the union meetingfrequently. This time, too, I wanted to go there in my individual capacity as a crystallographer and as the vice-president of the union,'' he said. Crystallography is Chidambaram's pet research area and he takes time from his job to conduct experiments and writes papers for peer-reviewed journals.

Asked if these type of sanctions would affect the nuclear industry he said, ``I don't think so since our programme is by and large indigenous. But it could affect the free exchange of ideas among scientists from different countries.'' Though Chidambaram did not respond when asked if the travel-sanction was a result of the nuclear tests, his technical advisor G R Balasubramanian, left no one in doubt: ``Obviously, it's the fallout of the May tests and the US will try to put more pressure on us using these methods. It's not surprising and was anticipated,'' he said.

Former director of Tata Institute of Fundamental Research (TIFR), Prof Virendra Singh said, ``There are similar instances (of scientist being deniedvisas) here, too, but I am not sure about the specifics. It will be troublesome if this continues.''

Another TIFR faculty, on condition of anonymity, said that the US' tough stand on granting visas would affect the scientific community at large. ``BARC and DAE units constitute just a fraction of the total scientific community in the country. They may not require the US or Europe anymore. Others certainly need it,'' he said.

``Some TIFR and IIT fellows were denied visas after the May tests. If the situation continues, we might have a problem,'' he said.