Most people think of Abdus Salam as a pioneering Particle Physicist who won the first Nobel Prize for Pakistan for his part in constructing the standard model of Particle Physics.
This was, indeed, a most important contribution. However, there is a lot more to Salam and his contributions. I would like to mention a bit about them, howsoever briefly.
The Americans like to call the standard model the “Weinberg-Salam model” and the standard alphabetic order would put it as the Glashow-Salam-Weinberg model, but it is well to remember that in fact the first person and major contributor was Salam, followed by Weinberg, with Glashow making one important contribution. Some people also recall that he had done work earlier that could have got him a Nobel Prize if Wolfgang Pauli had not shot down the idea.
Salam had sent the draft paper to Pauli for comments and Pauli sent back the message “Tell my young friend, Salam, to think of something better”. What is not so often talked about is that he had done work using symmetries to predict the Omega Minus particle, but his student (entrusted with writing up the paper) had submitted an incomplete version, missing the prediction of the particle mass and hence the Nobel Prize.
Few people give Salam proper credit for two lines of work that have had a major impact on research in Physics (though there is no experimental verification for either of them). One is the proposal of a Gauge Grand Unified Theory (GUT): a theory unifying the strong nuclear force with the Electroweak of the Standard Model. I recall hearing a seminar by him on the 28th of January 1971. (I had my PhD viva after the seminar).
Jogesh Pati and he had noted that the strengths of the three forces appeared to vary with energy in such a way that at some higher energy they may have been equal. If so, that may be an indication that they were one force at the higher energy but split into three as the Universe expanded and cooled. Since those high energies to test the theory could not be achieved in the 1970s (or even with our modern accelerators), he proposed using a consequence of the unification, that the proton would be very slightly unstable.
The low probability for proton decay would be offset by observing a sufficiently large number of them, so that some of them would decay. Though there is no evidence of proton decay, much work was done to test the idea, leading to new technological developments, and to develop improved models for the unification. The idea still remains part of the folk lore of Partricle Physics.
The other work, done with John Strathdee, was to present the proposal of Supersymmetry for the unification of the symmetry of particles with integer and half integer spin (like photons and electrons), put forward by Wess and Zumino with a formalism that made it accessible to other physicists and made it usable for actual calculations. Nowadays, when people work with Super strings and Super-membranes, they use the Salam-Strathdee formalism.
Despite these crucial contributions and numerous others that I have not mentioned, to Particle Physics, it is not his Physics that made Salam’s name a household word for so many people in the Third World. It was his dedication to the cause of developing Science in the Third World. After all, there are numerous Nobel laureates who are not known outside academic circles, but Salam’s name was famous.
Salam’s key message was that the Third World should not try to simply transplant the technology of the West, thereby remaining a market for its commodities. Instead, it must develop its scientific capability and rely on the spin-off (especially of observing things at the very edge of detectability) to produce technology ingenuously.
From his personal experience when he had returned home, he had concluded that the Third World did not manage to develop Science because its best scientists migrated to the West or became academically sterile. More than the salary, he felt it was the fact that there were no people to communicate with –– they were isolated.
To break the isolation and mitigate the loss of salary, he proposed a Centre where scientists of the Third World could rub shoulders with the stars of the Western firmament and thereby break the cruel isolation, while being provided a stipend that would ensure that they were not out of pocket but could even save a bit.
This was proposed to the International Atomic Energy Agency and the United Nations. Of course, it would not have been feasible to propose a Centre for all the Sciences, or even for experimental Science. As such, he proposed an International Centre for Theoretical Physics (ICTP), in which he could arrange for the best scientists to come. When he proposed it, the reply was “The Third World does not need jet planes, it needs donkey carts.” By persisting, he got them to agree to give a small amount as seed money, to demonstrate that nothing could be done for the Third World.
Instead Salam made the ICTP a resounding success! He “auctioned” the Centre to the country, and city, that offered the most support. The city of Trieste in Italy made the best offer. This place had been a bone of contention between Italy, Yugoslavia and the Austro-Hungarian Empire. It was politically desirable to have an international institution there.
The city was convinced by Salam’s arguments of how it would help them economically. It succeeded in doing so beyond all that Salam had said. They gifted Salam a villa near the Centre, and when Salam died the City of Trieste insisted that the Centre be named for him.
The ICTP arranged Conferences and courses where young (and even not so young) scientists from the Third World, could come and learn, or refresh and update their knowledge. They came from countries that often regarded their neighbors as enemies. At the ICTP they learned to live and collaborate with them and see them as friends.
It helped to engender a more tolerant peace-loving and vigorous group of young scientists who could influence the policies of their home countries and help to develop a scientific culture there. For this contribution, more than any other, he earned the fame and recognition that he was given in the Third World.
His name means “servant of Peace”, and that was what he had become. Apart from these contributions he became an icon and an inspiration and would always encourage young people in their attempts to pursue Science. When I chose to study Physics and go to the Imperial College of Science and Technology in London, where he was, it was to a large extent because of him. When he won the Nobel Prize, he used some of the proceeds to fund a Prize for Young Pakistani Scientists, given in rotation to Physics, Chemistry, Mathematics and Biology, and I was left to run it.
For the first Prize, I called it the Salam Prize. He objected to the name but accepted it when my name for it was endorsed by others. He would select those that he felt he could push and goad into joining in his mission of spreading Science. When he told me that I, at the age of 29, must do more for the cause, I had said “You don’t know how hard it is to do anything in Pakistan.” His response was “Do you think it was easy to get this Centre?
Do you think it is easy to run it? Where do you think the money comes from?” I was left ashamed of my lame excuse, and never tried to excuse myself for not doing that which needed to be done. However, much one did, Salam always wanted more –– and somehow one could always manage to do that extra bit. As an aside I might mention that he would encourage all the crackpots and then pass them on to me to sort out if there was any sense in their ideas –– or any sense could be made of them.
Author: Professor Emeritus
Physics Department
School of Natural Sciences
National University of Science & Technology
H-12, Islamabad, PAKISTAN