Supersymmetry arises naturally in string theory. (It was originally motivated by string theory.)

As I once told a newspaper reporter, in order to be sure to be quoted: discovery of supersymmetry would be more profound than life on Mars.

There are strong reasons to expect that low energy supersymmetry is the probable outcome of experimental and theoretical progress, and that it will soon be directly experimentally confirmed. By low energy, we mean (softly) broken supersymmetry with an effective soft Lagrangian whose mass parameters are typically of order the electroweak scale but otherwise not special or constrained.

One is left with the uneasy feeling that even if supersymmetry is actually false, as a feature of nature, and that accordingly no supersymmetry partners are ever found by the LHC or by any later more powerful accelerator, then the conclusion that some supersymmetry proponents might come to would not be that supersymmetry is false for the actual particles of nature, but merely that the level of supersymmetry breaking must be greater even that the level reached at that moment, and that a new even more powerful machine would be required to observe it!

... one thing that's worth mentioning, though, it that apart from the dream of understanding physics at a deeper level involving gravity, work in string theory has been useful in shedding lights on more conventional problems in quantum field theory and even in and as well with applications to mathematics. Apart from its intrinsic interest, those successes are one of the things that tend to give us confidence that we're on the right track. Because, speaking personally, I find it implausible that a completely wrong new physics theory would give rise to useful insights about so many different areas.

Superstring theory has been studied intensively since 1984, when the discovery of Green and Schwarz of anomaly cancellation convinced many physicists that it provides a consisten theory of perturbative quantum gravity, gauge interactions and chiral matter. The basic difficulties in quantizing general relativity and supergravity (non-renormalizability or at least strong coupling at the Planck scale) are visible at low order in the loop expanison, while superstring theory was shown to be well-defined and finite to all orders.

The reader may ask why in this book string theory and supersymmetry have not been discussed. ... The fact is that this book is about physics and this implies that the theoretical ideas discussed must be supported by experimental facts. Neither supersymmetry and string theory satisfy this criterion. They are figments of the theoretical mind.

I would expect that a proper elucidation of what string theory really is all about would involve a revolution in our concepts of the basic laws of physics - similar in scope to any that occurred in the past.

Generally speaking, all the really great ideas of physics are really spin-offs of string theory... Some of them were discovered first, but I consider that a mere accident of the development on planet earth. On planet earth, they were discovered in this order [general relativity, quantum field theory, superstrings, and supersymmetry]... But I don't believe, if there are many civilizations in the universe, that those four ideas were discovered in that order in each civilization.

Often, in great discovery the most important thing is that a certain question is found.

While it is never safe to affirm that the future of Physical Science has no marvels in store even more astonishing than those of the past, it seems probable that most of the grand underlying principles have been firmly established and that further advances are to be sought chiefly in the rigorous application of these principles to all the phenomena which come under our notice. It is here that the science of measurement shows its importance — where quantitative work is more to be desired than qualitative work. An eminent physicist remarked that the future truths of physical science are to be looked for in the sixth place of decimals.

A great discovery solves a great problem, but there is a grain of discovery in the solution of any problem. Your problem may be modest, but if it challenges your curiosity and brings into play your inventive faculties, and if you solve it by your own means, you may experience the tension and enjoy the triumph of discovery.

The greatest scientific discovery was the discovery of ignorance. Once humans realised how little they knew about the world, they suddenly had a very good reason to seek new knowledge, which opened up the scientific road to progress.

The most important discoveries will provide answers to questions that we do not yet know how to ask and will concern objects that we can not yet imagine.