Every year John Brockman’s Edge Foundation asks a large number of people in science and technology to write a short piece answering a chosen question, and this year the question is What Are You Optimistic About?
Among particle physicists, the overwhelming thing to be optimistic about is the LHC. For instance, Lawrence Krauss writes:
I am optimistic that after almost 30 years of sensory deprivation in the field of particle physics, during which much hallucination (eg. string theory) has occurred by theorists, within 3 years, following the commissioning next year of the Large Hadron Collider in Geneva, we will finally obtain empirical data that will drive forward our understanding of the fundamental structure of nature, its forces, and of space and time.
Wilczek describes himself as optimistic that “physics will not achieve a theory of everything”, taking the point of view that he hopes nature will continue to surprise us. He also denigrates the search for a fundamental theory of everything by noting what it has led to in the case of the string theory landscape:
At this point the contrast between the grandeur of the words “Theory of Everything” and the meager information delivered becomes grotesque.
Alexander Vilenkin on the other hand is optimistic about the multiverse and the anthropic landscape, saying it is implied by string theory, “our best candidate for the fundamental theory of nature”, and that he thinks that statistical predictions will be possible.
The person I agree with most is Gino Segre who writes:
So why am I optimistic? Because I believe that controversy, with clearly drawn out opposing positions, galvanizes both sides to refine their opinions, creates excitement in the field for the participants, stimulates new ideas, attracts new thinkers to the fray and finally because it provides the public at large with an entrée into the world of science at the highest level, exhibiting for them heated arguments between great minds differing on questions vital to them. What could be more exciting?
That sort of optimistic point of view on the whole string theory controversy is one that I hope more theoretical physicists will take, with string theorists acknowledging that there are serious questions that have been raised and that are worth debating.
Personally I’m a lot more optimistic now than I was a year ago that a more realistic view of string theory has started to take hold in many quarters, and that perhaps particle theory will move towards a healthier state. Like the Edge contributors, I see the fact that the LHC is now not far off as a cause for optimism. Perhaps it will produce the sort of surprising new insight into electroweak symmetry breaking needed to show the way forward. Even if it doesn’t do this, the likely failure to see superpartners or extra dimensions may encourage theorists to give up on ideas that don’t work and try and strike out in other directions.