The sole argument generally given to justify this picture of the world is that perturbative string theories have a massless spin two mode and thus could provide an explanation of gravity, if one ever managed to find an underlying theory for which perturbative string theory is the perturbative expansion.
One problem of the String Theory is that it's kind of a theory which can explain what the problems are, but the problems are such that you can't even pin it down and say this is exactly what it predicts, so lets go out and test it. So, it's not even capable of being wrong, or being falsified, or being showed to be wrong.
Beauty means a lot of different things to a lot of different people. A lot of different ways in which things can be beautiful. But this really has a very specific meaning and which is more along the lines of elegance which is that we say an idea is beautiful or elegant in mathematics or physics if a very simple principle or a very simple idea, or simple set of ideas, turns out to be very powerful and leads to all sort of unexpected structure and unexpected predictions.
The main thing to understand about the current state of physics is that we have - are in some sense, a kind of victim of our own success. We have an incredibly successful theory called the Standard Model. And it really explains everything that we can observe about and in terms of a very small number of elementary particles and some basic forces between them. And it's a quite beautiful theory and it really is just absurdly successful.
Just because you're starting from something which you know - a theory which you know is right and trying to further develop your understand of that theory is maybe a more fruitful thing to do than trying to just throw all that out and start afresh with something more speculative.
The fact that the laws of physics don't change as if you move in time has physical implications that there's this thing called energy and energy is conserved, and the same thing - and the fact that the laws of physics don't change of you move back and forth in different directions in space implies that there is something called momentum and momentum is conserve and doesn't change as you evolve in time.
Mathematics can have its problems, but it's actually hasn't seen a lot of the problems as some of the other sciences and so much of it in what people are doing is completely useless. Nobody kind of in really cares very much. You don't really have kind of right and left and people in ideology coming in because there isn't any. It just doesn't actually connect up to the kinds of things that people ideologically worry about. So most of mathematics just doesn't tell you anything one way or another about global warming or about healthcare or about any number of things that you might care about.
One of my colleagues likes to say that, mathematics is the - he thinks about the only subject that he knows in academia or in the real world where if two people disagree about something - if people are studying some mathematical object and there's supposed to be a proof and they disagree about whether this proof or not, the will go into a room, sit down and talk about it and fairly quickly or at the end of the day one of them will admit they're wrong.
