Supersymmetry: imagined superpartners, imagined grand unification
Supersymmetry is the invention of imaginary new particles for every particle we know, to allow a neat unification of Standard Model forces at an energy we will never reach, 10^16 GeV.
But heuristic QFT shows that the mechanism by which forces vary at short distances (ie high energy collisions) is penetration of the polarised vacuum field, which shields the core charge of a particle. Extending this approach shows that supersymmetry is unnecessary for unification, because the abstract Standard Model QFT could be missing some kind of physical constraints like the requirement for the conservation of the total energy of vector bosons when unification energy (ie complete breakthrough of the polarised vacuum field) is approached.
In addition, if you want string theory, then Tony Smith has pointed to a way of avoiding supersymmetry in string theory using the Lie algebra E6: http://cdsweb.cern.ch/search.py?recid=730325&ln=en
String theory is not predicting anything about supersymmetry. The source below is strongly pro-string, pro-supersymmetry:
‘… supersymmetry requires the existence of a new elementary particle for every known one. … It is believed that the reason that these particles have not yet been observed is because supersymmetry is a broken symmetry …
‘Unfortunately, current theoretical ideas are insufficient to accurately predict the superpartner masses … there are three distinct arguments that make qualititative predictions of the masses. … should be in the range of 100 GeV to 1000 GeV. …
‘The three arguments are the following:
‘First, supersymmetry leads to a softening of the short distance singularities of quantum field theory. If we require a sufficient softening so that the Higgs mechanism can break the electroweak symmetry (SU(2) X U(1)) at the observed 300 GeV scale, in which case the Higgs particles have masses of the same order of magnitude, then the scale of supersymmetry breaking must also be approximately the same.
‘The second argument concerns the unification of the electroweak and strong nuclear forces at very high energy (around 10^16 GeV). One can argue that such a unification is inconsistent with the current experimental data, if one includes the effects of only known particles in the extrapolation, but that it works if supersymmetry partner particles with masses in the 100 GeV to 1000 GeV range are included.
‘The third argument concerns the possibility that the lightest SUSY particle could be a form of dark matter accounting for a substantial fraction of the mass of the universe. This also requires the same range of masses!’
All this supposed 'evidence' fits into the category of UFO 'evidence', alien crop circle 'evidence', and Uri Geller's spoon bending 'evidence'. There is no science going on in 'string theory' which isn't even a speculative physical theory, just a nice exercise in mathematics being passed off as science with the help of obfuscating to get funds. I don't really see the point in Dr Peter Woit's latest attempt to generate interest in Susskind's book on string theory:
Susskind Turns Down Templeton Prize
OK, maybe they haven’t offered it to him yet, but over at the Edge web-site, in a comment about John Horgan’s recent piece about the Templeton Foundation, Susskind writes:
I don’t understand the idea that a convergence between science and religion is taking place. I don’t believe in any such convergence. Throwing huge amounts of money at scientists who claim to see such a convergence can only lead to a dangerous blurring of boundaries.
I hereby pledge to refuse any prize for advancing the so called convergence between science and religion.
I missed Susskind’s recent public talk here in New York, about his book which the New York Academy of Sciences describes as “revolutionizing the field of physics”. There is a podcast recorded just before his talk. He makes his usual points including claiming that the situation of the string theory anthropic landscape is similar to that of Darwin and the theory of evolution. He also claims that anyone who thinks it doesn’t have experimental implications is wrong, pointing to Weinberg’s “prediction” of the cosmological constant.
Woit is just giving publicity to an attention seeker with a post like that. Susskind has nothing to say about science. Who cares about Susskind's religion or lack thereof? It would be more educational for Woit to write a post about Distler's attempts to teach string theory in Texas.