String and M-theory: answering the critics

Using as a springboard a three-way debate between theoretical physicist Lee Smolin, philosopher of science Nancy Cartwright and myself, I address in layman's terms the issues of why we need a unified theory of the fundamental interactions and why, in my opinion, string and M-theory currently offer the best hope. The focus will be on responding more generally to the various criticisms. I also describe the diverse application of string/M-theory techniques to other branches of physics and mathematics which render the whole enterprise worthwhile whether or not "a theory of everything" is forthcoming.Comment: Update on EPSRC. (Contribution to the Special Issue of Foundations of Physics: "Forty Years Of String Theory: Reflecting On the Foundations", edited by Gerard 't Hooft, Erik Verlinde, Dennis Dieks and Sebastian de Haro. 22 pages latex

A classification of the dispersion surfaces in a magneto-ionic medium and a study of the associated radiation patterns scientific report no. 2

Dispersion surface classification in magnetoionic medium and associated radiation pattern

The Theoretical and Experimental Determination of the Input Impedance of a Small Loop of Electric Current Immersed in an Anisotropic Plasma

Exact expression for input impedance of small loop of electric current when loop is immersed in infinite, homogeneous, cold anisotropic plasm

Gender and the legal academy in the UK: a product of proxies and hiring and promotion practices

In this chapter we examine the differential numbers of men and women in each of the seniority levels of the legal academy with reference to qualitative studies on gender and the legal academy in the literature, and our initial analysis of the UK Higher Education Statistical Agency’s systematically collected data derived from all higher education institutions in the United Kingdom. We then apply the human resource management research literature to these data to seek to understand how decision-making in the academy may explain ongoing inequalities. Our research suggests that the continued disparity in male-female promotion trajectories is, at least in part, a function of the way in which talent, merit, or excellence is understood and operationalised in the academy more widely. We posit that the disparity in the numbers of men and women at the higher levels of the legal academy will only be successfully countered once we adopt a more sophisticated approach to analysing what makes an excellent law teacher/researcher/administrator and then develop and promote people on that basis

Electronic simulation of a barometric pressure sensor for the meteorological monitor assembly

An analysis of the electronic simulation of barometric pressure used to self-test the counter electronics of the digital barometer is presented. The barometer is part of the Meteorological Monitor Assembly that supports navigation in deep space communication. The theory of operation of the digital barometer, the design details, and the verification procedure used with the barometric pressure simulator are presented

Superqubits

We provide a supersymmetric generalization of n quantum bits by extending the local operations and classical communication entanglement equivalence group [SU(2)]^n to the supergroup [uOSp(1|2)]^n and the stochastic local operations and classical communication equivalence group [SL(2,C)]^n to the supergroup [OSp(1|2)]^n. We introduce the appropriate supersymmetric generalizations of the conventional entanglement measures for the cases of $n=2$ and $n=3$. In particular, super-Greenberger-Horne-Zeilinger states are characterized by a nonvanishing superhyperdeterminant.Comment: 16 pages, 4 figures, 4 tables, revtex; minor corrections, version appearing in Phys. Rev.

Freudenthal Dual Lagrangians

The global U-dualities of extended supergravity have played a central role in differentiating the distinct classes of extremal black hole solutions. When the U-duality group satisfies certain algebraic conditions, as is the case for a broad class of supergravities, the extremal black holes enjoy a further symmetry known as Freudenthal duality (F-duality), which although distinct from U-duality preserves the Bekenstein-Hawking entropy. Here it is shown that, by adopting the doubled Lagrangian formalism, F-duality, defined on the doubled field strengths, is not only a symmetry of the black hole solutions, but also of the equations of motion themselves. A further role for F-duality is introduced in the context of world-sheet actions. The Nambu-Goto world-sheet action in any (t, s) signature spacetime can be written in terms of the F-dual. The corresponding field equations and Bianchi identities are then related by F-duality allowing for an F-dual formulation of Gaillard-Zumino duality on the world-sheet. An equivalent polynomial "Polyakov- type" action is introduced using the so-called black hole potential. Such a construction allows for actions invariant under all groups of type E7, including E7 itself, although in this case the stringy interpretation is less clear.Comment: 1+16 pages, 1 Table, updated to match published versio

An octonionic formulation of the M-theory algebra

We give an octonionic formulation of the N = 1 supersymmetry algebra in D = 11, including all brane charges. We write this in terms of a novel outer product, which takes a pair of elements of the division algebra A and returns a real linear operator on A. More generally, with this product comes the power to rewrite any linear operation on R^n (n = 1,2,4,8) in terms of multiplication in the n-dimensional division algebra A. Finally, we consider the reinterpretation of the D = 11 supersymmetry algebra as an octonionic algebra in D = 4 and the truncation to division subalgebras