Interdisciplinary Science Reviews

The so called ‘glass ceiling’ has been defined by the (now defunct) Glass Ceiling Commission as ‘invisible, artificial barriers that prevent qualified individuals from advancing within their organisation and reaching full potential’. I have recently examined the research literature on this phenomenon and discovered not only that the associated imagery is very powerful, but that the principal message, with only a few exceptions, is that there is a shortfall of women compared to men in top jobs, and that therefore a glass ceiling must be operating to hold them back. In this article I argue the view that the glass ceiling perpetuates a notion which persuades women to expect to be unfairly treated. I develop this theme by considering male versus female attributes, evidence for male and female job satisfaction, the steadily rising participation of women at management levels, and women's aspirations. Some special consideration is given to women in science, engineering, and technology. Finally, I discuss ways forward in terms of non-interventionist measures such as the use of role models, mentoring, and networking, since the non-competitive and cooperative aspects of these initiatives appeal particularly to women and have proved to be successful in encouraging them to fulfil their potential.

Often in materials engineering we can envisage what new materials we wish to have and so point research in directions that make our aims achievable. As time progresses, such aims evolve, become increasingly diverse, and occasionally lead to quite unexpected provisions. From other viewpoints, we can also consider what we would like to be missing and this leads in further directions, to the removal of materials, or of specific elements within them, in relation to disposal, recycling, or purification to a level where subsequent additions can have highly beneficial effects. It is less obvious that, within materials, some atoms are always missing. These comprise only a small fraction, but enough to have major effects, and they can be regarded as vacancies that exist at places where atoms are normally situated. Their influence is greatest at elevated temperatures, for then they can move most easily, and so permit diffusion of the surrounding atoms. Their movement is random but under driving forces they drift in specific directions: under stress or chemical influences this can lead to distortion through transfer of atomic positions or to fracture through the formation of holes if the vacancies agglomerate. Such effects may be disastrous but, conversely, they can also be beneficial in assisting materials to bond together, especially when use can be made of the space created within them. It is natural to think of the characteristics of materials but important also to think of the usefulness of the space they provide. Lightweight, large scale structures covering wide spans come into this category, as do vessels for the containment of gases at high pressures. Sometimes, it is constructive to regard space as a valuable component of a composite material.

Since the dawn of the nuclear age, there has been interest in putting the nuclear genie back into the bottle. In the intervening decades there have been persistent efforts to promote the elimination of nuclear weapons. The International Pugwash Movement, for example, has struggled for more than 40 years to establish zero as the proper goal of nuclear arms control and to examine seriously the prerequisites and conditions that would permit nuclear elimination to become a plausible policy option. But such voices were always very much in the minority, and their preferred course was always distant from the main lines of debate about nuclear weapons policy and nuclear arms control. Indeed, as is quite evident, during the Cold War the superpower protagonists built vast nuclear arsenals, numbering tens of thousands on each side, and enshrined nuclear weapons at the centre of their defence strategies. The notion of eliminating nuclear weapons did not stir wide interest or support. In the last few years, this has begun to change rather dramatically. There has been a remarkable upsurge of interest in, and support for, the abolition of nuclear weapons. This upsurge has included a series of high profile studies examining the prospects for nuclear elimination as well as a widening web of prominent supporters of the idea of abolition. The mid and late 1990s have witnessed an unprecedented focus on nuclear abolition as a desirable objective worthy of serious policy consideration.

According to Hermann Weyl and in the words of Richard P. Feynman, an object is symmetric if one can subject it to a certain operation and it appears exactly the same after the operation. This paper generalises this definition of symmetry of objects in space to symmetries of the laws of nature. Consequences of the laws of physics that follow from their symmetries are derived and compared with the experimental evidence. It is pointed out that unobservability is at the root of all symmetries in the natural sciences. Symmetries of the laws of physics can be hidden by asymmetries of realisable states that follow from a lack of symmetry in the ground state of the system. If that is the case, transitions from states that share the symmetries of the laws, to states in the neighbourhood of the ground state that do not, involve symmetry breaking through self-organisation.

The most elementary manifestation of cultural change is the technological evolution of material artefacts. This has many similarities to bioorganic evolution, but is worth exploring as a phenomenon in its own right. For example, memes are non-Mendelian: they diversify and are selectively reproduced like genes, but are not enduring, perfectly replicable, or particulate, and can recombine across distant lineages. Considered as design concepts they can also evolve virtually, independently of the artefacts they encode and through whose selection they survive. Although variant populations of artefacts and memes are highly diversified, they are not generated blindly. Since technological entities are produced by conscious human agency to meet human needs, their variation and selection are necessarily non-Weismannian and, in certain significant senses, Lamarckian. But this does not exclude the appearance of typical macroevolutionary phenomena, such as satisficing adaptation, coevolution, locked in meme complexes, diversification into niches, and punctuated equilibrium. Nevertheless, technological evolution differs fundamentally from bioorganic evolution because it is a social process, in which institutions are becoming increasingly important. Above all, it involves human thought, which permits the incorporation of experience from a remembered past – ‘learning’ – and a projected future – ‘imagination’ – into the virtual phases of the evolutionary process. Technological change is thus, indeed, a dynamic VSR (variation and selective retention) evolutionary process, but gains hybrid vigour from its mixed Darwinian and Lamarckian parentage.