Commentary

A large-scale survey of American scientists reveals strong support for continued nuclear energy development. Most regard thermal fission as one of the few resources capable of contributing significantly to our short-term energy needs and rate the risks as acceptable. They are critical of the performance of government and the public and they would prefer that public interest groups, the news media, and the general public exert less influence over nuclear energy policy.

The development of a petrol price war owes much to the structure of petrol retailing and in particular to the spatial pattern of retail outlets. Local neighbourhood, retailer competition, stimulated by consumer price sensitivity with respect to clusters of service stations, influences not only the spatial pattern of prices but may also influence the range in prices during a price war, at least at the scale of an individual city.

A satisfactory definition of intelligence has never been found, and as a result it means different things to different people. What it is may remain too complex for a succinct definition, but the theory and practice of information handling have clarified what it does fur us: it enables us to guess better, and the discovery of unexpected orderliness is the chief means of doing this.

We propose that the function of dream sleep (more properly rapid-eye movement or REM sleep) is to remove certain undesirable modes of interaction in networks of cells in the cerebral cortex. We postulate that this is done in REM sleep by a reverse learning mechanism (see also p. 158), so that the trace in the brain of the unconscious dream is weakened, rather than strengthened, by the dream.

Some of the physical assumptions which are implicit in the proposed new definition of the metre are discussed, including the mass of the photon and the constancy of the fine structure constant.

It is fifty years since the publication of the report on the isolation, from coal tar, and identification of the potent chemical carcinogen benzo(a)pyrene, the culmination of over 10 years of research instigated and directed by E.L. Kennaway. The events leading to that discovery are of interest in themselves. Subsequent progress in unravelling the metabolic fate of polycyclic aromatic hydrocarbons has contributed to our understanding of the mechanism of chemical carcinogenesis.

Before we can attribute consciousness to animals we must first decide on our definition of the word.

Cuba may be moving into the big league of scientific nations at just the right time. Bob Ubell reports on a recent visit.

In June 1981, aircraft of the Israeli Air Force bombed the Iraqi research reactor 25 km from Baghdad and put it out of action. Richard Wilson, head of the Physics Department at Harvard University, describes a recent visit.

A correspondent with wide experience of Chinese affairs describes the state of science in China in the wake of the Cultural Revolution and speculates on the possibilities for the future.