2.3.1 The risk society The shift from an anthropocentric concern around issues of human poverty in industrial society towards a more ecocentric concern around environmental issues in the ‘risk society’ has been expressed by the German sociologist Ulrich Beck. His 1992 book Risk Society: Towards a New Modernity suggests a shift from the safety state of industrialised society, where conflicts were manifest in struggles amongst socio-economic groups, to a society where conflicts arise from issues of uncerta
2.2.3 Ecological economics Ecological economics, which formally came to prominence in the mid-1980s, represents a departure from reliance on the use of mainstream economic modelling. Instead, it branches out to actively engage with and incorporate the ethical, social and behavioural dimensions of environmental issues. In short, ecological economics attempts to provide an interdisciplinary approach to environmental issues, whereas environmental economics maintains the primacy of economic modelling. Mark Sag
6 Population growth Earlier it was stated that three factors check population growth. These are predation, disease and insufficient food supply. For much of our history, our ancestors’ numbers were indeed limited by wars, disease and famine. The world population remained relatively stable until around 300 years ago. Then at the beginning of the 19th century (100 years after population growth started its geometric increase), the demographer Thomas Malthus predicted that population growth would outstrip food pro
1 Legacies and inheritance There is no doubt that each one of us affects the lives of those who surround us. Many of our interactions with others are very obvious to us and could be described in terms of personal, professional and social relationships. But there are other, often unnoticed, interactions: the mother taking her children to school, the man buying his paper, the youth at the bus stop – all people we see regularly and only notice when they are not there. Younger people are often very worried about what oth
4.5 Global climate change I would like to turn now to the possible consequences of our use of energy for global climate change. Our pattern of energy use relies heavily on burning carbon-based fossil fuels, releasing carbon dioxide which spreads evenly around the globe and builds up slowly in the atmosphere. Carbon dioxide is a greenhouse gas, which means that it has the potential both to warm the atmosphere and to change our global climate. It is not the only greenhouse gas but is the most important of those e
4.3 The UK experience: competing trends But one striking example does not make an argument. To try to get a fuller and possibly fairer picture of energy use by domestic refrigerators I'd like also to look at the UK experience over the past few decades. To start with it helps to have a feel for which parts of the UK economy use the most energy. The UK Department of Trade and Industry (DTI, 1998), identifies four main economic sectors: domestic (households), industry, services and transport. In 2003 the domestic sector (h
5 Conclusion The issue of climate change draws attention to the power of human activity to transform the planet in its entirety, and it is brought into sharp focus by the predicament of low-lying islands like Tuvalu. As we have seen in this unit, the issue of rising sea level and other potential impacts of changing global climate also point to the transformations in the physical world that occur even without human influence. Oceanic islands provide a particularly cogent reminder that the living things wit
4.1 Uniting the developing countries Several attempts have been made to form a united front of developing countries to negotiate a better deal at the WTO. They have met with little success because there are substantial conflicts of interest between them, for example between agricultural importers and exporters, and between small countries and those larger developing countries that have been able individually to use the lure of opening their markets to get a better deal from developed countries. Conflicts of interest arise too be
2.2 The purpose of this activity For these short video extracts we have chosen to focus on two main viewpoints. Try not to look beyond the outline of the debate, for we are not expecting you to come to a conclusion about who is right and who is wrong – the issues are far too intricate for that. All you need to do is to recognise what the issues are and to be able to identify what arguments each side puts forward in support of its case. The key skill being developed is identifying the arguments used by various individ
References 1.3 Activities Activity 2A sets the scene by focusing on the ‘big picture’ where you will be asked to choose between four alternative visions of the future. This activity radically shifts the scale of investigation from the personal to the global. However, as with all systems, the emergent behaviour of societ 1.1 Aim This study unit introduces you to the proposition that our mental models change through learning, and 6.3 Summary of Section 6 In trying to find solutions to the specific problem of the water-boiler, where the need was for a particular response to a certain temperature change, we have gone into the principles behind the three classes of temperature effect – gradual, accelerating and sudden. This has provided you with mathematical models that are of real use in putting definite numbers to the magnitudes of these effects in any designs that are proposed. The ability to do this is j 5.4 Critical modelling Critical phenomena are the simplest to model of the three classes of temperature-dependent changes we have been examining. We don't need a power series such as 1 + αT+ βT2+…, nor exponentials such as exp(−Ea/kT). Instead we can describe the behaviour with logical expressions like these: if T < Tc, then property=subcritical value (or fu 4.2 Energy distribution Atoms without much thermal energy will not be doing very much. Consider fifty million million million (50 × 1018) silicon atoms, bonded into a single massive network; I've chosen silicon, but any elemental solid would do. It will be a speck just large enough to be seen without a microscope. You know that if it is heated it will expand, at some stage it will melt and then eventually it will vaporise – that is because thermal energy effectively ‘rattles it to bits’. Having the 4.1 Characteristics of processes activated by thermal energy This is a long section and needs to be studied carefully. Keep your eye on the overall goal of seeking useful thermal effects on which to base devices. This section continues the discussion of heat at an atomic level. You will need this background to appreciate the characteristics of processes activated by thermal energy – for example, the softening of glass in a gas flame, the diffusion of atoms through solids, the electrical conductivity of ceramics, and many chemical reactions. Suc 3.3 Thermal stresses When the temperature of an object increases (say, by ΔT) it expands. According to the linear model of thermal expansion the length increase is described by What if there is a temperature change, but some constraint prevents the proper thermal size changes? The constraint 2.1 Defining ‘model’ The word ‘model’ has a range of colloquial and technical interpretations, so we need first to establish the way in which this unit uses the term. As a start, we might suggest that a model is a simplified representation of reality, but even that simple definition raises some quite significant philosophical questions. A profound question is ‘what is reality?’ and I will briefly mention the distinction between modern and postmodern views of this later as an aside. Without getting 3.1 Introduction The basic optical-fibre link consisted of the source (laser or LED), the fibre and the detector, as was shown in Figure 1. Improvements in these components can increase the data rate, but the system is still a point-to-point transmission link and all signal processing, such as routeing 1.1 Uses of optical fibre in communication Using optical fibres, very high data rates (gigabits per second and higher) can be transmitted over long distances (tens of kilometres) without amplifiers or regenerators. As a consequence, optical fibre has completely superseded copper wires as the primary medium for cabled transmission over long distances. Until recently, however, optical fibre has been used less in LANs, where twisted-pair copper cable has been dominant. Similarly, fibre has been slow to penetrate the access network, from
