The speed of sound in gases is derived in a manner similar to what was done for the speed of waves on a string. The mass of the gas molecules provides the inertial contribution. The gas laws, along with approximation techniques, are used to estimate the return force. The appropriate process is adiabatic, and so the speed of sound depends on the adiabatic constant. The adiabatic constant, in turn, depends largely on the shape of the molecules. Excellent agreement is found between the rather simple theory and measured results. The speed of sound in a gas is found to depend on the (average) mass of the molecules, temperature, and the adiabatic constant (the shape of the molecules); however, there is very little pressure dependence when the pressure is near 1 atmosphere.

This chapter presents a discussion and derivation of the ideal gas law, starting with atoms and molecules. Collisions are characterized by the impulse, the change in momentum due to the collision, determined by the product of the average force during and the time duration of a collision. A free atom or molecule in a box is used to develop the concept of pressure on a wall and, ultimately, the ideal gas law for many noninteracting molecules. The distinction between gauge pressure and absolute pressure is necessary to understand before applying the gas laws. The root mean square (rms) speed for a typical molecule is estimated to be a bit faster than the speed of sound. That is, the molecules can be expected to be supersonic. Included is a discussion of isotopes and carbon dating and their connection to the musical scale.

This chapter considers the reciprocal productivity between Beckett’s Endgame and Shakespeare’s romance The Tempest. It examines the settings of the two plays, their dialectics of making and unmaking, their dynamics of confinement and release, the materiality of air and earth, and the notion of ending. It looks at the insular dominions of Prospero’s island and the space inhabited by Beckett’s characters in Endgame, and argues that the imperfections and shortcomings of a medium are not an end in themselves but become the grounds on which plays such as The Tempest and Endgame transcend the finitude of their art and reflect back on it, asserting its very finitude as a condition of possibility.In both plays, the game of chess figures as a structural and thematic component and reflects on the art of the playwright. The chapter analyses the brief scene in which Prospero discovers Ferdinand and Miranda playing chess. The scene functions as a mise-en-abîme, as a play-within-the-play, and becomes a metaphor for the play itself. In the many references to chess in Beckett’s works, above all in Endgame, chess, as this chapter argues, presents a matrix of multiplicity that remains tied to form.

In GC II 8, Aristotle shows that earth, water, air, and fire, are presented in every mixed body. Here Aristotle develops further the discussion of elemental mixtures started in GC II 7. He goes beyond anything done up to this point because the mixed bodies he is concerned with are not just the elemental mixtures discussed in GC II 7; rather, they are all the mixed bodies inhabiting the region around the center of the universe. Insofar as this region is the place where the natural processes of generation and corruption take place, GC II 8 prepares the grounds for the final section of the GC II (GC II 9-11).

This chapter reviews how literary and literal atmospheres have cut across each other in complex transactions of meaning and practice over the past 400 years. It traces how atmosphere was first literalised in early modern science, in a process that identified air as a new object of empirical knowledge while also awarding a new meaning of empirical objectivity to literalness. It then shows how this scientifically literal atmosphere was taken up in an expanded set of metaphoric and figurative uses from around 1800, in which such formulations as ‘political atmosphere’ and ‘poetic atmosphere’ breathed new life into traditional understandings of air that had moved fluidly between the spiritual and the empirical. The large-scale cultural re-metaphoricisation of air in this period formed the platform for the emergence of literary atmosphere as a specific practice of double troping, in which aerial figures were reflexively marked as at once figurative and literal. That marking proved integral to the emergence of both modernist poetry and the modern novel. But the discursive divisions and oppositions that underwrote it are brought under unprecedented pressure by climate change, which therefore requires new methods for the writing and reading of literary atmospheres.

This final chapter explores the aesthetics and materiality of stone, water and air. Theories of assemblage, non-human agency and differential time show how innovative was Scott’s approach to the relationships between people and the environments in which they live. Time frames are a key theme throughout the book: here, Jeffrey Cohen’s theory of lithic (stone) time, Rob Nixon’s account of the ‘slow time’ of many forms of environmental violence and Donna Haraway’s investigation into how animals over time became ‘companion’ species raise questions about permanence, solidity, transformation and modes of perception. Weather, seascapes and night skies are explored. Case studies compare Scott’s poetry and fiction with writing from American transcendentalism. Geographically, the chapter ranges from Scotland’s Borders, the Solway Firth, Shetland Isles and deeper Atlantic Ocean towards Iceland and Greenland. The chapter ends with episodes from Redgauntlet and Guy Mannering that look to the night sky, space and the stars.

This chapter reads the formal evolution of Heaney’s poetry as a partial return to the kind of poet he was in his early career. Devoting most attention to his final two collections, District and Circle and Human Chain, it traces the evolution of his forms out of the narrow stanzas of the bog poems through the 'poetics of airy listening' of his middle career. Discussing the figure of the blacksmith and the prominence of metal objects in Human Chain – as well the emphasis placed by the poet on the pastoral and the etymological – the chapter contends that in returning to the 'weight' of his early style (concentrated, dense), Heaney seeks a style which is universal and permanent. The use of refrains and short lines reminiscent of traditional song are highlighted as being part of this quest to be a 'poet for all times'.

The last part of Chapter 2 and the first part of Chapter 3 of De mundo (392a31–393a8) describe the cosmic layers further below the sphere of the moon, leading down to the very centre of the universe. This section provides a brief overview of the sublunary layers of the four elements (fire, air, water and earth), some of which will be discussed in more detail later in the text. The two main theses that constitute the reasoning behind this section are (i) continuity throughout the entire cosmos and (ii) the great variety of phenomena and processes within the sublunary domain. The layers are organised from the most active one at the top down to the most passive one at the centre of the universe. The continuity among the layers is demonstrated on each and every level. There is, however, no suggestion that each lower, less active substance gains all its characteristics from the more active substance above. For our author’s purpose it is sufficient to demonstrate that there is some relation, some communication among the layers which can later be used by the divine dunamis permeating the entire cosmos. The final part of the present section concerns the claim that the continents are large islands surrounded by an ocean.

The first part of Chapter 7 deals with oscillating water columns (OWCs). The concepts of radiation conductance and susceptance are introduced. The former is related to the radiated power, whereas the latter represents the reactive power. Expressions for the power absorbed by the OWC are derived, which are analogous to those of the oscillating body WEC. The potential energy of the OWC is also discussed. The last part of Chapter 7 deals with wave energy converters that move in modes other than the six conventional rigid-body modes. The theory of generalised modes are described, and some examples are given to illustrate the utility of the theory.

Reece discusses Diogenes of Apollonia’s claim that “all existing things are differentiated from the same thing and are the same thing” (DK 64B2, Simp. Phys. 151.31–32), namely air. He examines Diogenes’ principle that causal interaction and change require some sort of uniformity among the relata, and considers the questions which this principle raises.