In one of the reviews of the 1855 Leaves of Grass, an anonymous reviewer for the Swedenborgian Christian Spiritualist conceives of Whitman’s poetry (and poetry more broadly) as aligning with a tradition of spiritual mediumship.1 The great poets, that is, possess a medial capacity to channel and develop a “spiritual intercourse” with the muse, who is herself part of the transcendent realm. Having distinguished between the “two permanent types” of media – those singular agents who are lucky enough to receive “direct influx” from the divine source of love and wisdom, and a “second class of media” that channel “individual Spirits” and “societies of Spirits” – the reviewer proceeds to outline what is happening to the idea of mediumship as society transitions into a new and disorienting phase. “Many varieties of Mediumship,” the reviewer argues, “must be expected” in this moment of social and political turmoil, and not all of them either savory or desirable. The present age now produces imitators who merely “pour forth as Divine Revelations the froth and scum of a receding age”; confidence men who give “false notions of the state of man after death”; as well as other suspect figures who merely “come in contact with the outmost portion of the Spirit-life.” Then there are those more exceptional beings, best exemplified by Ralph Waldo Emerson, who “receive influxes from the upper mind-sphere of the age” and “[see] the future of truths as our Spirit-seers discern the future of man.”2

This chapter on Whitman’s 1856 edition of Leaves of Grass combines an analysis of its materiality as a commodity with readings of its textual content, arguing that both attempted to position Whitman’s poetry and persona within a simultaneously local and global literary marketplace. The edition’s double function of sales-pitch and self-commodification is highlighted by Whitman’s inclusion of Ralph Waldo Emerson’s reprinted letter, a bragging answer to it, his self-written reviews, and an international advertisement note alongside his first globalist text, “Poem of Salutation.” The imprint of the nineteenth century’s expanding global market is evaluated through Whitman’s ambitions to elevate his authorial status to worldwide recognition seemingly instantaneously with marketing techniques appearing across all genres in the 1856 edition. In this Whitman anticipated contemporary methods for manufacturing fame, as his model of the self-made poet tried to manifest success, measured by reader response, into reality before the fact.

This book has a two-fold objective: to teach and train students, and to intrigue and entertain everybody who likes physics and puzzles. The first chapter contains the 200 problems. If the reader's main objective is to use the book as a basis for studying physics, we recommend that the problems are tackled in the order they appear, though this does not necessarily represent their order of difficulty. Of course, if the reader is using the book for fun or as a challenge, he or she can freely ‘cherry-pick’ the questions.

It is an essential part of a physicist's skill to be able to recognise the type of problem in front of them, and to identify which areas of science and mathematics will need to be called upon. Almost needless to say, some of the problems could not be unambiguously assigned to, say, mechanics or gravitation or electromagnetism. Nature's secrets are not revealed according to the chapter titles of a textbook, but rather draw on ideas from various areas, and usually in a complex manner. However, after the present section, for information, we have included a list of topics, and the numbers of the problems that more or less belong to those topics. Some problems are listed under more than one heading. A list of symbols and numerical values for the principal physical constants, as well as several tables of material and astronomical data, not all of which will be needed, are provided in the Appendix at the end of the book. The Appendix also contains many standard mathematical results, drawn from the areas of vector algebra, conic sections, trigonometry, calculus and solid geometry.

The majority of the problems are not easy; some of them are definitely difficult. You, the reader, are naturally encouraged to try to solve them on your own and, obviously, if you do you will get the greatest satisfaction. If you are unable to achieve this, you should not give up, but turn to the relevant page of the hints in the short second chapter. In most cases this will help, though it will not give the complete solution, and the details will still have to be worked out. Once you have done this and want to check your result (or if you have given up and just want to see the solution) the final chapter should be consulted.

H1 Consider the motions of the bodies both in the original frame of reference and in another frame that moves with velocity v0 relative to the first one. Apply the Galilean transformation formulae.

H2 Be careful, the transformation principle due to Galileo Galilei applies only to inertial reference frames. The idea that Ann simply observes Bob moving towards her with a speed of 1 m s−1 is false.

H3 It is easier to solve the problem in a frame of reference fixed to the cart. A vector diagram of velocities, superimposed on a geometrical one showing the initial situation, should prove helpful.

H4 It is helpful to describe Joe's motion using a reference frame moving with the river water; imagine that we are in a boat that drifts with the river. Using this frame of reference, a suitable optical analogy and the application of Fermat's principle can help us to find Joe's optimal trajectory.

H5 The description of the disc's motion in a frame of reference fixed to the table is not easy. Try using a reference frame moving with the conveyor belt.

H6 The task can be tackled in several ways. One possibility is to analyse the turning process in an appropriate projection of phase space, namely in the vx– vy coordinate system. Another good idea is to use an inertial frame of reference moving relative to the ice in a suitably chosen direction.

H7 From the tangential and centripetal components of the acceleration, determine the horizontal and vertical ones.

H8 Finding accurate time intervals for the two sections of the motion is very difficult. To answer the question as posed, it is easier to compare an underestimate of the time to cover arc AP with an overestimated time for arc PB.

H9 Show that the axis of symmetry of a parabola makes an angle with the tangent to the parabola at any point P that is half the angle it makes with the line connecting P to the focus.

H10 Instead of using calculus, let us try to solve the problem using a variety of techniques, e.g. by investigating the number of real roots of a quadratic equation, or by using the properties and geometric representations of relevant vectors.