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This chapter discusses international criminal law (fighting political crimes) and transboundary police cooperation (fighting common crimes), though mechanisms such as the ICC, but also extradition and abduction
If you ask the average person what “magnetism” is, you will probably be told about refrigerator decorations, compass needles, and the North Pole – none of which has any obvious connection with moving charges or current-carrying wires. And yet, in classical electrodynamics all magnetic phenomena are due to electric charges in motion; if you could examine a piece of magnetic material on an atomic scale you would find tiny currents: electrons orbiting around nuclei and spinning about their axes.
In this chapter we study conservation of energy, momentum, and angular momentum, in electrodynamics. But I want to begin by reviewing the conservation of charge, because it is the paradigm for all conservation laws. What precisely does conservation of charge tell us? That the total charge in the Universe is constant? Well, sure – that’s global conservation of charge. But local conservation of charge is a much stronger statement: if the charge in some region changes, then exactly that amount of charge must have passed in or out through the surface. The tiger can’t simply rematerialize outside the cage; if it got from inside to outside it must have slipped through a hole in the fence.
This chapter discusses international law in context: how it relates to its political environment as well as to ethical concerns, and how the ethics of individual agents may be of relevance
What is a “wave”? I don’t think I can give you an entirely satisfactory answer – the concept is intrinsically somewhat vague – but here’s a start: A wave is a disturbance of a continuous medium that propagates with a fixed shape at constant velocity. Immediately I must add qualifiers: in the presence of absorption, the wave will diminish in size as it moves; if the medium is dispersive, different frequencies travel at different speeds; in two or three dimensions, as the wave spreads out, its amplitude will decrease; and of course standing waves don’t propagate at all. But these are refinements; let’s start with the simple case: fixed shape, constant speed, one dimension (Fig. 9.1).
This chapter discusses the basics of the law of treaties: what they are, how they are concluded, what efefcts they generate, and how they are to be terminated. It is built around the 1969 Vienna Convention on the Law of Treaties
If you walk 4 miles due north and then 3 miles due east (Fig. 1.1), you will have gone a total of 7 miles, but you’re not 7 miles from where you set out – only 5. We need an arithmetic to describe quantities like this, which evidently do not add in the ordinary way. The reason they don’t, of course, is that displacements (straight line segments going from one point to another) have direction as well as magnitude (length), and it is essential to take both into account when you combine them.
In this chapter, we shall study electric fields in matter. Matter, of course, comes in many varieties – solids, liquids, gases, metals, woods, glasses – and these substances do not all respond in the same way to electrostatic fields. Nevertheless, most everyday objects belong (at least, in good approximation) to one of two large classes: conductors and insulators (or dielectrics).
When charges accelerate, their fields can transport energy irreversibly out to infinity – a process we call radiation.1 Let us assume the source is localized2 near the origin; we would like to calculate the energy it radiates at time . Imagine a gigantic sphere, out at radius (Fig. 11.1).