This chapter examines how parties to treaties give effect to them in their domestic (internal) law. Every treaty in force is binding upon the parties and must be performed in good faith (pacta sunt servanda). A party may not invoke the provisions of its internal law as justification for its failure to perform a treaty. A state should therefore adopt any domestic legislation necessary to give effect to the treaty before it consents to be bound. There are two broad approaches to implementation of treaties, depending on a state’s constitutional provisions: monism and dualism. The essence of monism is that a treaty may, without legislation, become part of domestic law once it has been concluded and has entered into force for that state. The practice of France, Germany, The Netherlands, Russia, Poland and Switzerland is examined. Under the dualist approach, the rights and obligations created by treaties have no effect in domestic law unless legislation is in force to give effect to them. UK constitutional practice is examined, together with the interpretation and application of treaties by UK courts. US practice is similarly analysed.

The behavior of fluids is complicated. One approximate solution is that of sinusoidal traveling waves. Those waves traveling in air are what we hear. The amplitude of sound waves is very small compared to 1 atmosphere, and the range of amplitudes we experience is very large. A logarithmic scale—in particular, decibels—is used to compress that range. The contrast is made between loudness, a perceived quantity, and intensity, a measurable quantity. For human hearing, a change of intensity of approximately 10 dB corresponds to a perceived change in loudness of approximately a factor of 2. Several examples are presented that show how multiple sound levels, expressed using decibels, can be compared and combined.

Electrical forces, electric fields, and electric field lines are considered and can be understood as arising from positive and negative electrical charges. Of most importance on an everyday scale will be the charge imbalance between positive and negative, known as the net charge. A net charge can be stored using two electrical conductors that are near to each other but separated by an insulating region. A device designed to do this is a capacitor. Resistors are devices that act like friction in an electric circuit and are one type of impedance found in electronics. Capacitors and resistors are characterized by capacitance, C, and resistance, R, respectively. A resistor connected to a capacitor will have behavior characterized by a time constant, RC—the product of the resistance and capacitance. It is one example of many systems that have a characteristic time scale. Some basic electronic schematic symbols are presented and used to demonstrate the exponential behavior of RC circuits. Similar circuits can be used to filter electrical signals—for example, to block low- or high-frequency signals and thus change the overtone content.

The basics of wave propagation in three dimensions, including the wave nature of sound, are considered. When waves from a common source reach a common end point, but by different paths, wave interference can result. Wave amplitudes that add or subtract result in constructive and destructive interference, respectively. Diffraction results when the components of a continuum of sources, initially from the same source, arrive at an end point following different paths. Diffraction becomes very significant when the wavelength becomes comparable to, or larger than, the objects in its path. Diffusion of sound energy in a room will occur if the reflections look as if they are randomized. Increasing the amount of sound diffusion in a room is often desirable, so special acoustic treatments have been devised for this purpose that are known as diffusers. Some of those treatments are based on variable-depth walls, where the depths are determined by a numerical series, including pseudo-random numbers and some results from numbers theory.

Every state possesses the capacity to conclude treaties. Treaties between states may be expressed as being by heads of state or by governments, and less often by state agencies or ministries. Some special cases are examined: the Cook Islands and Niue, the Vatican City (the Holy See), Taiwan, Palestine, Turkish Republic of Northern Cyprus, Somaliland, Western Sahara and indigenous peoples. In the case of federations, for the most part, constituent units conclude non-binding instruments with other states or their territorial units. But, in some cases, the state may authorise the conclusion of a binding treaty by a constituent unit. The chapter examines treaty practice in respect of Belgium, Scotland, Wales, Northern Ireland, Bosnia and Herzegovina, Republika Srpska, the Federal Republic of Yugoslavia, Kosovo, and the Hong Kong and Macao Special Administrative Regions.

A star can be defined as a self-gravitating ball of gas, usually spherical or spheroidal, that is powered by nuclear fusion in its interior. In this text, we will go slightly beyond the boundaries of this definition to discuss protostars and pre-main sequence stars (not yet powered by fusion), stellar remnants (no longer powered by fusion), and brown dwarfs (too small to be powered by fusion).

In 1938, Ernst Öpik pointed out that if the process that comes into play is thermonuclear fusion, then main sequence stars are powered by fusion in their cores, and red giants are stars that have exhausted their central fuel.