The Ethnographic Atlas of G.P. Murdock, published in 1967, is a brave compilation. It lists particulars of 849 human societies, surveyed all over the world. From it we might hope to count numbers of societies that permit harems versus numbers that enforce monogamy. The problem with counting societies is that it is seldom obvious where to draw lines, or what to count as independent. This makes it hard to do proper statistics. Nevertheless, the atlas does its best. Of those 849 societies, 137 (about 16 per cent) are monogamous, four (less than one per cent) are polyandrous [females having more than one male partner], and a massive 83 per cent (708) are polygynous (males can have more than one wife). The 708 polygynous societies are divided about equally into those where polygyny is permitted by the rules of the society but rare in practice, and those where it is the norm. [p 208]

The anteaters don’t seem to have made it into North America, but three genera survive in South America, and very unusual mammals they are. They have no teeth at all and the skull, especially in the case of Myrmecophaga, the large gound-dwelling anteater, has become little more than a long, curved tube, a kind of straw for imbibing ants and termites which are chivvied out of their nests by means of a long sticky tongue. And let me tell you something amazing about them. Most mammals, like us, secrete hydrochloric acid[*] into our stomachs to aid digestion, but South American anteaters don’t. Instead, they rely upon the formic acid from the ants that they eat. This is typical of the opportunism of natural selection. [p. 215]

The famout D₃ line was first seen in 1868, when the spectroscope was for the first time directed upon a solar eclipse. Most observers supposed it to be the D line of sodium, but P.J.C. Janssen noted its non-coincidence; and very soon, when Lockyer and Frankland took up the study of the chromosphere spectrum, they found that the line could not be ascribed to hydrogen or to any then known terrestrial element. As a matter of convenient reference Frankland proposed for the unknown substance the provisional name of “helium” [after the Greek name for the sun, "helios"] …
Naturally there has been much earnest searching after the hypothetical element, but until very recently wholly without success ….
The matter remained a mystery until April, 1895, when Dr. Ramsey, who was Lord Rayleigh’s chemical collaborator in the discovery of argon, in examining the gas liberated by heating a specimen of Norwegian cleveite, found in its spectrum the D₃ line, conspicuous and indubitable … Cleveite is a species of uraninite or pitch blende, and it soon appeared that helium could be obtained from nearly all the uranium minerals.

In 1696 a window tax was introduced in Britain when the financially hard-pressed govenment started taxing properties based on the number of windows. The citizenry responded by bricking up windows and the darker houses are thought to have contributed to an increased incidence of rickets and tuberculosis.

Stars bigger than about eight Suns have a violent future. The temperature in these giants can rise so much, to around 3 billion degrees, that “silicon burning” takes place, in which helium nuclei can merge with nuclei close to silicon and gradually build heavier elements, stepping through the periodic table and finally forming iron and nickel. These two elements have the most stable nuclei of all, and no futher nuclear fusion releases energy. At this stage, the star has an onion-like structure with the heaviest elements forming an iron core and the lighter elements in successive shells around it. The duration of each of these episodes depends critically on the mass of the star. For a star twenty times as massive as the Sun, the hydrogen-burning epoch lasts 10 million years, helium burning in the deep core then takes over and lasts a million years. Then fuels get burned seriously fast in the core. There, carbon burning is complete in 300 years, oxygen is gone in 200 days, and the silicon-burning phase that leads to iron is over in a weekend.

The temperature is now so high in the core, about 8 billion degrees, that the photons of radiation are sufficiently energetic and numerous that they can blast iron nuclei apart into protons and neutrons, so undoing the work of nucleosynthesis that has taken billions of years to achieve. This step removes energy from the core, which suddenly cools. The outer parts of the core are in free fall and their speed of collapse can reach nearly 70 thousand kilometres a second. Within a second, a volume the size of the Earth collapses to the size of London. That fantastically rapid collapse is too fast for the outer regions of the star to follow, so briefly the star is a hollow shell with the outer regions suspended high over the tiny collapsed core.

The collapsing inner core shrinks, then bounces out and sends a shockwave of neutrinos through the outer part of the core that is following it down. That shock heats the outer part of the core and loses energy by producing more shattering of the heavy nuclei that is passes through. Provided the outer core is not too thick, within 20 milliseconds of its beginning, the shock escapes to the outer parts of the star hanging in a great arch above the core, and drives the stellar material before it like a great spherical tsunami. As it reaches the surface the star shines with the brilliance of a billion Suns, outshining its galaxy as a Type II supernova, and stellar material is blasted off into space.