fn7 The distinction between the artiodactyls and perissodactyls isn’t just an arcane detail of evolutionary biology but has become deeply embedded within religions. The Torah permits Jews only to eat mammals that both have cloven hooves and also chew the cud. Thus, evolutionarily speaking, only members of the ruminant branch of the artiodactyl ungulates are considered kosher or fit for consumption. Jewish scripture (Deuteronomy 14:6–8) also deals specifically with the camel, which despite being anatomically even-toed and also chewing the cud is proscribed as unclean (its feet have padded soles of hardened skin that hide the hoof).68 The Islamic faith, on the other hand, is less restrictive on the consumption of different mammalian species. The Quran only specifically excludes the meat of pigs, and in contrast to Judaism, camel is generally considered to be halal.69
fn8 It’s important to be clear that the first members of these new orders of mammals emerged at this time 55.5 million years ago, but the species within these orders that we are familiar with today did not evolve until much more recently – about two million years ago for the wild ancestor of the cow, for example.
fn9 We know about this from measuring the carbon contained in rocks on the sea floor. Carbon atoms are present as several variants with different atomic weights, known as isotopes. Light carbon is preferentially captured by key biochemical reactions, and so the molecules in living organisms, or the carbon dioxide or methane they release, contains more of the light carbon. When scientists analysed the carbon isotopes within limestone rocks laid down on the sea floor during the PETM (which is a way of measuring the atmosphere at that time) they found a huge jump in the proportion of light carbon. This means that the carbon dioxide or methane gas that had surged into the atmosphere to cause this temperature spike must have originally come from life.
4 The Geography of the Seas
fn1 In fact, as far as humans are concerned the seas of the Earth are barren deserts of water. As Samuel Taylor Coleridge wrote in The Rime of the Ancient Mariner: ‘Water, water, every where, Nor any drop to drink.’ Its salt levels mean that drinking seawater is lethal, and sailors need to carry stores of fresh water just like the caravans crossing the deserts.
fn2 The Phoenicians were a civilisation very much born of their natural environment. Emerging around 1500 BC on the narrow but fertile strip of land that today forms the coastline of Syria, Lebanon and Israel, they had access to both natural harbours on the eastern Mediterranean coast and forests of cedarwood for shipbuilding.13 The Phoenicians turned to the sea, and flourished for around a thousand years as expert mariners and merchants, establishing a widespread trade network and founding many colonies around the Mediterranean rim, including Carthage. They also invented the alphabet, and our word ‘Bible’ ultimately derives from the ancient Phoenician city of Byblos, which exported papyrus for writing.
fn3 The other side of the planet was covered by a vast uninterrupted ocean, Panthalassa, that was greater even than the Pacific today.
fn4 The port of Carthage lay on this raised lip, and the island of Sicily and the ‘toe’ of Italy are peaks of this same barrier.
fn5 Aden was also of key strategic value to the British from the mid nineteenth century. The port lies roughly equidistant from the Suez Canal, Mumbai on the western Indian coast and Zanzibar in East Africa, all of which were under British control at the time. During the heyday of steamships, Aden was an important way-station for loading coal and boiler water. It was for exactly the same reasons that the US annexed Hawaii in 1898, which served as a coaling station for American naval operations in the Pacific.22
fn6 Further fracturing of the continental crust at the northern end of the Red Sea formed the narrow gulfs of Suez and Aqaba, the latter of these splits extending to form Lake Galilee, the Jordan valley and the Dead Sea, whose shores are, at 400 metres below sea level, the lowest-lying land on the Earth’s surface.
fn7 India’s black peppercorns are botanically very different from bell (sweet) peppers and chilli peppers, which are both fruits of Capsicum plants native to Central and South America. These New World species were unknown to the rest of the world until the great fifteenth-century transfer of domesticated plants and animals that occurred after the European discovery of the Americas, known as the Columbian Exchange.
fn8 So much so that in the late seventeenth century, after the Second Anglo-Dutch War, it was agreed that the Dutch claim over Manhattan be ceded to the English in exchange for the spice island of Run, one of the smallest Banda islands. Run is just 3.5 kilometres long, but its acquisition allowed the Dutch to secure their nutmeg trading monopoly in the East Indies. Manhattan was swapped for nutmeg – and New Amsterdam renamed New York.
fn9 Europe at the time did already have access to many herbs and spices – saffron grown in Spain after its introduction by Arab traders, coriander and cumin native to the eastern Mediterranean, as well as the aromatic species indigenous across Europe: rosemary, thyme, oregano, marjoram and bay. But the exotic pepper, nutmeg, mace and cloves from the East were much rarer and therefore valuable in western markets.43
fn10 The landscape also dictated the nature of Greek warfare. The rugged terrain of narrow gorges and steep mountains and hills is not conducive to the wheeling chariot battles that had been common across the plains of Asia; nor is it well suited to cavalry formations. Instead, the Greek states developed armies of hoplites, foot soldiers armed with spear and shield who by the seventh century BC were trained to fight in tight phalanx formations. These hoplite armies were made up not of professional soldiers but citizens – farmers, craftsmen and traders – who brought their own bronze weapons and armour. Thus Greek battles weren’t decided by an elite class riding chariots or on horseback, but by the common citizens working together, each trusting the man to his right in the phalanx to protect him with his shield. This solidarity among the free men in Greek culture contributed to the early development of democracy within some city states, in particular Athens (although women, slaves and those who were not landowners were still excluded from the political process).45
fn11 Mt Etna is the tallest active volcano in Europe and one of the most active volcanoes in the world, erupting regularly with magma generated as the African plate is subducted beneath the Eurasian.
fn12 The Dardanelles are not just a vital marine chokepoint between the Mediterranean and Black seas, but also a strategic crossing point from Europe into Asia Minor. Alexander the Great crossed eastwards here in 334 BC to conquer Persia.48
fn13 Before the invention of the magnetic compass for navigation, sailing across open sea was just too dangerous when the night-time stars were obscured from view.
fn14 When in 1611 the Dutch established a new, faster passage from South Africa to the East Indies – the Brouwer Route which we’ll discuss in Chapter 8 – the key gateway, and thus their strategic focus, shifted from the Malacca Strait to the Sunda Strait between Java and Sumatra.
fn15 The island nation of Japan also underwent over two centuries of isolationism from the 1630s. During the Edo period, the sakoku (‘closed country’) policy barred most foreigners from entering Japan, and prohibited the Japanese from travelling overseas or building ocean-going ships. The only connection with the outside world was through a single trading post the Dutch were permitted to run on a tiny island within the bay of Nagasaki. Diplomatic and trade contact was reestablished after 1853 when steam-powered American warships arrived at the Japanese capital and forced the government to open their nation to the world.
5 What We Build With
fn1 Metals, such as bronze and then iron and steel, were initially in such short supply that they were used only for fastening other, more readily available, structural materials together, such as hard nails joining timber beams. It is only with the cheap availability of iron and steel since the Industrial Revolution, and machining techniques for the mass-production of parts, that metal has become a major structural component itself, for example as rebar elements within reinforced concrete or girders supportin
g bridges and modern high-rise buildings.
fn2 Thomas Jefferson, the third president of the United States, helped draft the Declaration of Independence, but also worked on the architectural designs of some of the new nation’s buildings. For example, he modelled the Virginia State Capitol on the first-century BC Roman temple, the Maison Carrée in Nîmes (which in turn influenced the design of other state capitols across the country), and his design of the library of the University of Virginia with its rotunda and dome emulated the Pantheon in Rome. Neoclassicism is perhaps most prominent in the city founded in 1790 as the new national capital on the banks of the Potomac River – Washington, DC. The Capitol Building (home of Congress), the Herbert C. Hoover Building (headquarters of the US Department of Commerce), the Treasury Building and the DC City Hall are all imposing examples of this neoclassical style. And the White House was designed by an Irish architect based on Leinster House in Dublin – later to become the seat of the Irish parliament – which itself mimicked architectural features of antiquity.
fn3 The term ‘crystal glass’ is something of a misnomer – the amorphous atomic structure of glass is in many ways opposite to that of the strictly regular repeating pattern of a crystal.
fn4 Similarly, the mass extinction at the close of the Cretaceous Period 65 million years ago ended the Mesozoic and ushered in the era of ‘new life’ (the Cenozoic). It created our world dominated by mammals and angiosperm flowering plants that we encountered in Chapter 3.
fn5 By comparison, the largest eruption in the last millennium, that of the Tambora volcano in 1815, released only 30 cubic kilometres of material – 160,000 times less.20
fn6 This sense also survives in the English language; originally a trapdoor was one that opens to stairs.
fn7 The end-Cretaceous mass extinction – that saw the death of the dinosaurs, along with three-quarters of all marine species – coincides with the eruption of the Deccan Traps onto India. This occurred 66 million years ago as the subcontinent was gliding north to its eventual collision into Eurasia, passing over a rising magma plume as it burst to the surface. The final straw for life was the impact of a 10-kilometre-wide asteroid or comet slamming into the Gulf of Mexico at the same time.
fn8 Indeed, Cleopatra lived closer in time to the modern world of iPhones and the glass pyramid of the Louvre gallery in Paris than she did to the ancient construction of the Great Pyramid at Giza.
fn9 This is the process by which almost all sand in the world’s beaches and deserts was formed.30 Quartz is also the base material we use today for making glass, and we refine it into the extremely pure silicon wafers of microchips and solar panels. Quartz didn’t exist on the early Earth – it was created by the action of plate tectonics over hundreds of millions of years. We saw earlier that convergent boundaries cause the crust to melt and form vast magma chambers. As the magma cools in these huge cauldrons, the first minerals to form leave the remaining magma with a higher and higher proportion of silica, which then crystallises as granite. While the primordial composition of the deep mantle is 46 per cent silica, the granite produced by this magma differentiation process has been enriched to about 72 per cent silica, high enough for crystals of quartz (pure silica) to form. Thus plate tectonics on our planet are like a chemical processing plant, acting to purify silica over time, and so make it available for human technologies. Incidentally, this means that if the Earth-like planets we are now discovering orbiting other stars don’t have plate tectonics, they may well have warm oceans, but no sandy beaches.
fn10 Today, one of the old kaolin quarries in Cornwall holds the Eden Project. This ecological tourist centre was constructed as a cluster of geodesic domes made of inflated plastic bubbles. These are innovative greenhouses that host tropical and Mediterranean biomes, and huddled within the crater-like pit they look almost like a sci-fi colony on Mars.
fn11 Whilst inspecting excavations for coal mines and canals in Somerset, the surveyor William Smith realised that different layers of rock were always found in the same sequence underground, and that these strata could be identified by the fossils they contained. He travelled across Britain to survey the strata exposed by natural escarpments and the quarries, canals and railway cuttings of the Industrial Revolution, resulting in 1815 in his geological map of Britain that shows the different rock strata present near the surface.33
6 Our Metallic World
fn1 As we explored in Chapter 4, much of the northern Mediterranean is volcanic, driven by the subduction of the African tectonic plate beneath the Eurasian. Despite the hazards of volcanic eruptions, however, volcanism also offers opportunities. Not only is volcanic soil rich and fertile for agriculture, but the Romans discovered that the properties of volcanic ash lent themselves to the manufacture of ‘pozzolanic’ cement. This was used for constructing everything from sea harbours (it set even when poured underwater) to aqueducts and the huge dome of the Pantheon, and the durability and mechanical strength of this Roman cement and concrete is still admired by structural engineers today.
fn2 No written records of the eruption itself have been recovered, although the Minoan Linear A script has never been decoded and this could possibly contain eye-witness accounts.24
fn3 The value that humanity has ascribed to gold through the ages is not just due to its rarity in the crust. Gold is unreactive, and so occurs as native metal – it is not bonded with other atoms in an ore – and its seams can be seen glinting out of a rock face or as flecks eroded out and redeposited in a river bed. This also means that it doesn’t tarnish – its lustrous gleam doesn’t dull; gold jewellery doesn’t react with the moisture of your skin, nor do gold coins corrode away: they are stable stores of wealth. While other metals have a plain, hueless, silvery shine, gold is also special for its distinctive colour. Both its noble unreactivity and colour are in fact effects of Einstein’s relativity. The outermost electron of the gold atom is moving at a fair fraction of the speed of light, and so owing to relativity becomes more massive and is pulled closer in to the nucleus. This both reduces its availability for chemical reactions and causes it to absorb blue light, so reflecting red and green to give a warm, golden colour.40
fn4 A second, minor spurt of BIF occurred around 1.8 billion years ago, producing the Gunflint and Rove Formations stretching between Minnesota and Ontario alongside Lake Superior.43
fn5 Before oxygen started to build up in the air, the atmosphere also contained no ozone layer which is itself formed from oxygen high in the atmosphere, and so harmful ultraviolet radiation from the sun would have streamed down to the surface of our planet. This high-energy light would also have driven chemical reactions within the atmosphere to create tiny droplets of hydrocarbons, enshrouding the early Earth in a smoggy photochemical haze. But the accumulation of oxygen in the air reacted with this yellowy haze to scrub it clean – and the skies turned blue.
fn6 When animals evolved much later, they provided new anoxic refuges within their own bodies. The oxygen-free gut of a ruminant like the cow recreates a small pocket of the primordial Earth, allowing anaerobic microbes to flourish and run their ancient metabolism that produces methane, which the cow then releases from both ends.
fn7 The first signs of charcoal in the fossil record, an indicator for wildfires, don’t appear until around 420 million years ago, when atmospheric oxygen levels first rose above 13 per cent.49
fn8 However, iridium is over a thousand times more common in asteroids, which were too small to undergo this differentiation process into iron core and silicon-rich mantle and crust. High concentrations of iridium in the thin clay layer around the world that marks the boundary between the Cretaceous and Palaeogene geological periods is therefore one of the strongest pieces of evidence that an asteroid or comet impacted the Earth 66 million years ago, at the time of the ‘dinosaur-killer’ mass extinction.
fn9 The name platinum comes from the Spanish for ‘little silver’. Platinum has a long history of being formed into ornaments by pre-Columbian South Ameri
can natives – the metal can be found among river-bed sand in Ecuador and Colombia – before it was first brought back to Europe by a Spanish military commander.56
fn10 Although not a metal, helium is also highlighted as being critically endangered. Helium is used not only for filling party balloons, but in ultra-cold liquid form serves to chill the superconducting magnets used in MRI scanners in hospitals, or in science labs around the world. Helium is actually the second most abundant element in the universe, but because it is such a light gas its atoms readily escape from the Earth’s atmosphere and into space (whereas the powerful gravity of the gas giant planets Jupiter and Saturn holds on to a substantial fraction of helium in their atmospheres). Helium on Earth is produced deep underground. When radioactive elements like uranium decay they release a form of radiation called alpha particles, which are just the nuclei of helium atoms. This helium becomes trapped underground by the same geological conditions as natural gas (itself formed in the same process as oil, as we’ll see in Chapter 9), and so most helium is commercially extracted from natural gas production. In this way, not only is helium gas mined from deep underground, but the floating balloons at a children’s birthday party are filled with atoms that were once fast-moving radiation particles.
fn11 Another particularly intriguing suggestion has been put forward for supplementing the supply of platinum group metals from naturally forming rocks. The lighter PGM elements – ruthenium, rhodium and palladium – are created in significant amounts as by-products from the atom-splitting of uranium in nuclear reactors, and could be economically extracted from the spent fuel rods. This represents real-life alchemy – transmuting one element into another – although not through the discovery of a philosopher’s stone but using means that would be beyond the comprehension of the alchemists of history: the atom-morphing reactions of nuclear fission.71
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