Human Universe (20 page)

The calculations are preserved as handwritten notes, in the Lunar Module System’s Activation Checklist. This was the checklist Lovell and Haise would have used to fly down to the Moon’s surface. Now useless, Lovell used the waste paper to write down instructions to put the ship on course for Earth. Two hours after they rounded the far side of the Moon, the LM engine fired, following Lovell’s handwritten checklist, increasing the speed of the spacecraft by 860 feet per second and buying them ten precious hours.

The most dramatic rescue in the history of human spaceflight stands as a testament to the brilliance of the three test pilots Lovell, Haise and Swigert, and also to the brilliance of the engineers on the ground who simply knew their stuff. NASA’s Apollo engineers were young by today’s standards; the average age of the team in mission control for the splashdown of Apollo 11 was 28 years old. This is one of the reasons why the United States reaped such a colossal economic reward from its investment in Apollo. The generation of scientists and engineers who worked on and were inspired by Apollo went out into the wider economy and delivered a huge investment return; a series of studies, including one by Chase Econometrics, showed that for every dollar invested in Apollo, at least $6 or $7 was returned as increased GDP growth. This should, of course, be bloody obvious – new knowledge grows GDP – but every generation of politicians seems to require re-educating to understand the difference between spending and investment. And while I’m polemicising, let me say that the usual political argument – that public support is needed for such large investments – is drivel. Firstly, the investment in NASA wasn’t that large, never exceeding 4.5 per cent of the Federal budget throughout the lifetime of Apollo. And secondly, it is a politician’s job to lead from the front. Make the case that investment in knowledge, in pushing the boundaries of human capabilities and exploring all frontiers, both physical and intellectual, is the key to the future wealth, prosperity and security of civilisation. Aspire to be Kennedy, not a hand-wringing apologist for intellectual and technological decline.

The nine Apollo flights to the Moon remain the furthest modern humans have explored beyond the Rift Valley in our 200,000-year history.
Homo sapiens
first left Africa in large numbers 60,000 years ago, so on geological timescales we didn’t hang around. Our ancestors followed waves of earlier hominins.
Homo erectus
were in South East Asia 1.6 million years ago, and half a million years later Neanderthals had colonised Europe and
Homo floresiensis
were in Southern Asia. The details of the migration 60,000 years ago are particularly well understood as a result of the combination of genetic, archaeological and linguistic studies. The precision comes in part from the tracking sequences of mitochondrial DNA, which is passed down from the mother and not shuffled by sex. This makes it relatively stable and easy to track – changes are caused by mutations alone. The most widely accepted interpretation of the data suggests that a small population of between 1000 and 2500 individuals left East Africa 60,000 years ago and moved north across the Red Sea and through Arabia. The group then split, moving into Southern Europe 43,000 years ago, and travelling through India and into Australia on roughly the same timescale. The crossing into North America, via eastern Russia, was probably later, around 15,000 years ago.

These early groups of humans were hunter-gatherers. It has been estimated that the basic social units would have reached a maximum of around 150 individuals. This is known as Dunbar’s number, after the British anthropologist Robin Dunbar, who suggests that the largest social group amongst any given population of primates is related to the size of their brains (specifically the neocortex). Dunbar’s number can be observed today in the size of the average person’s social network, both in the real world and online; our hardware – the brain – has not changed appreciably since the first humans appeared in Africa 200,000 years ago. These social groups would have lived in loosely bound tribes, perhaps reaching a size of between one and two thousand individuals, operating within an area of around 100 kilometres. Populations would stabilise, perhaps in response to social factors, but also as a result of increased mortality rates caused by parasitic diseases and diminishing per-capita resource availability, before fragmenting and spreading. In this fashion, the rate of progression of our ancestors across the globe has been estimated to have been around 0.5 kilometres per year, or 15 kilometres per generation. Population density did not rise significantly beyond these levels until these proto-societies shifted from a hunter-gatherer lifestyle to agriculture around 12,000 years ago. This shift was the trigger for the development of civilisation: the most important single step, following the migration out of Africa, in the journey from apeman to spaceman.

There are many competing theories as to the reason for the domestication of crops, but many note the correlation between the first evidence of agriculture and the beginning of the current inter-glacial period known as the Holocene, 12,000 years ago. In the fertile crescent around modern-day Jordan and Syria, people known as the Natufians were beginning to settle into larger communities, perhaps because of the relatively benign climate. The area would have been forested and rich in wild cereals, fruits and nuts, rather than the austere desert of today. One theory is that a brief 1000-year cold period known as the Younger Dryas, beginning around 10,800
BCE
, triggered drier conditions in the region, forcing the Natufians to begin cultivating the previously abundant wild crops on which they had come to rely. Whatever the reason, it is generally agreed that the foundational crops of modern agriculture, including wheat, barley, peas and lentils, were all to be found in the Fertile Crescent by 9000
BCE
, and by 8000
BCE
the banks of the Nile were being cultivated.

At approximately the same time, evidence of farming can be found in Asia’s Indus Valley, in China and in Mesoamerica. This suggests that there was no single environmental or developmental cause for agriculture, because it appeared independently at many sites across the world. Rather, our large brains and relatively large social groups were ready to take up the challenge when the need arose.

Once agriculture was established, larger numbers of people could live together, taking advantage of the more stable food supply. The freedom from continual hunting and gathering would have introduced a new aspect to human life – free time – and it was used to great effect. Some of the earliest farmers settled in a place known as Beidha in modern-day Jordan around 7000
BCE
. Living in round, stone-built houses, they grew barley and wheat and kept domesticated goats, engaged in ritual and ceremony and buried their dead. Importantly, each of these activities was carried out in specific areas of the settlements: the beginning of ‘town planning’. By the second century
BCE
a Semitic people known as the Nabataeans lived around Beidha. They employed new technologies to increase the reliability of farming and constructed walled agricultural terraces on the hillsides around the village to collect and store water. Animal husbandry was also expanding, with the domestication of cows, pigs, donkeys and horses. Even previously dangerous animals were coerced into living with humans; there is evidence that the Nabataeans kept dogs. As the great empires of Egypt, Greece and Rome prospered, the Nabataeans remained partially nomadic, driving their camel trains across the desert along the long-established trade routes between North Africa and India and the great cities of the Mediterranean. But then, around 150
BCE
, they decided to try something different. A few kilometres south of Beidha, in a narrow gorge naturally formed in the soft sandstone rock, they built the city of Petra.

Today tourists stream through a magnificent passageway lined with buildings carved out of the desert rocks and known as the Siq, but 2000 years ago the great and good of Mesopotamia, Rome and Egypt would have walked this route into this jewel of late antiquity.

The grandeur of the buildings is still overwhelming; they stand not as great architecture for their time, but as simply great, with no caveat. The most famous is called Al Khazneh, which means ‘Treasure Box’, because of the carved urn above the entrance which, Bedouin legend has it, contains the treasure of a Pharaoh. Monumental architecture is a common feature in the rise of human civilisation. It is a statement of power and grandeur to impress and cow outsiders, but it also serves an internal purpose, cementing the position of the rulers in the hierarchy and therefore providing the stability and security on which civilisation rests. Over time, a virtuous circle emerges: the buildings help the civilisation prosper, and the more prosperous the civilisation, the more impressive the buildings become.

Petra’s wealth was derived from its location. Built within a natural gorge, the area is prone to flash floods, which provided precious water in a landscape that was arid by the time the Nabataeans began to build. The city also sits at the fulcrum of the ancient nomadic trade routes along which wood, spices, incense and dyes were transported from Africa and India and into the great Mediterranean civilisation beyond. The appetite of the Greeks and Romans for exotic goods was insatiable; black pepper alone fetched 40 times its own weight in gold in a Roman market. Petra, because of its strategic location, controlled all that trade and taxed it. Today, 1500 years after the city was abandoned, it is still a magnificent site – an overused but entirely accurate statement. Talk to an archaeologist, however, and you quickly realise how much more impressive it would have been in its hey-day. The hillsides running down the valley from the carved tombs are scattered with rocks, but closer inspection reveals them to be bricks, the remains of houses, temples and palaces. Everything from Al Khazneh to the houses would have been covered in white plaster and painted in bright colours which would have appeared resplendent against the monochrome desert sands.

To build on this scale required a huge labour force; Petra was home to at least thirty thousand people living in a few square kilometres of desert. Such a population density required technological innovation on a metropolitan scale, and the Nabataeans, perhaps more than any other civilisation in antiquity, were masters of fluid engineering. Virtually every drop of rainwater that fell on the surrounding hillsides was captured in grooves and stored in giant reservoirs and cisterns. They were better at plumbing than the Romans, who employed the Petran engineers in Rome. Petra had the world’s first pressurised water system, which could deliver 12 million gallons of water a day into the city.

Outside the city, the irrigation system continued out into the surrounding fields, lining the hillsides in still-visible terraces; the Nabataeans didn’t simply build a city, they terra-formed a landscape. I stood and imagined the ancient valley views with some awe; the mountain slopes would have been green with maize, barley, pulses and vineyards – a desert turned green and feeding this grandest of desert civilisations for six centuries. Whenever I see the ruins of Petra, Rome, Athens or Cairo, I wonder what Earth would be like today if the great civilisations of antiquity had not fallen. I blame the philosophers for not discovering the scientific method earlier and inventing the electric motor. How hard can it be?