The History of the Pencil
The story of the pencil began with a lightning strike. Graphite, the main material used to produce pencils, was discovered in 1564 in Borrowdale, England, when lightning struck a local tree during a thunderstorm. Local people found that the black substance at the roots of the damaged tree was different from the ash of burnt wood. It was soft and therefore left marks everywhere. Chemistry was barely out of its infancy at the time, so people mistook it for lead, which was equally black but much heavier. It was soon put to use by local people to mark their sheep for ownership and calculation.
Britain proved to be a major country where graphite mines could be found and developed. Even so, the first pencil was invented elsewhere. As graphite is soft, it requires some form of encasement. In Italy, graphite sticks were initially wrapped in string or sheepskin for stability, becoming perhaps the very first pencil in the world. Later in the sixteenth century, an Italian couple made what were probably the first blueprints for the modern wood-encased carpentry pencil. Their version was a flat, oval and more compact type of pencil. Their concept involved hollowing out a stick of juniper wood. Shortly afterwards, in 1662, a superior technique was developed in Germany: two wooden halves were carved, a graphite stick was inserted, and the halves were then glued together—essentially the same method that is used to this day. News of the usefulness of these early pencils spread far and wide, attracting the attention of artists throughout the known world.
Although the graphite core in pencils is still referred to as lead, modern pencils do not contain lead, because the ‘lead’ of a pencil is actually a mixture of finely ground graphite and clay powders. This mixture is important because the amount of clay added to the graphite determines the intended hardness of the pencil, while the amount of time spent grinding the mixture determines the quality of the lead. The more clay that is added, the harder the pencil core becomes. Many pencils across the world, and almost all those in Europe, are graded according to the European system. This system uses B for black and H for hard. A pencil's grade is described by a sequence of successive Hs or Bs, such as BB and BBB for increasingly softer leads, and HH and HHH for increasingly harder ones. The standard writing pencil is graded HB.
In England, pencils continue to be made from whole sawn graphite. With the mass production of pencils, however, they became increasingly popular in many countries with each passing decade. As demand rose, the demand for graphite also soared.
According to the United States Geological Survey, world production of natural graphite in 2012 was 1,100,000 tonnes, with the major producers including China, India, Brazil, North Korea and Canada. In marked contrast to its use in pencils, graphite was also widely used for military purposes. During the reign of Elizabeth I, Borrowdale graphite was used as a refractory material to line moulds for cannonballs, resulting in rounder and smoother balls that could be fired farther and thereby contributing to the strength of the English navy. This particular deposit of graphite was extremely pure and soft and could easily be broken into sticks. Because of its military importance, this unique mine and its production were strictly controlled by the Crown.
The claim that the United States avoided pencils in space until it had spent $1,000 developing a zero-gravity writing instrument is fictional. Russian cosmonauts initially used grease pencils, which did not suffer from broken graphite tips. American astronauts also used pencils in space before a reliable pressurised space pen became available. They preferred mechanical pencils because these produced finer and clearer lines than the smudgy lines left by grease pencils. However, the graphite tips of mechanical pencils frequently broke. A broken piece of graphite floating inside a spacecraft could enter someone's eye or find its way into machinery or electronic equipment, causing an electrical short or other problems. Although a pressurised space pen was eventually developed, American astronauts continued to use mechanical pencils for many years.
Against the backdrop of an increasingly digital world, the future of pencils may seem bleak. In reality, however, pencils remain widely used in classrooms, meeting rooms and art studios. Many different users are likely to continue using them: students for mathematical work, artists for sketching, restaurant staff for recording orders, make-up professionals for applying cosmetics, and architects for producing blueprints. The possibilities seem limitless.
Skyscraper Farming
With a global food crisis predicted, a group of scientists is advocating an innovative alternative to conventional farming that could radically transform the way food is produced.
A Today's environmental scientists are in no doubt that the world's resources of fertile soil are rapidly deteriorating, and that new land for agriculture is becoming ever more sparse. Intensive farming, urbanisation, desertification and sea-level rises are all putting growing pressure on the planet's agricultural land and therefore on food supplies. Currently, 24 per cent of the world's 11.5 billion hectares of cultivated land has already undergone human-induced soil degradation, particularly through erosion, according to a recent study by the UK Government Office for Science.
B The global population is expected to exceed nine billion by 2050—up a third from today's level—and studies suggest that food production will have to go up by 70 per cent if we are to feed all of those new mouths. This means that scientists will have to develop new ways of growing crops if we are to avoid a humanitarian crisis. Indeed, UN Food and Agriculture Organization figures suggest that the number of undernourished people is already growing. And with escalating climate change, crop yields in many areas have been projected to decline.
C With this in mind, some scientists and agricultural experts are advocating an innovative alternative to traditional farming whereby skyscrapers packed with shelf-based systems for growing vegetables on each storey—known as ‘vertical farms’—could hold the key to revolutionising agriculture. Columbia University professor Dickson Despommier claims that vertical farming could boost crop yields many times over. A single 20-storey vertical farm could theoretically feed 50,000 people, according to Despommier. And if the theory translates into reality as proposed, 160 skyscraper-sized vertical farms could feed the entire population of New York City, while 180 would be needed to feed London, 289 to feed Cairo and 302 to feed Kolkata.
D It is a compelling vision, and one that has already been put into practice in Asia, albeit on a smaller scale. ‘But there are problems, such as initial investment and operating costs that are too great,’ says a spokesman for Japan's Ministry of Agriculture, Forestry and Fisheries. Nevertheless, Tokyo-based mushroom producer Hokuto Corporation is a model example of how a vertical farm can be profitable. With 28 vertical mushroom farms operating across the country, it produces some 68,000 tonnes of mushrooms annually. ‘Vertical mushroom farms have more advantages than ground-level farms,’ says Hokuto's Ted Yamanoko. Yamanoko goes on to highlight the relative cost-effectiveness of his organisation's farming practices, together with reduced emissions of greenhouse gases.
E And the impact of vertical farms could extend beyond feeding established urban populations. Despommier sees them as being capable of helping centres of displaced persons—such as refugee camps—in much the same way that Mobile Army Surgical Hospital units are deployed in emergency situations. ‘Developing an emergency-response system for crop production inside specially constructed modular and highly transportable greenhouses would allow for humanitarian interventions, at least for refugees who are forced out of their countries by political turmoil,’ he says. ‘If you have three or four storeys of food already growing someplace, they could become mobile units that could be picked up by helicopters and dropped into the middle of a crisis zone. The food would be ready to pick and eat. It could be designed to supply people with all the nutrition they need to make it through the crisis.’
F But it isn't only about increasing food production. Despommier is concerned about the harm that farming has done to the world's landscape over a relatively short time span, particularly the elimination of hardwood forests. ‘Farming is only 12,000 years old,’ he points out, ‘but it has already caused most of the ecological problems on Earth. Vertical farming would allow us for the first time to feed everyone on Earth and still return land to its original ecological function.’ Natalie Jeremijenko, associate professor at New York University, agrees. ‘The challenge that we have now is how we can design urban agriculture systems that not only reduce food miles, but also improve the world's ecosystems,’ she says. By significantly reducing the amount of land required for food production, vertical farms could help to enrich biodiversity. And according to Jeremijenko, this can, in turn, help to improve the productivity of conventional farms, as the health of agricultural land is often tied to the health of the surrounding ecosystems. Furthermore, vertical farming could dramatically cut the utilisation of fossil fuels and also reduce geopolitical tensions in countries where poor farming conditions cause conflict and malnutrition.
Whale Culture
A Most social scientists stubbornly resist the idea that animals have culture. Even such advanced cetacean mammals as whales and dolphins clearly don't have art, literature, or architecture. But patient observation over many years has begun to reveal behaviours that can only have been learnt from other whales. And that, say whale biologists, constitutes culture.
B So far, humpback and killer whales provide the best evidence of culture in cetaceans, and the song of the male humpback is among the most striking examples. Humpback populations in different oceans sing different songs, but within the same ocean they all stick to the same one. However, during the breeding season the sounds change, as it appears that females are drawn to novel songs. One male might add an extra set of groans; another might drop a series of grunts. Soon all the other males have altered their own rendition to incorporate the changes until they are once again singing the same song. Since this occurs among thousands of whales spread across a vast part of the planet, the change cannot be in response to any factor in the animals' environment. The latest version of the song can be learnt only from other whales—almost certainly by imitation.
C Culture plays an even bigger part in the life of killer whales. Nowhere is this more obvious than along the north-west coast of America, where killer whales are split into two distinct populations—‘residents’ and ‘transients’. They live in the same stretch of water, but they don't mingle. In effect, they belong to two quite separate cultures. Residents live in stable groups, or ‘pods’, made up of two or three mothers and their offspring—perhaps 20 whales in all. Calves stay with their mothers throughout adulthood, and in many years of observation no one has ever seen a whale switch pods. Transients travel in smaller, more changeable groups of between three and six.
D One of the most obvious distinctions between the transient and resident societies is the way they impart information. Killer whales detect prey with a range of echolocating clicks, but converse with a vocabulary of squeaks, whistles and whines. Transients have only a few such calls, and all transient societies share the same ones. Residents have a much more extensive repertoire, and each family group has its own unique and distinctive set of calls. Despite regular interaction between them, each resident pod sticks firmly to its own dialect. Research shows these dialects are maintained for at least 40 years.
E To qualify as part of killer whale culture, dialects must be learnt from other members of the pod. Animals with different dialects share the same waters, so the variations can't be a product of the physical environment. ‘And we can throw out the notion that the dialects are inherited,’ says Lance Barrett-Lennard of the University of British Columbia. He has spent the past seven years analysing DNA from 270 whales. His paternity tests reveal that female killer whales invariably attract mates from outside their own pod—males with a very different dialect. If dialects were programmed by genetics, call patterns from both father and mother would be passed on to the calf. ‘A calf uses the calls of its maternal pod very precisely. There's no input from the father,’ says Barrett-Lennard.
F The question still remains—is this culture? It is, according to Frans de Waal of Emory University in Atlanta, who argues that culture is just another biological adaptation that has evolved in many creatures. One benefit of viewing culture in this way is that you can start to understand how and why it might have arisen in these creatures. Whales have several biological attributes that give them an advantage in social learning. Apart from their advanced mental abilities, they are adept at recognising sounds—ideal for communication in the marine environment. Many species spend years rearing their offspring and live in small, stable, multi-generational societies, a social system that provides ample opportunity for teaching and learning.
G But why have cetaceans evolved the ability to learn from other group members? Experts in whale biology believe that ecological factors and the need to adapt to sudden changes in the environment played a large part in the emergence of culture. Although the ocean is a relatively stable habitat in many ways, it is highly changeable in one crucial respect—the availability of food. One moment there might be a plentiful supply of fish; the next, they have disappeared. When that happens, the past experience of senior members of the group—and the ability to share this knowledge—is a huge asset. The dialects of killer whales allow members of the group to identify each other, enabling them to share information about food hot spots. Among resident killer whales, this also allows females to avoid inbreeding by picking out a mate with a strange dialect from outside their pod, says Barrett-Lennard.
H The importance of sharing information seems to have led to biological changes in at least some species of whale. Female killer whales, like humans, are very unusual in that they live up to a quarter of a century after they have had their last offspring. This only makes sense if they have something useful to give their descendants. And what whale matriarchs offer is the most important thing of all—cultural knowledge, vital for the group's survival, passed directly from one generation to the next.