Many prehistoric societies constructed stone circles. These were created for various reasons, such as tracking the sun’s movement. The oldest such circle known to scientists can be found at Nabta Playa in Egypt. At around 7,000 years old, this circle predates England’s Stonehenge – probably the world’s best-known prehistoric stone circle by more than 1,000 years. Nabta Playa’s climate is extremely dry today, but this was not always the case. ( 26 ), heavy seasonal rainfall during the period when the circle was built led to the formation of temporary lakes, and these attracted cattle-grazing tribes to the area.
Nabta Playa’s first settlers arrived around 10,000 years ago. Archaeologists have uncovered evidence that these settlers created a system of deep wells that gave them access to water year-round, and that they arranged their homes in straight rows and equipped them with storage spaces. They also practiced a religion that focused on the worship of cattle, which were central to their lives. These discoveries are evidence that the settlers ( 27 ).
Research findings show that some of the circle’s stones would have lined up with the sun on the longest day of the year around 7,000 years ago. This suggests the circle was used as a calendar. One astrophysicist, however, believes the circle ( 28 ). He points out that the positions of other stones match those of stars in the constellation Orion at the time the circle was built. Because of this, he proposes that the circle was an astrological map showing the positions of stars in the night sky.
Beginning in the late nineteenth century, the Good Roads Movement transformed America’s landscape, helping to create the nation’s system of roads and highways. This movement ( 29 ). While most people today assume that the road system was first developed in response to the needs of automobile drivers, this is a myth. Actually, the demand started mainly with cyclists. The invention of the modern bicycle led to a cycling craze in the 1890s, and millions of Americans wanted better, safer roads to cycle on.
Cyclists began pressuring local governments to improve the quality of roads, which were often poorly maintained and dangerous. At first, the movement was resisted by farmers, who did not want their tax dollars to be spent supporting the leisure activities of cyclists from cities. Gradually, however, farmers ( 30 ). One reason for this was an influential pamphlet called The Gospel of Good Roads: A Letter to the American Farmer. It convinced many farmers by emphasizing the benefits of roads, such as making it easier for them to transport their crops to markets.
As automobiles became common, the movement quickly gained momentum. ( 31 ), the invention of the Ford Model T in the early 1900s led to many new drivers, who were also eager for better roads. Millions of these affordable cars were sold, and the increase in drivers put pressure on governments to build more roads and improve the quality of existing ones.
Recognizing Faces
Humans are generally very good at recognizing faces and quickly interpreting their expressions. This is achieved by having specific areas of the brain that specialize in processing facial features. The development of this ability makes sense in terms of evolution, since early humans would have needed to judge, for example, whether those around them were angry and therefore potentially dangerous. One unintended consequence, however, is that people often think they see faces on objects in their environment. People perceive these so-called false faces on a variety of objects, from clouds and tree trunks to pieces of food and electric sockets.
Researchers in Australia recently performed a study to learn more about how the brain processes false faces. Previous studies have revealed that for real faces, people’s judgment of what emotion a face is expressing is affected by the faces they have just seen. Seeing a series of happy faces, for example, tends to make people assess the face they next see as expressing happiness. In the Australian study, the researchers showed participants a series of false faces that expressed a particular emotion. They found that, as with real faces, the participants’ judgments of the emotions expressed by the false faces were affected by the ones they had just been shown. Based on this finding, the researchers concluded that the brain processes false faces in a way similar to how it processes real ones.
The researchers also noted that any object with features that even loosely resemble the layout of a human face two eyes and a nose above a mouth can trigger the brain to assess those features for emotional expression. In other words, the brain’s criteria for recognizing a face are general rather than specific. The researchers say this is one reason the brain can assess facial expressions so quickly.
The football-sized durian fruit is well known for its unpleasant smell and creamy, sweet flesh. Known as the “king of fruits,” durians are believed to have originated in Borneo, but they are now cultivated more widely, with over half of all durians consumed worldwide being grown in Thailand. Durians have long been popular throughout Southeast Asia, but their popularity is now spreading to other parts of the world. There are hundreds of kinds of durians, but the Musang King variety, which is grown almost exclusively in Malaysia, is one of the most highly valued. Durians contain high levels of vitamins, so they are often promoted for their health benefits, which has led to rising exports. In fact, experts predict there will be a 50 percent increase in shipments from Malaysia to China alone during the next decade. In order to take advantage of this situation, many Malaysian farmers have stopped producing crops such as palm oil in favor of producing durians.
Durian trees are not easy to grow, however. They require regular watering and feeding with fertilizer, and they are highly sensitive to temperature. Furthermore, they do not naturally grow in groves, but rather thrive when grown among other trees and shrubs, so growing them in an orchard as a single crop presents a challenge. Ensuring sufficient pollination of the flowers for the trees to produce a good harvest of fruit is a further difficulty for farmers. One characteristic of durian trees is that their flowers only release pollen at night, so insects such as honeybees that feed during the day do not pollinate them. Animals that are active at night take over the role of pollination, but only about 25 percent of a durian tree’s flowers ever get pollinated naturally. Because of this, many farmers resort to the labor-intensive practice of pollinating by hand.
Studies have shown that giant fruit bats are the main natural pollinators of durian flowers. However, these bats are chased away or killed by many farmers, who simply see them as pests because they cause damage and reduce profits by feeding on the fruit. The bats are also threatened as a result of being hunted and sold as food, since there is a belief in some Southeast Asian cultures that eating the bats’ meat helps to cure breathing problems. Without educating people about the benefits of giant fruit bats, the bats’ numbers may decline further, which could have serious consequences for durian farming.
During World War II, the British fought against Germany and Italy in the deserts of North Africa. Desert warfare was characterized by small battles between troops that were widely spread out, and there was a need to move quickly and at night to avoid both detection and the dangerous daytime heat. The area’s vast size and sandy terrain made transporting supplies difficult, and the lack of water severely limited operations.
However, for one British army officer, Major Ralph Bagnold, these harsh conditions presented a strategic opportunity. Having spent years exploring the North African desert before the war, Bagnold knew the terrain well, and he was convinced that a small, highly mobile motorized unit that could observe and track enemy forces would be invaluable. At first, British commanders rejected his proposal to form such a unit, believing airplanes were better suited for such long-range intelligence gathering. Bagnold insisted, however, that gathering information on the ground would be advantageous, and his persistence led to the formation of the Long Range Desert Group (LRDG), with Bagnold as commander, in June 1940.
The LRDG was an unconventional unit from the outset. Usual distinctions between ranks did not apply; officers and regular soldiers were on first-name terms, and they were all expected to perform the same tasks. Rather than seeking men who would fight bravely on the battlefield, Bagnold wanted individuals with great stamina, resourcefulness, and mental toughness men who could, for example, remain motivated and alert for extended periods despite limited access to drinking water. With specialized trucks adapted to desert conditions, the LRDG’s patrols were equipped to operate independently for around three weeks and over a range of more than 1,600 kilometers. All necessary items, such as fuel, ammunition, and food, were carried by the unit, so careful supply planning was extremely important.
The LRDG’s work mainly involved traveling deep behind enemy lines to observe their movements. The unit had access to a range of weaponry, and while the men were primarily trained to gather intelligence, they also planted mines and launched attacks against enemy airfields and fuel depots. When the Special Air Service (SAS) a British army unit formed in 1941 to conduct raids behind enemy lines suffered heavy casualties after parachuting into enemy territory on its first mission, the LRDG was tasked with bringing back the survivors. The rescue mission was a success, and because of its men’s extensive knowledge of the desert, the LRDG was given the responsibility of bringing the SAS to and from all future targets by land, providing both transportation and navigation. This almost certainly helped the SAS accomplish its raids with greater success and fewer casualties.
The LRDG’s greatest achievement came in 1943, when the unit found a route that enabled British forces to get around heavily defended enemy lines without being detected, allowing them to attack at weaker points in the defenses. This was a crucial turning point in the campaign in North Africa and contributed greatly to the British victory there. The LRDG went on to make significant contributions to the war effort in Europe until 1945.
