Tea and Industrial Revolution
A Alan Macfarlane thinks he could rewrite history. The professor of anthropological science at King's College, Cambridge has, like other historians, spent decades trying to understand the enigma of the Industrial Revolution. Why did this particular important event – the world-changing birth of industry – happen in Britain? And why did it happen at the end of the 18th century?
B Macfarlane compares the question to a puzzle. He claims that there were about 20 different factors and all of them needed to be present before the revolution could happen. The chief conditions are to be found in history textbooks. For industry to 'take off', there needed to be the technology and power to drive factories, large urban populations to provide cheap labour easy transport to move goods around, an affluent middle-class willing to buy mass-produced objects, a market-driven economy, and a political system that allowed this to happen. While this was the case for England, other nations, such as Japan, Holland and France also met some of these criteria. All these factors must have been necessary but not sufficient to cause the revolution. Holland had everything except coal, while China also had many of these factors.
C Most historians, however, are convinced that one or two missing factors are needed to solve the puzzle. The missing factors, he proposes, are to be found in every kitchen cupboard. Tea and beer, two of the nation's favorite drinks, drove the revolution. Tannin, the active ingredient in tea, and hops, used in making beer, both contain antiseptic properties. This -plus the fact that both are made with boiled water- helped prevent epidemics of waterborne diseases, such as dysentery, in densely populated urban areas. The theory initially sounds eccentric but his explanation of the detective work that went into his deduction and the fact his case has been strengthened by a favorable appraisal of his research by Roy Porter (distinguished medical historian) the skepticism gives way to wary admiration.
D Historians had noticed one interesting factor around the mid-18th century that required explanation. Between about 1650 and 1740, the population was static. But then there was a burst in population. The infant mortality rate halved in the space of 20 years, and this happened in both rural areas and cities, and across all classes. Four possible causes have been suggested. There could have been a sudden change in the viruses and bacteria present at that time, but this is unlikely. Was there a revolution in medical science? But this was a century before Lister introduced antiseptic surgery. Was there a change in environmental conditions? There were improvements in agriculture that wiped out malaria, but these were small gains. Sanitation did not become widespread until the 19th century. The only option left was food. But the height and weight statistics show a decline. So the food got worse. Efforts to explain this sudden reduction in child deaths appeared to draw a blank.
E This population burst seemed to happen at just the right time to provide labor for the Industrial Revolution. But why? When the Industrial Revolution started, it was economically efficient to have people crowded together forming towns and cities. But with crowded living conditions comes disease, particularly from human waste. Some research in the historical records revealed that there was a change in the incidence of waterborne disease at that time, the English were protected by the strong antibacterial agent in hops, which were added to make beer last. But in the late 17th century a tax was introduced on malt. The poor turned to water and gin, and in the 1720s the mortality rate began to rise again.
F Macfarlane looked to Japan, which was also developing large cities about the same time, and also had no sanitation. Waterborne diseases in the Japanese population were far fewer than those in Britain. Could it be the prevalence of tea in their culture? That was when Macfarlane thought about the role of tea in Britain. The history of tea in Britain provided an extraordinary coincidence of dates. Tea was relatively expensive until Britain started direct trade with China in the early 18th century. By the 1740s, about the time that infant mortality was falling, the drink was common. Macfarlane guesses that the fact that water had to be boiled, together with the stomach-purifying properties of tea so eloquently described in Buddhist texts, meant that the breast milk provided by mothers was healthier than it had ever been. No other European nation drank tea so often as the British, which, by Macfarlane's logic, pushed the other nations out of the race for the Industrial Revolution.
G But, if tea is a factor in the puzzle, why didn't this cause an industrial revolution in Japan? Macfarlane notes that in the 17th century, Japan had large cities, high literacy rates and even a futures market. However, Japan decided against a work-based revolution, by giving up labor-saving devices even animals, to avoid putting people out of work. Astonishingly, the nation that we now think of as one of the most technologically advanced, entered the 19th century having almost abandoned the wheel. While Britain was undergoing the Industrial Revolution, Macfarlane notes wryly, Japan was undergoing an industrious one.
Being Left-handed in a Right-handed World
The world is designed for right-handed people. Why does a tenth of the population prefer the left?
Section A
The probability that two right-handed people would have a left-handed child is only about 9.5 percent. The chance rises to 19.5 percent if one parent is a lefty and 26 percent if both parents are left-handed. The preference, however, could also stem from an infant's imitation of his parents. To test genetic influence, starting in the 1970s British biologist Marian Annett of the University of Leicester hypothesized that no single gene determines handedness. Rather, during fetal development, a certain molecular factor helps to strengthen the brain's left hemisphere, which increases the probability that the right hand will be dominant, because the left side of the brain controls the right side of the body, and vice versa. Among the minority of people who lack this factor, handedness develops entirely by chance.
Research conducted on twins complicates the theory, however. One in five sets of identical twins involves one right-handed and one left-handed person, despite the fact that their genetic material is the same. Genes, therefore, are not solely responsible for handedness.
Section B
The genetic theory is also undermined by results from Peter Hepper and his team at Queen's University in Belfast, Ireland. In 2004 the psychologists used ultrasound to show that by the 15th week of pregnancy, fetuses already have a preference as to which thumb they suck. In most cases, the preference continued after birth. At 15 weeks, though, the brain does not yet have control over the body's limbs. Hepper speculates that fetuses tend to prefer whichever side of the body is developing quicker and that their movements, in turn, influence the brain's development. Whether this early preference is temporary or holds up throughout development and infancy is unknown.
Genetic predetermination is also contradicted by the widespread observation that children do not settle on either their right or left hand until they are two or three years old.
Section C
But even if these correlations were true, they did not explain what actually causes left-handedness. Furthermore, specialization on either side of the body is common among animals. Cats will favor one paw over another when fishing toys out from under the couch. Horses stomp more frequently with one hoof than the other. Certain crabs motion predominantly with the left or right claw. In evolutionary terms, focusing power and dexterity in one limb is more efficient than having to train two, four or even eight limbs equally. Yet for most animals, the preference for one side or the other is seemingly random. The overwhelming dominance of the right hand is associated only with humans. That fact directs attention toward the brain's two hemispheres and perhaps toward language.
Section D
Interest in hemispheres dates back to at least 1836. That year, at a medical conference, French physician Marc Dax reported on an unusual commonality among his patients. During his many years as a country doctor, Dax had encountered more than 40 men and women for whom speech was difficult, the result of some kind of brain damage. What was unique was that every individual suffered damage to the left side of the brain. At the conference, Dax elaborated on his theory, stating that each half of the brain was responsible for certain functions and that the left hemisphere controlled speech. Other experts showed little interest in the Frenchman's ideas.
Over time, however, scientists found more and more evidence of people experiencing speech difficulties following injury to the left brain. Patients with damage to the right hemisphere most often displayed disruptions in perception or concentration. Major advancements in understanding the brain's asymmetry were made in the 1960s as a result of so-called split-brain surgery, developed to help patients with epilepsy. During this operation, doctors severed the corpus callosum—the nerve bundle that connects the two hemispheres. The surgical cut also stopped almost all normal communication between the two hemispheres, which offered researchers the opportunity to investigate each side's activity.
Section E
In 1949 neurosurgeon Juhn Wada devised the first test to provide access to the brain's functional organization of language. By injecting an anaesthetic into the right or left carotid artery, Wada temporarily paralyzed one side of a healthy brain, enabling him to more closely study the other side's capabilities. Based on this approach, Brenda Milner and the late Theodore Rasmussen of the Montreal Neurological Institute published a major study in 1975 that confirmed the theory that country doctor Dax had formulated nearly 140 years earlier: in 96 percent of right-handed people, language is processed much more intensely in the left hemisphere. The correlation is not as clear in lefties, however. For two thirds of them, the left hemisphere is still the most active language processor. But for the remaining third, either the right side is dominant or both sides work equally, controlling different language functions.
That last statistic has slowed acceptance of the notion that the predominance of right-handedness is driven by left-hemisphere dominance in language processing. It is not at all clear why language control should somehow have dragged the control of body movement with it. Some experts think one reason the left hemisphere reigns over language is because the organs of speech processing—the larynx and tongue—are positioned on the body's symmetry axis. Because these structures were centred, it may have been unclear, in evolutionary terms, which side of the brain should control them, and it seems unlikely that shared operation would result in smooth motor activity.
Language and handedness could have developed preferentially for very different reasons as well. For example, some researchers, including evolutionary psychologist Michael C. Corballis of the University of Auckland in New Zealand, think that the origin of human speech lies in gestures. Gestures predated words and helped language emerge. If the left hemisphere began to dominate speech, it would have dominated gestures, too, and because the left brain controls the right side of the body, the right hand developed more strongly.
Section F
Perhaps we will know more soon. In the meantime, we can revel in what, if any, differences handedness brings to our human talents. Popular wisdom says right-handed, left-brained people excel at logical, analytical thinking. Left-handed, right-brained individuals are thought to possess more creative skills and may be better at combining the functional features emergent in both sides of the brain. Yet some neuroscientists see such claims as pure speculation. Fewer scientists are ready to claim that left-handedness means greater creative potential. Yet lefties are prevalent among artists, composers and the generally acknowledged great political thinkers. Possibly if these individuals are among the lefties whose language abilities are evenly distributed between hemispheres, the intense interplay required could lead to unusual mental capabilities.
Section G
Or perhaps some lefties become highly creative simply because they must be more clever to get by in our right-handed world. This battle, which begins during the very early stages of childhood, may lay the groundwork for exceptional achievements.
Shoemaker-Levy 9 Collision with Jupiter
A
The last half of July 1994 witnessed much interest among the astronomical community and the wider public in the collision of comet Shoemaker-Levy 9 with Jupiter. The comet was discovered on 25 March 1993 by Eugene and Carolyn Shoemaker and David Levy, using a 450 mm Schmidt camera at the Mount Palomar Observatory. The discovery was based on a photographic plate exposed two days earlier. The Shoemakers are particularly experienced comet hunters with 61 discoveries to their credit. Their technique relied on the proper motion of a comet to identify the object as a non-stellar body. They photograph large areas of the sky, typically with an eight minute exposure, and repeat the photograph 45 minutes later. Comparison of the two photographs with a stereo-microscope reveals any bodies which have moved against the background of fixed stars.
B
As so often in science, serendipity played a large part in the discovery of the Shoemaker-Levy 9. The weather in the night of 23 March was so poor that the observers would not normally have bothered putting film into their camera. However, they had a box of old film to hand which had been partially exposed by accident some days previously, so decided to insert it into the camera rather than waste good film. Fortunately, two of the film plates, despite being fogged round the edges captured the first image of a very strange, bar-shaped object. This object, which Carolyn Shoemaker first described as a squashed comet, later became known as comet Shoemaker-Levy 9.
C
Other, more powerful, telescopes revealed that the comet was in fact composed of 21 cemetery fragments, strung out in a line, which accounted for the unusual shape. The term string of pearls was soon coined. Some graphic proofs obtained by the Hubble Space Telescope shows the main fragments which at that time spanned a linear distance of approximately 600,000 km. Initially the fragments were surrounded by extensive dust clouds in the line of the nuclei but these later disappeared. Some of the nuclei also faded out, while others split into multiple fragments.
D
The size of the original comet and each of the fragments was, and still is, something of a mystery. The first analysis of the orbital dynamics of the fragments suggested that the comet was originally some 2.5 km in diameter with an average fragment diameter of 0.75 km. Later work gave corresponding diameters of approximately 10 km and 2 km and these values are now considered more likely. There was considerable variation in the diameters of different fragments.
E
Further calculations revealed that the cemetery fragments were on course to collide with Jupiter during July 1994, and that each fragment could deliver an energy equivalent to approximately 500,000 million tons of TNT. The prospect of celestial fireworks on such a grand scale immediately captured the attention of astronomers worldwide!
F
Each fragment was assigned an identity letter A-W and a coordinated program of observations was put in place worldwide to track their progress towards impact with Jupiter. As the cemetery fragments reached the cloud tops of Jupiter, they were travelling at approximately 30,000,000 km. The impacts occurred during 16-22 July. All took place at a latitude of approximately 48 degrees south which nominally placed them in the SSS Temperate Region, however visually they appeared close to the Jovian polar region. The impacts all occurred some 10-15 degrees round the limb in the far side of the planet as seen from Earth. However the rapid rotation of the planet soon carried the impact sites into the view of Earth-based telescopes. The collisions lived up to all but the wildest expectations and provided a truly impressive spectacle.
G
Jupiter is composed of a relatively small core of iron and silicates surrounded by hydrogen. In the depths of the planet the hydrogen is so compressed that it is metallic in form; further from the center, the pressure is lower and the hydrogen is in its normal molecular form. The Jovian cloud tops visible from Earth consist primarily of methane and ammonia. There are other elements and compounds lurking in the cloud tops and below which are thought to be responsible for the colors seen in the atmosphere.
H
The smaller cemetery fragments plunged into Jupiter, rapidly disintegrated and left little trace; three of the smallest fragments, namely T, U and V left no discernible traces whatsoever. However, many of the cemetery fragments were sufficiently large to produce a spectacular display. Each large fragment punched through the cloud tops, heated the surrounding gases to some 20,000 K on the way, and caused a massive plume or fireball up to 2,000 km in diameter to rise above the cloud tops. Before encountering thicker layers of the atmosphere and disintegrating in a mammoth shock wave, the large fragments raised dark dust particles and ultra violet absorbing gases high into the Jovian cloud tops. The dark particles and ultra violet absorbing gases manifested themselves as a dark scar surrounding the impact site in visible light.
I
Somedays after collision the impact sites began to evolve and fade as they became subject to the dynamics of Jupiter's atmosphere. No one knows how long they will remain visible from Earth, but it is thought that the larger scars may persist for a year or more. The interest of professional astronomers in Jupiter is now waning and valuable work can therefore be performed by amateurs in tracking the evolution of the collision scars. The scars are easily visible in a modest telescope, and a large reflector will show them in some detail. There is scope for valuable observing work from now until Jupiter reaches conjunction with the Sun in November 2004.
J
Astronomers and archivists are now searching old records for possible previously unrecognized impacts on Jupiter. Several spots were reported from 1690 to 1872 by observers including William Herschel and Giovanni Cassini. The records of the BAA in 1927 and 1948 contain drawings of Jupiter with black dots or spots visible. It may be possible that comet impacts have been observed before, without their identity being realized, but no one can be sure.
