Tabla de contenidos para May-Jun-12 en Science Illustrated

In shoals, the individual fish constantly move and yet remain close to each other. The fish are in close sensorial contact and react quickly, which allows them to adjust to even slight changes of direction by the other fish. Vision is probably the most important sense that shoaling fish use, but their sideline organ is also important — it helps them register each other's movements and adapt to any changes. Collisions in fish shoals can't be avoided, but for the individual fish, this is a secondary concern to remaining in the shoal, which reduces the individual's risk during predator attacks. For periods of their lives, most fish swim together with peers in larger or smaller groups. Often, the groups are only loosely linked, but in approximately half of all bony…

It comes as no surprise to learn that the world's fastest computer (by far) takes up a large hall, or that its name is derived from the Japanese word kei, which means 10 quadrillion. On Nov. 2, 2011, K made 10 million billion calculations a second; equally impressive, during a test run that lasted 29 hours, its 88,128 processors did not register a single failure. With a capacity of 10.51 petaflops, K is already faster than the five next computers on the top 10 list combined. Its power consumption exceeds 10 million watts. That's quite a lot, but considering its capacity, K is actually one of the most efficient supercomputers. K will be used in many branches of research to do a number of different things, such as developing new…

After the latest ice age, most of the period's large land mammals became extinct. It was one of the most extreme examples of mass extinction on Earth, when one species after another — the woolly mammoth and woolly rhinoceros, among others — slowly disappeared. No one knows exactly what happened. But for a century, scientists have debated the cause intensely. Some point to the severe climate change, while others think the massive population decrease had to do with modern man. There are also theories of a fast killer, such as an ultracontagious disease or a cosmic disaster, such as a meteor or asteroid strike like the one that killed the dinosaurs 65 million years ago. The answer may soon be quite relevant, as some fear the same thing could happen…

Archaeological excavations in China reveal a primitive loom that may have been used in silk production. The first known record of silk production in China using the domesticated silkworm, Bombyx mori. Around this time, a legend arises that silk was “discovered” by a Chinese empress when a silkworm cocoon fell into her tea and unraveled when she pulled it out. The Silk Road — a network of trade routes originating in China that transport many “exotic” goods to Europe — reaches the West. Silk production begins in India. Silk reaches Rome for the first time. Silk is produced in Constantinople. Legend has it that monks smuggled silkworms here from China. Silk begins to flourish in Europe, especially in Italy and France. Scientists from Tufts University make the first reconstituted silk.…

Wounded zebra is brought down by lions The thermal camera reveals an inflamed and swollen area on the zebra's right foreleg. It's probably the same individual the photographer observed earlier, limping around with its herd. The lions may have found the wounded animal by listening for its uneven hoofbeats. Vigilant predators warm up for a night of drama Beneath a moonless sky on the vast Maasai Mara plains, a group of lions (background) moves around unseen a few yards from grazing zebras and wildebeests. The latter's night vision is especially poor, so the lions have plenty of time to select their prey. Herd on the defensive These eight wildebeests seem serene against the starry sky. But in reality, the animals have sensed a presence nearby and have gathered to be…

1 Divide this figure by two straight lines, leaving three identical parts. 2 Complete the figure. Every row, column and color must contain numbers 1–6. 3 Look carefully at the figure to the left. You must land on each of the colored squares once and end your journey on the red X. Navigate from square to square by following the numbers and letters on the squares. The numbers tell you how many squares to move to find the next square in the sequence, and the letters tell you in which direction to move. D = down U = up R = right L = left On which square must you start? 4 Use the pieces to form a rectangle of 8 x 13 squares. Headbreakers: Problem 1: Problem 2: Problem…

More than 500 years ago, a woman sat for a painter. The painter was Leonardo da Vinci, and his portrait of her, called Mona Lisa, became world famous — but the model's name did not. Now, Italian archaeologists searching for her grave in an abandoned convent in Florence have unearthed a skeleton beneath the floor that just may help them solve one of art history's greatest mysteries. Mona Lisa is a man. Or a princess. Or perhaps a prostitute, a transvestite or Renaissance genius Leonardo da Vinci's own mother. The world-famous painting, one of the greatest attractions at the Louvre (which is itself one of France's greatest attractions), could also be a self-portrait. Or perhaps the subject is not a real person at all, but simply the product of the…

What would happen if an earthquake that measured 8.0 on the Richter scale shook Southern California for six minutes? Scientists now know, thanks to America's Jaguar supercomputer. The powerful computer calculated geological data over a 24-hour period, resulting in the most precise simulation of an earthquake to date. In fact, since it was put into service in 2005, the Tennessee-based Jaguar has been very useful to a number of scientific causes. It's been used to simulate how blood flows through our blood vessels by calculating the way 260 million red blood cells interact with blood plasma; it has also calculated how hydrogen will fuse into helium in future fusion power plants. It's also been employed in the study of how hurricanes develop and in modeling change in the global climate…

A simple change to the way the silkworm cocoon is processed makes silk more flexible, paving the way for new applications in medicine and technology. The groundbreaking research that led to this finding was conducted at Tufts University in Massachusetts by a team led by biomedical engineering professor David Kaplan. The new silk-processing method, which was developed in 2005, imitates the way silk is composed in nature. Before it's spun by a silkworm, silk exists in the silk gland in a liquid, not a hardened, state. By slowly liquefying the contents of a silkworm cocoon in a humid environment, scientists have improved on nature by creating a “supermaterial” that can produce durable silk films and a range of other silk-based materials. These in turn could be used in such diverse…

More than 125 years have passed since the first gasoline-powered car appeared; today, there are more than 1 billion cars on Earth. Cars have made us more mobile than ever before — but they've also caused traffic jams, pollution and accidents. Since 1960, the number of vehicles on the planet has sextupled, and it will keep increasing along with the middle class in countries such as China and India. 2030 2,080,000,000 2010 1,000,000,000 2002 812,000,000 1990 650,000,000 1960 122,000,000 1 billion Counting all types (including pickup trucks, minibuses, etc.), there are now just over 1 billion cars in the world. One of the most noticeable Beetle changes came in 1957, when the windscreen grew 17% and the rear window 95%. 30 million is the number of roadside-assistance calls that AAA…

Scientists at Tulane University in New Orleans have discovered a promising new source for the creation of butanol, an excellent biofuel for internal combustion engines. They fed a newly discovered bacterium wet newspapers that had been processed in a blender. The bacterium ate the fibers and converted them to butanol. Finding this special microbe, called TU-103, was no easy feat for the scientists: To isolate it, they had to go through a truckload of droppings from New Orleans' Audubon Zoo. “We searched through the droppings of several zoo animals that eat grass, including giraffes, elephants, zebras and others,” says David Mullin, a molecular biologist at Tulane. The zebra droppings proved a success. “We managed to isolate a collection of butanol-producing bacterial strains, [of which] TU-103 is one member. We decided…

Every computer contains a processor, which makes calculations. In many new computers, two or more calculation units are integrated into one microchip, resulting in a processor with several cores. Supercomputers are systems in which many powerful computers — each with several processors, all of which have many cores, or calculation units — are connected. (The world's fastest supercomputer has 705,024 cores.) The cores contain a few gigabytes of memory each, in which they continuously store calculations, so that everything is saved and can be retrieved if an error occurs. Liquid from a cooling tower keeps the system from overheating. 1 K COMPUTER 2 TIANHE-1A 3 JAGUAR 4 NEBULAE 5 TSUBAME 2.0 6 CIELO 7 PLEIADES 8 HOPPER 9 TERA 100 10 ROADRUNNER…

By mapping all bacteria species in the intestines of many people of different nationalities, scientists have discovered three different intestinal types. Every one of us has one of the three types, and it has nothing to do with nationality or ethnicity. Each of the three types is dominated by one bacterium — Bacteroides, Prevotella, or Ruminococcus — and each has special characteristics that may influence our individual metabolism and health. Whenever you feel lonely, think about the trillions of bacteria moving about your guts and the fact that they outnumber your own cells by far. There may be more than 1,000 different species of intestinal bacteria, which constitute more than 2 pounds of your body weight. Consequently, the human intestine is one of the most complex, species-rich ecosystems in nature.…

With the invention of reconstituted silk, this natural material has undergone a renaissance. The new form of silk is superior in several ways to the materials typically used and can now be applied in a series of innovative ways. In the future, metamaterials made of silk will be able to make organs invisible, allowing doctors to see things hiding deep inside the body. Silk film's special ability to contour precisely to a given surface without harming living tissue makes it especially well suited to this purpose. A metamaterial made of silk film with a specially created surface can conduct electromagnetic radiation around the encapsulated organ, rendering it invisible. Doctors will be able to see problems in tissue or other organs behind it, so they won't have to move the organ…

Often hiding behind a deceptive facade of superficial charm and affability, psychopaths will strive to satisfy their own needs, even to the point of not caring about either the consequences or the most basic rules of social conduct that normal people follow. In fact, an estimated 1 percent of the population suffers such a lack of conscience and ability to empathize with others that they are thought to be psychopaths. After even the most ruthless misdeeds, psychopaths will often defend their actions, blame the victim, or find some other way in which they can claim innocence. But although these individuals would seem to be characterized by a complete lack of empathy, that does not necessarily mean that they are not aware of the consequences of their actions or that they…

1 Complete the figure with jacks (J), queens (Q), kings (K) and aces (A) in all four suits. Every row, column and diagonal must contain a card of each value and suit. 2 What number should go in the empty space? 3 Which symbol should replace the question mark? 4 Express this equation in a simpler way: 5 A Porsche, a Ferrari and a Mercedes came into the repair shop on Monday, Tuesday and Wednesday of last week. One of these cars was red. Using the following clues, determine the color of each car, the day it came in and the work that was done to it. Brain Trainers Page 66 Problem 1: Problem 2: 1. The figure contains a sequence of numbers running clockwise from 1 to 22. With…