Ciencia
Science Illustrated

Science Illustrated Nov-Dec-11

Science Illustrated is an upbeat, visually spectacular gateway to cutting-edge science, which covers a tremendous range of subjects: from paleontology to space exploration, and medical breakthroughs to the latest environmental insights. Science Illustrated aims to report on the world of science in a way that's dynamic, engaging and accessible for all.

País:
United States
Idioma:
English
Editor:
Bonnier Corporation
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1 min.
special road with no intersections

Scientists at North Carolina State University say that, in the future, traffic flow should be handled on broad thoroughfares. A large-scale survey has shown that special “superstreets” without intersections produce a much better traffic flow, provide greater capacity and limit accidents. Rather than waiting at a stoplight, drivers wishing to cross or make a left turn from a side street are first required to turn right onto the superstreet and then make a U-turn around a broad median — this method of turning is often referred to as a “Michigan left turn,” due to its frequent use in that state. The concept has been around throughout the United States for at least 20 years as well, but very few studies had examined the streets' effectiveness. The North Carolina State team assessed 13…

2 min.
cold sets the brain at rest

A medically induced coma requires an extreme type of general anesthesia that essentially deactivates the brain, which prevents the patient from being revived or reacting on her own. During an induced coma, cardiac rhythm, blood pressure and breathing are maintained mechanically or with the use of drugs. A patient can be placed in an induced coma with the administration of barbiturate drugs or by lowering the body temperature to around 91 degrees. The purpose of an induced coma is to allow the brain to rest after an injury, such as one that caused the brain to be deprived of oxygen; a blood clot; a blow to the head that caused pressure in the brain to increase; or a chemical imbalance in the nerve cells of the brain resulting from a drug…

1 min.
diamonds also have soft spots

Diamonds are the hardest known mineral in the world, but they can be cut with another diamond. When cutting a diamond with a diamond, it is crucial that the mineral not be equally hard in every direction — if the diamond did not vary in hardness, it would be almost impossible to cut. Diamonds are made of carbon arranged in a perfect crystal grid structure, in which every carbon atom is bound to four other carbon atoms. A diamond crystal belongs to the cubic crystal system, which is the simplest and most symmetrical crystal system. This means that a coordinate system with three equally long axes perpendicular to each other can be imposed into a diamond crystal. The simplest cubic crystal is a cube, and diamonds can actually grow like a…

1 min.
the wind must meet the wing at a certain angle

Almost all airplanes are capable of taking a 360-degree roll or making a loop, but not all of them can fly upside down for very long, as doing so requires a very good engine, a skilled pilot and a special wing profile. For example, if the wing is flat-bottomed with a considerable curve on the top side, the aircraft is not suited for flying upside down. A noninverted airplane stays aloft because the wind meets its wings at what is called the angle of attack at great speed. At this angle, the necessary lift is generated; if an aircraft is to fly upside down, the pilot must see to it that the wind meets the wings at the right angle in this position as well. The plane must also be constructed…

8 min.
scientists were close to giving up

When the Mariner 9 space probe entered into its orbit around Mars in November 1971, it was met with cheers from the control center in California. The probe had been on its way for six months, and it was the first ever to orbit Mars. A month later, hope had turned to dismay. Mars was bathed in the biggest dust storm ever observed, and the cameras caught nothing but a compact blanket of dust. In December, as the storm began to wane, four dark patches emerged. As the atmosphere cleared, scientists realized what they were seeing — four giant craters at the peaks of four volcanoes, each between 40 and 50 miles wide. The largest loomed 17 miles high, nearly three times taller than Mount Everest. It was the first evidence…

3 min.
1960

After 50 years, scientists have learned a lot about Mars, thanks to a multitude of probes and rovers. However, not all missions have been successful. Twice, the Russians attempt to send space probes to Mars. Both fail in the initial phase. 1962 The Soviet Union launches Mars 1, but it falls silent before reaching the planet. 1964 On Nov. 5, NASA launches Mariner 3, which fails. Mariner 4 launches on Nov. 28 and heads to Mars. Days later, the Soviets launch Zond 2 to Mars, but it disappears en route. 1965 In July, Mariner 4 flies by Mars at a distance of 6,200 miles and sends the closest images to date back to Earth. The images reveal a crater-covered surface much like the moon. 1969 Mariner 6 and 7 are launched, and both fly by Mars at a distance…