Ciencia
Science Illustrated

Science Illustrated May-Jun-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
Periodicidad:
One-off
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1 min.
rescuing the rescuers

Off the coast of Banks Island in the Canadian arctic, archaeologists have found the wreck of HMS Investigator, a British naval vessel abandoned at sea in 1853. Using sonar, a Canadian research team from Parks Canada found the wreck last summer in Mercy Bay, just east of the Beaufort Sea. The surprisingly intact hull lay on the bottom at a depth of about 36 feet. Most of the year, Mercy Bay is frozen over, and these frigid conditions may have helped to preserve the Investigator, in part because the cold, dark water is inhospitable to organisms that could degrade it. The ship, under the command of Captain Robert McClure, left England in 1850 to search for the Erebus and the Terror. The two vessels were carrying John Franklin's polar expedition, which…

2 min.
aurora shapes

QWhat is an aurora? AThese multihued curtains of light appear in the sky when particles in the Earth's magnetic field, energized by solar wind, collide with atmospheric molecules. The phenomenon, also known as the Northern and Southern Lights, is named after Aurora, the Greco-Roman personification of dawn, whose appearance is thought to have resembled the reddish glow of the lights. The sun is constantly emitting energetic particles, which are then whisked through space in the form of solar wind. When the wind hits the Earth's magnetic field, some solar particles are absorbed and transfer their energy to any other particles already present in the magnetic field. Auroras appear most frequently over the Earth's poles, 60 and 70 degrees north and south latitude, where the magnetic field bends inward. This curvature essentially funnels the…

1 min.
hormones and signaling molecules control follicle cycles

QWhy doesn't hair grow uniformly on the body? AEver wonder why your eyebrows don't grow as long as the hair on your head? In recent years, researchers have mapped a series of complex interactions between signaling molecules, hormones and follicles that affect how a human's five million hairs grow. But hair growth—particularly the mechanisms that drive the process—is still poorly understood. Signaling molecules program each hair follicle to either let a hair grow (anagen phase), stop its growth (catagen phase), or rest (telogen phase). The length of a hair depends on how long its anagen phase lasts, which can range from many years for a hair on your scalp to just a few months for eyebrow hairs. Female sex hormones, such as estrogen, prolong the duration of the anagen period for scalp…

8 min.
flares and ejections

The winter of early 2010 was an unusually cold one for much of Europe. Cities across the continent experienced heavy snowfall and record low temperatures. Airports and train stations shut down and roads were closed, leaving thousands of travelers stranded, sometimes for days. Crops froze, threatening the region's food supply. Hundreds of people died from the freezing temperatures. Recent research suggests that magnetic activity on the sun might have been behind the cold snap. Some of the sun's effects on our planet—disruptions in telecommunications caused by solar flares, for example—are well known, but the mechanisms that connect sunspots and weather have only recently been elucidated. As researchers continue to investigate how solar activity affects conditions on Earth, they are expanding our understanding of the planet's climate. Like the Earth, the sun has…

1 min.
cloud cover

The sun has a significant influence on the Earth's climate. But it's not the only thing climate researchers have to consider when constructing models. Several factors on Earth affect the climate as well: Masses of clouds increase the Earth's albedo, its ability to reflect sunlight back into space, and can cause cooling. Ocean Currents Warm and cool water and, by extension, warm and cool air masses are transported around the globe, in part, by ocean currents. Volcanic Eruptions When eruptions shoot ash into the atmosphere, more sunlight is reflected back out into space, which briefly cools the planet. Industry Soot and ash from factories can have the same effect as volcanic eruptions, but the greenhouse gases from man-made pollution cause temperatures to rise. Plant Life Fields reflect more sunlight than forests, but forests absorb more carbon.…

7 min.
historical evidence

Schools of female beluga sturgeon, their bodies swollen with eggs, swim up the Volga River from the Caspian Sea to seek out their spawning grounds. They lay their eggs on the pebbly river bottom before crowds of males arrive. The fertilized eggs later hatch into miniature sturgeon that may eventually make their way back to the Caspian Sea. Unfortunately, this pristine image no longer exists. Construction of the Volgograd dam on the river in 1955 blocked the fish from their spawning grounds. The sturgeon now found in the Volga originated in hatcheries and were dumped into the river in an effort to restore the population. It hasn't been enough. Between 1961 and 2002, the number of the fish entering the Volga—once the caviar industry's most productive river—fell by 89 percent. The total…