Nature diary

thonnamkuzhy: Spanish feminists slam female candidate for her nu...

thonnamkuzhy: Spanish feminists slam female candidate for her nu...: "A controversial poster appeared on April 13 in a display at the headquarters of the Democratic Party of Ciutadella on the Spanish island of..."

Scans Show Ancient Heart Disease

Mummy in the Machine

The mummy was among 52 from the Egyptian Museum in Cairo subjected to medical scanning by a joint U.S.-Egyptian team. The tests revealed that almost half of the dead have clogged arteries associated with a condition called atherosclerosis, which can lead to heart attack or stroke.

One of the mummies, a princess who died about 3,500 years ago, is now the oldest known case of the arterial disease, the researchers say.

"If the princess was in a time machine and I was to see her now, I would tell her to lay off the fat, take plenty of exercise, then schedule her for heart surgery," said study co-leader Gregory Thomas, a professor of cardiology at the University of California, Irvine. "She would require a double bypass."

Tsunami Pictures

Tsunamis

A tsunami is a series of ocean waves that sends surges of water, sometimes reaching heights of over 100 feet (30.5 meters), onto land. These walls of water can cause widespread destruction when they crash ashore.

These awe-inspiring waves are typically caused by large, undersea earthquakes at tectonic plate boundaries. When the ocean floor at a plate boundary rises or falls suddenly it displaces the water above it and launches the rolling waves that will become a tsunami.

Most tsunamis, about 80 percent, happen within the Pacific Ocean’s “Ring of Fire,” a geologically active area where tectonic shifts make volcanoes and earthquakes common.

Tsunamis may also be caused by underwater landslides or volcanic eruptions. They may even be launched, as they frequently were in Earth’s ancient past, by the impact of a large meteorite plunging into an ocean.

Tsunamis race across the sea at up to 500 miles (805 kilometers) an hour—about as fast as a jet airplane. At that pace they can cross the entire expanse of the Pacific Ocean in less than a day. And their long wavelengths mean they lose very little energy along the way.

In deep ocean, tsunami waves may appear only a foot or so high. But as they approach shoreline and enter shallower water they slow down and begin to grow in energy and height. The tops of the waves move faster than their bottoms do, which causes them to rise precipitously.

A tsunami’s trough, the low point beneath the wave’s crest, often reaches shore first. When it does, it produces a vacuum effect that sucks coastal water seaward and exposes harbor and sea floors. This retreating of sea water is an important warning sign of a tsunami, because the wave’s crest and its enormous volume of water typically hit shore five minutes or so later. Recognizing this phenomenon can save lives

Tsunami Pictures

Historic First: A Spacecraft Orbits Mercury

March 18, 2011: NASA's MESSENGER spacecraft successfully achieved orbit around Mercury at approximately 9 p.m. EDT on Thursday, March 17. This marks the first time a spacecraft has accomplished this engineering and scientific milestone at our solar system's innermost planet.

"This mission will continue to revolutionize our understanding of Mercury during the coming year," said NASA Administrator Charles Bolden, who was at MESSENGER mission control at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., as engineers received telemetry data confirming orbit insertion. "NASA science is rewriting text books. MESSENGER is a great example of how our scientists are innovating to push the envelope of human knowledge."

An artist's concept of MESSENGER orbiting Mercury.

At 9:10 p.m. EDT, engineers Operations Center, received the anticipated radiometric signals confirming nominal burn shutdown and successful insertion of the MESSENGER probe into orbit around the planet Mercury. NASA's MErcury Surface, Space ENvironment, Geochemistry, and Ranging, or MESSENGER, rotated back to the Earth by 9:45 p.m. EDT, and started transmitting data. Upon review of the data, the engineering and operations teams confirmed the burn executed nominally with all subsystems reporting a clean burn and no logged errors.

MESSENGER's main thruster fired for approximately 15 minutes at 8:45 p.m., slowing the spacecraft by 1,929 miles per hour and easing it into the planned orbit about Mercury. The rendezvous took place about 96 million miles from Earth.

"Achieving Mercury orbit was by far the biggest milestone since MESSENGER was launched more than six and a half years ago," said Peter Bedini, MESSENGER project manager of the Applied Physics Laboratory (APL). "This accomplishment is the fruit of a tremendous amount of labor on the part of the navigation, guidance-and-control, and mission operations teams, who shepherded the spacecraft through its 4.9-billion-mile journey."

For the next several weeks, APL engineers will be focused on ensuring the spacecraft's systems are all working well in Mercury's harsh thermal environment. Starting on March 23, the instruments will be turned on and checked out, and on April 4 the mission's primary science phase will begin.

"Despite its proximity to Earth, the planet Mercury has for decades been comparatively unexplored," said Sean Solomon, MESSENGER principal investigator of the Carnegie Institution of Washington. "For the first time in history, a scientific observatory is in orbit about our solar system's innermost planet. Mercury's secrets, and the implications they hold for the formation and evolution of Earth-like planets, are about to be revealed."

APL designed and built the spacecraft. The lab manages and operates the mission for NASA's Science Mission Directorate in Washington.

Super Full Moon

March 16, 2011: Mark your calendar. On March 19th, a full Moon of rare size and beauty will rise in the east at sunset. It's a super "perigee moon"--the biggest in almost 20 years.

"The last full Moon so big and close to Earth occurred in March of 1993," says Geoff Chester of the US Naval Observatory in Washington DC. "I'd say it's worth a look."

Full Moons vary in size because of the oval shape of the Moon's orbit. It is an ellipse with one side (perigee) about 50,000 km closer to Earth than the other (apogee): diagram. Nearby perigee moons are about 14% bigger and 30% brighter than lesser moons that occur on the apogee side of the Moon's orbit.

"The full Moon of March 19th occurs less than one hour away from perigee--a near-perfect coincidence¹that happens only 18 years or so," adds Chester.

A perigee full Moon brings with it extra-high "perigean tides," but this is nothing to worry about, according to NOAA. In most places, lunar gravity at perigee pulls tide waters only a few centimeters (an inch or so) higher than usual. Local geography can amplify the effect to about 15 centimeters (six inches)--not exactly a great flood.

The Moon looks extra-big when it is beaming through foreground objects--a.k.a. "the Moon illusion."

Indeed, contrary to some reports circulating the Internet, perigee Moons do not trigger natural disasters. The "super moon" of March 1983, for instance, passed without incident. And an almost-super Moon in Dec. 2008 also proved harmless.

Okay, the Moon is 14% bigger than usual, but can you really tell the difference? It's tricky. There are no rulers floating in the sky to measure lunar diameters. Hanging high overhead with no reference points to provide a sense of scale, one full Moon can seem much like any other.

The best time to look is when the Moon is near the horizon. That is when illusion mixes with reality to produce a truly stunning view. For reasons not fully understood by astronomers or psychologists, low-hanging Moons look unnaturally large when they beam through trees, buildings and other foreground objects. On March 19th, why not let the "Moon illusion" amplify a full Moon that's extra-big to begin with? The swollen orb rising in the east at sunset may seem so nearby, you can almost reach out and touch it.

Don't bother. Even a super perigee Moon is still 356,577 km away. That is, it turns out, a distance of rare beauty.

Super Full Moon videos

‘Solar Soldier’ Project Creating Power-Harvesting Uniforms for British Infantry

Solar-Powered Soldier The superimposed numbers are readings for anticipated sunlight. Engineering and Physical Research Sciences Center

Future camouflage uniforms will draw power from the sun during the day and from a soldier’s body during the night, turning infantrymen into true sunshine patriots. The system could provide continuous power for a radio, GPS and weapons, but at half the weight of traditional battery packs.

The Engineering and Physical Research Sciences Center in the UK is working on a new type of fabric that uses solar photovoltaic cells, thermoelectric devices and advanced lightweight batteries. Because the system absorbs heat, it could even serve as a type of wearable stealth cloak, making a soldier less susceptible to detection with infrared cameras.

Other militaries have been looking into solar energy use, which could be especially useful in sunny hot spots like the Middle East and Africa. A U.S. Marine Corps battalion is already usingportable solar panels to reduce battery weight, for instance. The system includes solar-panel tent shells and foldable arrays. Other systems designed to cut weight use fuel cells or li-ion batteries incorporated into armor.

But this new camouflage adds in thermoelectric energy, ensuring a constant power supply even when it’s dark or hazy.

Batteries can account for 10 percent of the 100-150 pounds of equipment that infantrymen currently carry, according to Duncan Gregory, a professor at the University of Glasgow who is working on the project. Reducing that weight could make infantry soldiers more comfortable, and therefore more mobile and perhaps more effective.

Beyond helping soldiers, the system could be used for powering satellites, keeping medicines cool in disaster areas, or supplying fresh food in hot climates, EPRSC said.

The $1.04 million project aims to have a prototype system by December.