Category: "Science and Technology"
Ethiopian researcher and his colleagues at University of Minnesota make sound loud enough to bend light on a computer chipNovember 28th, 2014
Ethiopian Engineer and his colleagues at University of Minnesota make sound loud enough to bend light on a computer chip
Ethiopian graduate student at University of Minnesota's School of Physics and Astronomy and his team of researchers made discovery that could improve wireless communications systems using optical fibers and ultimately be used for computation using quantum physics. The researcher, Semere Tadesse, is the lead author of the paper and currently studying for PhD at the University of Minnesota. He is a graduate of Alemaya University in Ethiopia and earned his Masters from Ghent University, Belgium.
“What’s remarkable is that at this high frequency, the wavelength of the sound is even shorter than the wavelength of light. This is achieved for the first time on a chip,” said Semere Tadesse, a graduate student in the University of Minnesota’s School of Physics and Astronomy and the first author of the paper. “In this unprecedented regime, sound can interact with light most efficiently to achieve high-speed modulation.”
During a thunderstorm, we all know that it is common to hear thunder after we see the lightning. That’s because sound travels much slower (768 miles per hour) than light (670,000,000 miles per hour).
Now, University of Minnesota engineering researchers have developed a chip on which both sound wave and light wave are generated and confined together so that the sound can very efficiently control the light. The novel device platform could improve wireless communications systems using optical fibers and ultimately be used for computation using quantum physics.
The research was recently published in Nature Communications, a leading research journal.
Ethiopia unveils telescope in first phase of space programme
Addis Ababa — Ethiopia unveiled Friday the first phase of a space exploration programme, which includes East Africa's largest observatory designed to promote astronomy research in the region.
"The optical astronomical telescope is mainly intended for astronomy and astrophysics observation research," said observatory director Solomon Belay.
The observatory, which will formally be opened on Saturday, boasts two telescopes, each one metre (over three feet) wide, to see "extra planets, different types of stars, the Milky Way, and deep galaxies," Solomon added.
The 3.4 million dollar (2.5 million euro) observatory, run by the Ethiopian Space Science Society (ESSS), is funded by Ethiopian-Saudi business tycoon Mohammed Alamoudi.
The observatory, 3,200 metres (10,500 feet) above sea level in the lush Entoto mountains on the outskirts of the Ethiopian capital Addis Ababa, is an ideal location because of its minimal cloud cover, moderate winds and low humidity, experts said.
When established in 2004, ESSS was labelled as the "Crazy People's Club", according to the group, but has gained credibility in the past decade with astronomy courses introduced at universities and winning increased political support.
The Ethiopian government is set to launch a space policy in coming years.
Solomon said the group originally faced sceptics in Ethiopia and abroad, who questioned whether space exploration was a wise use of resources in one of Africa's poorest economies, plagued in the past by chronic famine and unrest.
But Solomon said promoting science is key to the development in Ethiopia, today one of Africa's fastest growing economies largely based on agriculture.
"If the economy is strongly linked with science, then we can transform a poor way of agriculture into industrialisation and into modern agriculture," he said.
The ESSS is now looking to open a second observatory 4,200 metres (13,800 feet) above sea level in the mountainous northern town of Lalibela, also the site of the largest cluster of Ethiopia's ancient rock-hewn churches.
Photographs from the ESSS show scientists with testing equipment looking for the best site to put the next telescope on the green and remote peaks, as local villagers wrapped in traditional white blankets watch on curiously, sitting outside their thatch hut homes.
Solomon hopes to boost "astronomy tourism" among space fans interested in coming to one of the least likely countries in the world to boast a space programme, an added economic benefit.
The country will also launch its first satellite in the next three years, ESSS said, to study meteorology and boost telecommunications.
Ethiopia is not the first African nation to look to the skies; South Africa has its own National Space Agency, and in 2009 the African Union announced plans to establish The African Space Agency.
Sudanese President Omar al-Bashir, indicted by the International Criminal Court for war crimes, has also called for a continent-wide space programme.
Solomon said while the next several years will be about boosting research and data collection, along with promoting a strong local and regional interest in astronomy, he is not ruling out sending an Ethiopian into space one day.
"Hopefully we will," he said with a laugh.
Magma Blob Beneath Afar Rift In Ethiopia Puzzles Scientists
The Afar Rift in Ethiopia is marked by enormous gashes that signal the breakup of the African continent and the beginnings of a new ocean basin, scientists think.
The fractures appear eerily similar to seafloor spreading centers, the volcanic ridges that mark the boundaries between two pieces of oceanic crust. Along the ridges, lava bubbles up and new crust is created, slowly widening the ocean basin.
But a look deep beneath the Afar Rift reveals the birth announcements may be premature. "It's not as close to fully formed seafloor spreading as we thought," said Kathy Whaler, a geophysicist at the University of Edinburgh in Scotland.
Whaler and her colleagues have spotted 120 cubic miles (500 cubic kilometers) of magma sitting in the mantle under the Afar Rift. Hot liquids like magma like to rise, so the discovery is a conundrum.
"We didn't expect this, because magma wants to pop up like a cork in water; it's too buoyant compared to the surrounding medium in the mantle," Whaler told LiveScience's OurAmazingPlanet.
Ethiopians, Tibetans thrive in thin air using different genes
Ethiopians, Tibetans thrive in thin air using different genes
Scientists say they have pinpointed genetic changes that allow some Ethiopians to live and work more than a mile and a half above sea level without getting altitude sickness.
The specific genes differ from those reported previously for high-altitude Tibetans, even though both groups cope with low-oxygen in similar physiological ways, the researchers report. If confirmed, the results may help scientists understand why some people are more vulnerable to low blood oxygen levels caused by factors other than altitude — such as asthma, sleep apnea, heart problems or anemia — and point to new ways to treat them, the researchers say.
Living with less
Lower air pressure at high altitude means fewer oxygen molecules for every breath. “At 4000 meters, every lungful of air only has 60% of the oxygen molecules that people at sea level have,” said co-author Cynthia Beall of Case Western Reserve University.
The Real Home of Hurricanes: Ethiopia?
Source: ABC News*
By Ned Potter
We've seen the image so many times: the satellite picture of clouds in the Atlantic or the Caribbean, gradually taking the familiar spiral shape of a hurricane.
Most of us think of the storms as beginning over the steamy Atlantic waters, which provide fuel for hurricanes as they strengthen and threaten landfall.
But it turns out that many storms begin much farther away -- all the way over on the far side of Africa.
Watch "Focus Earth" Saturday on Discovery's "Planet Green" network.
They can start as thunderstorms in Ethiopia, picking up heat and energy as they drift westward across the Sahara desert.
"It's a remote part of the world, but it really does have a lot of implications for folks living downstream," said Jason Dunion, a scientist at the Hurricane Research Division of NOAA, the National Oceanic and Atmospheric Administration.
For years, Dunion and fellow researchers have been studying hurricanes to determine their true origins. That led them to take interest in tropical disturbances from as far away as the Red Sea.
"Only about one in 10 or so of these tropical 'waves' actually forms into a named storm," said Dunion, "but what's really interesting is they account for over half the hurricanes and tropical storms that we see in the entire Atlantic."
Hurricane Bertha, earlier this month, became a named storm just a few hundred miles off the African coast. It was also one of the longest-lasting hurricanes on record, though it did not make landfall.
Dolly, which hit south Texas on Wednesday, did not fit the out-of-Africa pattern. It formed in the Caribbean.
What determines if a particular disturbance will become a major hurricane, or fade to nothing as it crosses Africa? Among other things, scientists are curious about sand from the Sahara, which can be picked up by the wind and sometimes travel for thousands of miles.
Saharan sand -- along with small amounts of microbial life unique to Africa -- has been detected as far away as southern Florida.
Scientists believe the sand may suppress hurricane formation, though the theory is heavily debated. If there are more sand particles in the upper layers of the atmosphere, they theorize, raindrops may coalesce around them, and a storm may lose power before it can actually become a hurricane.
So forecasters look far beyond the tropical Atlantic for the ingredients of a tropical storm. By the time a storm is strong enough to be named, meteorologists may have been watching it for more than a week.
If they can understand a hurricane's true beginnings, they say, perhaps they can give more precise forecasts so that people have more time to get out of harm's way.