For more accurate timing

Scientists in the US have recently announced that they have been able to achieve a major breakthrough in the development of a new generation of atomic clocks [1]. Ye�s team at the National Institute of Standards and Technology, Boulder, Colorado, have made considerable improvements to the long-term stability of strontium optical clocks. These have been seen as a major contender for the next generation of atomic clocks designed to replace conventional microwave based clocks, which have reached their fundamental limit. Optical clocks have been plagued by stability problems due to vibrations from the environment. Ye�s group has been able to go around the problem by trapping a large number of ultra-cold atoms in a lattice of light using ultra-stable lasers. The improvement could lead to new clocks with a precision of 1 part in 1017.

Atomic clocks have been the main timekeeper for the most precise measurements of time and frequency such as those used in GPS geolocation devices since their inception in the 1960s. Currently, the second is defined as the period of time during which 9192 631 770 oscillations between two energy levels in a caesium atom have occurred. Our ability to measure time precisely is therefore related to our ability to detect when an atomic transition occurs and then count the number of times such an event occurs.
Scientists working in the field of meterology have long sought to build atomic clocks, which rely on optical transitions rather than microwaves, the former having higher frequencies, and should be expected to have a higher quality factor and respond only when a very specific frequency of laser light excites the atoms. It should be noted that the best current atomic clocks are already phenomenally precise at a level of 1015�; optical clocks are predicted to be at least 100 times more accurate. One member of Ye�s team put it this way�: �We can define the center, or peak, of this resonance with a precision comparable to measuring the distance from the Earth to the sun with an uncertainty the size of a human hair�.

One major drawback optical clocks have suffered from, until now, is unstability. That�s because they are easily affected by external perturbations. Ye�s breakthrough was achieved thanks to two major improvements. Firstly, he was able to trap hundreds of ultra-cold atoms in a single lattice, while conventional clocks rely on a singe ion, this means that the signal obtained is very strong and can be measured with high precision. The second improvement lies in using an ultra-precise customized probe laser that is highly resistant to noise caused by vibration and gravity, based on a design originally developed by 2005 Nobel laureate John Hall, a senior research associate at JILA.

Improved time and frequency standards have many applications. For instance, ultra-precise clocks can be used to improve synchronization in navigation and positioning systems, telecommunications networks, and wireless and deep space communications. It is hoped that better frequency standards will allow us measure whether the fundamental constants of nature such as the speed of light and the electric charge of the electron might have varied over time, a question of enormous importance for our understanding of the creation and future fate of the universe.

Finally, the JILA work has tackled a number of issues, which are common in the field of quantum information processing. Atoms trapped in a lattice allow logic operations to proceed for longer periods of time. The enhanced measurement precision also could make it easier for scientists to use optical lattices to engineer condensed matter systems for massively parallel quantum measurements.

Source: Science (2006). 314: 1430-1433"

How the Sahara can light up the world

Deserts in the Middle East and North Africa can help meet the growing electricity demand in the region and in entire Europe, two recent German research reports suggest.

Many people think that deserts, apart from being a rich source for oil, gas and dates, are areas that do not serve much humanity. However, the solar rays which burn all day onto the Sahara can be converted into large amounts of energy.

Each year, the sun beams as much solar energy onto the area as the amount of oil needed to cover the entire desert with a sea 30 cm deep. "That's a huge energy potential," says Franz Trieb, of the Institute of Technical Thermodynamics at the German Aerospace Center, and author of the two studies. "And against what some say, you wouldn't have to pave the entire desert -- one thousandth of the entire desert area in the region would be enough."

Solar thermal power plants across southern Europe and deserts in North Africa and the Middle East, which use mirrors to collect sunrays during the day and generate electricity at night, could supply as much as 15 percent of Europe's electricity needs by 2050, the reports indicate. The studies provide a support for switching to renewable energy sources for Europe's electricity generation in the future, and advise governments to take similar steps to Spain and Germany which have already set up solar energy feed-in tariff.

Electricity generated from renewable energy sources is still more expensive than power from fossil fuels, which puts off venture capitalists from investing into the technologies. But Trieb says this is wrong. Making the cost of renewable energy equivalent to fossil fuels before the year 2020 would take an investment of $75 billion, but that will be returned quickly, as the region would save $250 billion by 2050 when compared with a scenario whereby current energy sources continue to be used as usual.

The costs

The study showed that "If the initial investment would be equally distributed among all electricity consumers in the region, each of them would have to afford additionally $10 per year for electricity payments for a period of 15 years in order to finance the total market introduction of renewables", "After this period, all consumers will benefit from stable and low electricity costs." The money required is comparable to what is being spent on building the first commercial nuclear fusion reactor expected in 2050. By that time, that plant will not have reduced CO2 emission, while renewable energy will have avoided 28 billion tons of CO2 emissions.

For Africa and the Middle East, excess heat produced from the solar plants could be used for other relevant projects in the region such as water desalination. First of all, Trieb said, the solar plants in North Africa and the Middle East should be used to satisfy that region's own electricity hunger, which by 2050 will be as big as Europe's. "The electricity first and foremost is for the North African and Middle Eastern states," Trieb said. But after a decade or so, the sheer mass of energy could enable those states to sell cheap electricity to Europe, Trieb said, which -- in the best of all cases -- provides the poorer African states with additional income. "It would be great if the whole project had a stabilizing effect, socially and economically, for the African states."

North African and Middle Eastern states, including Algeria, Jordan, Libya and Morocco have already warmed up to the idea. Initial plans for constructing such plants are already under way, including one in Yemen costing about US$7.5 billion. If launched, desalinated water from the Red Sea would supply the city of Sana'a.

Source: United Press International, the Guardian, Scidev.net

More light shed on dark energy

Using the Hubble Space Telescope, astronomers at John Hopkins University in the US, concluded that dark energy has been fuelling the expansion of the universe since nine billion years ago. They also concluded that the dark energy can be explained by the “cosmological constant” first proposed by Albert Einstein.

When Edwin Hubbel made his discovery about the expansion of the universe back in 1929, it was clear that the cosmological constant introduced by Einstein to account for a static non expanding universe had to be taken out of the equations. Einstein himself called it the “the greatest blunder of my life”. The so-called cosmological constant is an “antigravity” force which is, as proposed by Einstein, a force built into the very fabric of space and time and acts as to balance the gravitational attraction, so the universe would be static and not collapse. 
In 1998 data from Hubbel and other telescopes confirmed that the rate of expansion of the universe was increasing. This meant that there is an “antigravity” force, which is working against gravity by pushing stars and galaxies away from each other hence expanding the universe increasingly. The energy required to do this work is usually termed dark energy. It seems, therefore, that after getting rid of it, the cosmological constant, needs to be put back into the equations to account for the dark energy.

Now Riess and colleagues from John Hopkins University studied light from 24 type-1a supernovae that exploded 8-10 billion years ago. Their observations indicated that dark energy was present nine billion years ago. Although it was weak at the start, the effect of dark energy started to grow, about five billion years ago, defeating gravity in a “cosmic tug of war” and since then the rate of expansion of the universe started to increase. The observations also confirmed that the cosmological constant remains the best explanation for dark energy

Source: PhysicsWeb, 17/11/2006. "Dark energy dates back nine billion years"

Call to the world's first successful womb transplant on humans!

Organ transplant is a life saving surgery and could be the only solution for threatening illnesses. It has known a remarkable development and an increase in the organs and the ethical issues it involves.

More than 15,000 women a year in the UK suffer from incapacity of becoming pregnant due to destroyed womb by fibroids or cancer treatment or as a result of an abnormality in their genetic make up [1]. Moreover, finding a surrogate mother to carry children for those women is very hard and sometimes impossible in some cultures/ religions.

Surgeons of the New York Downtown hospital have received approval from the review board to perform uterus transplants on humans. Dr. Del Priore announced that the surgery procedures would be carried out successfully next year if the patients were determined and tests and counselling took place at the right time.

The only previous womb transplant was attempted in 2002 by a medical team in KSA, where surrogacy is illegal. The womb was transplanted from a 46-year-old postmenopausal woman who had a hysterectomy to a 26-year-old woman who had lost her uterus after an excessive postpartum bleeding. However, the operation was not successful and the womb was removed due to the development of a blood clot in the uterus.

Many successful womb transplant trials were also achieved in sheep and mice following very specific immunity techniques. Nevertheless, Dr. Mats Brannstrom of Gothenburg University in Sweden who works on womb transplants in sheep believes there should be more studies on animals before trying it on humans.

Moreover, funding the needs of the surgery and the hazards that can arise from the transplant procedure are still causing a huge debate on whether to proceed with it before next year.

Any patient undergoing the surgery, would have to go through consecutive hindrances such as attending psychological sessions, reconsidering surrogacy, seeing a pregnancy-risk specialist and transplant support team. Thereafter, if the operation can be perfected for humans, it could help thousands of women with Rokitansky syndrome and many other abnormalities of the reproductive system. (N.A)

Source: The Daily Telegraph, 10/11/2006.

References:
[1] Boseley S. (March 7, 2002). Surgeons hail world's first womb transplant. The guardian. [Online]: http://www.guardian.co.uk/international/story/0,3604,663249,00.html

More mobility for Algerian mobile telephone operator

Major Algerian mobile phone provider Djezzy of Orascom Telecom Algerie (OTA) has recently launched its Blackberry services in Algeria, in partnership with the Canadian firm Research In Motion (RIM) [1]. Blackberry, developed and made by RIM, is a solution aimed to provide more mobility for its customers, allowing users to manage their e-mail, information and communications on the go.

As far as e-mail is concerned, Blackberry is fitted with the RIM’s "Pushmail" technology which allows e-mail messages to be directly delivered to the device, wherever it is located.

The technology is available through two packages proposed by OTA, namely Pro Djezzy and Perso Djezzy. Perso Djezzy is adapted for individual needs, including a device compatible with email services Pop3 and Imap4. In addition to the usual functionality found in a mobile phone, this package allows sending and reading e-mails, browsing the internet, downloading attachments, and managing calendars, contacts and diaries using PC synchronisation or the internet via Djezzy’s GPRS services launched last summer. Djezzy Pro on the other hand is more destined to business use, providing facilities for efficient mobile business management.

Blackberry services are available through two terminals namely the Blackberry 7290 and the Blackberry 8700, both including various software a solutions such as Microsoft Word, Excel and PowerPoint and Adobe PDF reader, in addition to a powerful web browser. In addition to their compactness, the two devices offer easy accessibility through a 33-key keyboard and an easy-to-use navigation key.

The novel service in Algeria has already attracted hundreds of customers to subscribe to it, only a few weeks after its introduction.

Source: El-Watan Daily, 04/12/2006.

References:
[1] http://www.rim.net/

China signs a science deal with Egypt and Algeria

China has started a scientific cooperation with Algeria and Egypt, news that has been widely welcomed by the scientific communities in both countries.

Early this month, just days after the China-Africa summit concluded, China's president Hu Jintao signed two deals with the leaders of Egypt and Algeria in Beijing, China.

The agreement between Egypt and China involves collaboration on research in many scientific and technological fields and the setting up of a common budget for joint scientific activities. Amongst these areas are information technology, health, traditional medicine, space technology, agriculture peaceful use of nuclear energy and technology transfer. Hassan Abdel Aal Moawad, professor of microbial biotechnology at Cairo's National Research Center, Egypt, says it will help establishing a knowledge-based economy in both countries. Moawad, a former president of Alexandria's Mubarak City for Scientific Research and Technology Applications, added that under the agreement, China will fund a fish-farming laboratory at Suez Canal University in Ismailia, Egypt.

The deal between China and Algeria will encourage scientific and technical exchanges and technological cooperation between companies and entrepreneurs of the two countries in energy and mineral resources research. In addition, collaboration in education, industry, information technology, communications, mechanical engineering, agriculture, water conservation and infrastructure construction will also be boosted according to the agreement. Sadallah Boubaker-Khaled, professor of mathematics at Algiers' Ecole Normale Supérieure in Algeria, says the plan will help promote science and sustainable economic development in Algeria and benefit the countries' scientific and technical communities.

Most recently, China had offered a similar deal to Mozambique, whereby China would implement a plan to develop Mozambique's various science and technology fields. This would involve joint research and scientist exchange programmes to encourage transfer of practical technology and strengthen e-governance, development of science parks and using traditional Chinese medicine to treat of AIDS.

Source: SciDev.Net.