Digging up troves of possible solar systems in Orion

A new image from NASA's Spitzer Space Telescope probes deep into the clouds of dust that permeate the nebula and its surrounding regions. The striking false-color picture shows pinkish swirls of dust speckled with stars, some of which are orbited by disks of planet-forming dust.

Spitzer, with its powerful infrared vision, was able to unearth nearly 2,300 such planet-forming disks in the Orion cloud complex, a collection of turbulent star-forming clouds that includes the well-known Orion nebula.

The disks - made of gas and dust that whirl around young suns - are too small and distant to be seen by visible-light telescopes; however, the infrared glow of their warm dust is easily spotted by Spitzer's infrared detectors. Each disk has the potential to form planets and its own solar system.

"This is the most complete census of young stars with disks in the Orion cloud complex," said Dr. Thomas Megeath of the University of Toledo, Ohio, who led the research. "Basically, we have a census of potential solar systems, and we want to know how many are born in the cities, how many in small towns, and how many out in the countryside."

A look at Orion's demographics reveals that the potential solar systems populate a variety of environments. Megeath and his colleagues found that about 60 percent of the disk-sporting stars in the Orion cloud complex inhabit its bustling "cities," or clusters, containing hundreds of young stars. About 15 percent reside in small outer communities, and a surprising 25 percent prefer to go it alone, living in isolation.

Prior to the Spitzer observations, scientists thought that up to 90 percent of young stars, both with and without disks, dwelled in cities like those of Orion.

"The Orion image shows that many stars also appear to form in isolation or in groups of just a few stars," said team member Dr. John Stauffer of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena. "These new data may help us to determine the type of environment in which our sun formed."

Astronomers do not know whether our middle-aged sun grew up in the stellar equivalent of the city or countryside, though most favor a large city scenario. Newborn stars like the ones in Orion tend to drift away from their siblings over time, so it is hard to trace an adult star's origins.

Megeath and his colleagues estimate that about 60 to 70 percent of the stars in the Orion cloud complex have disks. "It is an interesting question why this number isn't 100 percent. Eventually, we may be able to understand why some stars don't have disks," said Megeath.

Digging up troves of possible solar systems in Orion

Hunting Tumors and Exploring the Universe

X-rays picture broken bones. Microwaves warm leftovers. Both are parts of the electromagnetic spectrum, which also includes light and radio.

Meanwhile, little-known T-rays see through clothing, identify explosives and drugs, and detect tumors. Often overlooked, T-rays are even being used to explore the universe.

The electromagnetic spectrum runs from long-wavelength radio at one end to high-energy, short-wavelength X-rays and gamma rays on the other. Between microwaves and X-rays, in the least explored region of the spectrum, lie T-rays, or terahertz radiation, the most common form of radiation in the universe.

If you've never heard of T-rays, it's because scientists have had trouble harnessing them. Although the first scientific paper on the subject was published in the 1890's on the first page of the first issue of the journal Physical Review, the challenges of generating, detecting, and manipulating terahertz radiation have hindered the technology's research and development—until now.

With more efficient sources and detectors of terahertz radiation, researchers in the last decade have begun to develop waveguides, filters, and beam splitters to manipulate T-rays.

"At this point the technology is very young," said electrical engineer Daniel Mittleman, of Rice University's T-ray lab. "Terahertz is now where X-rays were in 1905," ten years after Wilhelm Conrad Rontgen discovered X-rays.

See right through

Many everyday materials, such as clothing, plastics, and wood look transparent under terahertz imaging. In addition, materials will absorb the radiation at varying frequencies, depending on the type of material.

Based on absorption frequencies, researchers have been able to identify specific explosives and drugs that have unique "fingerprints."

For example, an envelope containing a white powder looks ambiguous and looms ominously to the naked eye. But with the help of T-ray imaging, a postal work could decipher whether the powdery parcel contained methamphetamine or aspirin. Explosive devices would be more easily spotted inside luggage.

T-rays are already being put to work.

The technology is being used in some hospitals as a novel, noninvasive diagnostic tool for doctors hunting tumors. The technique cuts costs and pain related to previous diagnostic tools. Scientists at the University of Liverpool, England, hope to kill skin cancer cells by bombarding them with terahertz radiation.

Cigarette manufacturers such as Phillip Morris are researching ways to use T-rays for quality control in the factory.

After cigarettes are packed inside cartons, the imaging systems check the moisture content and tobacco density of each cigarette. While former methods may have put workers at risk of radiation, T-rays in a factory setting are not hazardous.

"It's a hi-tech solution to a low-tech problem, but no low-tech solution is available," Mittleman said. "So the high-tech solution is the best solution."

Pharmaceutical companies are also employing hi-tech solutions, verifying the contents of their pills without putting a finger on a capsule. Terahertz imaging can even measure the thickness of a pill's coating.

Hunting Tumors and Exploring the Universe

Figures of Buddha

The art of Buddhist figures in China took shape with the introduction of Indian Buddhism. The legend had it that on a certain night of the year 60, Ming Emperor Liu Zhuang in Eastern Han dreamed a golden man without knowing where he came from. The next day, the emperor called his subjects together to explain the dream. A minister named Fu Yi said Xitianzhu (in ancient India) had such a sage called Buddha dressed in gold. What the emperor had dreamed must be the Buddha. Then the emperor sent one of his attendants, Cai Yin, with thousands of soldiers, to Tianzhu on a diplomatic mission to seek Buddhist doctrine. In 67, they returned to China with Buddhist scripture and figures. This was the first record on China's Buddhist figures in ancient books, but it didn't tell what kind of figures they were. From the existing stone sculptures and pottery Buddhist figures, we will find that the Han people carved them according to the images of celestial beings in vogue at that time. In the Five Dynasties and 16 States, Buddhist figures in Chinese style began to show up. They were not reliefs or shallow-carved images attached to other objects, but whole Buddhist figures with complete body structure. The statues, however, still followed the suit of Indian models.

In the Northern Wei period, the art of Buddhist figures flourished and began to shake off trace from ancient India. At that time, emperors believed in Buddhism which resulted in a nationwide practice to cast figures. The early works were greatly influenced by the Indian arts. The most attractive was two gold-plated copper buddhas sitting abreast. Hebei region was then the figure-carving centre and had gathered many skillful craftsmen from the country. Among the Yungang Grottoes we found many ancient outstanding works.

Figures of the middle of the Wei Dynasty changed a lot in that Buddha's faces which once had been plump and decorous became fine and decated. In the late Northern Wei, Longmen style which laid stress on realness and meticulosity became the main stream in Buddhist figure carving. The works presented fine workmanship and a realistic approach. In the era of Xiaoming Emperor, this exciting artistic style was widely accepted as a rule for the then figure-carving craftsmen to follow.

Buddhist figures in Western Wei not only preserved the delicated and elegant bearings of Northern Wei but also were permeated with more artistic interest of life. The varied looks and unrestrained carriage were most fully displayed in the Grotto Temple on Maijishan Mountain.

Figures in Northern Qi were known for changeable techniques of expression and characterization. The combination of Buddhas and their family dependents presented a colourful Buddhist world. More attention was paid to the sense of beauty against against the gorgeous back light.

Early arts of Buddhist images in the Sui Dynasty carried on part of the Northern Dynasty style. At its mature period of stone carving, Sui Dynasty produces many outstanding Buddhist statues with unique characteristics and dignified gestures and magnificent dress.

When it is the Tang Dynasty, Buddha images were dressed in clothes so thin and light as if wet gauze sticked to the body. The half-naked body was well-developed, assuming a projecting and clear arc line from breast to waist. This feature in curved body line became an important rule to judge carving works of Tang Dynasty from those of the others periods.

Carved Buddha image works of the Song Dynasty were inferior to those in the Tang Dynasty in terms of number and scale. But new development was made to techniques of expression. Artists with superior skills characterized many figures with profound psychology and personality reflecting real life.

A broad review of China's carving arts of Buddhist figures showed that figures mainly followed the Indian styles at the beginning. The Northern and Southern Dynasties made some essential changes and improvements. China's first generation of Buddhist images with Han characteristics were thus created. Transforms of Bei Qi and the Sui Dynasty helped the Tang Dynasty creat a new peak of Buddhist figure carvings. This exotic art was finally localized and became popular. In the Song Dynasty, religious colour on Buddhist figures graduated faded and common delights of life were reflected. That is the main development of China's carving arts of Buddhist figures.

Figures of Buddha

Animal Experiments

Key Points

	More than 2.7 million live animal experiments were authorised in Great Britain in 2002. This number has halved in the last 30 years
	Around the world, animals are used to test products ranging from shampoo to new cancer drugs
	British law requires that any new drug must be tested on at least two different species of live mammal. One must be a large non-rodent
	UK regulations are considered some of the most rigorous in the world - the Animals Act of 1986 insists that no animal experiments be conducted if there is a realistic alternative
	Almost every medical treatment you use has been tested on animals. Animals were also used to develop anesthetics to prevent human pain and suffering during surgery

Does animal testing work?
Animal testing has helped to develop vaccines against diseases like rabies, polio, measles, mumps, rubella and TB Animal experiments can be misleading. An animal's response to a drug can be different to a human's Antibiotics, HIV drugs, insulin and cancer treatments rely on animal tests. Other testing methods aren't advanced enough Successful alternatives include test tube studies on human tissue cultures, statistics and computer models Scientists claim there are no differences in lab animals and humans that cannot be factored into tests The stress that animals endure in labs can affect experiments, making the results meaningless Operations on animals helped to develop organ transplant and open-heart surgery techniques Animals are still used to test items like cleaning products, which benefit mankind less than medicines or surgery

What are the alternatives to animal testing?

Is animal testing morally right?
Human life has greater intrinsic value than animal life Animals have as much right to life as human beings Legislation protects all lab animals from cruelty or mistreatment Strict controls have not prevented researchers from abusing animals - although such instances are rare Millions of animals are killed for food every year - if anything, medical research is a more worthy death Deaths through research are absolutely unnecessary and are morally no different from murder Few animals feel any pain as they are killed before they have the chance to suffer When locked up they suffer tremendous stress. Can we know they don't feel pain?

Animal Experiments