Following riots in the western region of Xinjiang, China’s central government has taken steps to block citizens from accessing foreign Web services. In addition to crippling Internet service in general, the authorities have blocked Twitter, removed unapproved references to the violence from search engines, and have now apparently moved to bar citizens from accessing Facebook.

The government has also recently blocked just about every Google service, including communication tools like Gmail, Google Apps and Google Talk. Twitter and YouTube have also been restricted for a while.

Urine-powered cars, homes and personal electronic devices could be available in six months.

Using a nickel-based electrode, scientists can create large amounts of cheap hydrogen from urine that could be burned or used in fuel cells. One cow can provide enough energy to supply hot water for 19 houses.

One molecule of urea, a major component of urine, contains four atoms of hydrogen bonded to two atoms of nitrogen. If you place a special nickel electrode into a pool of urine and apply an electrical current, hydrogen gas is released.

A urine-powered vehicle could theoretically travel 90 miles per gallon.

What do people do when they find a wallet on the street? Leave it? Take it to a police station? Post it back to the owner? Keep it, even?

The answer, scientists have found, depends rather more on evolution than morality.

Hundreds of wallets were planted on the streets of Edinburgh by psychologists last year. One of four photographs was inserted behind a clear plastic window in each of the wallets, showing either a smiling baby, a cute puppy, a happy family or a contented elderly couple. Some wallets had no image and some had charity papers inside.

When faced with the photograph of the baby people were far more likely to send the wallet back, the study found. The baby photograph wallets had the highest return rate, with 88 percent being sent back. Next came the puppy, the family and the elderly couple, with 53, 48 and 28 percent respectively. At 20 and 15 percent, the charity card and control wallets had the lowest return rates.

Scientists argue that it would be difficult to genetically code for feeling empathy exclusively towards your own child, and much easier to code for feeling empathy towards all children.

A recent study claims that young adults are not drinking enough milk -- at least according to press reports on the matter. But according to the study’s lead author Nicole Larson, the focus on the study was on calcium.

The words "milk" and "calcium" are often used interchangeably in the popular press. But while milk is a calcium source, no standard other than that of the National Dairy Council considers it the best calcium source.

The suggestion that you need to drink three glasses of the secretion of a cow's mammary glands in order to be healthy is a bit outrageous and doesn't fit the human evolutionary profile. In fact, most humans around the world cannot easily digest cow milk.

Yogurt has more calcium than milk and is easier to digest. Collards and other greens also have about as much or more calcium than milk by the cup. Greens, unlike milk, have the added benefit of vitamin K, also necessary for strong bones. Sesame is also very high in calcium.

When you measure calcium by cup of food product, milk is high on the list. When you view it by calorie, though, milk is at the bottom. A hundred calories of turnip greens have over three times as much calcium as 100 calories of whole milk.