Underwater cloak renders objects invisible to sonar
“We are not talking about science fiction. We are talking about controlling sound waves by bending and twisting them in a designer space,” said Nicholas Fang, mechanical science and engineering professor at the University of Illinois.
The team has developed a cloak, which is actually two dimensional discs consisting of acoustic circuits that channel sound waves at varying speeds.
“Basically what you are looking at is an array of cavities that are connected by channels. The sound is going to propagate inside those channels, and the cavities are designed to slow the waves down,” Fang told ScienceDaily.com. “As you go further inside the rings, sound waves gain faster and faster speed.”
The cloak is able to conceal objects of varying size and densities underwater. The next step is for the team to being experimenting with military applications for the technology, as well as soundproofing applications for hospitals and homes.
Chinese are working on stealth fighter
Images of a stealth fighter taxiing on a Chinese runway have been leaked to the Internet.
The photos first appeared on military websites and blogs, and are rumored to have been taken at the Chengdu Aircraft Design Institute.
The U.S. defense department says that China is years away from deploying a stealth fighter.
“Developing a stealth capability with a prototype and then integrating that into a combat environment is going to take some time,” U.S. director of naval intelligence Vice-Admiral David Dorsett told the BBC.
Currently the F-22 Raptor is the world’s only operational stealth fighter.
Spam falling
No, it’s not low-quality meat falling from the sky. What is actually falling is the number of junk emails sent per day. A study performed by Symantec shows that in August approximately 200 billion junk related emails were being sent per day.
That number has since declined to about 50 billion.
No one is sure why people are being spammed less often; however, it is know that most spam comes from something called a botnet.
A botnet is a network of infected computers that send spam to other computers.
Paul Wood, a senior analyst at Symantec Hosted Services, told BBC News that Rustock is the botnet responsible for 47-48 per cent of all spam, and during the month of December, Rustock represented only half of a percentile.
Explanation for male baldness found
The team of researchers told the Journal of Clinical Investigation that male baldness can be attributed to a lack of specific stem cells needed to grow new hair.
Bald areas will have the same number of stem cells responsible for making hair; however, there are fewer of a type of cells called the progenitor cell.
Dr. George Cotsarelis told the BBC that, “This implies that there is a problem in the activation of stem cells converting progenitor cells in bald scalp.
The hope is to develop a cream that could be applied to the bald areas to reactivate the stem cells necessary for hair growth.
