Super-massive Black Holes Grow Surprisingly Fast

This image depicts three hot blobs of matter orbiting a black hole. 

If placed in our Solar System, this black hole would appear like a dark abyss spread out nearly as wide as Mercury's orbit.

The three blobs (each as large as the Sun) would be as far out as Jupiter. 

They orbit the black hole in a lightning-quick 20,000 miles per second, over a tenth of the speed of light.

CREDIT: NASA/Dana Berry, SkyWorks Digital

Giant black holes are famous for their appetites, but these matter-munching monsters are even greedier than scientists once thought, a new study suggests.

The super-massive black holes that lurk at the center of most (if not all) galaxies are growing surprisingly quickly, the study found.

The result implies that these cosmic behemoths are sustained primarily by frequent small meals rather than rare and dramatic galactic mergers, as was previously believed.

Super-massive black holes are almost incomprehensibly huge, with some containing 10 billion or more times the mass of our own sun.

The research team used computer simulations to investigate how such black holes grow, especially in spiral galaxies like the Earth's Milky Way.

The astronomers found that, contrary to prevailing theory, central black holes can grow quite rapidly in quiet, merger-free spirals simply by sucking up galactic gas and other matter.

"These simulations show that it is no longer possible to argue that black holes in spiral galaxies do not grow efficiently," study lead author Victor Debattista, of the University of Central Lancashire in England, said in a statement.

"Our simulations will allow us to refine our understanding of how black holes grew in different types of galaxies."

Large, Fast and Rare Meteorite hits the Earth

Geology professor Qing-zhu Yin holds a fragment of the Sutter Mill meteorite that exploded over the Sierra foothills this past spring. (Gregory Urquiaga/UC Davis photo).

A meteorite that exploded as a fireball over California's Sierra foothills this past spring was among the fastest, rarest meteorites known to have hit the Earth, and it traveled a highly eccentric orbital route to get here.

An international team of scientists presents these and other findings in a study published Friday, Dec. 21, in the journal Science.

The 70-member team included nine researchers from UC Davis, along with scientists from the SETI Institute, NASA and other institutions.

The researchers found that the meteorite that fell over Northern California on April 22 was the rarest type known to have hit the Earth - a carbonaceous chondrite. It is composed of cosmic dust and presolar materials that helped form the planets of the solar system.

The scientists learned that the meteorite formed about 4.5 billion years ago was knocked off its parent body, which may have been an asteroid or a Jupiter-family comet, roughly 50,000 years ago.

Once it left the comet, it began its journey to Earth and exploded over Sutter's Mill, the gold discovery site that sparked the California Gold Rush.

As it flew toward Earth, it traveled an eccentric course through the solar system, flying from an orbit close to Jupiter toward the sun, passing by Mercury and Venus, and then flying out to hit Earth.

The high-speed, minivan-sized meteorite entered the atmosphere at about 64,000 miles per hour.

The study said it was the fastest, "most energetic" reported meteorite that's fallen since 2008, when an asteroid fell over Sudan.

"If this were a much bigger object and had landed in a more populated area, then this could have been a disaster," said co-author and UC Davis geology professor Qing-zhu Yin. "But, in this case, it is a happy."

Before entering Earth's atmosphere, the meteorite is estimated to have weighed roughly 100,000 pounds but most of that mass burned away when the meteorite exploded. Scientists and private collectors have recovered about 2 pounds remaining.

Cheetah Robot runs at 28.3 mph - YouTube

The cheetah bot is now able to run at 28.3 mph (45.5 kph), which is 0.5 mph faster than Usain Bolt's fastest 20 meter split, noted Boston Dyanmics, the company developing the robot in conjunction with the U.S. Defense Advanced Research Projects Agency (DARPA).

Getting the mechanical cheetah up to this speed required researchers to improve the computer instructions that control its legs and back, whose flexible design are key to its speed, IEEE Spectrum reported.

A few important limitations keep this version of the Cheetah stuck in lab, for now. It uses an outside power source that it does not carry.

It relies on a tether to keep it upright. Early next year, however, Boston Dynamics plans to perform outdoor tests of an untethered version, called WildCat.

The Mantabot - YouTube

Batoid rays, such as stingrays and manta rays, are among nature’s most elegant swimmers. They are fast, highly maneuverable, graceful, energy-efficient, and can cruise, bird-like, for long distances in the deep, open ocean, and rest on the sea bottom.

“They are wonderful examples of optimal engineering by nature,” says Hilary Bart-Smith, an associate professor of mechanical and aerospace engineering in the University of Virginia‘s School of Engineering and Applied Science.

They are designing an “autonomous underwater vehicle” that someday may surpass what nature has provided as a model. The vehicle has potential commercial and military applications, and could be used for undersea exploration and scientific research.

Fast and Accurate Knife-Edge Manoeuvres for Autonomous Aircraft - YouTube

Robot Locomotion Group at MIT have built a computer-controlled aircraft that flies accurately enough to navigate safely through a gap that is smaller than its wingspan.

Here they demonstrate multiple flights of this vehicle with on-board camera footage and high-speed video.

Many small flying robots still have all the grace and awareness of a drunken pigeon, except that comparison probably disrespects the pigeon.

MIT robotics engineers took inspiration from our fine feathered friends to make a flying robot with the lightning-fast reflexes to dodge through gaps smaller than its wingspan.

That does not quite rival the impressiveness of a bird in flight or a "Star Wars" Jedi tearing through the forest of Endor on a speeder bike, but it's pretty good for a mechanical creation.

Hot dog! Ready-to-eat meat contains few cancerous compounds

If given the choice between eating a hot dog or enjoying some rotisserie chicken, consider the hot dog.

That’s because hot dogs, as well as pepperoni and deli meats, are relatively free of carcinogenic compounds, according to Kansas State University research. But it’s a not-so-happy ending for bacon and rotisserie chicken — especially chicken skin — because both have higher levels of cancerous material.

J. Scott Smith, professor of food chemistry, and a K-State research team have been looking at such ready-to-eat meat products to determine their levels of heterocyclic amines, or HCAs.

These are carcinogenic compounds found in meat that is fried, grilled or cooked at high temperatures. Studies have shown that humans who consume large amounts of HCAs in meat products have increased risk of stomach, colon and breast cancers.

Ready-to-eat meat products are meat or poultry products that come in edible forms and don’t need additional preparation or cooking. Smith has already researched HCA levels in cooked meat and found that adding certain spices and marinades before cooking can reduce HCA content in the meat.

The ready-to-eat product project was a collaboration with several other K-State researchers, including Terry Houser, assistant professor of meat science; Melvin Hunt, professor of animal sciences and industry; Kanithaporn Puangsombat, December 2010 doctoral graduate in food science, Bangkok, Thailand; and Priyadarshini Gadgil, a K-State graduate who now works as a research scientist at the U.S. Department of Agriculture Center for Grain and Animal Health Research in Manhattan. Their research appears in a recent issue of Meat Science, the journal of the American Meat Science Association.

The study focuses on eight types of ready-to-eat meat products: beef hot dogs, beef-pork-turkey hot dogs, deli roast beef, deli ham, deli turkey, fully cooked bacon, pepperoni and rotisserie chicken.

“These are the most common types of ready-to-eat products, and their use has increased in recent years because of convenience,” Smith said. “For this research, we took each of these products and prepared them as a consumer would.”

The researchers heated up the hot dogs and bacon in a microwave, cooked the pepperoni on a pizza either in the oven or a microwave and used the chicken and deli meat as obtained. After doing so, they studied the meat to determine whether it contained five different types of HCAs according to nanograms per gram, ng/g.

Pepperoni had the least HCA content, 0.05 ng/g, followed by hot dogs and deli meat, 0.5 ng/g). Such amounts are low, and the researchers concluded that consuming such ready-to-eat meat products contributes very little to HCA intake.

Fully cooked bacon, with 1.1 ng/g, and rotisserie chicken meat, with 1.9 ng/g, contained all five types of HCAs tested. Rotisserie chicken skin had significantly higher HCA levels, with 16.3 ng/g. This is because chicken skin contains more fat and protein and less moisture, and HCA levels tend to increase as moisture decreases, Smith said.

“Based on this research, HCA consumption can be reduced by not eating chicken skin,” he said.

The reasons for lower HCA content in some of the other ready-to-eat products may be because of the higher water content in the ready-to-eat products. More moisture prevents many HCAs from forming. Ready-to-eat products are often enhanced products, meaning they have a water solution with flavoring added to them.

“Hot dogs and deli meat may have low HCA levels because they are manufactured at low temperatures,” Smith said. “The low HCA levels may also be from ingredients that are added to the meat and prevent HCAs from forming while the meat is cooking.”

Fast Spinning Asteroid skims Earth atmosphere

This photo taken on Nov. 16, 2010 shows the asteroid 2010 WA as it passes within 24,000 miles (38,000 kilometers) as seen by astronomers using a telescope at the Magdalena Ridge Observatory in New Mexico.

It is about 10 feet (3 meters) wide. Credit: Dr. William Ryan/Magdalena Ridge Observatory/2.4-meter Telescope/New Mexico Tech

Lose That Weight Now! You know you want to.

Here is some good advice from another doctor who is on the cutting edge in the treatment of obesity, Dr Phil.

He talks to patients about how their weight is contributing to medical problems and encourages them to aim for a modest weight loss by making simple changes such as cutting out fruit juices and Cola or other high-calorie beverages and walking in five- to 10-minute increments several times a day. "I encourage patients to lose 5% to 10%, see where they are and then try for another 5% to 10%," he says.

He and his staff, which includes other physicians, dietitians and behavioural psychologists, insist that patients keep good food journals, which the health professionals review. "A lot of time they aren't eating the wrong foods, but they are just eating too much," he says.

Most 90% of people can lose weight with diet, exercise and behaviour modification. The longer people keep food logs, the better they do, he says. When people get off track, it's because they are often no longer keeping food journals and they're not being weighed weekly.

He believes primary-care doctors could make great strides in helping patients lose weight by inviting them to come into the office every week to be weighed: "That helps keep them focussed and accountable."

Achieving steady weight loss is not easy, because it means a change in your lifestyle or behaviour and most patients know it, he says. "Despite some patients being prompted and guided to do all the right things, their minds are completely resistant to the necessary behavioural change required, and therefore they experience less or no weight loss."