Science Scene - Penguin Physics

With thousands of Emperor penguins(Aptenodytes forsteri) huddled close together for warmth on the ice sheets of Antarctica, there seems bound to be some competition for a toasty spot near the middle. But these enormous clusters manage to bring each penguin in for a chance to warm up—all without causing a dangerous crush. How do they do it?

A team of researchers positioned a high-resolution, time-lapse camera to capture the surprisingly subtle and complex movement dynamics of one penguin pack near the Neumayer Antarctic Research Station. An analysis of the video revealed the coordinated movements that were invisible to the human eye in real time.

In the sped-up video, they could see that the "Emperor penguins move collectively in a highly coordinated manner to ensure mobility while at the same time keeping the buddle packed," the researchers noted in a new study, which published online Wednesday in PLoS ONE. "Every 30-60 seconds, all penguins made small steps that travel as a wave through the entire huddle. Over time these small movements lead to large-scale reorganization of the huddle." And the reshuffle takes time, with each stepmeasuring just five to 10 centimeters.

The wave pattern was not unlike that of a a sound wave traveling through a fluid, pointed out the research team, which was led in part by Daniel Zitterbart, of the Department of Physics at the University of Erlangen-Nuremberg in Germany. "In general, individual penguins do not change their position relative to their neighbors, and they do not force their way in or out of a huddle," they noted.

In dense crowds, people also tend to move in waves. But we are not so orderly, which often leads to chaotic crushes and occasionally death. "Why these waves are uncoordinated, turbulent and dangerous in a human crowd but not in a penguin huddle remains an open question," Zitterbart and his and colleagues wrote. Another lingering unknown is whether the evenly paced penguin waves are the work of a few leaders, like enthusiastic fans at a baseball game, or whether each penguin "follows a well-defined hierarchy among group members, similar to the collective behavior in pigeon flocks."

But however the wave gets going, it seems to do the trick. Most of the penguins featured in the film were carrying an egg and were in the midst of fasting—all the while facing temperatures of -33 to -43 degrees Celsius with howling August winds of 8.3 meters per second. 

Space Shuttle Tribute

Below is a summary of the program, followed by an outstanding 8-minute look at all 135 missions.  It brought tears to my eyes.  Well Done NASA.  (Source)


Now that Atlantis has safely returned to Earth and the 30-year space shuttle program has drawn to a close, it's time to look back at the reign of Discovery, Atlantis, Endeavour and the tragically shortened careers of Challenger andColumbia. Since 1981 NASA has launched 135 shuttle missions, reaching destinations such as the Mir space station, the Hubble Space Telescope and the International Space Station.

In those three decades the shuttle has had its triumphs—fixing the initially flawed Hubble, for one—and its tragedies. Below is a video tribute to the space shuttle, prepared by our colleagues at Nature, which touches on all those highs and lows. (Scientific American is part of Nature Publishing Group.) The tribute features footage from every shuttle flight, including the STS 135 mission that concluded this morning, and features a good number of the 355 individuals who flew on the shuttles.

Science Scene - Heart of the Matter

Never mind your dentist. Your cardiologist might want you to brush your teeth more often.


Neglecting to brush twice a day could lead to a 70 percent increased risk of cardiovascular disease, according to a new large population-based study.

Researchers examined self-reported oral hygiene habits and coronary disease in 11,869 adults aged 35 and older (with a mean age of 50) from the Scottish Health Survey—a study conducted once every three to five years—between the years 1995 and 2003. The team followed up with subjects after an average of eight years to see if they had had a heart attack or coronary disease.

Even though the researchers found that those who reported brushing their teeth less than twice a day were more likely to be male, older, smokers and to have other health issues (such as diabetes, hypertension and obesity), the team controlled for those variables and others and still found that tooth brushing is associated with cardiovascular disease. The association held even after adjusting for socioeconomic group, visits to dentist, BMI, family history of cardiovascular disease, hypertension and diagnosis of diabetes.

Although the study isn't proof of causation, the researchers highlight inflammation as a possible mechanism behind the link between periodontal disease and heart disease.  Chronic inflammation—and the body's response to it—is thought to be a factor for heart disease, and as the authors noted, periodontal disease "is one of the most common chronic infections and is associated with a moderate systemic inflammatory response."

Source

Science Scene - Out Of This World :o)

Another entry brought to you courtesy of Scientific American. As an engineer, can I say that I love this site, and if not, PI in your face :o)

The Japanese government is prepared to spend some 2 trillion yen on a one-gigawatt orbiting solar power station—and this week Mitsubishi and other Japanese companies have signed on to boost the effort.

Boasting some four kilometers of solar panels—maybe of the super efficient Spectrolab variety but more likely domestically sourced from Mitsubishi or Sharp—the space solar power station would orbit some 36,000 kilometers above Earth and transmit power via microwave or laser beam.The benefit? Constant solar energy production as the space-based power plant never passes out of sunlight. The downsides? Only enough power for roughly 300,000 Japanese homes at a price tag of $21 billion, according to Japan's science ministry (about 127 million people live in Japan in some 47 million households).

The Japan Aerospace Exploration Agency (JAXA) aims to have a system in space by 2030. The first step will be launching a test satellite that will gather solar power and beam it back to Earth, probably in 2015. Already, ground tests show that some solar power (180 watts) can be beamed successfully.

In the U.S., where space solar has been on the drawing board since at least the 1960s, California's Pacific Gas & Electric [Disclaimer, I used to work for PG&E] has pledged to buy power from a planned 200-megawatt space solar station put together by Solaren that is still being developed.

But the U.S. government has mixed feelings about space solar. Despite some $80 million spent over decades by NASA, the alternative energy source is no closer to fruition using public funds. And other government agency estimates put the price tag for space solar at $1 billion per megawatt—making this the most expensive power source identified to date in any solar system.

To save you from doing all the math and junk, at my utility, we use $1000/KW as a new generation number, which is $1/W. So, $1B per Megawatt (ten to the sixth) is $1000/W. Yes folks, that means this solution is 1000 times more expensive than other sources of energy. While coming up with alternatives to greenhouse gas producing power sources is getting more difficult, earth based solutions such as nuclear and carbon sequestration, are anticipated to be in the $2,500 - $3,500 per KW range. This is still much cheaper than mirrors in space.

One Way Ticket :o)

Landing humans on Mars is a completely achievable feat with current technology—if you are okay with the idea of a one-way ticket.

The problem today isn't the launch capabilities or the guidance systems or the navigation. It is the energetic particles from the sun, which can rip apart DNA. Space travelers returning home from a Mars mission would soon die from this radiation poisoning, if they managed to survive the experience at all. A protective shield would simply be too massive to be practical; assuming no technological breakthroughs, the shield would weigh around 400 tons.

It has been noted that a one-way trip would be more sensible. It has even been suggested that we could send senior-citizen volunteers to the Red Planet, where they could spend their final months conducting experiments, laying the groundwork for future permanent settlements and digging their own graves.

A round-trip Mars mission might be achievable, though—not with faster rockets, but with biomedical advances. Drugs that safely combat the effects of radiation poisoning seem to be the only way to make a voyage back home feasible.

I loved reading this entry about the possibility of sending people to Mars to forge the way into our next frontier. I know I can think of a few non-senior citizen people I would like to volunteer for this expedition, how about you :o) To see the full entry, go over to Scientific American.

First Fire Ants, Killer Bees, Rasberry Ants, What Next

While I am not a fan of bees (I think I am allergic, last time I got stung I had a welt the size of a travel Kleenex package on my thigh), I know how vital they are to pollination, not only for flowers and fruit in our yards, but for worldwide agricultural production. Today, care of The Nature Conservancy and Scientific American - 60 Second Science, I came across this article regarding the latest threat to the honey bee. I clicked through to the links, I find the information fascinating :o)


Viruses, grueling journeys, monoculture diets. U.S. honeybees have had it rough lately, and millions have perished from the mysterious colony collapse disorder (CCD). But now some of the nation's bees have a new threat to contend with: ants. And not just any ants. These ants are crazy—Rasberry crazy ants (Paratrenicha species near pubens), to be precise.


Named for their helter-skelter scamper, which contrasts with most ants' standard rank-and-file march, the tiny invasive ants were first noticed in near Houston, Texas, in 2002 and have been destroying electronics, pestering picnickers and gunking up sewage pumps ever since. And now they have started to go after local honeybee hives, according to a recent Associated Press report.


Beekeepers say the omnivorous ants swarming the hives appear to be less interested in the sweet honey inside than they are in the bee larvae there. And once a hive is decimated, the ants will take over and use it to raise their own young. One beekeeper reported that the ants had destroyed about 100 of his hives in the past year. Aside from the crops they help to pollinate, the bees also produce about 4.9 million pounds of honey a year, the AP said.


But these insidious ants have yet to gain state recognition as agricultural pests, which would free up more money for research into their lifecycles and biology. But in order to gain that title, the Texas and U.S. departments of agriculture require more study. And many feel that time is of the essence.


"This is absolutely idiotic," Tom Rasberry, an exterminator and the ants' namesake, told the wire service. "If killing honeybees does not put it in the ag pest category, I don’t know what does."


These ants are on the march—or scatter, as it were. Local researchers note that they are spreading north at a good clip and are now found in more than 10 Texas counties. They're easily transported accidentally through trash and plant material, according to the information on the University of Texas A&M Center for Urban & Structural Entomology Web site. Bees and electronics don't seem to be the only targets of these crazy ants. They also appear to have a taste for everything from ladybugs to fire ants. But even the experts are frustrated by the lack of knowledge about these new nuisances.


"There are literally thousands of things we need to find out," Rasberry said, "otherwise we're going to do just like we did with the fire ant and wait until it was too late."