Science•
on January 5th, 2010•
In astronomy and cosmology, dark matter is theoretical matter that is undetectable by its emitted radiation, but whose presence can be inferred from gravitational effects on visible matter. As important as dark matter is believed to be in the universe, direct evidence of its existence and a concrete understanding of its nature have remained elusive.
Unsolved problems in physics: What is dark matter? How is it generated? Is it related to supersymmetry?
Can we use Dark Matter as an Energy Source for Rocket Technology?
Current rocket technology can not send the spaceship very far, because the amount of the chemical fuel it can take is limited. Dark matter (DM) may be used as fuel to solve this problem. A DM engine uses dark matter annihilation products as propulsion. The acceleration is proportional to the velocity, which makes the velocity increase exponentially with time in non-relativistic region. The important points for the acceleration are how dense is the DM density and how large is the saturation region. The parameters of the spaceship may also have great influence on the results. We show that the (sub)halos can accelerate the spaceship to velocity $ 10^{- 5} c \sim 10^{- 3} c$.
3D Model of dark matter, reconstructed from measurements of weak gravitational lensing with the Hubble Space Telescope.
Written by Todd Borghesani
Aerospace, Science•
on January 5th, 2010•
NASA internships are a perfect way to launch your future. Most people do not realize how many types of scientific and engineering specialties are employed by the Agency. The great people at NASA really care about your “real world” education. Do not hesitate to apply!
NASA Ames Summer 2010 Graduate Student Internship Programs
The Systems Teaching Institute is offering a 10- to 12-week summer research program for graduate students in fields relevant to the research done at NASA’s Ames Research Center in California. Selected students will gain hands-on experience working with cutting-edge research and development teams, an increased understanding of the NASA mission, and mentoring in research management skills. Besides working closely with Ames scientists and engineers, students will have the opportunity to attend seminars tailored to their level of expertise, career development workshops, and an end-of-summer symposium where they can share their results with other student interns. Awards (in the form of travel support to a national conference) will be given for the best symposium poster presentations.
For further information about this opportunity, visit http://uarc.ucsc.edu/sti/grad_10.shtml. Questions regarding this opportunity may be submitted by e-mail to Dr. Natalie Batalha at nbatalha@science.sjsu.edu or Amy Gilbert at amy.gilbert@adm.ucsc.edu.
2010 NASA Planetary Biology Internship
The NASA Planetary Biology Internship Program provides opportunities each year for 10 interns to undertake research at NASA research centers, NASA-sponsored laboratories, and academic institutions. The pursuit of such studies is expected to broaden the base of this new science by encouraging people in many different fields to take part. Applicants must be enrolled in graduate school.
Students accepted in the PBI program will be expected to carry out research with a NASA-sponsored investigator for eight weeks, usually during the summer months. Typical programs in which interns may become involved include: global ecology and remote sensing; microbial ecology and bio-mineralization; advanced life support; and origin and early evolution of life.
Applications are due Feb. 15, 2010. For more information, visit http://www.mbl.edu/education/courses/other_programs/pbi.html . Please e-mail questions about this opportunity to Michael Dolan at pbi@geo.umass.edu.
2010 Summer Undergraduate Research Fellowships
Caltech’s Summer Undergraduate Research Fellowships, or SURF, project introduces undergraduate students to research under the guidance of seasoned mentors at Caltech or the Jet Propulsion Laboratory. Students experience the process of research as a creative intellectual activity and gain a more realistic view of the opportunities and demands of a professional research career.
Please e-mail any questions about this opportunity to the Caltech Student-Faculty Programs office at sfp@caltech.edu.
Written by Todd Borghesani
Science•
on January 1st, 2010•
Russia’s top space researchers will hold a closed-door meeting to plan a mission to deflect 99942 Apophis, an asteroid that will fly close to Earth two decades from now, said Anatoly N. Perminov, the head of Russia’s space agency, during an interview on Russian radio on Wednesday.
Mr. Perminov said Apophis, named for the Egyptian god of destruction, is about three times the size of the Tunguska meteorite, apparently the cause of a 1908 explosion in Siberia that knocked over an estimated 80 million trees. He said that according to his experts’ calculation, there was still time to design a spacecraft that could alter Apophis’s path before it made a dangerous swing toward Earth.
“I don’t remember exactly, but it seems to me it could hit the Earth by 2032,” he said, adding, “We’re talking about people’s lives here. It’s better to spend several million dollars and create this system, which would not allow a collision to happen, than wait for it to happen and kill hundreds of thousands of people.”
In fact, Apophis’s chances of hitting Earth have been downgraded since it was discovered in 2004, NASA said this year. Scientists originally thought the orbit of the 1,000-foot-long asteroid gave it a 2.7 percent chance of hitting Earth on its first approach in 2029, but after studying its path they said it would remain 18,300 miles above the planet’s surface.
Find the original article posted on the NY Times
Engineering, People, Science•
on December 20th, 2009•
Guess what’s on the U.S. Air Force’s wish list this holiday season. Sony’s popular PlayStation 3 gaming console. Thousands of them. The Air Force Research Laboratory in Rome, N.Y., recently issued a request for proposal indicating its intention to purchase 2,200 PlayStation 3 (PS3) consoles.
But the military researchers don’t plan to play “Call of Duty: Modern Warfare 2″ or any of the season’s other blockbuster games. They plan to string the consoles together into a massive supercomputer and study how well they can enhance the military’s high-performance computing systems.
Once the researchers configured the hardware, they installed the Linux operating system on them, turning the gaming consoles into a military-grade supercomputer. Linderman said their first PS3 cluster was used in applications such as high-definition video processing and “neuromorphic” computing, which mimics the way the human brain perceives and processes images and information. When the new cluster of 2,200 PS3 consoles arrive in the next month or so, he said they will likely be used for similar projects.
Researchers Across the Country Harness Power of PlayStation 3. David Bader, a professor and executive director of high performance computing at the Georgia Institute of Technology, has been involved in a number of projects involving PlayStation clusters.
When the PlayStation launched in 2006, he said, its processor far surpassed those of its generation. “Sony wanted a processor that they could use inside a game box that would be able to render the games but also incorporate real-world physics, emotion and really new aspects to game playing,” Bader said.
The same chip that enabled high-octane game play also powered Toshiba’s high-end HD TVs and technology created by IBM for oil and gas exploration.
At Georgia Tech, Bader has researched the possibility of using PS3 clusters in aircraft monitoring and financial risk assessment.
One project proposed using PlayStation 3 consoles on board commercial airplanes, he said. Consoles would not only provide in-flight entertainment for each passenger, but also serve as sensors around the aircraft that would alert the pilot to potential problems and failures.
Astrophysicists at the University of Massachusetts at Dartmouth are using a cluster of PS3 consoles to research gravitational waves and black holes. And even the U.S. Immigration and Customs Enforcement agency’s Cyber Crimes Center has used linked PS3s to solve Internet crimes.
It takes a very unique team to bring a visionary’s imagination to life. Cameron, who has served as an adviser to NASA to investigate a camera for a Mars mission, is known for taking the science in his flicks very seriously. So how did he do?
Here we check on some of the movie’s scientific bona fides with top researchers in their respective fields to see where artistic license and scientific plausibility meld. As fantasy and reality are melded in CG worlds, the entertainment sector offers opportunities for computer scientists, artists, engineers, designers and scientists across all disciplines.
Technologies of Avatar: Amplified Mobility Platform
For work, combat and stomping through Pandora’s rainforest, humans gear up in Amplified Mobility Platform (AMP) suits. These armored exoskeletal vehicles are very similar to the Armored Personnel Units featured in The Matrix Revolutions and the power loader in Cameron’s own Aliens, but with an enclosed cockpit.
From this perch in the machine, the movements of a human operator’s arms and legs are translated to the suit’s exterior limbs and “amplified.” The operator swings his arm several inches, and the AMP’s corresponding giant metal arm scythes a 10-foot arc.
“The super hydraulics are all very strong so [the AMP suit] can crush buildings and do all the things that, like, a tank could do,” says Avatar vehicle designer Ty Ruben Ellingson in a promotional video. The Herculean strength granted to the AMP suit’s operator lets space marines tote giant 30-mm autocannons into battle as easily as one might carry a rifle. In further characterizing the AMP suit, John Rosengrant, design supervisor for Stan Winston Studios, says it’s “an Apache helicopter with legs.”
The Science: For decades, the U.S. military has been looking into powered exoskeleton suits that could let soldiers lug around heavy equipment—as well as bigger guns—while aiding in rescue work, construction and injury rehabilitation.
The Army’s research and development branch, DARPA (Defense Advanced Research Projects Agency) issued various grants since 2000 under its Exoskeletons for Human Performance Augmentation program, including funding for the Raytheon Sarcos team. Their machine, called XOS, weighs 150 pounds and fits around the wearer’s arms, legs and back.
This aluminum robot’s hydraulics allow the wearer to lift 200 pounds hundreds of times without tiring, yet the XOS suit remains nimble enough to allow the man-cum-machine to climb stairs or kick a soccer ball. The key hurdle for the Raytheon Sarcos device is independently powering it. For now, the XOS remains tethered to an external power source.
The World of Avatar: Alpha Centauri
The white-yellow glow of Alpha Centauri A, a star very similar to our Sun, illuminates the giant gaseous planet Polyphemus and its tropical moon Pandora. On this lush world, great beasts roam the jungles and pterodactyl-like creatures soar through the sky. A sentient, blue-skinned humanoid species known as the Na’vi has evolved here and learned to live in harmony with nature.
The Science: Alpha Centauri A is one of the three stars that make up Alpha Centauri, which is located 4.37 light years away, making it our solar system’s closest stellar neighbor. This proximity has inspired an intense hunt to reveal the exoplanets that could be right next door.
Last January, a team led by Yale astronomer Barbara Fischer began a five-year survey of Alpha Centauri using a 1.5-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. Her group is looking for rhythmic, telltale patterns in the wavelengths of a star’s light caused by the gravitational tugging of orbiting worlds.
This “wobble technique” has already ruled out the presence of Jupiter- or Saturn-scale exoplanets (like Polyphemus) around the Alpha Centauri stars. But “there’s a very good chance,” Fischer says, that planets with masses near that of Earth’s could grace this star system. “There’s still so much we don’t understand about planet formation around single stars,” Fischer says—let alone triple-star systems like Alpha Centauri. So in terms of what may be out there, “it’s almost an open slate.”
The orbital mechanics of the two stars at Alpha Centauri’s heart, often called Cen A and Cen B, indicate where planets are likely to reside. The stellar duo gravitationally tangos as close as 11 astronomical units (AUs, the average distance from the Sun to Earth) to each other before swinging as far apart as 36 AU. (The third star, a red dwarf called Proxima Centauri, circles this couple at a considerable distance and is too faint for Fischer’s team to study, but it could boast small planets, too.)
Given this setup, the orbits of exoplanets that formed 2 AU away and more from Cen A and Cen B would get destabilized by the other star and eventually get shot right out of the system, Fischer says.
Fortunately, if life has taken root in the Alpha Centauri system, it is not likely to suffer this fate. The habitable Goldilocks zone—the not-too-hot, not-too-cold orbital band where water can be liquid on a planet or a moon’s surface—is situated closer to both Cen A and Cen B. The former, a bit bigger than the Sun, has a Goldilocks zone of around 1.2 AUs out.
From Cen B, at about 90 percent of the Sun’s mass, this zone is found at about 0.75 AU. Since both stars are chemically similar to the Sun, the same general mixture of elements that allowed life to develop on Earth should have been available in the primordial soups of both Cen A and Cen B’s planetary brood.
For now, the jury is still out on whether the Alpha Centauri system has smaller, Earth-like worlds in life-friendly regions, but Fischer expects answers shortly. “By the end of year four [2012], we’ll really know,” she says. Meanwhile, other efforts led by famed planet-hunter Michel Mayor of the University of Geneva and a new initiative by the University of Canterbury in the United Kingdom may render the verdict even sooner.
For more on the science facts and science fiction in Avatar, read the full story on Popular Mechanics.