Science & Technology

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Princeton pair sets world record in packing puzzle

Kitta MacPherson
Princeton University
Wed, 12 Aug 2009 23:13 UTC

© Princeton University/Torquato Lab
Princeton researchers have beaten the present world record for packing the most tetrahedra into a volume. Research into these so-called packing problems have produced deep mathematical ideas and led to practical applications as well.

Finding the best way to pack the greatest quantity of a specifically shaped object into a confined space may sound simple, yet it consistently has led to deep mathematical concepts and practical applications, such as improved computer security codes.

When mathematicians solved a famed sphere-packing problem in 2005, one that first had been posed by renowned mathematician and astronomer Johannes Kepler in 1611, it made worldwide headlines.

Now, two Princeton University researchers have made a major advance in addressing a twist in the packing problem, jamming more tetrahedra -- solid figures with four triangular faces -- and other polyhedral solid objects than ever before into a space. The work could result in better ways to store data on compact discs as well as a better understanding of matter itself.

Fungus Found in Humans Shown To Be Nimble in Mating Game

Brown University
Wed, 12 Aug 2009 22:58 UTC

Providence, Rhode Island - Brown University researchers have discovered that Candida albicans, a human fungal pathogen that causes thrush and other diseases, pursues same-sex mating in addition to conventional opposite-sex mating.

Scientists have observed this same-sex mode of reproduction in other fungi, but this is the first time they have identified it in Candida albicans, the most common human fungal pathogen.

Details are highlighted in the August 2009 edition of the journal Nature.

"This discovery really surprised us," said Richard Bennett, assistant professor of biology in the Department Molecular Microbiology and Immunology at Brown. "Candida albicans has two mating types - a and alpha - and it was assumed that mating could only occur between these two cell types. We now know that a mechanism exists for same-sex mating, and thus sex could be more prevalent in this species than previously recognized."

Confession: NASA can't keep up with killer asteroids

Seth Borenstein
Associated Press
Wed, 12 Aug 2009 20:18 UTC

NASA is charged with seeking out nearly all the asteroids that threaten Earth but doesn't have the money to do the job, a federal report says.

That's because even though Congress assigned the space agency this mission four years ago, it never gave NASA money to build the necessary telescopes, the new National Academy of Sciences report says. Specifically, NASA has been ordered to spot 90 percent of the potentially deadly rocks hurtling through space by 2020.

Even so, NASA says it's completed about one-third of its assignment with its current telescope system.

NASA estimates that there are about 20,000 asteroids and comets in our solar system that are potential threats to Earth. They are larger than 460 feet in diameter - slightly smaller than the Superdome in New Orleans. So far, scientists know where about 6,000 of these objects are.

Rocks between 460 feet and 3,280 feet in diameter can devastate an entire region but not the entire globe, said Lindley Johnson, NASA's manager of the near-Earth objects program. Objects bigger than that are even more threatening, of course.

Just last month astronomers were surprised when an object of unknown size and origin bashed into Jupiter and created an Earth-sized bruise that is still spreading. Jupiter does get slammed more often than Earth because of its immense gravity, enormous size and location.

Comment: And recently Venus too: Smashing days! New bright spot observed on Venus

Comment: Maybe NASA isn't keeping track of them, but someone is and they're not gonna tell us when something is about to hit.

Diebold Quietly Patches Security Flaw in Vote Counting Software

Kim Zetter
Wired.com
Wed, 12 Aug 2009 19:29 UTC

Premier Election Solutions, formerly Diebold, has patched a serious security weakness in its election tabulation software used in the majority of states, according to a lab that tested the new version and a federal commission that certified it.

The flaw in the tabulation software was discovered by Wired.com earlier this year, and involved the program's auditing logs. The logs failed to record significant events occurring on a computer running the software, including the act of someone deleting votes during or after an election. The logs also failed to record who performed an action on the system, and listed some events with the wrong date and timestamps.

Traces of planet collision found

British Broadcasting Corporation
Wed, 12 Aug 2009 00:43 UTC

A Nasa space telescope has found evidence of a high-speed collision between two burgeoning planets orbiting a young star.

Astronomers say the cosmic smash-up is similar to the one that formed our Moon some four billion years ago, when a Mars-sized object crashed into Earth.

In this case, two rocky bodies are thought to have slammed into one another in the last few thousand years.

Details are to be published in the Astrophysical Journal.

Can oil form without organic matter?

Amy Callaghan
Cosmos Online
Tue, 11 Aug 2009 23:31 UTC

Sydney: New research reveals that the hydrocarbon elements of oil and gas may be able to form deep in the Earth's crust with out the need for fossilised organic matter.

A team led by researchers at the Carnegie Institution's Geophysical Laboratory, in Washington DC, have studied the chemical reactions of methane at high temperatures and pressures and under oxidising conditions. They say that this shows that - theoretically at least - oil can form deep in the Earth's crust without the need for decomposing plants or animal material.

Most of the crude oil and gas we use was formed hundreds of millions of years ago when vast forests decomposed under great heat and pressure below sediment in the Earth's crust.

Archaeologists find cuneiform tablets in a 2,700-year old Turkish temple

University of Toronto
Tue, 11 Aug 2009 23:24 UTC

An example of cuneiform tablet

Excavations led by a University of Toronto archaeologist at the site of a recently discovered temple in southeastern Turkey have uncovered a cache of cuneiform tablets dating back to the Iron Age period between 1200 and 600 BCE. Found in the temple's cella, or 'holy of holies', the tablets are part of a possible archive that may provide insights into Assyrian imperial aspirations.

The assemblage appears to represent a Neo-Assyrian renovation of an older Neo-Hittite temple complex, providing a rare glimpse into the religious dimension of Assyrian imperial ideology," says Timothy Harrison, professor of near eastern archaeology in the Department of Near & Middle Eastern Civilizations and director of U of T's Tayinat Archaeological Project (TAP). "The tablets, and the information they contain, may possibly highlight the imperial ambitions of one of the great powers of the ancient world, and its lasting influence on the political culture of the Middle East." The cella also contained gold, bronze and iron implements, libation vessels and ornately decorated ritual objects.

Human Sacrifice? Archaeologist creates stir with new book on Cahokia Mounds

George Pawlaczyk
Belleville News-Democrat
Tue, 11 Aug 2009 12:16 UTC

Human sacrifice! Victims buried alive! Read all about it in Cahokia -- Ancient America's Great City on the Mississippi.

According to this new book by University of Illinois archaeologist and professor of anthropology Tim Pauketat, the mound builders were not always the idyllic, corn-growing, pottery-making, fishing-hunting gentle villagers depicted in various dioramas at the Cahokia Mounds State Historic Site in Collinsville.

Pauketat said these long-vanished people practiced human sacrifice of women and men on a mass scale and weren't always careful to bury only the dead.

Computer scientists take over electronic voting machine with new programming technique

Daniel Kane
University of California - San Diego
Tue, 11 Aug 2009 00:01 UTC

Voting machines must remain secure throughout their entire service lifetime, and this study demonstrates how a relatively new programming technique can be used to take control of a voting machine that was designed to resist takeover.

Computer scientists demonstrated that criminals could hack an electronic voting machine and steal votes using a malicious programming approach that had not been invented when the voting machine was designed. The team of scientists from University of California, San Diego, the University of Michigan, and Princeton University employed "return-oriented programming" to force a Sequoia AVC Advantage electronic voting machine to turn against itself and steal votes.

Tiny 'MEMS' devices to filter, amplify electronic signals

Emil Venere
Purdue University News
Mon, 10 Aug 2009 23:44 UTC

© (Purdue News Service photo/Andrew Hancock)
Jeffrey Rhoads, a Purdue assistant professor of mechanical engineering, and graduate student Venkata Bharadwaj Chivukula use equipment called a vacuum probe station in research to develop a new class of tiny mechanical devices.

West Lafayette, Ind. -Researchers are developing a new class of tiny mechanical devices containing vibrating, hair-thin structures that could be used to filter electronic signals in cell phones and for other more exotic applications.

Because the devices, called resonators, vibrate in specific patterns, they are able to cancel out signals having certain frequencies and allow others to pass. The result is a new type of "band-pass" filter, a component commonly used in electronics to permit some signals to pass through a cell phone's circuitry while blocking others, said Jeffrey Rhoads, an assistant professor of mechanical engineering at Purdue University.

Such filters are critical for cell phones and other portable electronics because they allow devices to process signals with minimal interference and maximum transmission efficiency. The new technology represents a potential way to further miniaturize band-pass filters while improving their performance and reducing power use, Rhoads said.