Submitted by celler on Thu, 2014-04-17 09:33
Number theorists are particularly interested in prime numbers (those integers that cannot be divided by any number other than itself and 1) and Diophantine equations. Diophantine equations are polynomial equations (those with two or more variables) in which the coefficients are all integers. It is these equations that are the inspiration for a recent proof offered by Dinakar Ramakrishnan, Caltech's Taussky-Todd-Lonergan Professor of Mathematics and executive officer for mathematics, and his coauthor, Mladen Dimitrov, formerly an Olga Taussky and John Todd Instructor in Mathematics at Caltech and now professor of mathematics at the University of Lille in France. What Ramakrishnan and Dimitrov showed is that a specific collection of systems of homogeneous equations with six variables has only a finite number of rational solutions (up to scaling).
Submitted by jsconrad on Wed, 2014-04-16 08:15
Caltech biologist Elliot Meyerowitz and colleagues have found that the unusual shape of pavement cells, found on the leaves of flowering plants, represents a state of balance—an individual cell's tug-of-war to maintain structural integrity while also dynamically responding to the pushes and pulls of mechanical stress.
Submitted by jsconrad on Thu, 2014-04-10 11:48
Caltech researchers uncover a mechanism for how fruit flies regulate their flight speed, using both vision and wind-sensing information from their antennae.
Submitted by kfesenma on Thu, 2014-04-10 10:52
A lot can happen to a rock over the course of two and a half billion years. It can get buried and heated; fluids remove some of its minerals and precipitate others; its chemistry changes. So if you want to use that rock to learn about the conditions on the early Earth, you have to do some geologic sleuthing: You have to figure out which parts of the rock are original and which came later. That is a tricky task, but now a team of Caltech researchers has developed and applied a unique technique that removes much of the guesswork.
Submitted by kfesenma on Thu, 2014-04-03 11:00
In 2005, NASA's Cassini spacecraft sent pictures back to Earth depicting an icy Saturnian moon spewing water vapor and ice from fractures, known as "tiger stripes," in its frozen surface. It was big news that tiny Enceladus—a mere 500 kilometers in diameter—was such an active place. Since then, scientists have hypothesized that a large reservoir of water lies beneath that icy surface, possibly fueling the plumes. Now, using gravity measurements collected by Cassini, scientists have confirmed that Enceladus does in fact harbor a large subsurface ocean near its south pole, beneath those tiger stripes.
Submitted by jsconrad on Thu, 2014-04-03 09:30
For years, researchers have been interested in developing quantum computers—the theoretical next generation of technology that will outperform conventional computers. Instead of holding data in bits, the digital units used by computers today, quantum computers store information in units called "qubits." One approach for computing with qubits relies on the creation of two single photons that interfere with one another in a device called a waveguide.
Submitted by kfesenma on Tue, 2014-04-01 12:00
One day while casually reading a review article, Caltech chemical engineer Mikhail Shapiro came across a mention of gas vesicles—tiny gas-filled structures used by some photosynthetic microorganisms to control buoyancy. It was a light-bulb moment. Shapiro is always on the lookout for new ways to enhance imaging techniques such as ultrasound or MRI, and the natural nanostructures seemed to be just the ticket to improve ultrasound imaging agents.
Submitted by celler on Mon, 2014-03-17 07:45
Astronomers announced today that they have acquired the first direct evidence that gravitational waves rippled through our infant universe during an explosive period of growth called inflation. This is the strongest confirmation yet of cosmic inflation theories, which say the universe expanded by 100 trillion trillion times in less than the blink of an eye.