Nature's editors have picked their favorite research papers of 2007, and three studies involving MIT scientists are among the 18 selected.
Topics covered by the MIT papers include the search for extrasolar planets, a new technique for weighing single cells and the future of irregular verbs.
A research group including MIT associate professor Sara Seager reported new information about the atmosphere of an extrasolar planet located about 904 trillion miles from Earth.
The team, based at Goddard Space Flight Center, used NASA's Spitzer Space Telescope to capture the most detailed information yet about an extrasolar planet.
The researchers analyzed the light emitted from a planet known as HD 209458b. They expected the planet to have water vapor, but the analysis did not show any signs of water vapor in the atmosphere. The team's other major finding was evidence of sandy particles known as silicates in the planet's atmosphere. NASA scientists hypothesize that clouds of those particles could be blocking emissions from water vapors.
MIT researchers reported a new way to measure the mass of single cells with high accuracy. The new technique, developed by Scott Manalis, associate professor of mechanical and biological engineering, and others at MIT, allows cells to remain in fluid while they are measured.
In the new system, cells or particles are pumped through a microchannel that oscillates within a vacuum. As the sample is pumped through, the frequency of oscillation changes slightly, and the mass of the sample can be calculated by measuring that change.
So far, the researchers have weighed particles with a resolution down to slightly below a femtogram (10 -15 grams). The work could lead to the development of inexpensive, portable diagnostic devices.
A team from MIT and Harvard exploring language evolution reported on the pressures on irregular verbs to evolve over time.
The researchers, including Erez Lieberman, a graduate student in the Harvard-MIT Division of Health Sciences and Technology, developed a formula to predict how long it takes irregular verbs that do not take an "-ed" ending in the past tense to "regularize" as the language evolves.
Their study, based on an analysis of the English language as it evolved from Old English, found that English verbs are regularized at a rate that is inversely proportional to the square root of their usage frequency. In other words, a verb used 100 times less frequently will evolve 10 times as fast.