Dickinson Reveales that the Twirling Seeds of Maple Trees Spin Like Miniature Helicopters As They Fall to the Ground
Research by Michael H. Dickinson, the Zarem Professor of Bioengineering and David Lentink of Wageningen, reveals that, by swirling, maple seeds generate a tornado-like vortex that sits atop the front leading edge of the seeds as they spin slowly to the ground. This leading-edge vortex lowers the air pressure over the upper surface of the maple seed, effectively sucking the wing upward to oppose gravity, giving it a boost. The vortex doubles the lift generated by the seeds compared to nonswirling seeds. "There is enormous interest in the development of micro air vehicles, which, because of their size, must function using the same physical principles employed by small, natural flying devices such as insects and maple seeds," says Dickinson. [Caltech Press Release]
Michael Winterrose and Brent Fultz Use High-Pressure "Alchemy" to Create Nonexpanding Metals
Graduate student Michael Winterrose, and Brent Fultz, professor of materials science and applied physics, and colleagues, describe the exotic behavior of materials existing at high pressures in a paper in the June 12th issue of Physical Review Letters. By squeezing a typical metal alloy at pressures hundreds of thousands of times greater than normal atmospheric pressure, the material does not expand when heated, as does nearly every normal metal, and acts like a metal with an entirely different chemical composition. This insight into the behavior of materials existing at high pressures becomes doubly interesting when you consider that some 90 percent of the matter in our solar system exists at these high pressures. [Caltech Press Release]
Sheila Shull Has Won One of the Two 2009 Schmitt Staff Prizes
The Schmitt Prize recognizes a staff member of the Caltech community whose contributions embody the values and spirit that enable the Institute to achieve excellence in research and education. Sheila has been with Applied and Computational Mathematics (ACM) for almost 30 years and takes care of almost every aspect of the day-to-day activities in ACM, including proposal submission and grant management; management of staff members, visitors, and students; organization of international conferences; recruitment of students and instructors; utilization of space; and, most importantly, "care and feeding" of the ACM faculty, which is not without its challenges. As one of her nominators wrote: "It is people like her, in direct daily contact with faculty and students, that truly define the atmosphere in our Institute." Kudos Sheila!
John Doyle Discovers the Importance of Fire in Global Climate Change
Scientists Discover Importance of Fire in Global Climate Change. Researchers including John Doyle, Caltech's Braun Professor of Control and Dynamical Systems, Electrical Engineering, and Bioengineering, Emeritus, have determined that fire must be accounted for as an integral part of climate change. Their research shows that intentional deforestation fires alone contribute up to one-fifth of the human-caused increase in emissions of carbon dioxide. According to the article, increasing numbers of natural wildfires are influencing climate as well. [Science Magazine article]