Inside Science News Service

A collection of brief stories from the world of science

August 28, 2008
By Jim Dawson
Inside Science News Service

A Smarter Hurricane Evacuation System Developed By MIT Student

With Tropical Storm Gustav threatening to become a hurricane as it takes aim at the U.S. Gulf Coast next week, emergency managers in cities that may be hit sometime next week are struggling with critical decisions about evacuating hundreds of thousands of people from harm's way. If ordered too early, evacuations are costly, and if the hurricane doesn't hit, such false alarms undermine future evacuation orders. If ordered too late, gridlock can result and people can be trapped when the storm hits.

As part of the research for his doctoral dissertation, MIT student Michael Metzger has developed software that could allow emergency managers to better decide early on whether to order evacuations. More importantly, according to Metzger, the software provides a systematic plan to allow people to be evacuated more efficiently by doing it in stages. Metzger analyzed data from 50 years of hurricanes, comparing the information available at various times as a hurricane approached with data from the actual storm's passage. He then produced software that gives a scientifically consistent framework to plan for an oncoming hurricane, and that planning includes an evacuation system that focuses on moving different categories of people rather than different geographical locations. By spacing out the evacuation of different groups over a period of about two days, he said, the process would be more efficient, and allows officials to "pull the trigger earlier." His system would, for example, evacuate the elderly first, then tourists, followed by families with children, then the remaining population. "All in all, this is a complex balancing act," he said in a release from MIT. Federal and state emergency planners are working with Metzger to implement his system.

Offshore Oil Platforms at Risk from Hurricanes

A Rice University professor of civil and mechanical engineering has studied the damage done to oil drilling platforms by Hurricanes Katrina and Rita in the Gulf of Mexico and found that oil rigs are susceptible to heavy damage. Katrina and Rita, both Category 5 storms with sustained winds of up to 175 miles-per-hour, hit an estimated 3,000 drilling platforms and 22,000 miles of pipelines when they swept across the Gulf in September, 2005. According to Rice's Satish Nagarajalah, 115 platforms were destroyed, 52 others suffered major damage, 19 floating drill units went adrift or were damage, and 535 pipeline segments were damaged. "If one major deep-water production platform is destroyed, you're talking about a $1 billion or more loss," Nagarajalah said in a Rice University release. "If it's multiple rigs and platforms in a variety of water depths, then we're talking billions of dollars." That damage can translate to higher gasoline prices, he said. Nagarajalah noted that oil platforms in shallow water are fixed security to the sea floor, while deep-water, floating drilling rigs are tethered in place. His research is aimed at determining the particular vulnerabilities of the different systems and providing advanced knowledge to drilling companies about what kind of damage to expect from different types of hurricanes.

Eyes Forward Helps Humans See Through Objects

Hold a pen in front of your eyes as you read this text. If you read with only one eye, the pen blocks some of the letters. Read with both eyes and, while you'll probably see two pens instead of one, you'll also be able to read all of the letters. Welcome to evolution's version of X-ray vision. A researcher at the Rensselaer Polytechnic Institute in Troy, New York, has linked this "see through things" aspect binocular vision in humans, chimps and other animals with forward facing eyes to evolutionary adaptations based on environment. Most creatures, such as horses, rabbits, reptiles, fish and insects, have eyes located on either side of their heads, which gives them panoramic vision and allows them to see behind themselves. Cognitive scientist Mark Changizi found that eye position - forward facing or sideways facing - depends on two variables: the clutter, or lack thereof in an animal's typical surroundings and body size relative to the objects creating the clutter. After studying 319 species across 17 mammalian orders, Changizi found that animals in non-cluttered environments tend to have sideways-facing eyes. "Animals outside of leafy environments do not have to deal with clutter . . . so there is never any X-ray advantage to forward-facing eyes for them," he said. But in leafy surroundings, "animals tend to have a wide field of binocular vision, and thus forward facing eyes, in order to see past leaf wall. This X-ray vision makes it possible for animals with forward-facing eyes to visually survey a much greater region around themselves than sideways-facing eyes would allow." As humans no longer live mostly in forests or jungles, he noted, a million years from now "it might be difficult for us to look the new human population in the eyes, because by then they might be facing sideways."

Scientists Discover Why It's Hard to Swat a Fly

Their brains may be tiny, but flies do sophisticated, almost instantaneous calculations that allow them to leap away from a looming threat with amazing speed. Using high-resolution, high-speed digital imaging of fruit flies being threatened with swatter, Caltech scientist Michael Dickinson discovered the secret of fly evasiveness. The instant a fly sees a threat with eyes that have an almost 360 degree field of view, its brain calculates the location of the threat, comes up with an escape plan, and places its legs in an optimal position to hop out of the way in a direction opposite the threat. If the threat comes from the front, for example, the fly moves its middle legs forward and leans back, then raises and extends its legs to push off backward. Similar acrobatics allow a fly to leap forward, or to either side. "Our experiments showed that the fly somehow 'knows' whether it needs to make large or small postural changes to reach the correct preflight posture," Dickinson said. So what the best way to swat a fly? "It is best not to swat at the fly's staring position, but rather to aim a bit forward of that to anticipate where the fly is going to jump when it first sees your swatter," he concluded. Dickinson's research is being published in the journal Current Biology.

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