Monday, July 07, 2003

Protecting City's with "Soft" Walls The New Scientist -- Surrounding city centres and likely terrorist targets with "soft walls" will make it impossible for hijacked planes to get anywhere near them. So say the inventors of an avionics system that creates no-fly zones that pilots cannot breach. Since the terrorist attacks on 11 September 2001, anti-aircraft missile batteries have been installed to protect buildings in Washington DC and other US cities. Less drastic solutions have also been suggested. Aerospace company Northrop Grumman, for instance, has proposed installing the electronics from its Global Hawk pilotless plane in passenger aircraft to allow ground control to take over a hijacked plane and land it remotely. Others say automatic landing systems could steer planes to safety without human intervention. All these solutions have disadvantages, says Edward Lee at the University of California in Berkeley. They require radio links between the plane and air traffic control, and these can be jammed, or hacked into. They could even allow planes to be hijacked from the ground if terrorists managed to take over air-traffic control sites. Lee and his colleagues have an alternative. They propose modifying the avionics in aircraft so that the plane would fight any efforts by the pilot to fly into restricted airspace. So if a plane was flying with a no-fly-zone to the left, and the pilot started banking left to enter the zone, the avionics would counter by banking right. Lee's system, called "soft walls", would first gently resist the pilot, and then become increasingly forceful until it prevailed. (07/07/03) INTERdependence is the Human Condition Timothy Wilken, MD writes: Abraham, Buddha, Confucius, and Jesus understood the underlying connectedness of all humanity. Their admonitions to us contain high awareness of our human INTERdependence. This is why they taught us not to kill, not to steal, not to molest, not to fraud, not to coerce. They understood that the conflict of Adversity was not for humankind. They understood that the indifference of Neutrality was not for humankind. They understood that humans were meant to be Synergists. So, they taught us to be our brother's keeper. (07/07/03) The Sun and Earth's Weather BBC Science -- In 1801, astronomer William Herschall noted a relationship between sunspots and the price of wheat. The Sun acts to shield the Solar System from the full effects of cosmic rays He saw that the more sunspots there were, the lower the price of wheat. Fewer sunspots and the price rose. The suggestion was that Earth's weather depends on the Sun's natural variability - and 200 years later, scientists are still debating this effect. Though few now dispute that humans are contributing to global warming through car and industrial emissions, there are healthy arguments over just how important this influence is - and whether the Sun's impact may have been underestimated. One popular theory - currently being tested in Denmark - is that variation in solar activity acts on climate indirectly through its effect in limiting cosmic rays hitting the Earth as they journey across our galaxy. "I knew that people had been seeing correlations between solar activity and the climate on Earth, and I knew that people dismissed it as being entirely accidental," Professor Henrik Svensmark, of the Danish Space Research Institute (DSRI), told BBC World Service's Discovery programme. "However when I looked at the correlations at that time, I saw that there was too much to be really accidental." (07/07/03) Swivelling Eyes and Pivoting Minds Howard Bloom writes: Each epoch presents new puzzles. The culture or subculture built around the most relevant answer comes out on top. All groups wish for fame and fortune. It comes to those whose combination clicks the tumblers of a shifting lock. Athens put her chips on pluralism. She was a breeder of cross-cultural diversity. Sparta bet on the one-size-fits-all hypothesis - a cradle-to-grave, cookie-cutter conformity. Subcultural gambles followed the same schemes. Socratics challenged old rock solids and romped through rebellious multiplicities. Pythagoreans, at least while Pythagoras was running the show in his Croton enclave, imposed obedience to just one master and hammered home uniformity. Which hypothesis, the courting of many voices or the push for only one, would prove the rightest of them all? The answer would emerge through trials of circumstance whose tides continually rise and fall. Remember the five elements of the complex adaptive system: conformity enforcers, diversity generators, utility sorters, resource shifters, and intergroup tournaments? In the last few chapters we've examined utility sorters - bio responders which shut us down and slam us in a shell or open us up and let us romp like hell. Now to put intergroup tournaments and resource shifters under the lens of scrutiny. (07/07/03) Extinction threat to ancient plant group BBC Environment -- The oldest seed plants known, the cycads, are now among the most threatened on Earth, scientists say. Cycads, plants resembling palms, first appeared in the fossil record about 300 million years ago. But today they face a risk of extinction four times greater than the average for plants. One of the worst threats comes from the trade in wild plants for the horticultural trade. The plight of the cycads, which are found in Asia, Africa, Australia and the Americas, is described in a report by IUCN-The World Conservation Union. The report, Cycad Status Survey And Conservation Action Plan, was prepared by the cycad specialist group of IUCN's species survival commission. There are about 297 cycad species and sub-species, varying from small plants found beneath the forest canopy to tall ones growing in the canopy itself or out in the open. Despite their venerable lineage, the report says, 53% of all cycads are threatened with extinction, compared with an average 12.5% for plants in general. Two species are already extinct in the wild, and IUCN says the pressures of modern lifestyles suggest more are likely to follow suit. (07/07/03) Kew is newest 'world wonder' BBC Science -- Kew Gardens is to join the likes of the Taj Mahal and the Great Wall of China as a modern wonder of the world. The Amorphophallus titanum plant attracted hundreds of people to Kew The Royal Botanic Gardens in south-west London was recognised as a "unique cultural landscape" by the United Nations, which has given it World Heritage Site status. The 132-hectare site contains some of the world's largest and most famous botanical glasshouses and historic buildings. There are also gardens which the more than one million yearly visitors can enjoy. Kew director Professor Peter Crane spoke of his delight after the decision by the United Nation Educational, Scientific and Cultural Organisation (Unesco). "Being awarded World Heritage Site status is hugely exciting for us. It is a stamp of approval that puts us in the company of the best of the best and it brings with it increased prestige and public awareness." (07/07/03) Is Solar Sailing Possible? The New Scientist -- The next generation of spacecraft propulsion systems could be dead in the water before they are even launched. A physicist is claiming that solar sailing - the idea of using sunlight to blow spacecraft across the solar system - is at odds with the laws of thermal physics. Both NASA and the European Space Agency are developing solar sails and, although never tested, the concept is quite simple. A solar sail is essentially a giant mirror that reflects photons of sunlight back in the direction they came from. Although photons do not have mass, they are considered to have momentum, so according to the law of conservation of momentum, the photon loses some of its energy to the sail as it bounces off, giving the sail a shove in the opposite direction. But Thomas Gold from Cornell University in New York says the proponents of solar sailing have forgotten about thermodynamics, the branch of physics governing heat transfer. Solar sails are designed to be perfect mirrors, meaning that they reflect all the photons that strike them. Gold argues that when photons are reflected by a perfect mirror, they do not suffer a drop in temperature. That brings in a thermodynamic law called the Carnot rule, which basically states that you never get something for nothing: if there is no temperature change when the photons are reflected, it is impossible to extract any free energy from them to push the sail along. (07/07/03) SARS Contained! CNN Health -- The World Health Organization has declared the SARS virus outbreak contained around the world after removing Taiwan, the last region on its list of affected areas. The island, which had seen soaring numbers of infections in May, has not reported a single new case during the past 20 days -- the benchmark figure by which an outbreak can be judged contained. Announcing Saturday that the global outbreak had been contained, WHO Director General Dr. Gro Harlem Brundtland warned countries around the world not to let down their guard against the virus, saying they must remain vigilant against the disease which has claimed 812 lives. "Today is a milestone," she said, but it came with the warning that "the world is not SARS free. There are still close to 200 SARS patients in hospitals," Brundtland said in a statement from WHO headquarters in Geneva. "It is possible that cases have slipped through the net." (07/07/03) 5:42:49 AM

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