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Space travel for the super-rich
This universe
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Space travel for the super-rich The farsighted enthusiasts who offered the prize are all wealthy members of an aerospace-promoting organisation caned Ansari. The team that won the spoils was led by a prolific designer, Burt Rutan, 61 ,who runs an aircraft construction company in California and was already celebrated for building a superlight machine in which his brother Dick and a fellow-aviator Jeanna Yeager made the first nonstop flight around the world without refuelling in 1986. Burt’s prizewinning craft Space Ship One and its White Knight launcher cost more than S20 million to develop but his company enjoys huge financial support from billionaire Paul Allen, co-founder of the Microsoft Corporation. The Rutan team’s achievement has captured the imagination of spaceflight enthusiasts everywhere and flamboyant billionaire Richard Branson who heads Virgin Airlines has ordered a fleet of spacecraft with the object of selling orbital flights to seriously rich would-be astronauts. So is commercial space travel about to begin?
Fuel weight problem The huge spacecraft with which we are familiar is fuelled by liquid hydrogen and liquid oxygen burned by rocket engines with an efficiency of over 95% — leaving scant room for improved performance. And for the craft to achieve orbital speed, no less than 90% of its weight at take-off consists of fuel. So a 100-tonne machine on its launchpad consists of 90 tonnes of fuel and only 10 tonnes of metal, crew and electronic
equipment. Today’s ideal rocket-launched spacecraft must have a minimally thin case encompassing its contents just as an eggshell surrounds its albumen and yolk. To be reusable a commercially viable spacecraft’s heatshield, retrorockets, crew, passengers and perhaps parachutes must be crammed into just 10% of its launch weight — not an easy trick to achieve, though aerospace scientists have been striving to pull it off for about 30 years. Every component of a reusable spacecraft relying on today’s liquid fuel must be hugely reduced in weight and that necessity is what aerospace scientists forever work towards. Already the heavy computer that guided the Space Shuttle of the 1980s has been replaced by something the size of a laptop. Electrical cables are superseded by fibre optics and heatshields become lighter through advances in materials technology. What makes Burt Rutan’s aerospace vehicle so different is that instead of being launched by a massive rocket it is carried to high altitude by an aircraft, White Knight. Which then releases the spaceship to continue its climb to the edge of Space. There is no immensely heavy fuel to be lifted in tanks that later have to be Jettisoned. The whole concept is different enough to open a completely new era of aerospace design that can lead to comparatively low-cost space travel providing wealthy tourists the chance to view our world from high above its atmosphere. The big problem to crack is speed. To stay in orbit a vehicle needs a horizontal speed of 17,000 mph. Space Ship One’s velocity is not much more than 2000 mph. But now that Ansari is offering $ 50 million to the first team to build an aerospace craft that can actually orbit the earth, how soon might it be before an innovator like Burt Rutan claims that prize?
Watch this space! — AF |
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This universe
Q. What is meant by the spin of a subatomic particle?
A. Fundamental particles behave as if they have definite, quantised values of intrinsic angular momentum. This is usually referred to as spin. Even nuclei have spin. In systems of more than one particle, such as atoms, one also has another angular momentum, called orbital angular momentum. The energy levels of systems are influenced by the interaction of angular
momentum in a known, calculable manner. Conservation of angular momentum influences the outcome of interaction between particles. It seems truly amazing that if one keeps within the discipline of quantum mechanics, one can almost imagine electrons spinning like tops. Charged spinning particles also produce magnetic moments, which also enter the understanding of energetics of atoms and nuclei in a known way. In the every day world of a citizen, Magnetic Resonance Imaging is an oft-repeated phrase. The resonance is between the energy levels of atoms and molecules and the external magnetic field. It turns out that the spin of fundamental particles is a property that has a deeper significance, in the sense that it divides their world into two distinct families. Particles with half-integral spins, such as the proton and electrons etc. are called Fermions and are subject to the Pauli exclusion principle. This has had a fundamental bearing on the real world of atoms and their structure and properties, including, of course, chemistry and biology. Bosons, with integral spin are outside the regime of this Principle and their statistics are equally, though differently, a central determinates of the world as it is. Q. Isn’t it possible that atoms don’t exist? As far as I know, they have never been directly observed, and their existence is based only upon experimental observations. Is it possible that, instead of atoms, only pure energy exists, and chemical reactions occur as pure energy transformations?
A. You never see atoms or particles with the naked eye. You only learn about them through experiments and other manifestations. All chemical reactions are determined by the properties of atoms. In order to understand the natural world, you must use the properties of atoms and molecules as determined by a great variety of experiments. No my friend, it would be a grave error to dispute the existence of atoms (and indeed, of sub-atomic particles), given the weight of accumulated evidence. They are centrally involved in determining how your so-called “pure energy” would behave. Please reserve your skepticism for other, less certain and more speculative, ideas. |
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Molecular wires A project by University of Delaware researchers that could break down the brick wall of miniaturisation and revolutionise modern electronics through the formation and control of wires made of molecules is featured on the cover of the February 15 issue of the American Chemical Society journal, Langmuir. The important new results produced by the UD research team are “the ability to produce molecular wires at very precise positions, and to control the length of the wires through confinement inside of molecule corrals,” according to Thomas P. Beebe Jr., professor of chemistry and biochemistry. Beebe said modern electronics, such as computer processors or the micro-circuitry that makes a cell phone fully functional, have hit a “brick wall” in attempts at further miniaturisation. “Computer speeds have been increasing because engineers have been able to make the brains of computers, the transistors, smaller and smaller,” Beebe said. “The brick wall refers to the smallest possible building blocks for these transistors — atoms and molecules.” A fishy therapy Shark cartilage is for sale all over the Web. Powders of it, packaged in jars and capsules, are among the products offered at sites specialising in herbal remedies, vitamins, health wares, and bodybuilding aids. These Internet sites claim that the cartilage skeletons of sharks and their close relatives-skates and rays-offer various health benefits. Inhibiting cancer is often at the top of the list. To support that contention, sellers point to studies indicating that something in shark cartilage can inhibit the blood vessel growth that tumours rely on for access to nutrients. However, shark-cartilage therapy, a large segment of the food-supplements industry, is based on severely flawed premises, according to some scientists. A new report by one group of them contradicts the view that sharks don’t get cancer. Several major recent and ongoing studies have also failed to show any cancer benefit in people from powdered shark cartilage, although a few studies report promise in a mix of chemicals extracted from cartilage as a potential anticancer pharmaceutical. Even if current cartilage therapy isn’t directly harmful, many clinicians worry that its promotion also encourages patients to give up on proven or potentially more-useful therapies. Robots in ICU UCLA Medical Centre has announced initial clinical tests of the RP-6 mobile robot system in its neurosurgery intensive care unit (ICU). The RP-6 robot, made by InTouch Health Inc. in Santa Barbara, Calif., allows doctors to “virtually” consult with patients, family members and health care staff at a moment’s notice, even if miles away from the hospital. Intensivists — the physicians who specialise in the care of critically ill patients — in the neurosurgery department at UCLA are using RP-6 to provide additional monitoring from their homes and offices of ICU patients in response to studies showing that intensivist presence in the ICU can decrease morbidity, mortality, length of stay and cost of care. The project, to be funded through an assistance agreement with the U.S. Army Medical Research and Materiel Command, Telemedicine and Advanced Technology Research Center, located at Ft. Detrick, Md., will be led by professor and Chief of Neurosurgery Dr. Neil Martin, associate professor Dr. Paul Vespa and associate professor Valeriy Nenov, all of the David Geffen School of Medicine at UCLA. There is a nationwide shortage of intensivists. There are fewer than 6,000 practicing intensivists in the United States today and more than 5 million patients admitted to ICUs annually. Therefore, only about 37 percent of ICU patients receive intensivist care, yet having trained intensivists in the ICU results in better outcomes and decreased length of stay in the ICU and hospital. These specialists are familiar with complications that may occur and are therefore better able to minimise errors. |
Prof Yash Pal
Early in October, 2004, a private US aerospace company succeeded in claiming a 10-million-dollar prize for the first team to fly a machine carrying three people to the edge of space, 100 kilometres (62 miles) above the earth, and bring it safely back again to repeat the feat within two weeks of the original flight. When what was called the X-prize was announced, some people thought it impossible for present-day constructors to win. In fact it inspired a whole string of imaginative comparatively low-cost designs for manned spacecraft built entirely free of government funding.