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| SCIENCE TRIBUNE | Thursday, April 18, 2002, Chandigarh, India |
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Search for intelligent life beyond earth When planets get aligned Optical wireless communication
Clothes designed by computers Safety of mobile phones Speech melody controls speakers |
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Search for intelligent life beyond earth
Basically, SETI researchers go in for either widefield search or targeted search. While the widefield search involves the survey of a large area of sky at one go, targeted search focusses on intensive investigation of a limited number of stars for possible emanation of the signals. Over the last four decades, a number of SETI projects promoted by individual researchers and scientific organisations have been looking for signs of alien life, of course, without success. All said and done, none of the SETI researchers is clear as to the nature of signals they may receive from extra-terrestrial civilisations in the depths of the outer space. The most recent SETI project aimed at search for extra-terrestrial intelligent life is seti@home, makes use of 305-metre radio telescope at Puerto Rico. Covering more than one fourth of the sky, this SETI survey makes use of the spectral frequency of hydrogen, the most primitive element in the cosmos. However, the renowned astrophysicist Sir Arnold W. Wolefandale, Emiritus Professor at the University of Durham, there is no intelligent life in outer space. Defining intelligent life as one which can communicate effectively with humans, he did not discount the presence of life forms in outer planets. Despite the billions of stars and the sun being the third generation star, there has been no trace of any intelligent life form in the universe. He pointed out that billions of stars have existed before the sun was found and even if some stars had interstellar life forms, they should have had civilisations. He, however, stressed that it would be an important area of astronomical research in the coming decades to continue to look for other intelligent life forms on other planets. For such a research work would give a boost to the next generation of technology and stimulate economic development. As things stand now, it will be a
difficult preposition to answer many of the questions such as: Are the
humans the most intelligent creatures in the Universe? If intelligent
life exists in an earth-like planet somewhere in the universe, how
will they interact with earthlings? and what would be the intelligence
level of alien civilisations? These and hundred other similar
questions will continue to agitate the humanity till SETI evolves to a
level at which it will be able to convincingly prove or disprove the
existence of extra-terrestrial intelligence. |
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When planets get aligned Some of you might have heard about the planetary alignments. Planets always will appear to lie along a straight line (since all of them are roughly in the Solar Plane) in the sky and during an alignment, they all concentrate near a point. However, since our own Earth is not a part of this alignment, other aligning planets will not converge strictly close to a point, but will appear as dispersed along a short line in the western sky in the following order from horizon-above: 1. Mercury 2. Venus 3. Mars 4. Saturn 5. Jupiter The first four among these are in actual alignment, which means that if the observer stands on any of these, the rest will converge to a very narrow region. (Attached fig. shows Delhi sky for Apr. 18 at 7:00 pm). Another interesting event involves a stray wanderer — yes, a comet named Ikeya-Zhang is paying us a visit these days. Recently, it had a (projectional of course) rendezvous with Andromeda and all astronomy-related sites were decorated with breathtaking images. Make sure to visit some of them and more importantly, spare time to watch the pre-dawn northern sky. Though I couldn’t see it as sky is overcast, but a 3.5 magnitude comet should be an easy sight even in our polluted cities. Here are some interesting links: http://www.spaceweather.com/ http://skyandtelescope.com/news/current/article_570_1.asp http://antwrp.gsfc.nasa.gov/apod/image/0204/ikeya-zhang_casado.jpg
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Optical wireless communication Digging of streets to lay optical fibre cable is a cumbersome process. Free Space Optics has provided an alternate solution. Optical Wireless Communication or Free Space Optics (FSO) is fast emerging as the latest development in the area of computer communication. The high bandwidth of optical fibre cable coupled with immunity to electromagnetic interference has already enabled successful convergence of voice, video and data signals. High-speed optical fibre based solutions have solved the problems of long distance networks. The problem arises when the convergence has to be achieved in local loop or the first mile. Digging of streets in a metropolitan area to lay optical fibre cable is a cumbersome process. Free Space Optics has provided a requisite wireless communication solution to overcome this drawback. Optical Wireless Communication provides for the transmission of digital signals over the beams of light across the environment (Free Space). The lasers are used to transmit the beams. The receivers constitute of a photon detector. The process of transmission and reception here is Line of Sight. The information is transmitted here on the infrared frequencies and this does not require government approval. The data sheets confirm that the transmission of data on an optical wireless medium has been successfully tested on buildings placed 3.5 km apart. The reliability of Optical Wireless
Communication is in question during a foggy day. The transmission over this
medium is vulnerable to the effect of "fog". Researchers are trying
to overcome this drawback by combining the optical wireless and microwave
radio. When the fog interrupts the lasers then the microwave will be functional
and during the rainy day the reverse shall be true. Such a hybrid system will
provide 99.9% reliability in the area of optical wireless communication. |
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NEW PRODUCTS & DISCOVERIES Harvesting "green" pharmaceuticals As drugs derived mostly from bacteria and animal cell culture may trigger immune responses, researchers have taken the task of harvesting several pharmaceutical products from plants, which do not pose such disadvantages. Today, more than one in four pharmaceutical products are manufactured by means of biotechnology and genetic engineering. Until now, drugs such as insulin, interferon and vaccines against jaundice were mostly derived from bacteria or animal cell cultures. Yet these methods have several disadvantages. The proteins produced in bacterial or mammalian cell cultures can trigger immune responses or transmit pathogens such as HIV or viral strains of hepatitis, a report in Fraunhofer Gesellschaft said. "Plants, on the other hand, do not produce any bacterial toxins, virus particles or pathogens that might represent a health risk for humans," points out Stefan Schillberg from the Fraunhofer Institute for Molecular Biotechnology and Applied Ecology IME. Therefore, in future, Fraunhofer researchers intend to harvest lots of pharmaceutical products from plants. The scientists use plants as a type of "organic-factory" to produce drugs economically and safely, the report said. PTI Clothes designed by computers Researchers have successfully transferred the entire development cycle of manufacturing clothes — from the type and mixture of fibres used, their shape and size to the structures they form in the fabric — onto computers thereby enabling a whole sector of industry to benefit from the use of sophisticated mathematical methods. Consumers want to buy high-quality products, and manufacturers want efficient, economical production processes. They expect kitchen clothes to be highly absorbent, babies’ diapers to get thinner and filters to absorb the tiniest particles or droplets. Experts in the textile industry say this all depends on the ideal combination of fibre, their shape and size and the structure they formed in the fabric — which took months of painstaking experimental research and tests, a report in Fraunhofer Gesellschaft said. However, all this was changed after Franz-Josef Pfreundt of the Fraunhofer Institute for Industrial Mathematics ITWM developed the new technology. Companies that manufacture porous materials such as fabrics, felts, paper and ceramics have been quick to realise that this method could save them a great deal of time and money. Encouraged by this response, the scientists now intend to investigate other material properties such as structure durability using computer simulations. PTI Safety of mobile phones The safety of mobile phones is under fresh scrutiny after researchers have discovered that their emissions have an unexpected effect on living creatures — the microwave emissions typical of mobile phones make a type of worm more fertile. Until now, regulations designed to protect people from microwave radiation — from mobile phones, microwave ovens and radar systems — have been based purely on avoiding heating from the microwave radiation. There is no evidence that cellphone emissions have harmed people’s health, a report in New Scientist said. William Stewart, head of the British government’s "independent expert group" on mobile phones is taking the results seriously. "These results are very important and potentially far-reaching. Independent confirmation is crucial and we need this quickly," he said. Microwaves do not have enough energy to break even weak chemical bonds inside our cells, so scientists believe they cannot do any damage unless they are strong enough to heat up the cells. PTI Speech melody controls speakers Linguistic researchers have discovered how speakers of dutch use speech melody to indicate that they wish to continue speaking during a conversation and that melodic cues prove especially important when the sentence structure suggests that they have in fact finished speaking. In a normal conversation between two people, the speakers take over from one another very rapidly but the question is how each lets the other know when he or she can start speaking. It is usually the sentence structure which provides the most important information, while melodic cues only play an auxiliary role.
Johanneke Caspers from the Faculty of Arts, Phonetics Laboratory,
Leiden University, has identified a melodic cue which is an exception
to this general rule, a report in NWO Research report said. PTI
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SCIENCE & TECHNOLOGY CROSSWORD Clues: Across
Solution to last week’s Crossword
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From
time immemorial, man has been speculating on the possibility of
intelligent life thriving beyond the spaceship earth. And the
primeveal human quest to find an answer to the question whether we are
alone in the universe received a big boost with the advances in space
research in tandem with technological strides that enabled the
engineering of tools to scan the sky and look for tale-tale evidence
of radio emissions. While the existence of primitive life in faroff
planets has never been disputed, the existence of intelligent
civilisation beyond earth has for long remained a passionately debated
controversial issue. The search for intelligent life in outer space
using the technological tools led to the evolution of a new discipline
called SETI (Search for Extra Terrestrial Intelligence).
As
it is, SETI falls back on telescopes and satellites to look for
signals from "alien civilisations". The concept of SETI was
first elucidated in a research paper published in the widely respected
journal Nature way back in 1959. The most favourite methodology
followed by SETI researchers is to send radio signals out into space
in the hope that some intelligent civilisation in universe may pick
them up. Radio waves are used because they have an inherent capability
to traverse long distances. The so called Drake equation arrived at by
the astrophysicist Franke Drake continues to guide the search for
intelligent life forms beyond earth.
1.
Chemical name of Vitamin B2.