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| SCIENCE & TECHNOLOGY |
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Arctic spring comes early Prof Yash
Pal THIS UNIVERSE |
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Use outer space to enrich human life: Kalam President A.P.J. Abdul Kalam, who, during his stint with the Indian Space Research Organisation (ISRO) had played a pivotal role in designing and developing India’s basic civilian space vehicle SLV-3, has unveiled his unique Space Vision 2050, which stresses making use of outer space for improving the lot of humanity in the years ahead. Calling upon nations to come together and share expertise and space platforms, Kalam points out that humanity could stand to benefit enormously by focusing on the Moon and Mars in the years ahead. He is of the clear view that in 50-70 years, there will be an industrial complex on the moon to mine minerals and space industrialisation could take off from the moon. Kalam also feels that the clues about the availability of water and helium on the lunar surface would form the basis for the industrialisation centring round the moon. Clearly Kalam wants India to be a major player in space industrialisation and for such an eventuality, he says, there was a need for young Indian space scientists to take up the challenge. He is hopeful that the Indian Institute of Space Science and Technology being set up by ISRO in Thiruvananthapuram would cater to the needs of grooming young Indian space scientists to take up innovative space projects of the future. “India has to be a part of the global space infrastructure effort. The space market will grow and there will be demand for highly skilled space scientists” observed Kalam. Noting the threats of space borne disasters, asteroids and nuclear conflicts, he said that the immediate need is to look towards an alternate habitat and Mars could be the ideal choice for this. “The creation of an alternate habitat on Mars is like a fail-safe mechanism for problems on earth” observes Kalam. With the race to explore the Red Planet hotting up, Kalam had sometime ago urged ISRO to send a probe to Mars as a precursor of its long term plan for planetary exploration. As it is, USA. Russia, Japan, China and the European Space Agency (ESA) have all announced their ambitious plans to explore Mars in great depth. In response to Kalam’s plea, ISRO Chairman G. Madhvan Nair had stated that ISRO will be in a position to build and send a probe to Mars by making use of its available resources and expertise, in about five years of getting a go-ahead. For long, Kalam has remained a passionate champion of bringing down the cost of getting into space by innovating high performance rocket systems. Kalam is clear in his perception that unless launch costs are brought down by a substantial extent, the fruits of space exploration would not reach all of humanity. “The payload fraction of the current genre of expendable launch vehicles does not exceed even one to two percent of the launch weight’ observes Kalam. As such, he feels that there is a strong need for all countries to work together to develop low cost “space access systems”. On another front, Kalam has stressed the need to create an international space force to protect space assets of various space faring nations. Stressing the need to extend the lifespan of satellites through various measures, he hope that ISRO would be in a position to design, develop and operate a space satellite service station. Kalam is also of view that India with its leadership position could drive the development of a series of satellite systems for the advancement of humanity. Specifically, Kalam envisions a World Knowledge Platform where satellites like Edusat would network to provide quality education for all across the world. He has also mooted a similar world healthcare platform. The proposed knowledge platform, he said, would ultimately democratise access to knowledge. For this would imply the same level of access to data for a child in the remote sub-Saharan rural backyard and a student in an American urban centre. “If the world becomes flatter and shrinks, it will be due to space scientists who network themselves and through them they will bring nations and humanity closer” observes Kalam.
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Arctic spring comes early The Arctic spring is coming two weeks ahead of time compared to a decade ago with birds, butterflies, flowers and small animals all appearing earlier in the year as a result of climate change. A study of a range of animals and plants living in the high Arctic has revealed that many of them are responding to the earlier spring by flowering or laying their eggs significantly ahead of their normal times of the year. On average the breeding and flowering seasons in the Arctic have shifted by 14.5 days but some species of mosquitoes have begun laying their eggs 30 days earlier than in the mid 1990s, said Toke Hoye, of the University of Copenhagen in Denmark. “Our study confirms what many people already think, that the seasons are changing and it is not just one or two warm years but a strong trend seen over a decade,” Dr Hoye said. “This is the most extensive study of its kind in the Arctic in terms of the number and variety of species and in terms of the replication of the observations,” he said. The findings, published in the journal Current Biology, show the shift in the spring season has been greater in the Arctic than elsewhere in the world. Previous studies have shown that plants in Europe are flowering 2.5 days earlier than a decade ago, whereas globally animal and plants are appearing 5.1 days earlier each decade. The study investigated the time of year when insects, butterflies, spiders and birds began laying eggs or emerging from their winter hibernation. They also looked at the time of first flowering of Arctic plants. Dr Hoye said the movements in the season of six species of plants, 12 species of arthropods and three bird species must be tied to the earlier times of the year when the snow melts in the Zackenberg region of Northeast Greenland, where the study was carried out. “It’s an indication that for the plants, arthropods and birds there’s a change in their shared physical environment that results in a change in their behaviour. That must be when the snow melts,” he said. “We know that the snow is melting about two weeks earlier than it did a decade ago in this part of the Arctic. Given the wide selection of species we studied in each group, we can see no other explanation for the shift in their behaviour,” he said. “We were particularly surprised to see that the trends were so strong considering that the entire summer is very short in the High Arctic – with just three to four months from snowmelt to freeze up at our Zackenberg study site.” Records of global temperatures show that the polar regions, and especially the Arctic, are experiencing some of the largest increase in average temperatures. Dr Hoye warned that the change in timing of emergence, egg-laying and flowering could disturb local food webs with some animals appearing ahead or behind of others on which they rely for food.
— The Independent
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THIS UNIVERSE The important properties we need to define for any moving particle are its total energy and momentum. In the non-relativistic regime, when the velocity of the particle is much less than the velocity of light, kinetic energy is given by the expression ½ mv2 and momentum by mv. Here m is the mass of the particle and v is velocity. For a photon the energy is given by hí, where h is the Planck constant and í the frequency of the photon. Its momentum would be hí/c. When a photon looses energy it does not slow down but its frequency reduces, as does its momentum. These are not just postulates but self-consistent consequences of the special theory of relativity of Albert Einstein. A man jumps from the roof of a building that is four meters high. He is a hurt but he survives. Then he jumps from five meters and again he survives. He then increases the height to five meters and one centimeter. This time he is killed. Did this last one centimeter kill him? He was killed by that one centimeter on top of the five meters. Do not give any magical power to that one centimeter by itself. Remember that story about the last straw that broke the camel’s back? Incidentally you realize that while narrating your story you were not engaged in a proper experiment. It could have very well happened that the second time over he might have jumped from a mere three metres height and broken his neck! You would be wrong to conclude from this that four metes is a safer height than three metres!
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