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| SCIENCE & TECHNOLOGY |
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Can we ever live on Mars?
Battle against aging
A vaccine that can be stored in potato
Now power from bullock carts Prof Yash
Pal This
universe |
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Dr Steven Cutts considers the many problems to be solved before astronauts can land on Mars and discusses the prospects of migrants from earth ultimately establishing Martian settlements. Venus might provide a second home for mankind if scientists ever succeed in taming its truly ferocious atmosphere. They are actually working on the daunting problem of turning the hostile planet into a human supporting world and have even named the process terra-forming but the job of solving its immense difficulties is likely to take them at least another hundred years. So what about Mars? Its force of gravity is about one-third of Earth’s but that would be an advantage when it came to sending spaceships home. The first manned craft to fly there will need to be launched as separate components for assembly in orbit before its crew board it from a space shuttle. However cheerfully the Mars-bound pioneers smile for the TV cameras, none of them will harbour any illusions about the high risk of catastrophic failure their mission courts. When the shuttle has retreated to a safe distance the spacecraft’s crew will fire the rockets that send their ship out of Earth orbit on a new trajectory from which there is no turning back. The voyage to Mars will last about six months and they may have to spend as long again on the planet when they get there before it is in a position in relation to Earth that permits a half-year’s return trip. Their pioneer mission might take them away for 18 months if not forever. Already the Russians have kept cosmonauts in orbit for more than a year but, unlike them, the Mars explorers will have no chance of rescue if their mission goes wrong. Most plans for missions to Mars involve a crew of six cosmonauts. It will make sense to send them in two spaceships separated by a few miles so that if one malfunctions its occupants can be rescued by their teammates in the second vessel. Conditions aboard the craft will be severely cramped by vast stockpiles of equipment, spare parts and food whose bulk can help to protect crew members from radiation in outer space.
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World
over women have always craved for ways to erase those annoying lines around eyes and neck that come with age. If a new study on age reversal is to be believed, it might just be a dream come true for millions of the fairer sex. Researchers studying a childhood syndrome have shown that some features of premature aging like wrinkles may be reversed in the lab. In the study, published in the issue of Nature Medicine, researchers saw that premature aging was linked to genetic mutations of a protein
found in cells. They then found that by changing the protein-sythesis machinery of the cells, the genetic mutations linked to the premature aging process are not formed. A medical website which has published this research says while these are preliminary findings, the results clearly establish a “proof of principle” for the reversal of the premature aging process in this syndrome and potentially in normal, healthy people. “A great deal of reserach and effort is going on to study whether it is possible to reverse the aging process. But it cannot be said for sure that aging can be reversed. However, a number of cosmetic treatments are available today which to some extent slow the process and help clear wrinkles and blemishes,” says Dr Anil Kumar Malik, a cosmetic and laser surgeon. — PTI |
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A vaccine that can be stored in potato
A
group of biologists have designed an edible vaccine against Hepatitis-B virus that can be stored inside a genetically-altered potato, hence doing away with the need of cold storage. Charles Arntzen and his colleagues from Arizona State University took a gene out of Hepatitis-B virus and incorporated it in the potato plant, which responded by producing the virus antigen, the Nature magazine reported. Once ingested, this antigen protein creates an immune response in the human body that acts as a booster shot against this virus. Genetically modified potatoes can thus provide as effective protection against disease as delivered by a vaccine, the researchers say. The Hepatitis-B virus attacks the liver and claims lives of more than half a million people each year. The conventional vaccines requires cold storage, which may not be readily available in remote areas of developing countries with warm climates. Medical workers often have a tough time determining whether a delivery of the relatively costly Hepatitis-B vaccine has received accidental exposure to heat, rendering it ineffective, Arntzen was quoted as saying. This prompted Arntzen’s team to undertake this research. Nature magazine quoted the team as saying that although this approach is unlikely to supercede initial vaccinations, however, it could replace the repeated booster injections needed to maintain immunity.
— PTI |
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After “gobar gas”, its “bullock power” can be harnessed as a source of non-conventional energy. Using a pair of bullocks, pulleys and transformers connected to a device, Pune-based retired mechanical engineer Chandrakant Pathak claims he can generate energy for computers and sound systems, sprinkler irrigation systems, oil and flour mills, recharging batteries and more. “A single-phase 240 volt airconditioner can be run by two bullocks,” says Pathak. His “bullock-energy generated devices” were showcased at the Rural Science Congress in a two-day exhibition at Wardha recently. “As per the 17th animal census of 2003, Maharashtra has over 81 lakh cattle in six divisions, capable of producing 3,000 MW electricity (0.5 horse power per bullock).” “Even if 50 per cent of present cattle population is put to use this way, it can generate enough energy to bring about 70 per cent of dry land (in the country) under cultivation,” he adds. These bullock energy devices can wipe out the defecit or the shortfall of electricity generation in Maharashtra, he claims. Pathak’s calculations show that cost the of 11 bullocks is equal to a tractor, which means “Maharashtra has a power of eight lakh tractors still untapped.” “But these tractors require fuel (diesel) worth Rs 2,500 crore per year besides maintenance. If one goes for purchasing eight lakh tractors, a whopping Rs 16 crore would be required,” he says. Vibha Gupta, chairperson of Magan Sangrahalaya Samiti, Wardha (National Museum of Rural Technology which was started by Mahatma Gandhi in 1938), which organised the Congress, says the exhibition has provided an opportunity for many innovators like Pathak to catch up with some of the best practices and success stories in alternate energy sector. The Congress is meant to create platform for groups working on alternative science and technologies, Gupta says. Khadi and Village Industries Commission (KVIC) can play a role as a link between innovators of alternative science products for marketing, Gupta adds. Participants from 22 states with eco-friendly inventions using local resources had displayed and demonstrated their works at the Congress.
— PTI |
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This universe Q Why the length of days and nights is different in summer and winter ? Are there any places where days and nights are equal during all seasons?
A The answer to this question can be found in any middle school book but since the question has been asked I will attempt an answer. Let us remind ourselves of two motions of the earth. One is related to movement of the earth around the sun. The earth takes one year to complete to complete one circle around the sun. Indeed that is the manner in which we define a “year”. This motion takes place in a plane we called the ecliptic. The earth is nearly spherical. It also rotates around an axis,
like a top. One complete rotation takes 24 hours and we call this period a day. For this qualitative discussion we will assume that the periods of “a year” and “a day” remain fixed and there are 365 days in a year. While the earth is rotating and going around the sun, the direction of the axis of rotation remains fixed, meaning that its orientation with respect to the normal to the ecliptic remains constant. This angle is 22.5 degrees. There is nothing sacred about this number; it just came to be so early during the creation of the solar system. In order to fix this in your mind play with light bulb as the sun and a spinning ball going around that bulb as the earth. Imagine now that the axis of rotation of the earth was normal to the ecliptic - the plane in which the earth goes around the sun. In such a situation the tilt of all parts of the earth surface would have remained constant all through the year as the earth went about its
journey. Since the earth is spherical the northern and the southern parts would have been poorly lit and remained rather cool. The equatorial region would be permanently hot. There would be no seasons. The length of the day would be 12 hours everywhere on earth. The tilt of the earth axis causes the seasons; as the earth moves around the sun we get the summer of the northern hemisphere when the North Pole of the earth axis is tilted towards
the sun. At the same time the South Pole is tilted away from the sun causing the winter of that hemisphere. It is easily seen that the length of the day is also affected by the tilt and the time of the year. You can visualise that there would be some periods when locations near one of the poles would be lit for months while those on the other would be are left in cold night - six month long day and equally long night is a reality for these polar regions. All this is taught at the end of the middle school. What is usually left unclear is the fact that conservation of angular momentum requires that both the plane of earth revolution around the sun and the direction of the axis of the earth rotation remain fixed in space (and with respect to each other). |
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New Products and Discoveries IN a colony of tree wasps, workers on nursemaid duty crawl this way and that along the bottom of their nest, tending the youngsters in the comb. Most of the workers dutifully look after the queen’s offspring, stopping only to spit a runny meal into the mouth of a pale, lumpy larva snug in its cell. But one of these workers is up to no good. This selfish worker stays still for a minute or two in a suspiciously crouched position. She’s laying her own egg in an empty cell. Such rogue egg laying is a crime against insect society. The wheels of justice, however, don’t require a special caste of investigators and prosecutors. Punishment among insects is meted out by ordinary workers — and sometimes the queen herself — says biologist Tom Wenseleers, who has watched dozens of hours of black-and-white videos from infrared security cameras that he’s trained on nests of tree wasps. In the most dramatic episodes, the egg sneak finds herself surrounded by a posse of vigilante workers. “They’re grabbing on to her; they try to sting her,” says Wenseleers of the Institute for Advanced Study in Berlin. Harnessing microbes Taking a new approach to the painstaking assembly of nanometer-sized machines, a team of scientists at the University of Wisconsin-Madison has successfully used single bacterial cells to make tiny bio-electronic circuits. The work is important because it has the potential to make building the atomic-scale machines of the nanotechnologist far easier. It also may be the basis for a new class of biological sensors capable of near-instantaneous detection of dangerous biological agents such as anthrax. The approach, reported on March 17 at a meeting of the American Chemical Society, suggests that microbes can serve as forms for complicated nanoscale structures, perhaps obviating, in part, the need for the tedious and time-consuming construction of devices at the smallest scale. Poultry feed
from manure Jeff Tomberlin’s research could lend a whole new meaning to the phrase “grub for a living.” Tomberlin, a Texas A&M entomologist, is looking into the possibility that black soldier fly larvae — “grubs” to the uninitiated — could be used to turn livestock manure into high-protein feed. The concept itself has been proven practical for reducing poultry litter: The flies lay their eggs in the animal manure without much encouragement. The eggs hatch into larvae that eat the manure as if it’s caviar, growing into fat little creatures that are 40 percent or more protein. The chickens do what chickens do naturally, eat the worm-like larvae with relish, said Tomberlin, who has a joint appointment with Texas Cooperative Extension and the Texas Agricultural Experiment Station. Nano hazards Nanomaterials, the current darlings of industry, are showing up in products ranging from cosmetics to electronics. However, new animal studies indicate that inhaling these microscopic spheres and tubes could cause big trouble, especially for workers who manufacture and handle them. That message came through loudly in New Orleans last week at the Society of Toxicology meeting, where several dozen reports unveiled details about how nanopollutants interact with the body. Most of the studies focused on the effects of lung exposures because the particles’ size — just a few billionths of a metre in diameter — permits them to reach the most vulnerable lung tissue. John T. James of NASA’s Johnson Space Center in Houston, and his colleagues squirted nanoparticles into the respiratory tracts of mice and then examined the rodents after one week and after three months. Although sootlike carbon nanospheres caused no harm, an equal mass of commercially available carbon nanotubes wreaked significant lung damage, even killing a few animals. |
A spate of robotic probes toward Mars has refocused world attention on the planet that has always figured largest in fictional concepts of space exploration. Will astronauts ever land on Mars? Might future generations of Earth-dwellers even be able to migrate there? There are two planets beside our own that might be suitable for human colonisation. One is Venus. Much the same size as earth with a similar force of gravity, it has a dense atmosphere with plenty of clouds. That’s the good news. Unfortunately, Venus is so hellishly hot that a block of lead placed on its surface would turn to liquid in seconds.