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Heat from meat
Prof Yash
Pal
This Universe
Innovative ideas for reaching space
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Heat from meat
The dietary differences have developed among regions, social classes and people of various religious groups. Before humans first practised agriculture, ancient hunter gatherers had evolved a complex relationship with their environment. With the development of agriculture, people narrowed their food selections so drastically, that now all over the world only three cultivated plants, viz. wheat, rice, and maize make up two-thirds of the human diet. The same is true of animal protein products which are mainly pork, chicken and beef. It may be noted that it takes three to five times as many farm resources to produce a single calorie or a gram of protein of meat or dairy product, compared to cereal grains, legumes, or tuber crops. Global meat production has increased fivefold since 1950 and in 2004 estimated production was 258 million tons. This huge production is possible only through factory farming. In China alone, there are an estimated 14,000 confined feeding operations, and about 15 per cent of its pork and chicken production comes from factory farms. This production of meat does not come without environmental costs. The FAO has calculated that meat production accounts for nearly a fifth of global green houses gas emissions. Dr. R.K. Pachouri thus before proceeding to the International Meet on Climatic Change has made a powerful point that to save the world from global warming; we have to develop the habit of eating less meat. His argument that by skipping meat once a weak, the emissions can be brought down, needs credence. Obviously, eating meat does not cause emissions, but the problem lies in the production processes, huge land clearances required for ranching animals, the mounds of farm waste produced and the way feed is grown for animals. Meat production also comes at the cost of oil as each stage of production, from growing feed to transporting and processing animals, is highly energy consumptive. Producing one calorie of beef takes 33 per cent more fossil fuel energy than producing a calorie of potatoes. Confined Animal Feeding Operations (CAFOs) are operations that crowd hundreds of animals, cows, pigs or chickens, or turkeys together, with little or no access to light and fresh air and little opportunity to act naturally. This artificial environment creation themselves require large amount of energy for heating, cooking and lighting. The CAFO waste, high in nitrogen, comes largely from animal feed, or from the fertilizer used to grow it. Factory farm depends on chemical fertilizers to grow food rather the manure waste, as it can be readily shipped to corn growers and feed corn to factory farms. In each case, the basic input is no longer produced by the landscape in which it is used for sustainable production. For example in the United States, of the total annual production of 600 million tons of waste annually, only half of it gets effectively used into the crop cycle, the remainder ends up polluting air, water and the soil itself. This raw waste, exposed to air, produces large amount of gaseous ammonia, not only a source of immediate public health problems but also contributing to global warming. Next is methane produced during the process. Methane is sixty times more potent at capturing heat energy than carbon dioxide. It is estimated that methane will cause 15 to 17 per cent of all global warming experienced in this century. Therefore, the worry is real. Conversion of small traditional agro-livestock production systems into big farms are causing nutrient imbalances in the countries like China, Thailand and Vietnam. While farmers with five pigs can have a well-managed, well developed closed-loop recycling system, where they can use manure to fertilizer these crops, farmers with 500 or more pigs can no longer follow these sustainable practices. As the meat and animals are shipped across border, and oceans, diseases like avian flue, BSE, and foot-and –mouth (FMD) can become a global phenomenon. In fact, factory farm provides the perfect conditions for disease to spread from livestock to people. Avian flue is just the most recent example of how animal diseases can threaten the human health. Since its biggest and worst modern outbreak in Asia during 2003, it continues to affect human health and poultry production. The virus responsible for the flue continues to change, even becoming more lethal with every new outbreak. One way to overcome the problem of factory meat production is to raise animals on pasture as it is less environmentally destructive. But owing to enormous demand of land for ranching, it has also started showing disastrous consequences. According to a 2004 report by the Centre for International Forestry Research, rapid growth in Brazilian beef sales from 40 per cent to 74 per cent has accelerated destruction of forest from 41.5 million hectares in 1950 to 58.7 million hectares in 2000. This is not all. Soybean production for animal feed is destroying Brazil’s forests as well. By the end of 2004, more than 16,000 km of rain forests were cleared for farming soybeans for poultry and pork industries. It is only by raising cattle in a way that is compatible with the surrounding environment, can save the forests. Recent studies in the Philippines, Brazil and Thailand suggest that small livestock farms may be more efficient than larger production operations at generating profits per unit of out put. Production of meat is however demand driven. Many governments for political reasons, often encourage meat consumption by providing agricultural price support for feed grains, tax incentives for feedlot operators, guaranteed minimum prices, and through providing godowns for storage of surpluses and the evil goes on. Unless the people and communities decide to change their diet habits, the factories will continue to produce animal protein.
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This Universe
How do astronomers and scientists distinguish between
different galaxies in the universe?
We use different types of telescopes in astronomy. They are not only to observe the universe in visible light we are familiar with but also in other "colours" ranging from radio-waves on one side to infrared, visible, ultraviolet, x-rays, gamma rays and high energy cosmic rays. Each of these measurements gives different information about the character of the astronomical objects. The instruments used behind the telescopes also vary depending on what we want to find out. Much analysis and calculation is also involved. For this we use the science and mathematics we have already learnt and a lot that has to be newly developed. It is found that the universe speaks to us through different windows of radiation. The information obtained from these windows is complimentary. I have mention that telescope lenses can have a diameter of several meters. For radio waves one can effectively use diameters that are hundreds of kilometres, by combining several telescopes spread around the world. There are proposals for telescopes on the moon and spread around in earth orbit working in concert. Just to remind ourselves of the difference between naked eye observation and that through a large telescope we have to remember that our eyes have a pupil diameter of a millimetre or two as compared to lens diameters of many meters, and more, for modern telescopes. The ability of such telescopes to resolve very close objects is often degraded by density fluctuations in the atmosphere. That is why the best telescopes one or set up at high altitudes and now also in space.
Readers wanting to ask Prof Yash Pal a question can e-mail him at palyash.pal@gmail.com
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Innovative ideas for reaching space
Despite rapid technological advances, a real breakthrough in space transportation is yet to be realised. However, well conceived plans of many privately owned outfits to send tourists on a sub-orbital ride could radically alter the dynamics of space travel. Everything going as planned, Richard Branson’s Virgin Galactic hopes to inaugurate the era of regular space ride by the end of this decade and many space travel enthusiasts from across the world have already booked their seats for the “exotic experience of space ride” offered by Virgin Galactic. In the meantime, National Aeronautics and Space Administration(NASA) of US has announced a US$2-million prize for suitable and workable ideas for designing and developing a space elevator aimed at substantially reducing the cost of getting into space. The stunning advances in nano technology as highlighted by the emergence of ultra strong, flexible carbon nano tubes, has given a big push to the once esoteric concept of space elevator. Researchers say that carbon nano tubes on account of their massive strength and immense flexibility are ideally suited for designing a space elevator .As pointed out by Bradly Edwards, a well known physicist and a staunch proponent of the ideas of space elevator is of view that novel technologies such as improved laser beam based energy systems and nano carbon tube fibre could pull off the trick. In a related development, a group of scientists in Japan are toying up with the idea of giving a practical shape to the concept of “cosmic lift” that could routinely take passengers into space. However, realizing a cosmic lift would need new engineering feats and innovative technological elements in that it is designed to move up and down 22,000-miles cable. As a matter of fact, these cables of massive strength would need to be anchored to the ground. And as pointed out by Professor Yoshio Aoki, an active associate of Japan’s Space Elevator Association, these cables would need to be 180 times stronger than the steel. Significantly, in early 1990s, Zivan Zabar and his graduate students at the Polytechnic University at Brookings, USA had worked on turning their idea of “coli action’ into a veritable ”space gun” capable of shooting satellites and other payloads straight out into space in one quick sweep. This so called space gun was essentially an electromagnetic device that accelerates a projectile by creating a powerful magnetic field. However, the gun was required to be over 1000-ft long to be “able to push a satellite at a velocity sufficient enough for its journey into upper atmosphere. But after each launch, the gun many need some repairs and rehaul for its subsequent use. But like many other radical ideas aimed at developing novel devices to reach space, this concept too could not assume a practical shape. |
Various cultures of the world have adopted different plants as their main food crop, or staple. However, there are some societies that eat almost entirely plants, whereas others use a substantial amount of animal-derived foods. For example in India, plants contribute 80 per cent of the dietary protein (cereals and legumes), but in the United States plants provide only 20 per cent of dietary protein. The remaining comes from animals and animal products.
Distant galaxies are very far away. In order to see them or detect them we have to use rather large telescopes. A large telescope has a lens that can have a diameter of several meters. The shortest distance at which two objects can be seen separate is called the resolution of the telescope. This resolution depends on the diameter of the lens— larger the diameter smaller is the angular distance at which two stars can be seen as separate. Also a large diameter of the lens allows more light to be gathered. That is how the galaxies are seen. They can be separated from each other and their detailed structures can be studied.
For many years now, vigorous efforts have been on to reduce the cost of satellite launching and turn space travel into a routine, affordable proposition. For the current space transportation scenario is highlighted by the prohibitive cost—along with attendant risks—of launching satellites and putting humans into space.