Thursday, November 29, 2012



Biodiesel is any biomass-derived diesel fuel substitute. Today, biodiesel has fuel substitute. Today, biodiesel has come to mean a very specific chemical modification of natural oils. Oilseed crops such as rapeseed and soybean oil have been extensively evaluated as sources of biodiesel.

Oilseed crops yield natural oils, generally present in the form of Triacylglyc4erols (TAGs). TAGs consist of three long chains of fatty acids attached to a glycerol backbone. The algae species can produce up to 60% of their body weight in the form of TAGs, holding potential as an alternative source of biodiesel. It does not compete with the existing oilseed market, which is already on the verge of meeting demands.

The use of vegetable oils as alternative fuels has been around for 100 years when the inventor of the diesel engine Rudolph Diesel first tested peanut oil in his compression ignition engine. The rapid introduction of cheap petroleum quickly made petroleum the preferred source of diesel fuel, so much so that today's diesel engines do not operate will when operated on unmodified TAGs. Natural oils, it turns out, are too viscous to be used in modern diesel engines.

In the 1980s, a chemical modification of natural oils was introduced that helped to bring the viscosity of the oils within the range of current petroleum diesel. By reacting these TAGs with simple alcohols (a chemical reaction known as "transesterification"), we can create a chemical compound known as an alkyl ester, but which is known more generically as biodiesel. Its properties are very close to those of petroleum diesel fuel.

Commercial experience with biodiesel has been very promising. One of the biggest advantages of biodiesel compared to many other alternative transportation fuels is that it can be used in existing diesel engines without modification, and can be blended in at any ratio with petroleum diesel. Biodiesel performs as well as petroleum diesel, while reducing emissions of particulate matter, CO (Carbon monoxide), hydrocarbons and Sox (Oxides of sulphur). Emissions of NOx (Oxides of nitrogen) are, however, higher for biodiesel in many engines. Biodiesel virtually eliminates the notorious black soot emissions associated with diesel engines. Total particulate matter emissions are also much lower. Other environmental benefits of biodiesel include the fact that it is highly biodegradable and that it appears to reduce emissions of air toxics and carcinogens (relative to petroleum diesel). Suffice it to say that, given many of its environmental benefits and the emerging success of the fuel in Europe and USA, biodiesel is a very promising fuel product.


Microalgae Biodiesel

Why should we use microalgae for diesel? There are a number of benefits, four of which are outlined here.


1. Energy Security: Affordable energy contributes to reducing poverty, increasingly productivity and improving the quality of life. India meets nearly 30% of its total energy requirements through imports. With the increase in share of hydrocarbons in the energy supply/use, this share of imported energy is expected to increase. The challenge, therefore, is to secure adequate energy supplies at the least possible cost.

Our almost complete reliance on petroleum in transportation comes from the demand for gasoline in passenger vehicles and the demand for diesel fuel in commerce. Bioethanol made from terrestrial energy crops offers a future alternative to gasoline, biodiesel made from algal oils could do the same for diesel fuel.


2. Climate Change: CO2. Thus, is recognized as the most important (at least in quantity) of the atmospheric pollutants that contribute to the greenhouse effect. The burning of fossil fuels is the major source of the current build up of atmospheric CO2. Thus, identifying alternatives to fossil fuels must be the key strategy in reducing greenhouse gas emissions. While no one single fuel can substitute for fossil fuels in all the energy sectors, biodiesel from algal oils could make major contribution to the reduction of CO2 generated by power plants and commercial diesel engines.


3. Synergy of Coal and Microalgae: Many of our fossil fuel reserves, especially coal, are going to play significant roles for years to come. On a worldwide basis, coal is, by far, the largest fossil energy resource available. It will remain the mainstay of world baseline electricity generation, accounting for half of electricity generation by the year 2015. A typical coal-fired power plant emits flue gas from stacks containing up of 13% CO2. As pressure to reduce carbon emissions grows, this will become an increasingly acute problem for the world.

Algal farms could help recycle the carbon emitted. Large algal farms could be located adjacent to power plants. the bubbling of flue gas from a power plant into these ponds provides a system for recycling of waste CO2 from the burning of fossil fuels. The concept of coupling a coal fired power plant with an algae farm provides an elegant approach to recycle the CO2 from coal combustion into a useable liquid fuel.


4. Terrestrial versus Aquatic Biomass: Algae grow in aquatic environments. In that sense, microalgae technology will not complete for the land already being eyed by proponents of other biomass-based fuel technologies. More importantly, many of the algal species can grow in brackish water – that is, water that contains high levels of salt. Algae technology will thus not put additional demand on freshwater supplies needed for domestic, industrial and agricultural use. Land use needs for microalgae complement, rather than compete, with other biomass-based fuel technologies.



In India, the first Green Revolution raised the productivity by developing varieties that could mature quicker and varieties that could mature quicker and grow at any time of the year, thereby grow at any time of the year, thereby permitting farmers to grow more crops each year on the same land. Cereal yield increased manifold leading to bountiful food grains. India became the largest wheat producer. High yielding rice increased from 12% to 67%.

The first Green Revolution relied heavily on the use of large amounts of fertilizers, pesticides and other agricultural inputs. This coupled with continued expansion of farming areas led to self-sufficiency in food production.

The major scientific pathway of Green Revolution of the late 1960s was productivity enhancement of cereal grains, particularly wheat and rice. A quantum jump in the productivity and production of wheat and then rice transformed the image of India as a 'begging bowl' to a 'bread basket'.

Today, nearly 40 years later, the Green Revolution is aptly recognized as 'forest or land saving agriculture'.

If the yield improvement associated with the green revolution in wheat and rice had not taken place, India by now would have had to convert nearly 80 million hectares of forest land to produce the current level (-207 million tons) of harvest of food grains. The Green Revolution that raised the ceiling of yield also reinvigorated the entire agricultural production machinery in the country. In particular, it restored self-confidence in India's agricultural capability.


Adverse Impacts

There can be no doubt that the first Green Revolution lifted the country out of a situation immediately after independence when the prospects of famines and scarcity of food commodities loomed large. The rapidly expanding population could have made matters all the more worse. It was the Green Revolution that helped tackle the food security issue with increased agricultural productivity.

However, the Green Revolution did have some adverse impacts too which are being felt in the long run. Since the emphasis was mainly on cereals like rice and wheat there was a loss of productivity as far as pulses, fruits and vegetables were concerned. The present rate of fruit and vegetable production will not be able to cope with the future demand as the population is increasing rapidly.

Besides, production of the same type of cereals such as rice and wheat year after year gradually decreased soil fertility making it difficult for pulses and other vegetables to grow. Monoculture (the cultivation of same crop variety for a prolonged period) also led to breakdown of the plant's resistance to pests and diseases which is an unwelcome offshoot of the first Green Revolution.

Another criticism often directed at the first Green Revolution is the indiscriminate use of fertilizers and pesticides that is today threatening the agri-future of the country. Excessive and inappropriate use of fertilizers and pesticides led to widespread environmental damage polluting waterways, poisoning agricultural workers and killing beneficial insects and other wildlife.

The first Green Revolution also did not take care of certain areas like rained, hilly, coastal, dry land and arid zones which could be developed properly for production of exportable items like fruits, honey, mushroom, milk, meat etc.

 Critics of the Green Revolution have also argued that owners of large farms were the main adopters of new technologies because of their better access to irrigation water, fertilizers, seeds and credit. Small farmers were either unaffected or harmed because the Green Revolution resulted in lower product prices, higher input prices and efforts by landlords to increase rent or force tenants off the land. The Green Revolution also encouraged unnecessary mechanization, thereby pushing down rural wages and employment.

Faulty irrigation practices also led to salt build-up and eventual abandonment of some of the best farming lands. Ground water levels have retreated in areas where more water is being pumped for irrigation than can be replenished by the rains.


Second Green Revolution

The challenges of meeting the food requirements of the ever increasing population and plateauing productivity of agricultural lands can only be met by a second Green Revolution. what do we have in mind when we talk of the Second Green Revolution? This, in fact, refers to practicing sustainable agriculture. That is, protecting natural resources from becoming increasingly degraded and polluted and using production technologies that conserve and enhance the natural resource base of crops, forests, inland and marine fisheries.


To help bring food security to the 8 billion people projected by 2025, the world needs another Green Revolution. The Green Revolution that began in the 1960s helped keep food supply ahead of rising demand over the past 30 years. By doubling and tripling yields, it bought time for developing countries to start dealing with rapid population growth.

But the Green Revolution represented only a "temporary success", as Norman Borlaug, the Danish-American plant geneticist who was one of its architects, noted upon receiving the 1970 Nobel Peace Prize. Borlaug pointed out that it is not enough to boost yields on existing croplands; slowing population growth also is crucial.

The first Green Revolution raised the productivity of the three main staple food crops – rice, wheat and corn. Between 1950 and 1990 grains yields increased by nearly two and a half times, from 1.06 metric tons per hectare to 2.52 tons. The second revolution must aim at raising the productivity of other important food crops such as sorghum, millet and cassava – foods produced and consumed mainly by the world's poor.

So far, the outlook for a second Green Revolution is uncertain. Because most increases in food supplies must come from currently cultivated land, raising productivity will require new technologies and better farming practices. Besides, green technologi4es will have to be specially focused on dry land agriculture and to benefit small and marginal farmers. Soil health enhancement through concurrent attention to the physics, chemistry and microbiology of the soils is equally important. Also of vital concern are water harvesting, water conservation and sustainable and equitable use of water.


Apart from the actual focus on farming practices, attention also needs to be paid to issues such as access to affordable credit and to crop and life insurance reform. Equally important are development and dissemination of appropriate technologies and improved opportunities, infrastructure and regulations for marketing of produce.


Strategies for Second Green Revolution:

Several strategies have been talked about to usher in the second Green Revolution that would lead to increased agricultural productivity and will be at the same time sustainable without long-term damage to the soil or the environment. Some of these are discussed here.


Micro-irrigation System:

The government has given special thrust to improving agricultural productivity with heavy investments in micro-irrigation systems. The government is likely to adopt the recommendations of the task force on micro-irrigation. One of the key recommendations is increasing the area under irrigation by 14 million hectares over the Eleventh Plan period (2007-08 to 2011-12).

Adoption of micro-irrigation technology will enable optimal synergies of the three components of the Green Revolution – improved seeds, water and fertilizers. Some countries have already adopted micro-irrigation techniques to use their water more efficiently and to improve productivity. Micro-irrigation systems enable direct and concentrated application of water to root zones of crops, through specially designed emitters and piping networks. At present, only 1.2 mn hectares of farmland in India is covered under micro-irrigation out of a potential 69 mn hectares. The task force has recommended increasing the area under micro-irrigation from the current 1.3 mn hectares to 69 mn hectares.


Organic Farming:

Green revolution technologies involving greater use of synthetic agrochemicals such as fertilizers and pesticides with adoption of nutrient-responsive, high-yielding varieties of crops have boosted the production output per hectare in most cases. However, this increase in production has slow4ed down and in some cases there are indications of decline in productivity and production. moreover, the success of industrial agriculture and the green revolution in recent decades has often masked significant adverse effects such as damage to natural resources and human health as well as agriculture itself.

Environmental and health problems associated with agriculture have been increasingly well documented, but it is only recently that the scale of the external costs has attracted the attention of planners and scientists. As the external costs of farming are no internalized in the price of food, tax payers (or more likely the future generations) will have to pay the bill that is getting bigger every day. Increasing consciousness about conservation of environment as well as of health hazards caused by agrochemicals has brought a major shift in consumer preference towards food quality, particularly in the developed countries.

Global consumers are increasingly looking forward to organic food that is considered safe and hazard-free. The demand for organic food is steadily increasing both in developed and developing countries, with annual average growth rate of 20-25%. Worldwide, over 130 countries produce certified organic products in commercial quantities.


Precision farming:

Agriculture is the backbone of our country and economy, which accounts for almost 18.5 per cent of GDP and employs 52 percent of the population. Though this is a rosy picture of our agriculture, how long will it meet the growing demands of the ever-increasing population? This is a difficult question to answer, if we depend only on traditional farming.

Agricultural technology available in the 1940s could not have been able to meet the demand of food for today's population, in spite of the green revolution. similarly, it is very difficult to assume that the food requirement for the population of 2020 AD will be supplied by the technology of today. To meet the forthcoming demand and challenge we will have to move towards new technologies for revolutionizing our agricultural productivity.

The term "Precision Farming" or "Precision Agriculture" is capturing the imagination of many people concerned with the production of food, feed, and fiber. It offers the promise of increasing productivity, while decreasing production costs and minimizing the environmental impact of farming.


Precision farming provides a new solution using a systems approach for today's agricultural issues such as the need to balance productivity with environmental concerns. It is based on advanced information technology. It includes describing and modeling variation in soils and plant species, and integrating agricultural practices to meet site-specific requirements. It aims at increased economic returns, as well as at reducing the energy input and the environmental impact of agriculture.


Green Agriculture:

Green agriculture is a system of cultivation with the help of integrated pest management, integrated nutrient supply and integrated natural resources management systems. This is widely practiced and promoted in China. Green agricultural does not exclude the use of minimum essential quantities of mineral fertilizers and chemicals pesticides.



Eco-agriculture is defined as an approach that brings together agricultural development and conservation of biodiversity as explicit objectives in the same landscapes. (Eco-agriculture: Strategies to Feed the World and Save Wild Biodiversity, Island Press, Washington, 2003).


Eco-agriculture aims at mutually reinforcing relationships between agricultural productivity and conservation of nature. Innovative eco-agriculture approaches can draw together the most productive elements of modern agriculture, new ecological insights and the knowledge that local people have developed from thousands of years of living is harmony with nature.


White Agriculture:

White agriculture is a system of agriculture based on a substantial use of microorganisms, particularly fungi. The concept of white agriculture took shape in 1986 in China.

White refers to the white-coated scientists and technicians performing high tech processes to produce food directly from micro-organisms or to use them to augment and improve green agriculture.


One straw Revolution: One-straw revolution is a system of natural farming proposed by Masanobu Fukuoka. Its four principles are:

·         No cultivation (no ploughing or turning the soil),

·         No chemical fertilizer or prepared compost,

·         No weeding by tillage or herbicides (weeds play a part in building soil fertility; they need to be controlled, but not eliminated), and

·         No dependence on chemicals or poisonous pesticides.


Future of Indian Agriculture

The future Indian agriculture depends upon our ability to enhance the productivity of small holdings without damage to their long-term production potential. Transforming green revolution into an evergreen revolution using one of more of the several pathways described here will usher in a win-win situation for both farmers and ecosystems. Crop-livestock integration and introduction of stemnodulating legumes or pulse crops in rotation will facilitate the building up of soil fertility. Instead of placing the above mentioned seven approaches to sustainable agriculture in different compartments, it will be prudent to develop for each farm an ever-green revolution plan based on an appropriate mix of the different approaches which can ensure both ecological and economic sustainability.

Over the past 50 years, agricultural growth has exceeded population growth in most parts of the world. These food production successes have helped to diminish the potential for conflict over food, land and water resources. but the easy targets of opportunity in agriculture have largely been exploited. More difficult ones lie ahead, which are often seriously complicated by problems of high population density, poverty and declining resource bases, both in quantity and quality, and inadequate systems of governance.

While we cannot lost sight of the aggregate need to increase food and agricultural production (the pile of food), we must also pay much more research and development attention to the special production and nutritional needs of the chronically food insecure. Expanding the reach of science and technology to areas and farmers that were by passed during the original green revolution combined with foreseeable improvements in overall crop productivity can make it possible to achieve sustainable food security for all. Higher farm incomes will permit smallholder farmers, especially in marginal lands, to make added investments to protect the natural resource base.

Those low-income countries that have been most successful in reducing hunger have generally had more rapid economic growth in their agricultural sectors. However, economic growth alone is insufficient for eliminating hunger because so many hungry people are often excluded from society and are unable to demand rights and live beyond the reach and benefits of markets. Effective social safety nets are also needed to ensure that those who cannot produce or buy food still get enough to eat.

Globalization has brought with it great changes in the integration of international markets  and financial systems and significant economic progress and benefit of three, possibly four,  billion people. But, there are as many as 2.5 billion people at risk of becoming permanently marginalized from these market systems, destined to lives of perpetual poverty and despair. The only way to attain food and nutrition security is by improving marginal and dry land agriculture in a sustainable manner by implementing the second green revolution.


Second Green Revolution Important Consideration

·         Although agriculture, animal husbandry and fisheries are the major source of food security, the entire agriculture rehabilitation programme is yet to receive the much needed attention of the Government and non-governmental organizations.

·         The strategy for food security needs to particularly focus on those who are under BPL as well as small, marginal farmers, landless wage earners, nutrition deficient and problematic areas through a three-pronged strategy, namely

a) Increase in income and agriculture wage by increasing farm productivity

b) Provision of additional off-farm and non-farm employment

c) Effective and strong PDS.

·         Benefits of research must reach farmers for improving yield and enhancing production

·         Improvements in infrastructure for marketing

·         Soil health enhancement

·         Better water management practices

·         Access to affordable credit

·         Private public partnerships

·         Decentralization and participation by the poor in development programmes

·         Opportunity for assured and remunerative marketing for dry land arm products

Wednesday, November 28, 2012



1. Electron volt is the unit of:

a) Energy                 b) Charge                          c) Current                                  d) Potential difference


2. In a perfectly elastic collision, the physical quantity which is conserved is:

a) Mass                    b) Kinetic energy            c) Potential  energy               d) Angular momentum


3. The product of moment of inertia and angular acceleration is equal to:

a) Torque                b) Force                             c) Work                                      d) Angular momentum


4. The SI Unit of electric field intensity is:

a) Volt/ coulomb              b) Newton/ampere

c) Newton / coulomb        d) Metre/volt


5. A wound watch spring has:

a) No energy stored in it                                               b) Mechanical kinetic energy is stored in it

c) Mechanical potential energy stored in it                   d) Electrical energy stored in it


6. When the door of a refrigerator kept in a room is opened and is kept open for some time, the temperature of the room will:

a) Rise                       b) Fall                                  c) Remain unaltered             d) None of these


7. Doppler shift in frequency does not depend upon:

a) The frequency of the source                 b) speed of the observer

c) The frequency of waves produced        d) The distance from the source to the observer


8. If a represents the charge of an electron and V the potential difference between two points, eV represent:

a) Torque                b) Momentum                c) Energy                 d) Power


9. The angular speed of the minutes' hand of a watch in radian /sec is:

a) Pie/60                  b) Pie/30                      c) Pie 3600               d) Pie 1000


10. Of the following physical quantities which have the same dimensions are:

a) Energy and Torque                     b) Impulse and work     

c) Impulse and forque                   d) None of these


11. The power factor of a series LCR circuit for the condition of resonance is:

a) 1                             b) 1/√2                               c) 0                                               d) ½


12. The frequency of a human male's voice as compared to that of a female is:

a) Low                       b) High                                c) Equal                                      d) None of these


13. It is possible to recognize a person by hearing his voice because his voice has a definite:

a) Pitch                     b) Quality                          c) Frequency                            d) Intensity


14. A quantity not involved directly in the rotational motion of a body is:

a) Moment of inertia         b) Torque

c) Angular velocity           d) Mass


15. A fan produces a feeling of comfort during hot weather because:

a) Our body radiates more heat in air         b) Fan supplies cool air

c) Conductivity of air increases                   d) Our perspiration evaporates rapidly


16. The energy and momentum of a photon are given by E= h õ and p = h ë respectively. The velocity of photon will be:

a) Ep                          b) E/p                                  c) P/E                                          d) E/p2


17. The speed of light in diamond is 2/5 of its speed in air. The refractive index of diamond is:

a) 2                             b) 2.5                                   c) 4                                               d) 5


18. When light travels from one medium to another, which of the following quantities never undergoes a change:

a) Velocity           b) Wavelength

c) Frequency      d) Refractive Index



1.a          2.b          3.a          4.c          5.c          6.a          7.d          8.c          9.d          10.a

11.a        12.a        13.b       14.d        15.d        16.b        17.b       18.c


Wednesday, November 21, 2012



Steps in electing the U.S. President

The President is elected every four years and can serve for only two terms. According to the U.S. Constitution, the president must be a native-born citizen of at least 35 years of age and a resident for at least 14 years.

(1) The Ticket:

Presidential candidates choose their running mate to be Vice-President.


(2) Nov 6, Election Day:

The President is not chosen directly by the people but by an Electoral College. The winner of the popular vote takes all the Electoral College votes in very state apart from Maine and Nebraska.


(3) Dec 17, Electoral College:

President and Vice-President formally elected by body of 538 electors – candidate with 270 electoral votes wins. Electors equal to total membership of congress – 435 Representatives, 100 Senators, plus three electors from District of Columbia.


(4) Jan 6, Congress:

Electoral votes formally counted. If no candidate wins 270 majority, president is selected by House of Representatives.


(5) Jan 20, 2013:

Inauguration oaths taken – new presidential term starts.


General Information:

Since 1824, four presidents have lost popular have lost popular vote but won presidency: John Quincy Adams (1824), Rutherford Hayes (1876), Benjamin Harrison (1888), and George W. Bush (2000).

It may be confusing, it may not be perfect, but it has gone on like clockwork for over 200 years providing America stability, say supporters of the U.S. election system as it is set to be tested again the Tuesday's tight presidential race. The U.S. presidential election system, featuring the Electoral College, was established by Article Two of the constitution, as a compromise between those who wanted Congress to choose the President, and those who preferred a national popular vote.

On Election Day, voters, generally, cast votes to select the candidate of their choice, but the ballot is actually voting to select the electors of a candidate.

Under the Constitution, each State is allocated a number of Electoral College electors equal to the number of its Senators and House Representatives in the U.S. Congress. The District of Columbia is given three electors.

Most States, excluding Maine and Nebraska, employ the "winner-takes-all" system, meaning whichever ticket wins the popular vote wins all of the State's electoral votes.

Any pair of presidential and vice-presidential candidates who gain at least 270 electoral votes of the total 538 are claimed the winners.

Though the president and vice-president elect can be yielded on the Election Day, the official voting for them by the Electoral College is held on the first Monday after the second Wednesday in December.

The Electoral College is but one of the many quirks in the U.S. electoral system. Yet there is not central body to supervise the elections. There is a Federal Election Commission (FEC), but it only supervises and enforces campaign fiancé laws.

The process of registering voters, conducting the balloting and counting the votes is left to State and local election officials, who have varying degrees of independence in how they do it.

In yet another quirk, questions of public policy may also be placed on the ballot for voter approval or disapproval. For instance, election 2012 in has more than 1,000 issues including right to die in Massachusetts, gay marriage in Maine, abortion in Florida and Montana, death penalty in California and segregation in Alabama.

Though since 2000 America has moved toward adoption of direct recording electronic (DRE) devices, some States still have paper ballots where one has to an "X" in front of a candidate's name to "laver" machines to the controversial "punch-card" machines used in Florida.

Complicated, one may wonder. Yet there is reluctance to change. For as Thomas Neale, a specialist in American national government at Congressional Research Service, says "It's not perfect" but "we've had a pretty good record, 47 of 51" of popular vote winners becoming President.

But more important, an amendment of the Constitution requires ratification by three-fourths of the States, and the states are not going to give up their turf anytime soon.



Astronomers have found convincing evidence for a super massive black hole in the center of the giant elliptical galaxy M87, as well as in several other galaxies. In 1994, the Hubble Space Telescope data produced an unprecedented measurement of the mass of an unseen object at the center of M87. For many years x-ray emission from the double star system Cygnus X-1 convinced many astronomers that the system contained a black hole. With more precise measurements available recently, the evidence for a black hole in Cygnus X-1 is very strong.

The mathematics of general relativity is so rich, complex, and fascinating that theoretical physicists have spent years investigating the geometry of black holes, these efforts have yielded some surprising results. For instance, in the 1930s Einstein and his colleague, Nathan Rosen, discovered that the full geometry of a black hole could connect our universe with a second domain of space and time that is separate from ours.


Multi Universe

Some physicists, who over the years have explored the properties of the black hole's core using Einstein's equations, revealed the wild possibility that it might be a gateway to another universe that tenuously attaches to ours only at a black hole's center. Roughly speaking, where time in our universe comes to an end, time in the attached universe just begins.

The interiors of black holes are deeply mysterious places, forever beyond our view, where the accepted laws of physics provide no guide. This has not, however, discouraged physicists from speculating about what goes on there. One idea is that the shrinking interior of a black hole shrinks only so far before it rebounds as another universe with slightly different laws of physics. Not in our universe, mind it, because it is a law of black holes that nothing that is inside can ever get our again, but somewhere else. Black holes give birth to baby universes, then the universes that are geared up to produce the most black holes will spawn the most offspring universes. This brings out the idea of multi universe and all other theoretical speculations relating to black holes.


White Holes

The equations of general relativity have an interesting mathematical property, namely, they are symmetric in time. That means we can take any solution to the equations and imagine that time flows backward rather than forward and we will get another valid solution to the equations. If we apply this rule to the solution that describes black holes, we get an object known as a white hole.

Since a black hole is a region of space from which nothing can escape, the time-reversed version of a black hole is a region of space into which nothing can fall. In fact, just as a black hole can only suck things in, a white hole can only spit things out. White holes are a perfectly valid mathematical solution to the equations of general relativity, but that doesn't mean that they actually exist in nature.


Worm Holes

The combination of black and white holes is called a wormhole. A conveniently located wormhole would provide a convenient and rapid way to travel very large distances, or even to travel to another Universe. Maybe the exit to the wormhole would lie in the past, so that we could travel back in time by going through. Wormholes almost certainly do not exist. As we said above in the section on white holes, just because something is a valid mathematical solution to the equations doesn't mean that it actually exists in nature.

These mathematical curiosities have inspired some scientists to speculate about using a wormhole is a short cut to get from one place in our universe to another, or to a parallel universe. But detailed calculations reveal a major obstacle: The powerful gravity of a black hole causes the wormhole to collapse almost as soon as it forms. As a result, to get from one side of a wormhole to the other, you would have to travel faster than the speed of light, which is not possible.



Oceans cover about 75% of the world's surface and 90% of the seas lie beyond the shallow continental margins. Most oceans are deeper than two kilometers and are home to some of the most diverse life on the earth.

We are familiar with animals that live on the surface of the ocean where sufficient light penetrates and photosynthesis takes place in plants. Unlike the surface zone, however, the deep-sea zone is a habitat with pretty inhospitable living conditions. The pressure there is so immense that we would be crushed if we go down there! The temperature is nearly freezing; food is very scarce and there is no light at all!

In addition, the sea floor in some regions consists of volcanic areas, which release fluids that are hundreds of degrees hotter and sometimes may even contain toxic substances that kill organisms still manage to survive in such hostile conditions! These creatures have evolved body structures, behaviours and body chemistries that enable them to survive in such unusual environments.


Oceanic Depths

Oceanographers divided the open ocean or pelagic zone into five layers:

1. The epipelagic zone: The first layer that extends up to 200 meters. It is the photic zone or sunlit zone that receives sunlight.


2. The mesopelagic zone: The second layer also known as the dim light zone or twilight zone. This extends from 200 m to 100 m and forms the border of the photic zone above and darker zone below.


3. The bathypelagic zone: The deep sea starts from hereafter. This is the third layer extending from 1000 m to 4000 m. the sunlight doesn't penetrate deep into this layer. Hence this zone is also called midnight zone.


4. The abyssopelagic zone: This is the fourth layer extending from 4000 m to sea floor. The name of this zone comes from a Greek word meaning "no bottom" and refers to the ancient belief that the open ocean was bottomless! The water here is almost freezing and its pressure is immense.


5. The hadal zone: This zone includes waters found in the ocean's deepest trenches.


Survival Strategies

The deep-sea creatures tolerate or avoid extreme conditions by adopting a variety of survival strategies. Some of the most interesting strategies are given here.


i) Tolerating Pressure: This is a serious problem for deep-sea animals. The pressure increases about one atmosphere (atm) for every 10 m we descend into the ocean. So at 100 m, pressure will be about 11 atm. At such a high pressure, only pressurized submersible vehicles can give us protection. Without such protection, the enormous pressure can cause serious damage due to the presence of large air spaces inside our bodies. However, this immense pressure has little effect on the animals living in this region, as they have bodies that are completely filled with water! Many fishes have a swim bladder that contains gases. The volume of gases in the bladder can be adjusted as they move up and down.


ii) Bioluminescence: This is an extraordinary feature exhibited by the animals living in deep seas. It is a chemical process that results in the release of light through specialized organs called light organs. Light is produced either through symbiotic bacteria living on the fish or through specialized self-luminous cells called photophores.


Bioluminescence occurs when certain chemicals are mixed together. At least two chemicals are required to produced bioluminescence. The first one is known as a luciferin. This is the chemical that actually creates the light. The second chemical is called luciferase, an enzyme that actually catalyzes the chemical reaction. When these chemicals are mixed together in the presence of oxygen, light is produced. A by-product of this process is an inert substance called oxyluciferen.


Tuesday, November 20, 2012



1. In 1572, famous astronomer Tycho Brahe discovered two Supernovas. These Supernovas were located in the constellation….

a) Cassiopeia         b) Virgo             c) Hercules      d) Perseus


2. Lagoon Nebula (Ms) and Omega Nebula (Mix) belong to which star constellation?

a) Cepheus            b) Cygnus          c) Sagittarius    d) Pisces


3. Sirius, the brightest star belongs to which star-constellation?

a) Canis major       b) Taurus            c) Crater           d) Caring


4. The distance between Sun and Earth is one Astronomical unit (1 A.U) that is equal to:

a) 169, 598, 500 km      b) 159, 598, 500 km        c) 189, 589, 500 km      d) 149, 600, 000 km


5. Which planet is called Morning Star?

a) Mercury      b) Venus             c) Mars         d) Saturn


6. Cassini mission was set to the planet:

a) Venus         b) Saturn            c) Sun           d) Mercury


7. The Sun is seen the longest against which zodiacal constellation?

a) Aries           b) Taurus            c) Virgo         d) Libra


8. The whole celestial sphere is divided into how many star constellations?

a) 100             b) 98                  c) 72              d) 88


9. Who proposed the heliocentric hypothesis?

a) Kepler            b) Tycho Braha             c) Nicolas Copernicus                 d) Ptolemy


10. Among these one is not a space shuttle:

a) Atlantis        b) Columbia                    c) Discovery             d) Kalpana


11. Name the Russian launch vehicle that placed India's first satellite Aryabhata in orbit:

a) Delta            b) C-1 Intercosmos          c) Vostok         d) Arianne


12. Which was America's first satellite?

a) Tel Star         b) Bird         c) Explorer – 1        d) Mariner


13. Who gave the first evidence of the 'Big Bang Theory'?

a) Edwin Hubble            b) Albert Einstein           c) Stephen Hawking           d) C.V. Raman


14. There are more than ……….. galaxies in the observable universe?

a) 1012                    b) 1011             c) 1022             d) 1015


15. How many stars are present in a typical galaxy?

a) 107 to 1012         b) 105 to 1010                  c) 109 to 1012                d) 108 to 1015


16. Name the fifth largest of the modern constellations, which was also included in Ptolemy's constellation.

a) Hercules     b) Pegasus            c) Perseus       d) Cepheus



1.a      2.c          3.a          4.d          5.b          6.b          7.c          8.d

9.c      10.d       11.c         12.c        13.a        14.b        15.a        16.a



Incandescent Bulbs: - Incandescent bulbs contain a filament that is heated, giving off light in the process. The filament is delicate and eventually burns out. Special gases are introduced into the bulbs to increase their useful life although this does not increase its efficiency. Regular incandescent bulbs are very inefficient as over half the energy consumed by them produced heat and not light.


Tungsten Halogen Bulbs: - Tungsten-halogen (or quartz) bulbs are quite similar to the incandescent bulbs but are 10-15% more energy efficient than the standard incandescent. Compared to incandescent lamps, halogen lamps produce a brighter, whiter light and are more energy efficient because they operate their tungsten filament at higher temperatures. However, they can generate excessive heat and could be a fire hazard.


Light Emitting Diodes (LED):- Another source of lighting that is gaining importance is LED – small, solid light bulbs, which are extremely energy efficient. Until recently, LEDs were limited to single bulb use in applications such as instrument panels, electronics, penlights, etc. Recent improvements in manufacturing technology have lowered the cost of LEDs and their range of application has increased. the bulbs are now available in clusters, from 2 to 36 bulbs and are popular especially for batter-powered items like flashlights. Their life is about 10 times that a CFL and they use a fraction of the wattage of incandescent bulbs. Moreover, because of their low power requirement, they can be lighted using solar energy thereby allowing their use in remote areas.

However, LEDs offer only focused light and are best as task specific lighting such as reading light, spotlights, signage lightening, etc. They do not radiate light in 360°. New designs using diffuser lenses with clustered bulbs are trying to address this problem. A lot more needs to be done for more residential application of LED lights.


Compact Fluorescent Light Bulbs:- The demand for CFL has risen sharply over the past few years. According to Elcoma (Electrical Lamp Manufacturing Association), New Delhi, the production of GLS (General Lighting Service) bulbs and FTLs (Fluorescent Tube Lights) has increased only by about 30% and 37% respectively but at the same time the production of CFLs has increased by 370% during the last five years.

The primary reason for the increase in their demand and production is their energy efficiency. Compact fluorescent light bulbs (CFLs) use fluorescent technology in a compact size that can be used in place of standard light bulbs, are much more energy efficient and last 8 -10 times longer than the ordinary bulbs. The primary difference between a CFL and FTL is in size. CFLs are made in special shapes to fit in standard household sockets, like wall fixtures, table lamps, etc. in addition, CFLs generally have integral ballast that is built into the light bulbs whereas most fluorescent tubes require separate ballast independent of the bulbs and thereby need special fixtures. Both offer energy efficient light, but an added advantage is that CFLs are available in different shapes and sizes.

The watts needed by regular incandescent bulbs and CFLs to produce the same amount of light is roughly as follows:

CFLs fill our rooms with the same amount of light using 60-75% less energy than a standard incandescent bulb. Although the initial cost of a CFL is higher, the cost saving over the life of the bulb can be striking.

So, by replacing one 60-watt incandescent light bulb by a 13 watt CFL you save about Rs. 1500/- over its lifetime; if you replace more the saving would be much greater. And don't forget the heat – the standard incandescent bulbs give away most of the energy consumed as heat thereby increasing the cooling costs of homes and offices in summer. At the same time, mercury is an essential ingredient for most energy efficient lamps. The amount of mercury in a CFL can be upto 4 mg/bulb.

Fluorescent bulbs contain low-pressure mercury vapour and argon, an inert gas, with electrodes at each end. Ultraviolet (UV) light is emitted when electric current is passed through mercury vapour. The UV light is itself invisible, however, when this ultraviolet radiation hits the white fluorescent coating inside the tube, it is absorbed by coating and emitted as visible light – the illumination we see. As CFLs do not use heat to produce light they are much more efficient as compared to regular incandescent bulbs.


CFLs Posing Mercury Hazard?

Mercury is found naturally in the environment and its emission can come from both natural and man-made sources. The highest source of mercury in air comes from burning of fossil fuels such as coal. Coal based thermal power plants are an important man made source of mercury. The thermal power plants may account for upto 40% of mercury emissions in the air (Thermal Power Plants in the US are required to reduce their mercury emission by 70% by 2018). A CFL uses 75% less energy than an incandescent light bulb and lasts 6-10 times longer. A power plant may emit upto 10 mg to Hg to produce the electricity to run an incandescent bulb compared to only 2-4 mg of mercury to run a CFL for the same time.

Another argument is that the mercury emissions from thermal plants are air-borne and pose a lower risk of exposure but when the same mercury is deposited in the organic dumps/water bodies through the disposal of broken or discarded CFLs, it may transform into methyl mercury which is a neurotoxin that is likely to enter the food chain. However, one has to remember that the air emission of mercury from a thermal power plant also eventually lands on the vegetation, soil, etc. thereby entering the food chain.


Environmental Benefits:- In addition to generating cheap electricity, coal fired Thermal Power Plants release massive amounts of carbon dioxide, the greenhouse gas linked to global warming. Every incandescent lamp replaced by a CFL helps to fight global warming. In addition to carbon dioxide Thermal Power Plants also release, sulfur dioxide (the main cause of acid rain); nitrogen oxides (cause smog and acid rain); radioactive pollutants and mercury.

The amount of mercury in CFLs compared to all other sources of mercury exposure (thermometers, emissions from coal fired Power Plants, etc.) is so little that it does not substantially contribute to the problem of mercury exposure. In fact, the amount of mercury produced from generating electricity to burn an incandescent bulb is more than that for the electricity for a CFL and the amount of mercury contained in a CFL combined. So there is still less mercury going into the environment from using CFL. It is estimated that replacing a single incandescent bulb with a CFL will keep half-ton carbon dioxide out of the atmosphere over its lifetime.


Limitations of CFL Bulbs:- Not all CFL can be used with dimmers since this can shorten their life. Earlier the fluorescent bulbs flickered when they were turned on; it took a few seconds for the ballast to produce sufficient electricity to excite the gas inside the bulb. Due to improvement of technology the flicker is now insignificant, although the bulbs do require a short warm up period for reaching full lighting. Moreover, it is best not to use CFLs in fixture that is turned off and on frequently as this shortens their life.

CFLs can also cause disturbance in the working of electronic devices like televisions, radios, remote controls, etc. as such devices may intercept the light coming from a CFL as a signal. In such cases it is better to increase the distance. Use in bathrooms may also shorten the life of the CFL due to humidity.


Disposal Options:- At present there is no substitute for mercury in the CFLs. However, manufacturers claim to have taken several steps bulb. Although CFLs used in houses are not legally considered as hazardous waste, it is in the interest of the environment to dispose off the CFLs properly upon burnout. There should be an option for its safe disposal in the treatment, storage and disposal facility and it should be regulated in the same way as used battery, used oil, etc. The best way would be to place the CFLs in a sealed plastic bag and send it to the nearest collection centre. Large commercial users of CFLs must be required to recycle it.

CFL's are safe to use in homes. No mercury is released when the bulbs are in use as the mercury content in each bulb is very small. Even when the bulb breaks there is no immediate health risk if it is cleaned up properly. The glass fragments and fine particles of the broken bulb must be collected by sweeping – not by vacuuming and then the area should be wiped with damp cloth. The damp cloth and the fragments may be placed in plastic bag before disposing. Opening the doors and windows ventilates the room. We need to pay attention to the recycling of CFLs as a little bit of mercury in each bulb can become a real problem as the production and sales are booming very fast.

It is clear, that although there are certain limitations or drawbacks of using CFLs, the benefits in terms of saving energy thereby fossil fuels), reduced greenhouse gas emissions and other environmental issues related to burning of coal are far greater. What is needed is further research for improving the CFLs and reducing / replacing the mercury in them.

Many countries are now banning or are in the process of banning the incandescent bulbs in favour of CFLs as a part of initiatives to reduce both energy consumption and greenhouse gases blamed for global warming. The Indian Government is also taking steps for introducing CFLs in preference to incandescent bulbs. In addition to the steps already taken for promoting the use of CFLs we may think of providing subsidy on them (that is. energy saving measures) in preference to providing subsidy on power itself.

But what is needed is a mass movement. Only then we could help repair the damage we have wrought on our environment.

Monday, November 19, 2012

Quiz : Astronomy Quiz

Quiz : Astronomy Quiz


1.     In how much time does moonlight reach the Earth?

a) 1.3 Seconds                             b) 13 seconds

c) 1.3 minutes                             d) 13 minutes


2.     Squadron leader, Rakesh Sharma, the first Indian in space was launched aborad :

a) Vostak                                      b) Sayuz T 11

c) Salyut 7                                    d) Salyut 4


3.     Triton and Nereid are the satellites of :

a) Pluto                                         b) Jupiter

c) Uranus                                      d) Neptune


4.     The bright head of the comet is known as

a) Pointer                                     b) Nucleus

c) Coma                                        d) Shooter


5.     The mean distance between the Earth and Sun as well as the distances within the Solar System are represented by :

a) Light Year                                 b) Astronomical Unit

c) Parsec                                       d) Angstrom


6.     Sirius, the brightest star outside the Solar System is also known as :

a) Dog star                                   b) Proxima Centauri

c) North Star                                d) Delta Cephei


7.     Actinometer is an instrument used to measure :

a) Head radiation                        b) Speed of planets

c) Solar radiation                         d) Distances from the Sun


8.     The first spacewalk was undertaken by :

a) Yuri Gagarin                             b) Neil Armstrong

c) Edwin Aldrin                            d) Lt. Col. Alexei Leonov


9.     'Shooting Starts' in another term used for:

a) Meteors                                   b) Comets

c) Asteroids                                  d) Supernovae


10. Corona, the outermost layer of Sun's atmosphere is visible only during :

a) Total solar eclipse                   b) Annular solar eclipse

c) Partial solar eclipse                 d) Lunar eclipse


11. Our galaxy, the Milky Way, was first studied extensively by :

a) Harlow Shapley                             b) Copernicus

c) Galileo                                            d) Ptolemy


12. At perihelion, the Earth is at a distance of 147 million kms from Sun and at Aphelion the distance between them is :

a) 149 million kms                      b) 152 million kms

c) 170 million kms                      d) 155 million kms


13. Ratio between the total solar radiation falling upon the surface of a body and the amount reflected is called :

a) Mirage                                      b) Illumination

c) Albedo                                      d) Terrestrial radiation


14. The eclipse of the moon shows :

a) Angular shadow of Earth       b) Circular Shadow of Earth

c) An elliptical shadow               d) No shadow


15. Selenography is the study of :

a) Surface of moon                     b) Galaxies

c) Surface of sun              d) Asteroids'


16. Sunspots are the dark spots on the Son's surface. The bright areas of the photosphere are known as :

a) Light Spots                               b) Patches

c) Holes                                        d) Faculae



Answers :


1. a                        2. b                 3. d                 4. c                  5. b


6. a                        7. c                  8. d                 9. a                  10. a


11. a               12. b               13. c                14. b               15. a               16. d

Radioactive Dating

Radioactive Dating


Þ    Rocks are made up of many individual crystals, each comprising several different chemical elements like iron, magnesium, silicon, etc. Although most elements are stable, atoms and some elements are unstable in their natural state as they undergo radioactive decay. Radiometric dating is the process of determining the age of rocks from the decay of such radioactive elements.


Þ    There are several techniques of radioactive dating, each using a different radioactive element or a different way of measuring them.


Þ    The radiocarbon method was developed by Willard F. Libby for which he received the Bobel Prize in Chemistry in 1960. This method has been used to date samples as old as 50,000 years.


Þ    Radiocarbon dating can be done on ancient samples of wood, charcoal, bones, peat and organic – bearing sediments, besides carbonate deposits such as tufa, caliche, and marl; and dissolved carbon dioxide and carbonates present in oceans, lakes and ground – water sources


Þ    Potassium – Argon dating is a viable technique for dating very old archaeological materials. Geologists have used this method to date rocks as much as 4 billion years old. The radioactive isotope of Potassium, Potassium – 40 (K – 40) decays to the gas Argon (Ar – 40). By comparing the proportion of K – 40 to Ar – 40 in a sample of volcanic rock, and knowing the decay rate of K – 40, the date of formation of that rock can be determined.


Þ    Radiocarbon dating depends on measuring the amount of C – 14 in a sample and then calculating the age since death by considering the half – life.


Þ    Radiocarbon dating relies on a simple natural phenomenon. As the Earth's upper atmosphere is bombarded by cosmic radiation, atmospheric nitrogen is broken down into an unstable isotope of carbon – C – 14. As – C – 14 reacts identically to the stable forms of carbon, C – 12 and C – 13, if becomes attached to complex organic molecules through photosynthesis in plants and becomes part of their molecular makeup. C – 14 thus becomes fixed in the biosphere through food chain. The process of ingesting C – 14 continues as long as the plant or animal remains alive. However, when it dies, there is no replenishment of radioactive carbon, but only decay occurs, whereby C – 14 is converted back to N – 14.


Þ    The gas counting method and liquid scintillation counting are two important methods of radiocarbon dating.


Þ    The method of counting C – 14 used by Libby and his co – workers involved measuing radioactivity using modified Geiger counters. The next development in counting technology was the conversion of sample carbon of CO2 gas for measurement in Gas Proportional counters.


Þ    The Accelerator Mass Spectrometry (AMS) method is for direct C14 isotope counting in just milligram – sized samples.


Þ    Using radiocarbon dating, archaeologists have been able to ascertain the timing of major prehistoric events live the development of agriculture in various parts of the world.


Famous Scientist

Famous Scientist


  1. 'Bose – Einstein Statistics' was deduced by Einstein and which one of the following?

a) Debendra Mohan Bose                               b) Satyendra Nath Bose

c) Jagadish Chandra Bose                               d) Sahaya Ram Bose


  1. The Theory of Quanta was postulated by :

a) William Crookes                                         b) J. J. Thomson

c) Louis de Broglie                                          d) Max Planck


  1. 'Exclusion principle' was proposed by

a) Pauli                                                            b) Heisenberg

c) Schroedinger                                               d) A. H. Compton


  1. 'Uncertainly Principle' was proposed by :

a) Niels Bohr                                                   b) C. V. Raman

c) Zeeman                                                       d) Heisenberg


  1. Who got the Nobel prize in Chemistry in 1911?

a) Rutherford                                                   b) Marie Curie

c) Prof Soddy                                                   d) Becquerel


  1. The Indian scientist who died in a plane crash was :

a) K. S. Krishnan                                              b) Homi Jahangir Bhabha

c) C. V. Raman                                                d) S. Bhagavantam


  1. Iodine was discovered by :

a) Bernard Courtois                                         b) Cavendish

c) Scheele                                                        d) Brandt


  1. The fundamental law of thermo – chemistry was discovered by :

a) F. Joliot                                                        b) Lawrence

c) Otto Hahn                                                   d) Germain Henri Hess


  1. Germanium was discovered by :

a) C. Winkler                                                   b) Cavendish

c) Kirchhoff                                                      d) Klaproth


  1. The phrase, 'Chance favours the prepared mind', was said by :

a) Louis Pesteur                                              b) Charles Darwin

c) Blaise Pascal                                               d) Newton


  1. Who patented more than 1000 inventions?

a) Thomas Edison                                           b) Newton

c) Faraday                                                       d) Coulomb


  1. The book, 'Einstein's Theory of Relativity', was written by :

a) Einstein                                                       b) Heisenberg

c) Max born                                                     d) R. A. Millikan


  1. The birth anniversary of which scientist, on 11th February, is observed as National Inventors Day in the U. S.

a) Thomas Edison                               b) Enrico Fermi

c) J. J. Thomson                                   d) L. C. Pauling


  1. Some particles follow – Dirac Statistics. These particles are named after which scientist :

a) Dirac                                               b) S. N. Bose

c) Chadwick                                         d) Enrico Fermi


  1. Both further and son got noble Prize in the same year in Physics. Father's name was Sir William Henry Bragg and son was :

a) William Lawrence Bragg                b) William Louis Bragg

c) William Lewis Bragg                       d) William Lorentz Bragg




Answer Sheet


1. b                  2. d                  3. a                  4. d                  5. b     


6. b                  7. a                  8. d                  9. a                  10. a


11. a                12. c                13. a                14. d                15. a