Man and Energy

Man has needed and used energy at an increasing rate for sustenance and well-being ever since he came on the earth a few million years ago. Primitive man required energy mainly in the form of food. He got this by eating plants or animals which he hunted. Subsequently he discovered fire and learnt how to use it. He used fire for cooling as well as for keeping himself warm. Thus his energy needs increased day by day and he started to make use of wood and other biomass to supply the energy.

After a while, man started to cultivate land for agriculture. For domesticating and training animals to work for him he needs more energy. With further demand for energy, man began to use the wind for sailing ships and for driving windmills, and the force of falling water to turn water wheels. Till this time it would not be wrong to say that the sun was supplying all the energy needs of man either directly or indirectly and that man was using only renewable sources of energy.

With the discovery of the steam engine (A.D 1700), the Industrial Revolution began and brought about a great many changes. For the first time, man started to use a new source of energy – coal, in large quantities. A few years later, the other fossil fuels, oil and natural gas began to be used extensively. The fossil fuel era of using nonrenewable sources had begun.

Man started to produce electricity using either fossil fuels or water power and he developed power generating stations. The electricity brought a great change in man’s movement. For the first time, man got the power of machine.

A new source of energy- nuclear energy- came on the scene after the Second World War.

Already, nuclear energy is providing a small but significant amount of the energy requirements of many countries.

In the past few years, it is obvious that fossil fuel resources are fast depleting .This is particularly true for oil and natural gas. Thus the fossil fuel era is gradually coming to an end. Based on the World wide survey(shown in fig.), it will now be possible to make some observations and draw some conclusions for the world as a whole.

a) The production of oil appears at maximum around 1980 and is now slowly declining. On the other hand, the production of natural gas is still rising. Present data shows that most of the reserves of oil and natural gas are likely to be consumed in another 50 years.

b) As oil and natural gas become scarcer, a great emphasis will fall on coal. The production of coal likely will touch a maximum somewhere between the years 2030 and 2060 and it could be consumed by 2250 AD.

Thus the need for alternative energy sources will be established. Now it is obvious that though man’s large scale use of commercial energy (coal, oil, natural gas, hydroelectric power and nuclear power) has brought a better quality of life, it has also brought many problems. Perhaps the most serious of these is the harmful effect on the environment. It causes serious air pollution problems in many areas because of the localized release of large amounts of harmful gases into the atmosphere. It causes the phenomenon of global warming which now a matter of great concern. Keeping the environment in mind, now we are badly in need of alternative energy sources. Later part of this sires, I’ll discus about some of them.

Thank you.

Not Catastrophism: Erosion of Earth

In the eighteenth century scientists believed that Earth’s surface had remained unchanged until cataclysmic events (like the flood of Noah)-called catastrophism. Catastrophism claimed that all of the changes in the earth’s surface were the result of sudden, violent (catastrophic) changes. In that time scientists tried to understand the planet’s surface structures by using Catastrophism. They studied the earth, its history, its landforms, and its age based on Catastrophism. And they led to wildly inaccurate guesses and misinformation.

But in the 1780s, 57-year-old, James Hutton (amateur geologist) decided to try to calculate the age of the earth more accurately by studying the earth’s rocks. And soon he realized that something possibly was wrong with Catastrophism and no catastrophic event could explain the rolling hills and meandering river valleys.

The earth, Hutton realized, was shaped slowly, not over night. Rain and wind are the main forces which change our Earth’s surface bit by bit, year by year. He discovered that the earth’s surface continually and slowly changes, evolves. He discovered the processes of erosion of Earth that gradually built up and wore down the earth’s surface. And water, wind, ice and wave (coastal erosion) are the main agents of erosion that change the shape of the earth’s surface.

But what built up the earth? He finally concluded that the heat of Earth’s core built up hills and mountains by pushing out ward. Mountain ranges were forced up by the heat of the earth. Wind and rain slowly wore them back down. With no real beginning and no end, these two great forces struggled in dynamic balance over eons, the real time scale for geologic study.

With that great discovery, James Hutton forever changed the way geologists would look at the earth and its processes. This discovery provided the key to understanding our planet’s history and launched the modern study of earth sciences.
However you may enjoy some clips on youtube about power of wind and atomosphere-here is one of them in Arizona
http://www.youtube.com/watch?v=aBnGqQN_9hQ

Third law of Thermodynamics: is it broken?

There are always some invisible barriers in the physical science - the edge of the detectable universe-the cosmological horizon is one, and the relativistic speed limit,Beyond which no object can accelerate, is another .A third such barrier is absolute zero Temperature, the state beyond which matter cannot be cooled, in which all molecular motion ceases .

Absolute zero, as a theoretical concept, was found as early as 1699, in the work of the French physicist Guillaume Amontons, conducted experiments in temperature and it’s measurement, but still it is a mystery why it is unattainable. The numerical value of absolute zero is -273.15 degrees Celsius or -459.67 degrees Fahrenheit.

The first significant step in the direction of achieving absolute zero was taken in the 1880s when a French mining engineer named Louis-Paul Cailetet liquefied Oxygen,At about-200 degrees Fahrenheit .Today, when temperature of less than a degree above Absolute zero are achievable, this trend continues at the University of Florida, is Gainesville, where a new cryogenics laboratory has been opened recently.

The first law of thermodynamics (also known as law of conservation of energy) holds that energy can neither created nor destroyed. It establishes an exact relation between heat and work. But it does not tell us the direction of energy transformation.

The second law, which governs the direction of the flow of heat, dictates that during every transformation of energy, a certain amount is dissipated and so, is unavailable for doing work. It introduces a new thermodynamic variable named Entropy which is the measurement of disorder. With disorder, entropy increases.

By an orderly sate of molecules in a substance we mean that at any instant we can be sure in specifying their arrangement within the substance.

The third one was proposed, in 1906, by Walther Nernst, of the University of Berlin (for which he won the 1920 Nobel Prize in chemistry).

Physicists previously had assumed that, when cooled, molecules and atoms gradually slow down until, at absolute zero, they come to rest. But Quantum Mechanics does not allow that. The lowest energy available to an atom, called its ground state energy, is not zero. The associated with this state cannot be shared with other objects ( it cannot “flow”) or be interpreted as heat, so it does not count as disorderliness. Reasoning in this manner, Nernst reached at a new understanding of absolute zero: rather than the absence of motion, it indicates the absence of disorder, that means, a state of perfect order.

Surveying the specific heat –six year latter Nernst discovered a remarkable fact: During the approach toward absolute zero, or perfect order, each step is more difficult than the preceding one. Temperature decreases less with each successive removal of heat. Nernst proposed a stronger form of the third law: Absolute zero is unattainable.

In principle, according to the statistical nature of order, there is a small but finite probability that an object will reach a temperature of a billionth of a Kelvin, or even zero. This is the base of Gainesville physicists.

Oceans Control Global Weather

By pumping massive amounts of heat through the oceans, vast ocean currents control weather and climate on land.

American statesman, inventor, and scientist Benjamin Franklin conducted the first scientific investigation of the Gulf Stream at 1770 and discovered its importance to Earth’s weather

and climate. His work launched scientific study of ocean currents, ocean temperature, the

interaction of ocean current with winds, and the effect of ocean currents on climate. Franklin’s discoveries mark the beginnings of modern oceanographic science.

The Atlantic Ocean’s Gulf Stream is the most important of our world’s ocean currents.

It is a major heat engine, carrying massive amounts of warm water north to warm Europe. It

has directed the patterns of ocean exploration and commerce and may be a major determinant of the onset of ice ages. Finally, it is the key to understanding global circulation patterns and the interconnectedness of the world’s oceans, weather, and climates.

The Gulf Stream is bigger than the combined flow of the Mississippi, the Nile, the Congo, the Amazon, the Volga, the Yangtze,and virtually every other major river in the world.

Cancer and Power lines

Epidemiologists in Denver , Los Angeles and Sweden are asking us to believe that magnetic fields of 2 milligauss from power distribution lines are a serious cause of childhood Leukemia . And they believe that low frequency electromagnetic fields ( like ovens and TV sets) of modern life threaten our health .

However, laboratory studies on animals and cell cultures have shown that weak magnetic fields can have effects on several biological processes. For example, they may alter hormone and enzyme levels and the rate of movement of some chemicals through living tissue. In the long term, they may have an effect on the incidence of cancer or other adverse health effects.

But the studies have been criticized . The studies were using data gathered from second hand

sources . They all suffer inadequate statistical samples ; in some cases , it is as little as only one case of cancer per year . The studies are mutually inconsistent and self- contradictory .

Well , "Do the all-pervasive low-frequency electromagnetic fields of modern life threaten our health ? Most probably not , judging from comparisons with the natural fields present in the

environment and in our bodies ." said William R. Bennett Jr , is a professor of Physics at

Yale University .

Well , Let's consider some natural sources of exposure .

The Earth's magnetic field is generated predominantly by circulating currents of uncertain origin well below the crust . The fields varies over the Earth's surface from about 300 mG at the equator to 700 mG at the poles .A representative value over the continental United States is

about 450 mG , about 200 times that from typical distribution lines . The magnetic field may vary about 0.1-0.3 mG due to photoionization of molecules in the upper atmosphere . For unusual solar activity sudden fluctuations often exceed 100 mG .

Again Earth's static electric field is directed downward normal to the earth's surface and is about

120 V/m near ground level , about three times the field from a 12-KV distribution line .

So, If you live in a house near one of these high-voltage power lines, you shoud not move.

But based on what we know now, we can never say there is no risk, but we can say that the risk appears to be extremely small.

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