The A-Z of Global Warming- Fossil Fuels: by Simon Rosser

Copyright (c) 2008 Simon Rosser
This article is taken from The A-Z of Global Warming and discusses fossil fuels. The generation of electricity from burning carbon rich coal has a greater impact on the atmosphere than any other single human activity. In 2003 the power industry created 44.5% of all manmade carbon dioxide (CO2) according to the World Resources Institute, Climate Analysis Indicators Tool (CAIT). If one looks at emissions of carbon dioxide alone (ignoring all other greenhouse gases), then for the year 2000, the figure is just under 33%, and the latest figure available from 2003, as mentioned above shows an increase for this sector to 44.5%. The latest figure however excludes CO2 from land use change.
So what are fossil fuels, and how are they formed? Well fossil fuels form deep in the earth's crust over millions of years from enormous pressure and heat which converts dead plant and animal matter into hydrocarbons in the form of coal, oil or natural gas, which can then be dug up and burnt as fuel.
As these fossil fuels have formed over millions of years they are no longer considered to be part of the natural carbon cycle as they have effectively been "locked up" within the earth's crust and rocks etc.
In 2005 alone some 28 billion tonnes of CO2 was released into the atmosphere, from burning fossil fuels, which is equivalent to about 800 tonnes a second!
Out of all the fossil fuels the worst culprit is coal, which is used as the fuel in coal fired electricity power stations for the production of electricity. Generating electricity through carbon rich coal however has a greater impact on the atmosphere than any other single human activity.
The power industry creates over twice the amount of CO2 as is produced by the transport sector.
Basically electricity generation hasn't changed much from the 19th century with large power plants burning fossil fuels for the creation of electricity, and this model looks set to continue for some time to come.
Within the rapidly expanding economies of India and China, coal fired electricity plants will dramatically increase. In fact China, the USA and India are the top three producers in the world.
Apart from carbon dioxide, burning coal produces a host of other chemicals, such as sulphur dioxide, which causes acid rain, Nitrous oxide and other heavy metals.
What makes matters worse is that coal is the world's most widely available fossil fuel and there is around 200 years of coal left, if it is used at its current rate. This will be pretty academic however as according to the latest report by the Intergovernmental Panel on Climatic Change, if the burning of fossil fuels continue unchanged, the Earth could warm by as much as 6 degrees Celsius (10.8 F) by 2100. This would mean almost certain extinction of most of life on the earth.
One only has to look at pictures from recent news stories showing industrial cities in these developing countries to see the pollution and clouds of smog hanging over the cities and blocking out the sunlight.
It is estimated that by the year 2030, 55% of all power stations built in the Asia pacific region will be coal fired.
The transport sector in 2000 accounted for around 14% of greenhouse gas emissions, or 20% of CO2 alone (ignoring other greenhouse gases), in 2003. The majority of these emissions are from road transport, with aviation second, followed by shipping and rail last. Emissions from the aviation sector are expected to grow the quickest however.
So whilst developed and especially developing nations continue to build power stations to gobble up the Earth's supply of fossil fuels, serious harm is being done to the atmosphere which will continue to elevate global temperatures as higher CO2 levels add to the greenhouse effect.
There are in fact enough fossil fuels left to take the world to levels of CO2 concentrations of around 750ppm and above, (around 330 ppm more than present) which would elevate temperatures to such an extent that it would be catastrophic for all of Earth's inhabitants. CO2 as a result of burning fossil fuels is only one of the many greenhouse gases, which is contributing to the warming of the atmosphere. In the next article we will look at Earth's greenhouse gases, which are essential to life on Earth, but which are now warming the planet as their levels steadily increase.

How To Use a Telescope - Galileo's First Telescope and its History: by John B. Mayall

Galileo Galilee is known as the "father of telescopes" and rightly so. He is the inventor of the telescope and every telescope made after his invention follows the same principle that he used. Galileo's telescope was a primitive prototype of the telescopes that are used widely today. However, the principles he used are the very same ones still being used to this day. Galileo's telescope used two lenses - one concave and one convex - inside a tube-light shaped device. Convex lenses are those lenses whose edges curve inwards and concave lenses are lenses that have outward curves at the edge. The eyepiece in the telescope was constructed with the concave lens. Spy glasses, invented around the same time and used by militants to observe enemy activity in camps, were a major inspiration to Galileo in making his own telescope.
When two lenses are combined together, they are able to collect more light than individual lenses. This is the main principle behind Galileo’s telescope. Most of the telescopes in use today, use the same principle. The human eye also works on a similar principle, but cannot collect too much light. Telescopes are able to gather more light because of the double lenses used in its construction. These lenses gather light and build an image by focusing the light at a point. Refraction is the mechanism in use to form such images. As a result, telescopes are also called refracting telescopes or refractors. The phenomenon by which the collected light bends and forms images is known as refraction.
Images were magnified by a factor of 30 in Galileo's invention. However, the shape of the lenses he used was such that his image became blurred and distorted. But no one had ever invented something so exciting with which to observe the night skies before Galileo's telescope. Galileo used his telescope to view the moon and observe it closely. He was also the one to figure out that the magnification factor of a telescope was provided by the ratio of the power of the concave lens to the power of the convex lens. So he premised that the simplest way to increase this magnification factor was to use a high power concave lens with a weaker convex lens.
In Galileo's time, there were only low strength lenses available. Due to this restriction, Galileo decided to make his own lenses. He was soon able to achieve a magnification of 9x with lenses hat he had ground himself. His telescope was fitted with his own lenses. It was just another feather in his already well-decorated cap.
As time passed, Galileo improvised on his primitive telescope, making several modifications to it. He also demonstrated his invention at the Senate of Venice, and several senators climbed the highest towers of the time to observe the horizon with Galileo's invention. They viewed the distant ships from their perches and decided that the telescope was a very useful military device.
The telescope changed the face of Astronomy and became an indispensable part of the study. Several inventors used the same principle and made telescopes of their own. Gradually over the years, the study of astronomy benefited immensely from the telescope and its uses. The same principle was employed in the construction of much more powerful telescopes that made it possible to understand our plane and its surroundings more comprehensively, all thanks to Galileo's wonderful invention.