Global warming
Surface temperature measurements recorded daily at hundreds of locations for more than 100 years indicate that the Earth's surface has warmed by about 1 degree Fahrenheit in the past century. This warming has been particularly strong during the last 20 years, and has been accompanied by retreating glaciers, thinning arctic ice, rising sea levels, lengthening of growing seasons for some, and earlier arrival of migratory birds. In addition, several other data support that conclusion. But are humans to blame? Scientists delving into the earth's history have found quite a different global warming: an ancient, natural, 1500-year warming-cooling cycle driven by a known cycle in the magnetic activity of the sun. Written history tells us the Medieval Warming was a mild-weather period from the 11th to 13th centuries, with temperatures 1 to 3 degrees Fahrenheit warmer than today. It was followed by the Little Ice Age, with temperatures 2 to 4 degrees Fahrenheit lower, harsh storms, encroaching glaciers, and crop-failure famines. History also records an earlier Roman warming, it too, followed by a mini-ice age. So are we just experiencing a natural warm period in the earth's cycle or is man to blame? Global warming can also be called the greenhouse effect, which is a natural occurrence that maintains Earth's average temperature at approximately 60 degrees Fahrenheit. The greenhouse
Global warming
Global warming is the observed increase in the average temperature of the Earth's atmosphere and oceans in recent decades. The greenhouse effect, is the process by which an atmosphere warms the planet. Gases such as methane and carbon dioxide that stop some thermal energy escaping from the atmosphere. Global warming is the warming up of the planet above the temperature it "should" be. It is such a concern at the moment as it seems that the temperature is rising at a rate far faster than ever before and it is thought that it may be the activities of the human population over the last 150 years or so that is doing it. Mean temperatures over the whole planet have risen by about 0.6? C (just over 1? F) in the last 100 years. More than half of this increase has happened in the last 25 years. The temperature records used to calculate this are extensive, they have been assembled from thousands of observation sites on land and sea covering a large, representative portion of the Earth's surface. Checks and allowances have been made for any bias that may have arisen from the weather stations or instrument changes.This is a worry because while the planet can cope with changes in temperature which are known to have happened over periods of tens and hundreds of thousands of years in the past and certainly over millions of years. The current rate of change is much, much faster than any
green house effect
GREEN HOUSE EFFECT The greenhouse effect, first discovered by Joseph Fourier in 1824, and first investigated quantitatively by Svante Arrhenius in 1896, is the process in which the absorption of infrared radiation by an atmosphere warms a planet. Without these greenhouse gases, the Earth's surface would be up to 30 °C cooler. The name comes from an incorrect analogy with the way in which greenhouses are heated by the sun in order to facilitate plant growth. In addition to the Earth, Mars, Venus and other celestial bodies with atmospheres (such as Titan) have greenhouse effects. In common parlance, the term greenhouse effect may be used to refer either to the natural greenhouse effect, due to naturally occuring greenhouse gases, or to the enhanced (anthropogenic) greenhouse effect, which results from gases emitted as a result of human activities (see also global warming, scientific opinion on climate change and attribution of recent climate change). The Basic Mechanism The Earth receives energy from the Sun in the form of radiation. To the extent that the Earth is in a steady state, the energy stored in the atmosphere and ocean does not change in time, so energy equal to the incident solar radiation must be radiated back to space. Radiation leaving the Earth takes two forms: reflected solar radiation and emitted thermal infrared radiation. The Earth reflects about 30% of
The revolution in history of Science and Technology.
The revolution in history of Science and Technology The Revolution occurred during the time of 1450 to 1700, was a rational movement concerning the theories about humanity's position in the universe and methods for determining them as well. It appeared primarily to the middle and upper classes in the urban areas of Renaissance cities. The Revolution occurred in the areas of science such as astronomy, mathematics, and physics; and it also led to changes in medieval universities, and maritime exploration. Many scientists and philosophers contributed their own small portion to the Scientific Revolution. This essay will give a brief outline of their life and explain their contribution to the world of science and technology. Scientist & Philosophers: Nicholas Copernicus (1473-1543) was a Polish clergyman and astronomer. He was the first contributor during the Renaissance that developed theories. He theorized that the sun was at the center of the universe and that Earth, planets, and stars revolved around a motionless sun. He had other scientist prove his idea with mathematics and physics. His Theory: To understand the contribution Copernicus made to the astrological community, you first need to understand the theory that had been accepted at the time of Copernicus. The question of the arrangement of the planets arose about 4000 BC. At this time the Mesopotamians believed
1) Give information on the main source (naturally occurring/man made) of a selected gas.
) Give information on the main source (naturally occurring/man made) of a selected gas. Global warming, for almost a century, has been a very controversial issue. Scientists, determined to prove once and for all that man made sources are the main cause for global warming, have been surmounting more and more evidence to support this. The noticeable increase of late in the average temperature of our Earth has raised concerns. These concerns are regarding exactly what chemicals we should we using in our day to day lives. How are these chemicals, in the form of gases, causing global warming? Are they really enhancing the greenhouse effect? If so, how we can lessen the production and release of these harmful chemicals into our atmosphere? All these questions will be brushed over in this assignment. There are quite a few chemicals that are considered influential in the greenhouse effect. These chemicals (which are all gaseous) include CO2 (carbon dioxide), CH4 (methane), N2O (nitrous oxide), Halocarbons (mainly chlorofluorocarbons or CFCs), and O3 (ozone). The following table shows the sources of these gases and their relative effectiveness at trapping heat relative to CO2. CO2 is mainly responsible for the natural greenhouse effect, although events such as deforestation may now be pushing CO2 levels higher than normal. Gas Main Source Heat trapping effectiveness compared
Creative Writing
Before And After A War The fields used to go on for miles. Vast amounts of luscious greenery, smothering every ounce of the gravely earth like a thick duvet. Tiny seed saplings nourished themselves; they were bedded into the smallest patch of dirt to maintain that extra bit of warmth, even though the sun sizzled brightly in the glistening blue sky. There were lots of unusual flowers here. All dotted around the place, so rich and luxurious, like a freshly made canvas which an artist has flicked their runny paint upon. It was picture perfect. Something that should be hung up in a grand hall for everyone to notice. It was so peaceful here. The sound of blue birds and robins, singing lullabies in the tall towers of the trees as they swung swiftly in the light breeze. I liked to come here to relax. So quiet. The humming from a Queen bee as it nestled upon a fox glove, collecting pollen. Such a simple life. So carefree. You could smell the sweet pollen tainting everything which went right up my nose making it twitch and itch vigorously. Their, flower scents would trail throughout the air like some kind of fragrant ghost. It was very deserted and was quite a secluded area. It was good to come here and think from time to time, to clear my head. When trudging through this emerald wasteland you could occasionally see the scurrying of a hare, darting around fidgeting in it's
Lifecycle of a Sun
Life Cycle of the Sun ) Before nuclear fusion, when the sun was still being created in the interstellar nebula, it was just a protostar. A protostar forms when gravity and pressure begin to condense matter in the centre of the nebula, but no nuclear fusion is yet taking place. When nuclear fusion begins, a star is "born". Our sun started burning hydrogen at 4.5 billion years ago. When the sun started it was a little smaller, less bright and cooler than it is today. 2) The sun is in the middle of its lifespan, and is currently in the main sequence phase. At this stage in its life the sun is fusing hydrogen into helium. 3) As the Sun becomes older, it grows slightly larger, brighter and hotter. At about 1.1 billion years from now the Sun will be 10% bigger than it is now. As a result, the extra solar energy will dry up Earth's atmosphere and many kinds of life. In about 3.5 billion years, the sun will be 40% bigger and will probably mean that all life on Earth will cease to exist. The next stage will be for the sun to become a Red Giant. 4) Then the sun is 12.2 billion years old it will enter the Red Giant phase. The sun will become big enough to completely consume the planet Mercury. As a red giant, the sun will be cooler in temperature, but brighter. When the Sun reaches its maximum size as a red giant, helium fusion will occur in the core, and the star will begin to
GCSE Astronomy Revision Notes
TOPIC 1 EARTH, MOON AND SUN TOPIC 1.1 PLANET EARTH . What three features distinguish Earth from other planets in our solar system? * Liquid water, atmosphere, life . Explain how Raleigh scattering makes the sky appear blue. * When blue light hits oxygen and nitrogen in the atmosphere, it is absorbed and reemitted in any direction. This is due to the shorter wavelength of blue light compared to other colours, meaning that it is scattered more often than other colours, which pass through more easily. This is why the sun appears more orange at sunset – the light passes through more atmosphere, so more light is scattered, so only the most red light passes through, as all of the blue light is scattered. . Why is Earth’s atmosphere beneficial to humans? * The atmosphere keeps the Earth at a relatively warm temperature suitable for life. It also protects Earth’s surface from ultraviolet radiation. This is due to the ozone gas filtering out these rays. It contains oxygen and carbon dioxide, which are needed for life. . Name three causes of light pollution. * Shopping centres, floodlights, street lights, etc . Why is light pollution undesirable for astronomers? * It makes it difficult to see fainter stars and galaxies. . What shape is the Earth? * Oblate spheroid (squashed sphere). The diameter is greater at the equator than it is at the poles. . What is the
The origin of life
The origin of life When considering the many theories involving "How life began" You must not consider a few main theories but a few main theory groups. Because there are literally hundreds of theories on this subject which can be grouped in to three main categories and then in to various sub categories. ) Creation science This consists of about twelve theories that are based on the book Genesis all slightly varying in their interpretation. These can be split into two main groups, New and Old earth creationists. * New earth creationists believe that god created the earth its life forms and the universe less than a thousand years ago. They also believe the world was created within six days * Old earth creationists believe that the world is billions of years old they disagree with the new earth creationists because scientific evidence shows that the earth is considerably older than ten thousand years. Although they follow science on the earths age they believe that the earth was created as described in genesis. However they believe that the six days creation described in the bible in fact was stretched over a large period of time. Creation science is of course all based around Christianity there are of course many other religions which in turn all have their own creation beliefs. 2) Scientific views This as the name suggests is the belief that life originated by a number
The Life Of A Star
The Life of Star Space may seem empty, but actually it is filled with thinly spread gas and dust. This gas and dust is called interstellar medium. The atoms of gas are mostly hydrogen which is H2, and the gas atoms are typically about a centimeter apart. The dust is mostly microscopic grains and combines only a few percent of the matter between stars. The dust is mostly carbon and silicon. In some places, this interstellar medium is collected into a big cloud of dust and gas known as a nebula. This is the birthplace of stars because the gas and dust is what makes up a star. Small Stars: Stage 1- Stars are born in a region of high density which is located within the Nebula, and condenses into a huge sphere-like shape of gas and dust and contracts under its own gravity within a central pull. Stage 2 - A region of condensing matter will begin to heat up and start to glow forming a Protostar. If a protostar contains enough matter of hydrogen the central temperature reaches 15 million degrees centigrade. Stage 3 - At this temperature, nuclear reactions in which hydrogen fuses to form helium will start. Stage 4 - The star begins to release energy, stopping it from contracting even more and causes it to shine. This means that it is in its main sequence in its life as a star. Stage 5 - A small star will be remaining in its main sequence for about 10 billion years, until all
