I am writing about a scientific book called 'The Guide To The Galaxy' by Nigel Henbest and Heather Couper
Critical Account of Scientific Reading I am writing about a scientific book called 'The Guide To The Galaxy' by Nigel Henbest and Heather Couper and published by the Press Syndicate of the University of Cambridge 1994. This book is about the galaxy in which our planet and our solar system lie. It contains information that goes beyond what most people or people with limited scientific knowledge know. The book talks about the efforts and the hard work by early scientists to discover more and more about our galaxy. It also talks about the most sophisticated techniques used nowadays to probe the galaxy. The first chapter investigates the discovery of our galaxy, illustrating the work by early thinkers and scientists. It starts with the origin of the name of our galaxy, Milky Way, which was named by the Romans. The chapter also talks about the conception of other civilisations about the 'Milky Way', such as the Greeks and their theory 'a stream of milk which gushed from the breast of the goddess Juno as she nursed the thirsty infant Hercules', while the North Americans thought of it as a route of ghosts on their way to the 'land of the hereafter'. The Eskimos saw it as a guide to travellers. The chapter then talks about some scientists like Galileo Galilei and his efforts in inventing the telescope, which took our knowledge of the galaxy into a whole new level. The
Using a Ballistic Pendulum To Demonstrate the Law Of Conservation of Momentum.
November 3, 2003 Using a Ballistic Pendulum To Demonstrate the Law Of Conservation of Momentum Abstract The concepts of conservation of momentum and conservation of mechanical energy were investigated and used to demonstrate that the law of conservation of momentum is valid. A ballistic pendulum was used to show that the initial velocity of a projectile could be determined using these concepts. To verify the results of the ballistic pendulum experiment, the initial velocity was also calculated by firing it horizontally and calculating the time and distance traveled. The percent difference between the two values for initial velocity was 13.0%. Introduction One of the most useful laws of physics is the law of conservation of momentum. For instance, in an inelastic collision, the change in momentum of the combined objects can be used to figure the momentum of the objects before the collision. In this experiment, a ballistic pendulum was used to demonstrate that the law of conservation of momentum is valid. A ballistic pendulum is a pendulum that begins in a vertical resting position, while a projectile is fire at the end of the pendulum. The pendulum must be capable of incorporating the projectile so that the collision is inelastic and the projectile and pendulum move as a single unit. Examples would be a bullet into a block of wood, or a ball into a trapping basket,
Critically assess why it is difficult to accurately forecast the amount of anthropogenic climate change we can expect to see by 2050
In this essay the author will assess the difficulties with forecasting the amount of anthropogenic climate change we can expect to see by 2050. The author will use quotes, definitions and examples where appropriate. Over the past 100 years, the world has seen an increase in global average temperatures. Since 1860, the global average temperature has increased by '0.6 degrees Celsius with a ninety-five percent confidence'. (Houghton, J, 2004:56) This increase is believed to be cause of the greenhouse effect, which "...refers to the reduction in outgoing infrared radiation to space due to the presence of the atmosphere." (Harvey, L, 2000:95) This greenhouse effect is induced by natural and anthropogenic sources. The greenhouse effect is partly attributed to the emissions of 'greenhouse gases', such as water vapour, carbon dioxide, methane, ozone and nitrous oxide. (The Royal Society, 2002) The gases form a blanket over the earth which traps the sun's radiation resulting in conditions similar to a greenhouse, see Figure A. Figure A The 'Greenhouse Effect' (Houghton, J, 2004:18) Anthropogenic Carbon Dioxide (CO2) is a gas that is believed to be of main concern, as it is a prominent contributor to an 'Enhanced' Greenhouse effect. Since the industrial revolution, CO2 levels have increased by 30 percent, from 280 parts per million per volume in the 1700 (Houghton, J, 2004) to
The Global Water Crisis
The Global Water Crisis The Global Water Crisis Excess and shortage By 2010 about 2.5 billion people in the world are projected to lack access to safe drinking water. At least 30 per cent of the population in China, India, Mexico and the U.S is expected to face severe water stress. By 2025, the supply of water in India will be 700 cubic km per year, while the demand is expected to rise to 1,050 units. Control over this scarce and vital resource, will of course, be a source of guaranteed profits. Vandana Shiva[1] "We're all downstream." Ecologists' Motto. [2] The has been much talk lately of the looming water crisis, it is a crisis that is picking up steam, scope, and receiving increasing attention, as more and more people become aware of its implications, consequences, environmental impact, and most alarmingly, its potential for economic gain. A year ago a paper on this subject would have been almost surprising in the facts that it would reveal. In the past month however, there has been a noticeable increase in the coverage and notice this crisis is receiving, and rightly so. "This collective resource is becoming rarer because it is being overexploited by a consumerist and pollution--generating humanity. The warning signs are clear: falling water tables, shrinking rivers and lakes, widespread pollution, creeping desertification."[3] These and many other signs are all
Double Slit Interference
RYERSON UNIVERSITY DEPARTMENT OF PHYSICS TITLE OF EXPERIMENT: Double Slit Interference Objective and Background: The objective of the experiment was to observe the patterns of interference and diffraction produced by monochromatic light, in this case laser light, passing through double-slit apertures, and confirm that the bright fringes on the pattern have the same positions computed by theory. In 1801, an English physicist named Thomas Young performed an experiment that strongly inferred the wave-like nature of light. Because he believed that light was composed of waves, Young reasoned that some type of interaction would occur when two light waves met. Laser light produces an intense beam of monochromatic (single frequency) light. All the waves across the beam are in phase. The beam illuminates the slits, which are narrow to ensure adequate diffraction. The diffracted beams from the two slits overlap causing the waves in the beam to superimpose. The interference pattern due to the superposition of the waves appears on the screen as alternate dark and bright bands, called fringes. The bright fringes are caused by constructive interference and the dark fringes by destructive interference. The angle between the central fringe and bright fringes obeys the following formula: (m = 0, 1, 2, 3 ...) where d is the distance between two slits, is the angle that the mth maximum
A Closer Look at Global Warming
A Closer Look at Global Warming The warming of the Earth has been the subject of intense debate and concern for many scientists, policy-makers, and citizens for at least the past decade. Climate Change Science: An Analysis of Some Key Questions, a new report by a committee of the National Research Council, characterizes the global warming trend over the last 100 years, and examines what may be in store for the 21st century and the extent to which warming may be attributable to human activity. The committee was made up of 11 of the nation's top climate scientists, including seven members of the National Academy of Sciences, one of whom is a Nobel Prize winner. The Evidence for 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, the report says. Part of the debate over global warming centers on disparities between the surface temperature and upper-air temperature. While the Earth's surface temperature has risen, data collected by
Boreal Forest case study.
Boreal case study The diagram below summarises some of the key ways trees in the boreal forest have adapted to the abiotic factors of this area Case study - The fate of Siberian forests Background information Total area = 8.8 M sq km; (57% world Boreal Forest). The Siberian approach to forests! In Boguchany, Siberia, 20,000 prisoners are set to work logging for punishment - the resultant timber is not used, its purpose was merely to occupy prisoners time. This represents a criminal waste of forest! Such deforestation devastates local ecosystems and reduces wildlife food sources for indigenous people. To make better use of the logs, the Boguchany dam (a local HEP project) is being built for processing logs. This at least reduces waste, but puts further stress on the forest... more forest destruction will occur by flooding for the reservior. Meanwhile in the neighbouring region of Bratsk, Siberia, 100,000 Ha forest has been destroyed by air pollion from aluminium smelters, power stations and chemical factories. This also affects humans ....local mortality rates increased 25% in last 10 yrs. Temperate forest case studies The Forestry Commission in the UK are pursuing MPF (multipurpose forestry). Timber, employment, landscapes, watersheds, biodiversity, habitat considered together (but timber production takes priority!). UK has 10% tree cover but only 2.5%
Volcanism throughout the solar system.
AA2281 Exploring the Solar System Assessment F: Volcanism throughout the solar system "Volcanism is one of the major processes, whereby a planet transfers heat produced in its interior outward to the surface" (Encyclopedia of the solar system).Volcanism is part of the process of bringing material up from the deep interior of a planet and spilling it forth on the surface where it cools and becomes solid. At least three quarters of the surface rocks on earth and Venus can be attributed to volcanic activity. There are two styles of volcanic activity explosive or effusive. Explosive is when magma is disrupted into fragments which are called pyroclasts by the expansion of exsolved gases. Effusive eruption is when magma escapes through a vent, there is no significant disruption, but a lava flow is formed. To understand the volcanic processes of the earth the products of volcanic activity have been studied under a wide range of environmental conditions such as gravity and atmospheric pressure. There are quite a few other planets which have volcanoes on the surface, including Venus, Mars, and Jupiter's moon Io. Other planets exhibit the results of volcanic activity. These include Mercury, the Earth's Moon, Jupiter's moon Europa, and perhaps Neptune's moon Triton. Planetary bodies, like Jupiter's moon Europa also exhibit icy volcanism where water takes the place of lava. Eruptions
Chemical Preservatives.
Title: Chemical Preservatives .Calcium disodium EDTA It was found in "mayonnaise". Properties It is the salt of ethylene diamine tetraacetic acid (EDTA). Utilization It is applied as a chelating agent. Its function is to control the reaction of metal ions with some organic and inorganic components that will result in deterioration of foods. Apart from that, the preservative also acts as antioxidant antimicrobial agent, especially against gram-negative bacteria. Mechanisms of action Ca disodium EDTA blocks the normal reaction of metal ions by binding to their reactive sites. This increases its efficiency as an antioxidant. Consequently, the oxidation of ascorbic acid and fat-soluble vitamins is hindered and also the rancidity of the product. The resistance of gram-negative bacteria is overcome by the removal of lipopolysaccharide containing membrane. 2.Calcium Propionate (C6H10CaO4) It was found in " wholemeal bread rolls". Properties It is the salt of propionic acid. It is only soluble in water but insoluble in alcohol. Utilization The antimicrobial activity is particularly against mycotoxin forming moulds, less so against bacteria. No inhibition effect has been demonstrated against yeast. Therefore, it is mainly used for bread preservation, as it will not interrupt the leavening in
Experiment 3 - Stoichiometry Reaction
Experiment 3 Title: Stoichiometry Reaction Objectives: To decompose sodium hydrogen carbonate (sodium bicarbonate) by heating, and to accurately measure the degree of completion of the reaction by analyzing the solid sodium carbonate product. Introduction: Stoichiometry is the calculation of quantitative (measurable) relationships of the reactants and products in a balanced chemical reaction. It can be used to calculate quantities such as the amount of products that can be produced with the given reactants and percent yield. Stoichiometry calculations are based on the fact that atoms are conserved. They cannot be destroyed or created. Numbers and types of atoms before and after the reactions are always the same. This is the basic law of nature. From the atomic and molecular point of view, the stoichiometry in a chemical reaction is very simple. However, atoms of different elements and molecules of different substances have different weights. We must be able to relate the amount of heat evolved in a laboratory scale reaction to that involved when two molecules react. The scaling factor used to relate readily useable quantities to the molecular scale is called the mole. 1 mole = 6.023 x 1023 molecules = Avogadro's number of molecules In this experiment, several reactions will be performed and physical measurements will be made that subsequently relate to the molecular
