MARCH 2006
Spectrum
Science Department
Email: spectrum@bedfordschool.org.uk Bedford School Website www.bedfordschool.org.uk
Preface
From biochemistry to quantum mechanics and astrophysics, this edition of SPECTRUM offers it all. We have been able to show such a range of expertise through the enthusiasm of all contributors to this publication. In general the topics addressed here are not on any examination syllabus, the aim however is to inspire students to continue their studies in science to A-level and beyond. To do this none of the terms and ideas are too complex. Instead the articles are designed to stimulate readers with snippets of information on each subject matter. SPECTRUM also seeks to promote further research and thought in all scientific matters. For that reason we have created an email address of spectrum@bedfordschool.org.uk. If you have any comments on this publication, we would be very grateful for your feedback. The articles were created by eight Bedford School pupils who have researched an area of science which particularly appeals to them and produced an article each for SPECTRUM. There is something here for everyone, whether they favour biology, chemistry or physics. We hope that you find SPECTRUM an enjoyable and thought-provoking read. With all the hard work that has gone into producing this publication all those involved deserve your appreciation. Edward Johnson
Editorial Board
Dominic England Edward Johnson
Spectrum Members
Jonathon Andrews Janak Bechar Justin Bell Phillip Cai Dominic England Edward Johnson Edmund Lam Dhaval Panchal Nikhil Vaghela
No part of SPECTRUM may be reproduced without the consent of the editors and the authors concerned. We cannot accept liability for mistakes or misprints.
March 2006 Edition
Special thanks to Dr. Mines and Mrs. Spina for all their help in publishing this edition of SPECTRUM.
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Contents
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The Link Between Sport Survival And Instinct
Phillip Cai
6 8
1000 Songs Impossibly Small
Edward Johnson
The Future of Invisibility
Dhaval Panchal
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Avian Influenza
Nikhil Vaghela
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Stem Cells and Their Potential Future in Medicine Particle Wave Duality
Jonathan Andrews
14 16
Justin Bell
The Solar System
Edmund Lam
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Quarks and Leptons – into the World of ornamental garden pixies Make your own planet
Janak Bechar
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Contents
Dominic England
The Link between Sport, Survival and Instinct
What do a stunt-plane pilot, surfer, and snowboarder all have in common? Are those self-proclaimed „adrenaline junkies‟ really what they claim they are? And what link does chronic severe depression have with a person who regularly does extreme sports? As you‟ve probably guessed reading this article will answer all these questions, and hopefully a bit more too.
The slightly boring stuff: Adrenaline is a hormone secreted by your adrenal glands (you‟ve got two, one on top of each kidney – GCSE Biology!) Its chemical structure is C9H13NO3 (Yes, it‟s organic!) and other than being a biochemist‟s nightmare, it might actually save your life – or so we‟re told by our teachers anyway… The more interesting (and relevant) stuff: Adrenaline starts „pumping‟ through your bloodstream (literally) in times of „stress‟, yes you heard me, both physiological and psychological stress. Ever wondered what causes the „butterflies in your stomach‟ and other symptoms of nervousness before an exam, being interviewed by the police, or being attacked by a mountain bear? You guessed it. Adrenaline prepares you heavily for physical work or strain, as a result, it‟s often referred to as the „fight or flight‟ hormone, because it helped animals and our ancestors (and still does) get ready to combat threats or get as far away as possible.
Adrenaline is a word heard all too much in
today‟s sports – especially those classified „extreme‟, such as surfing, snowboarding, and bungee-jumping. It is often used in conjunction with the words „junkie‟, „addict‟, and „rush‟, making it seem like some kind of drug. So what exactly is adrenaline anyway?
hh
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The not-so-good-side of adrenaline: As adrenaline secretion is caused by a mental „stress reaction‟ against something that could potentially harm your body, there are certain instances, especially in today‟s far more social existence when compared to our primitive struggle for survival, where adrenaline is pumping through your body without an actual
When these people cease sport, adrenaline stops pumping and the body reacts to the sudden lack of adrenaline – this is an „adrenaline low‟ and the person suddenly feels depressed and sad at not being active. Such people are known as „adrenaline junkies‟, now do you see how this thing is so much like a drug! From doing sport you suffer an „adrenaline rush‟ where you subconsciously feel much more capable, daring, and physically active, much like certain drugs like speed or amphetamines, though an adrenaline rush keeps your judgement within sensible bounds at least, and has no really dangerous side effects. □ SPECTRUM
Ever wondered what causes the butterflies in your stomach? You guessed it. Adrenaline
need to spur into physical action. This is more commonly known as „stress‟ – yep, the bane of the modern-day student, the IB boy‟s best friend, and the tyrannical shadow of today‟s workers. Put simply, a „stress reaction‟ in the life of someone like me might be a nasty teacher setting you a difficult prep – the „natural stress reaction‟ would be to lump him one, run away, or both. You get this every lesson of every day, and you‟ve got yourself one large stress buildup. People today suffer greatly from „stress‟ because they have difficulties handling the constant pressure.
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Adrenaline – Lead Article The Link Between Sport, Survival and Instinct
Adrenaline will: Cause your heart to beat faster Raise your blood pressure levels Stimulate secretion of glucagons which causes the liver to convert stored glycogen into glucose via hydrolysis Cause you to breathe deeper and faster, and open up breathing passageways Dilate your pupils (drug-like or what?) Divert blood flow from most organs to the brain, muscles, heart, and lungs the only organs involved in physical strain Act as a neurotransmitter in your nervous system As you can see it‟s a pretty good thing you‟ve got it available to you, imagine how pathetically unprepared top sportsmen would be in their games. Don‟t even start with what would happen at the Olympics!
Evidently „stress‟ „sporting anticipation‟ and „fear‟ are all caused by the same thing, a rather strong link, therefore doing sports is a very good way of stress relief, as your adrenaline hormones aren‟t going to waste. Also, the most capable sportsmen in the world can convert their „nerves‟ and „anticipation‟ into initiative and action effortlessly. What‟s wrong with exploiting your fear and reversing it into your most basic natural advantage? Absolutely nothing. Junkies, addicts, and rushes You‟ve heard the terms before, so are these people liars? Strangely enough no, there is an element of truth – a person who regularly practices sport, especially „extreme sports‟, will eventually get used to adrenaline pumping through his body and the resulting „high‟ of such physical performance.
Phillip Cai
1000 songs, impossibly small
To get a feel for how small the Ipod nano is, you really have to hold it yourself. It is astonishingly small, thinner than a standard HB pencil in fact, so small that when I heard about it, I had to have one. But I asked myself two questions about it; how do they make it so small? And how does it work? In this article I plan to answer those questions as best I can and hopefully do the nano justice. Thanks to the huge advances in memory storage over the past few years the Ipod nano is able to use two tiny Samsung flash memory modules to store all its music and photos. These modules are about 20mm long and 13mm wide, yet each of them can hold 2 gigabytes of storage, this is how the nano is quite so small. Flash memory works in a very complex way and it would be very hard to explain in detail in a science magazine. Therefore I will just give you
a flavour of how it works. As with all digital storage of information, flash memory simply stores a series of voltages as 1s or 0s, these are called bits and the nano stores 3.2 x 1010 of them. Flash memory is a type of EEPROM (electrically erasable programmable read-only memory) microchip but there is a difference between standard EEPROM chips and flash memory. Flash memory can write and erase data in much bigger chunks than EEPROMs can. The basic process by which they work is very similar though. A curious and complicated process called Folwer-Nordheim tunnelling is used. Two transistors are separated from each other by a thin oxide layer. One of the transistors is known as the floating gate, and the other one is the control gate. The floating gate's only link to the row, or wordline, is through the control gate. As long as this link is in place, the cell has a value of 1,
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to change the value to a 0 we need tunnelling to alter the placement electrons in the floating gate. A charge comes from the column, or bitline, enters the floating gate and drains to the ground. This charge causes the floating-gate transistor to act as an electron gun. Excited electrons are pushed through and trapped on the other side of the thin oxide layer. A cell sensor measures the level of charge going through the floating gate. If the charge passing through the gate drops below 50-percent threshold, the value changes to 0. When the memory is blank each cell will have a value of 1. Therefore in order to store data a series of 1s are changed to 0s and to erase all the data stored on a flash memory device we simply have to apply a higher voltage charge to create an electric field and return all cell values to 1. That is the basic idea of flash memory and it is a lot more effective for use in mp3 players than regular hard drives which have been used before. Flash memory can be made smaller, it consumes less power, and it is quicker to write data to and to erase data. The only disadvantage is that it is more expensive per GB of storage. Two other things that have been made remarkably tiny in the nano are the LCD screen and the battery. Rather than go into too much detail about these, I decided to investigate how the click wheel, used on most Ipods, works. The click wheels on all Ipods before the nano were manufactured by Synaptics, however for the nano, Apple decided to manufacture the wheel themselves to save money. The principle by which they all work however is very similar. The click wheel is effectively a touchpad similar to the ones found in almost every laptop today. They function by sensing an electrical property called capacitance. Whenever two
electrical conductors become near to one another without touching, their electrical fields interact to form capacitance. The surface of the touchpad is a series of metal electrodes, covered by an insulating layer, which protects the sensor from wear by preventing your finger from actually touching the electrodes. The human finger is also a conductor so when you place your finger on a touchpad a tiny capacitance forms. A microchip attached to the touchpad monitors the amount of capacitance in every electrode. By sensing an increase in capacitance the sensor can detect that your finger is touching. By measuring which electrodes have the most capacitance the touchpad can also locate where your finger is on the touchpad, to an accuracy of 1/1000th of an inch. Using this information a computer or in this case an Ipod can sense when your finger is moving around the click wheel and it knows when to scroll down the lists on the screen. So there you have it, I have explained briefly how two of the most interesting parts of an Ipod nano work and in doing so have shown how they make it quite so small. If I were you I would go out and buy one for yourself and see with your own eyes what a feat of technology the Ipod nano is. □ SPECTRUM
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1000 Songs Impossibly Small
Edward Johnson
The Future of Invisibility
Ever wonder why modern fighter jets are looking stranger than ever? Curvy bodies, angular faces, hidden weapons systems? The answer to that is Radar stealth. Most modern fighter/attack aircraft are “stealthed”, in that they are virtually invisible to the enemy radar, and so cannot be detected when attacking ground targets, or even other enemy jets. Most of the time, the enemy is destroyed before they can even make visual contact with the attacker. Radar, the technology used to detect vehicles such as aircraft, is often used as a single word, however, it is actually an acronym, standing for “RAdio Detection And Ranging”.. How RADAR works: Radio waves are sent from the antenna and bounce off the round surfaces of regular aircraft. Metal surfaces, along with surfaces that are perpendicular to the direction the radio wave is travelling, make excellent reflectors. This is the basis for radar stealth, i.e. the opposite of the above principles.
The two main ways of obtaining radar stealth are 1. An aircraft shape that reflects the radar signals away from the radar equipment. 2. Covering the airframe with materials that absorb radar signals. An example of this shape is shown by this diagram: The angular surfaces reflect the radar signals away from the equipment. The main example of this early stealth technology is the F-117 “Nighthawk”, which first saw action during the first Gulf War, with its “bunker buster” laser guided bombs. However,
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the nature of its “stealthy” shape, angular with plenty of jagged, flat surfaces, leads to aerodynamic instability, making it immensely difficult to fly manually, hence it cannot be flown without computer assistance. This earned it the nickname “the wobbly goblin”. Modern stealth jets have a combination of these deflecting airframe shapes, along with materials that help with absorbing/scattering radar signals. These are built into the composite materials, such as carbon fibre, which make up the airframe of the aircraft. Composite materials are much better at absorbing/ not reflecting radar signals, as they are non-metallic. The composites used often contain high amount of ferrites as filling. Within these composite panels, there are special structures, known as re-entrant triangles. Radar waves penetrating the skin of the aircraft get trapped in this structure, bouncing off its internal faces and losing energy. This approach to stealth was first seen on the SR-71 “Blackbird”, also famous for being the world‟s fastest air-breathing aircraft. A stealth aircraft must use a different arrangement. Often, a stealth design has the vertical element of the tail tipped at an angle, as in the image above. The most radical approach is to eliminate the tail completely, as in the B-2 Spirit. As well as altering the tail, stealth design must bury the engines within the wing or fuselage, or in some cases where stealth is applied to an existing aircraft, install baffles in the air intakes, so that the turbine blades are not visible to radar. The shape of the aircraft must be devoid of complex bumps or protrusions of any kind if it is to be stealthy. This means that all weapons, fuel tanks, and other stores may not be carried on under wing pylons but must be stored internally. Furthermore, a stealth aircraft loses its stealth capabilities when it opens its bomb bay doors. Another method to add to the stealth character of the aircraft is by using Radar Absorbent Materials, (RAM). These are often applied especially to the edges of metal surfaces. The RAM coating is also known as “iron-ball paint”, and contains tiny spheres coated with carbonyl iron ferrite. The way this works is the radio waves induce an alternating magnetic field in the material, which leads to the conversion of their energy into heat.
Current generation stealth planes are painted black, and operate only at night, for obvious reasons. This has its limitations as the enemy know, or can easily guess that bombing raids would be during the cover of darkness. The question now is who knows what the future holds? My guess is optical camouflage. After all the technology deployed in these fascinating aircraft, the only real chance you‟d see one of them is at an air show. If not, then you‟d better take cover! □ SPECTRUM
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Stealth Aircraft - The Future of Invisibility
Dhaval Panchal
Avian Influenza, the Truth
A lot has been said in the media about avian influenza or bird flu as we more commonly know it and a lot of this information has been vastly exaggerated. This article will help to put aside the misconceptions that you may have about the virus and its effects on humans.
What is Avian Influenza? Avian influenza is an infection caused by avian influenza viruses. These flu viruses occur naturally among birds; wild birds worldwide carry them in their intestines although they do not get ill from them. Bird flu is very contagious among birds and can make some domesticated birds very ill and kill them. The type currently causing concern is the H5N1 virus. The H5N1 Virus There are many different subtypes of avian influenza viruses. These subtypes differ because of certain proteins on the surface of the virus. Each different combination of proteins is a different subtype. These viruses do not usually infect humans although we know they can do. There are only three known subtypes of human flu viruses and it is likely some genetic parts of these viruses came from the bird flu viruses originally. The risk At present, H5N1 is not easily transmitted from bird to human, so the risk of infection is extremely low. However during an outbreak of
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bird flu among poultry there is a risk to people who are in contact with the infected birds. The big worry though is that H5N1 could pick up genes from conventional human flu viruses and mutate, making it both highly lethal and highly infectious. This is because it would be a radically new pathogen which could be transmitted from person to person which is not currently possible; no one would have natural immunity to it. How does it spread to humans? Avian influenza was first identified in Italy around a century ago. It was not thought to be transmissible to humans until 1997, when the first human cases were seen in Hong Kong. Humans catch the disease through close contact with live infected birds. Birds excrete the virus in their faeces, which dry and become pulverised, and then are inhaled. Symptoms are similar to human flu. Researchers are now concerned as it
explored, but the risk is that they could be partially effective or even useless because the virus‟ genetic shape will change and not be recognised by the antibodies. Concerns have already been prompted by news that a Vietnamese patient has become partially resistant to Tamiflu, a drug being used to combat bird flu.
Is it safe to eat chicken? YES. Experts say avian influenza is not a food borne virus, so eating chicken is safe. However the World Health Organization recommends, to be absolutely safe all meat should be cooked to a temperature of 70oC. □ SPECTRUM
has been found that the virus affects all parts of the body and not just the lungs. This means many illnesses may have been misdiagnosed and were actually avian influenza.
There is not yet a definitive vaccine, but prototypes that offer protection against the H5N1 strand are being produced. The problem is that no one knows the precise shape that it will take after mutating to the feared highly contagious form. Several prototypes are being
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Avian Influenza
Has a vaccine been found?
Nikhil Vaghela
Stem Cells and their Potential Future in Medicine
Imagine being able to make a disabled person walk, or help return the memory of an Alzheimer’s patient, even something like replacing skin that has been damaged in a dangerous accident. All of this would be possible through the use of stem cells. However, like in other areas of modern science, it is shrouded in controversy for many ethical and legal reasons. What are stem cells? Unlike other cells in our bodies, stem cells are unspecialized cells that have the remarkable potential to develop into any different cell type in the body. Also they have the power to multiply indefinitely. When a stem cell divides, it can either remain a stem cell or it has the potential to develop into a more specialized cell such as a brain cell or a red blood cell for example. Stem cells are generally broken into 4 types: embryonic stem cells, foetal stem cells, umbilical stem cells and adult stem cells. However it has been realised that stem cells can be obtained from many other areas of the body. In April 2001 stem cells were found in fat sucked out from liposuction patients at the University of Pittsburgh. When were stem cells discovered? More than 20 years ago, scientists discovered ways to obtain stem cells from early mouse embryos. After much study and research, on the 5th November 1998, scientists announced they could isolate stem cells from human embryos and grow them in the laboratory. The embryos had been donated as they had not been used for „in-vitro fertilization‟.
Stem Cells and their Potential Future in Medicine
Once embryonic stem cells have been produced, they can be made into any type of cell through the process of differentiation (see diagram on opposite page). They can then be made into Neurons, Epithelial cells or Hepatocyes liver cells for example.
What are the differences in the different stem cell types? Scientists primarily work on embryonic and adult stem cells of humans and animals. There are certain advantages and disadvantages of each source and its potential uses. Embryonic
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stem cells can become any type of cell because they are pluripotent. Adult stem cells are generally limited to developing into different cells of the tissue they originated from. Large numbers of embryonic stem cells can be grown in culture, which is not so easy to do with adult stem cells. This is where the difference plays an important role especially when large numbers of cells are required for cell replacement therapies. A potential advantage for using adult stem cells is that a patient‟s own cells could be used. They could be expanded in culture and then reintroduced into their body. The advantage is there will not be the difficult problem of the cells being rejected by the patient‟s immune system, as there might be with the use of embryonic stem cells. This will also relieve the patient, the hassle of having to take immunosuppressive drugs.
endless and we are only at the very beginning of the road to the future of medicine. □ SPECTRUM
At the moment, to treat patients with damaged organs and tissues; organ and tissue donation is being used. However there is the problem of the availability and suitability of these organs and tissues. Stem cells offer the possibility of a renewable source of replacement cells to treat certain diseases (regenerative medicine). Some of the possible diseases and conditions that could be treated using this method are: Parkinson‟s, Alzheimer‟s, heart disease, stroke, diabetes, arthritis, spinal cord injury and burns. Another possible use for stem cells could be for testing new drugs. This is already happening with other cell types but this is very limited and the use of stem cells would greatly enhance drug screening. This could also be used to test out how certain toxins affect different cells and also in understanding birth defects. Stem cells have caused controversy for many ethical reasons, such as „killing‟ new life and „playing God‟. But as it stands, the possibilities of stem cells are
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Stem Cells and Their Potential Future in Medicine
What is the potential of stem cells in medicine?
Jonathan Andrews
Wave Particle Duality
Historically light has often been viewed as a particle rather than a wave with Isaac Newton thinking of light in this way. However a famous experiment carried out by Thomas Young around the year 1805 brought this view into question. This was the „Double Slit Experiment‟, which involved shining light on two parallel slits and observing the pattern created on a screen behind. The pattern observed was a series of light and dark lines parallel to the slits as shown below: interference to occur there must be waves going through each slit? The answer is, the photon acts as a wave so is affected by quantum behaviour whereby it has a probability of going through either slit. The hard concept to come to terms with however is that it is considered to go through both slits and a phenomenon known as „probability interference‟ occurs. Due to the results of this experiment for almost 100 years the wave theory of light was widely accepted. However, if light is shone on a piece of photographic paper in a short burst, we would see something like that shown in the picture below. We can see that the intensity of the image increases the longer the paper is exposed for. The intensity of the image is determined by the number of silver grains deposited and we can see that the pattern of the deposited grains is random. This suggests that the light that deposited them was made of particles rather than waves. The concept of wave-particle duality was the start of „modern‟ physics in the late 19th century. Max Plank created a formula in 1900 for the energy of an electromagnetic wave but he thought that he had fudged the mathematics to make it work so was not convinced. His formula (later proved by Einstein) stated that
These lines can only be explained as the interference between light waves. In the brighter spots there is „constructive interference‟, where two peaks of the wave coincide as they hit the screen thus „adding‟ to each other. The dark spots occur where a peak and a trough coincide at the screen, cancelling each other out. This is known as „destructive interference‟. However, if you fire just one photon at a time and have a screen that is sensitive enough to detect the photon then the photon would still show the affects of interference. Obviously if light were a particle then firing a single „particle‟ would result in it going through one of the slits and hitting the screen. If this were the case then there would be no interference as interference can only occur when the light passes through both slits. So why is the single photon affected by interference when it is passed through alone, as we know that for
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the energy of a wave E, was equal to its frequency f, multiplied by Plank‟s constant h (~6.6 x 10E-34). E=hf. The photoelectric effect is a phenomenon whereby if light is shone on a metal it can cause it to ionize (lose an electron). This occurs when a photon of sufficient energy collides with an electron and knocks it out of its orbit. According to Plank‟s equation, electromagnetic waves will have a higher energy if their frequency is higher. This is regardless of their amplitude as would be the case with classic waves (e.g. a tidal wave has high energy with high
(photographic paper and photoelectric effect). The answer is that it is either: both a wave and a particle; or it is something else that we can‟t visualize, appearing to us as a particle or a wave depending on how we look at it. This strange double reality still puzzles scientists today and as yet no one can justifiably claim to fully understand what light is and why is behaves as it does. □ SPECTRUM
So is light a wave or a particle? The answer depends on how we look at it. Wave Particle Duality
amplitude). If light were to be viewed as a wave then if the amplitude were increased then the energy of the wave would increase. It was observed that very bright red light (lower frequency) was unable to ionize some metals that low intensity blue light (higher frequency) could. This shows that the amplitude has no effect on the maximum energy of the wave and suggests particle-like behaviour of light. So is light a wave or a particle? Well, it is definitely true that photons can act as waves (as in the double slit experiment) and as particles
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Justin Bell
The Solar System
The Solar System might not be an unfamiliar term to most of you who study the sciences. But try and ask yourself: How much do you know about the Solar System? Other than that there are 9 planets (which you may say is not true)? If you answer nothing – or nothing much, then read on. Here I will unveil secrets of the Solar System which are rarely known. What is the Solar System anyway? The Solar System is the most famous planet system within the Universe – or at least the Galaxy so far. It has a gigantic ball of extremely hot gas, known as the Sun, as the star and the centre of the system, and around it there are 9 planets which rotate around the Sun in orbits. The Planets The 9 planets – Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto should be very familiar to you. But how much do you know about them? Mercury Mercury is the closest planet from the Sun and it is the second smallest after Pluto. It is so close to the Sun such that light only takes 19.3 seconds to reach it, compared to 8 minutes for the Earth. 75% of Mercury is made up of a large iron core. Even though it is the closest planet from the Sun, it can have a minimum surface temperature of -173 °C.
Venus Venus is a very inhospitable planet for a human to stay on. Although it is further away from the Sun, its surface temperature can reach 482°C, due to the runaway greenhouse effect, caused by the atmosphere of mostly carbon dioxide. It is hotter than Mercury, and it is hot enough to melt lead. Venus rotates from east to west, so if you were on Venus, the Sun would rise from the west. In a clear night, Venus is the brightest star in the sky. Venus is covered by lava flows and it has several large shield volcanoes.
Earth Everyone is familiar with the planet we live on. So why bother saying much about it? Earth is not a sphere, it is an oblate spheroid. Earth completes 1 orbital in 365.2422 days. That‟s why we have 1 extra day every 4 years. Mars One may say that Mars is probably the best planet to live on other than Earth. But is it really so? Its surface temperature is below zero and CO2 makes up much of its atmosphere.
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The highest mountain in the Solar System is located on Mars, known as Olympus Mons and it rises 24km in height. Mars is so far the only planet that is suspected to have had life before. Jupiter Jupiter is the largest planet in the Solar System, and is a gas planet, composed of 90% hydrogen, 10% helium, with traces of ammonia, methane and water. It also has the most moons in the system.
Neptune Neptune is the outermost gas giant. It orbits the Sun every 164.79 years. Wind blowing on Neptune is the fastest in the solar system – it can travel at up to 1,200 miles per hour (typical speed of a commercial jet is 550 mph) There is a “Great Black Spot” similar to the “Great Red Spot” on Jupiter, which is the size of the Earth. Pluto Pluto is the smallest planet in the Solar System. It is only the size of our moon and it is the only planet which has never been “visited” by any spacecraft. Pluto is not always the most distant planet – for 20 years out of its 249 year orbit, it is closer to the Sun than Neptune. Pluto is the only planet to be discovered by an American – all the others were discovered by Europeans. More than this – the 10th planet? On 29th July, 2005, the Solar System was redefined. Dr. Mike Brown and his crew, claimed that they had discovered the 10th planet of our Solar System. It is temporarily named 2003 UB313 and it is said to be the size of 1.5 times that of Pluto. However, controversies soon arose about whether it is really a planet. So is it a planet anyway? You‟ll have to decide yourself. □ SPECTRUM
If Jupiter was hollow, more than 1,000 earths could fit in it– it‟s that big! There is a “Great Red Spot”, which represents a storm that has been blowing for more than 400 years. Saturn Saturn is the second largest planet in the Solar System. It is famous for its beautiful ring, which is the only one in the system visible from Earth.
If there was a large enough tank filled with water, Saturn would float on it In places near its equator, wind can blow at up to 1,100 miles per hour! Uranus
Uranus is the closest of the 3 outermost planets, discovered between the 19th and 20th century. It is so much further from the Sun than Saturn, that Uranus orbits once every 84.01 year when Saturn only needs 29.45 years. Uranus is tipped on its side – which means its poles, instead of its equator faces the Sun. Methane at the top of Uranus‟s atmosphere absorbs red light, thus giving it a green-blue colour.
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The Solar System
Edmund Lam
Quarks and Leptons – into the world of ornamental garden pixies
The last decade of the nineteenth century witnessed the birth of a new scientific era. Prior to that time, matter and electricity were viewed as separate entities, with little or no relationship to one another and the atom was considered to be an indivisible particle of matter. The scientists of the last century so feared the consequences which might flow from any theoretical subdivision of the ultimate particle, the atom, that men like Büchner declared that „divisibility of the atom would lead to a doubt of the very existence of matter itself!‟ The aim of this article is to attempt to make sub-atomic science accessible, not only to the members of the 6th form but to juniors of the Upper school. For sure, we know that the atom is indeed not the smallest particle that composes matter. More and more particles are being discovered every year that leads us to exclaim what a strange world we all inhabit. For example, with recent knowledge of how known particles behave, there is a certain probability (however small) that an object would materialise randomly from another part of the Universe and appear on Earth! We know for sure that all matter in the Universe is composed of atoms. So, what is the atom? Well, here‟s a brief description: Thanks to Rutherford‟s model of the atom we can say without too much trouble that the basic particles that compose it are electrons, neutrons and protons, as learnt in GCSE chemistry and physics. The electron, with a 1- charge can not be split into anything simpler to our knowledge. However, neutrons and protons can. Now we enter into a world of quantum mechanics! Neutrons appear in the nucleus of the atom and have a neutral charge (hence the name neutron). Within the neutron are located three types of subatomic particles: up quarks, down quarks and gluons. As illustrated, we can see three quarks, two of which are by gluons, they literally stick the quarks together. Quarks give protons their charge. An Up Quark has a charge of +2/3 whilst a Down Quark has a charge of -1/3. And so, in order for a neutron to have no charge, it must contain 1 Up Quark and 2 Down Quarks. Using the same principle, a proton (a 1+ particle remember) must contain 2 Up Quarks and one Down Quark. Please see table below: Quark-Up
Charge: +2/3.
Quark-Down
Protons contain two, neutrons one.
Charge: -1/3.
Protons contain one, neutrons two.
So, what are leptons? They are defined as „Fundamental particles that are relatively nonreactive and capable of an independent existence: electrons, muons, tau particles and neutrinos.‟ So in other words, they are a generalised word for describing sub-atomic particles (smaller that the atom) that can exist independently. The following table illustrates some of the particles that fall under the „lepton‟ heading: Electron
Charge: -1
Electron-neutrino
Responsible for electricity and chemical reactions.
Charge: none.
Also possibly no mass. They move in their billions through our bodies per second!
This table can be misleading in the sense that it suggests that there are only 2 leptons. The leptons above are the most simple in form and behaviour. The other leptons are significantly more complex and need more scientific explanations. A chart of all the leptons and their
electric charges is shown on the opposite page.
Down
and one of which is an Up Quark. These quarks are bound together
Quarks
Mankind has only just entered the world of quantum mechanics in the last 70 years. Even though we have a better understanding of the atom, mankind still doesn‟t have enough knowledge to predict the behaviour of the atom. Perhaps the most exciting development as a result of the modelling of these particles
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I trust that I have not only given you an incite into the world of quantum particles but have also shown you a useful application of our knowledge of these particles. □ SPECTRUM
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Quarks and Leptons – into the world of ornamental garden pixies
behaviour is that of nuclear fusion: the process of combining atoms to create heavier elements and in the process, releasing huge amounts of energy. This new technology has the potential to solve the earth‟s energy problems and essentially, harness the power of our own Sun! Experiments with the advanced new Tokamak device, a doughnut-shaped reactor, will start in July or August. If the experiments prove successful, China will become the first country in the world to build a fully-functioning Tokamak fusion device! The ITER programme, still in its initial stages, involves Russia, Japan, the United States, the European Union, China and the Republic of Korea. The aim of this programme is to create a viable working prototype of the fusion reactor. A model of this is currently being
built in France and will be ready within 10 years! Scientists believe that deuterium, extracted from seawater, can be used to produce enormous amounts of energy from a deuterium-tritium fusion reaction under huge temperatures of 100 million oC. After nuclear fusion, the deuterium extracted from one litre of seawater will produce energy equivalent to 300 litres of petrol!
Janak Bechar
1. Start -> Photoshop 2. Open the file: X:\Academic\Upper\departments\science\Student Science Group\Make Your Own Planet.psd. I have started the process of making a planet for you due to the slow system when using the rendering functions. 3. Now let‟s begin! 1. Click CTRL / CMD D, to unselect the planet then go around the edges with the Smudge tool (A hand with a pointing finger). This creates small anomalies to the planet to make it more realistic. 2. Now whilst holding CTRL click on the layer “Planet” then go to Filter -> Distort -> Spherize, do this at 100% on Normal mode. 3. Click Select -> Modify -> Contract at 3 pixels. 4. Then Select -> Feather at 2 pixels 5. Then click CTRL / CMD + SHIFT + I so that the black surrounding the planet (and a ring around the planet) are selected. 6. To create a blurred effect around the planet click Filter -> Blur -> Gaussian Blur at about 5 pixels. Now your planet is done, except for the fine tweaking... 7. Select all (CTRL / CMD + A). Now to make the image more defined go to Image -> Adjustments -> Levels. 8. In this window play around with the 3 arrows beneath the graph until you‟re happy with your planet. 9. Next if your not satisfied with the colours I chose go to Image -> Adjustments -> Hue / Saturation. Click the colorize box and then play with the sliders until you get the planet you like. 4. Now you‟ve done the most important bit, but with a little exploration you can add other planets to your image, stars, suns or anything you want!
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