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					MARCH 2006
                                           Spectrum
Science Department

          Email:
                                 Preface
spectrum@bedfordschool.org.uk

    Bedford School Website
                                 From biochemistry to quantum mechanics and
   www.bedfordschool.org.uk      astrophysics, this edition of SPECTRUM offers it all.
                                 We have been able to show such a range of expertise
Editorial Board                  through the enthusiasm of all contributors to this
Dominic England
Edward Johnson                   publication. In general the topics addressed here are
                                 not on any examination syllabus, the aim however is to
Spectrum Members                 inspire students to continue their studies in science to
Jonathon Andrews                 A-level and beyond. To do this none of the terms and
Janak Bechar                     ideas are too complex. Instead the articles are
Justin Bell
Phillip Cai                      designed to stimulate readers with snippets of
Dominic England                  information on each subject matter. SPECTRUM also
Edward Johnson                   seeks to promote further research and thought in all
Edmund Lam                       scientific matters. For that reason we have created an
Dhaval Panchal
Nikhil Vaghela                   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
No part of SPECTRUM may          pupils who have researched an area of science which
be reproduced without the        particularly appeals to them and produced an article
consent of the editors and the   each for SPECTRUM. There is something here for
authors concerned. We
cannot accept liability for      everyone, whether they favour biology, chemistry or
mistakes or misprints.           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
     March 2006 Edition          all those involved deserve your appreciation.


                                                                        Edward Johnson




 Special thanks to Dr.
Mines and Mrs. Spina
  for all their help in
publishing this edition
   of SPECTRUM.                                  2
                        Contents

4    The Link Between Sport Survival And        Phillip Cai
     Instinct




6    1000 Songs Impossibly Small                Edward Johnson



8    The Future of Invisibility                 Dhaval Panchal




10   Avian Influenza                            Nikhil Vaghela




12   Stem Cells and Their Potential Future in   Jonathan Andrews
     Medicine


14   Particle Wave Duality                      Justin Bell



16   The Solar System                           Edmund Lam




18   Quarks and Leptons – into the World of     Janak Bechar
     ornamental garden pixies

20   Make your own planet                       Dominic England
                                                                   Contents




                                  3
                                  The Link between Sport,
                                      Survival and Instinct




                                                         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
 What do a stunt-plane pilot, surfer, and                other than being a biochemist‟s nightmare, it
 snowboarder all have in common? Are                     might actually save your life – or so we‟re told
 those self-proclaimed „adrenaline junkies‟ really       by our teachers anyway…
 what they claim they are? And what link does
 chronic severe depression have with a person            The more interesting (and relevant) stuff:
 who regularly does extreme sports? As you‟ve            Adrenaline starts „pumping‟ through your
 probably guessed reading this article will answer       bloodstream (literally) in times of „stress‟, yes
 all these questions, and hopefully a bit more           you heard me, both physiological and
 too.                                                    psychological stress.     Ever wondered what
                                                         causes the „butterflies in your stomach‟ and
 Adrenaline is a word heard all too much in              other symptoms of nervousness before an
 today‟s sports – especially those classified            exam, being interviewed by the police, or being
 „extreme‟, such as surfing, snowboarding, and           attacked by a mountain bear? You guessed it.
 bungee-jumping. It is often used in conjunction         Adrenaline prepares you heavily for physical
 with the words „junkie‟, „addict‟, and „rush‟,          work or strain, as a result, it‟s often referred to
 making it seem like some kind of drug. So what          as the „fight or flight‟ hormone, because it
 exactly is adrenaline anyway?                           helped animals and our ancestors (and still
                                                         does) get ready to combat threats or get as far
                                                         away as possible.

hh
                                                     4
                                                                                                           Phillip Cai
                                                         Evidently „stress‟ „sporting anticipation‟ and
Adrenaline will:                                         „fear‟ are all caused by the same thing, a
        Cause your heart to beat faster                 rather strong link, therefore doing sports is a
        Raise your blood pressure levels                very good way of stress relief, as your
        Stimulate secretion of glucagons which          adrenaline hormones aren‟t going to waste.
         causes the liver to convert stored              Also, the most capable sportsmen in the
         glycogen into glucose via hydrolysis            world can convert their „nerves‟ and
        Cause you to breathe deeper and faster,         „anticipation‟ into initiative and action
         and open up breathing passageways               effortlessly. What‟s wrong with exploiting
        Dilate your pupils (drug-like or what?)         your fear and reversing it into your most
        Divert blood flow from most organs to           basic natural advantage? Absolutely nothing.
         the brain, muscles, heart, and lungs -
         the only organs involved in physical            Junkies, addicts, and rushes
         strain                                          You‟ve heard the terms before, so are these
        Act as a neurotransmitter in your               people liars? Strangely enough no, there is
         nervous system                                  an element of truth – a person who regularly




                                                                                                           Lead Article The Link Between Sport, Survival and Instinct
As you can see it‟s a pretty good thing you‟ve           practices sport, especially „extreme sports‟,
got it available to you, imagine how pathetically        will eventually get used to adrenaline
unprepared top sportsmen would be in their               pumping through his body and the resulting
games. Don‟t even start with what would                  „high‟ of such physical performance.
happen at the Olympics!
                                                         When these people cease sport, adrenaline
The not-so-good-side of adrenaline:                      stops pumping and the body reacts to the
As adrenaline secretion is caused by a mental            sudden lack of adrenaline – this is an
„stress reaction‟ against something that could           „adrenaline low‟ and the person suddenly feels
potentially harm your body, there are certain            depressed and sad at not being active. Such
instances, especially in today‟s far more social         people are known as „adrenaline junkies‟, now
existence when compared to our primitive                 do you see how this thing is so much like a
struggle for survival, where adrenaline is               drug!
pumping through your body without an actual
                                                         From doing sport you suffer an „adrenaline
                                                         rush‟ where you subconsciously feel much
   Ever wondered what                                    more capable, daring, and physically active,
                                                         much like certain drugs like speed or
  causes the butterflies in                              amphetamines, though an adrenaline rush

      your stomach?                                      keeps your judgement within sensible bounds
                                                         at least, and has no really dangerous side
      You guessed it.                                    effects. □ SPECTRUM

       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,
                                                                                                           Adrenaline –




and you‟ve got yourself one large stress build-
up. People today suffer greatly from „stress‟
because they have difficulties handling the
constant pressure.


                                                     5
                          1000 songs, impossibly
                                          small




To get a feel for how small the Ipod nano is,          a flavour of how it works.
you really have to hold it yourself. It is
astonishingly small, thinner than a standard HB        As with all digital storage of information, flash
pencil in fact, so small that when I heard about       memory simply stores a series of voltages as 1s
it, I had to have one. But I asked myself two          or 0s, these are called bits and the nano stores
questions about it; how do they make it so             3.2 x 1010 of them. Flash memory is a type of
small? And how does it work? In this article I         EEPROM (electrically erasable programmable
plan to answer those questions as best I can           read-only memory) microchip but there is a
and hopefully do the nano justice.                     difference between standard EEPROM chips and
                                                       flash memory. Flash memory can write and
Thanks to the huge advances in memory                  erase data in much bigger chunks than
storage over the past few years the Ipod nano is       EEPROMs can. The basic process by which they
able to use two tiny Samsung flash memory              work is very similar though. A curious and
modules to store all its music and photos. These       complicated process called Folwer-Nordheim
modules are about 20mm long and 13mm wide,             tunnelling is used. Two transistors are separated
yet each of them can hold 2 gigabytes of               from each other by a thin oxide layer. One of
storage, this is how the nano is quite so small.       the transistors is known as the floating gate,
Flash memory works in a very complex way and           and the other one is the control gate. The
it would be very hard to explain in detail in a        floating gate's only link to the row, or
science magazine. Therefore I will just give you       wordline, is through the control gate. As long
                                                       as this link is in place, the cell has a value of 1,




                                                   6
                                                                                                           Edward Johnson
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                   electrical conductors become near to one
threshold, the value changes to 0.                        another without touching, their electrical
When the memory is blank each cell will have a            fields interact to form capacitance. The
value of 1. Therefore in order to store data a            surface of the touchpad is a series of metal
series of 1s are changed to 0s and to erase all           electrodes, covered by an insulating layer,
the data stored on a flash memory device we               which protects the sensor from wear by
simply have to apply a higher voltage charge to           preventing your finger from actually touching
create an electric field and return all cell values       the electrodes. The human finger is also a
to 1.                                                     conductor so when you place your finger on a
                                                          touchpad a tiny capacitance forms.
That is the basic idea of flash memory and it is a
lot more effective for use in mp3 players than            A microchip attached to the touchpad
regular hard drives which have been used                  monitors the amount of capacitance in every
before. Flash memory can be made smaller, it              electrode. By sensing an increase in
consumes less power, and it is quicker to write           capacitance the sensor can detect that your
data to and to erase data. The only                       finger is touching. By measuring which
disadvantage is that it is more expensive per GB          electrodes have the most capacitance the
of storage.                                               touchpad can also locate where your finger is
                                                          on the touchpad, to an accuracy of 1/1000th
Two other things that have been made                      of an inch. Using this information a computer
remarkably tiny in the nano are the LCD screen            or in this case an Ipod can sense when your
and the battery. Rather than go into too much             finger is moving around the click wheel and it
detail about these, I decided to investigate how          knows when to scroll down the lists on the
the click wheel, used on most Ipods, works.               screen.

The click wheels on all Ipods before the nano             So there you have it, I have explained briefly
were manufactured by Synaptics, however for               how two of the most interesting parts of an


                                                                                                           1000 Songs Impossibly Small
the nano, Apple decided to manufacture the                Ipod nano work and in doing so have shown
wheel themselves to save money. The principle             how they make it quite so small. If I were you
by which they all work however is very similar.           I would go out and buy one for yourself and
The click wheel is effectively a touchpad similar         see with your own eyes what a feat of
                                   to the ones            technology the Ipod nano is. □ SPECTRUM
                                   found         in
                                   almost every
                                   laptop today.
                                   They function
                                   by sensing an
                                         electrical
                                         property
                                            called
                                     capacitance.
                                   Whenever two




                                                      7
            The Future of Invisibility




Ever wonder why modern fighter jets are                   The two main ways of obtaining radar stealth
looking stranger than ever? Curvy bodies,                 are
angular faces, hidden weapons systems? The                     1.  An aircraft shape that reflects the
answer to that is Radar stealth. Most modern                       radar signals away from the radar
fighter/attack aircraft are “stealthed”, in that                   equipment.
they are virtually invisible to the enemy radar,               2.  Covering the airframe with materials
and so cannot be detected when attacking                           that absorb radar signals.
ground targets, or even other enemy jets. Most            An example of this shape is shown by this
of the time, the enemy is destroyed before they           diagram:
can even make visual contact with the attacker.
                                                          The angular surfaces reflect the radar signals
Radar, the technology used to detect vehicles             away from the equipment.
such as aircraft, is often used as a single word,         The main example of this early stealth
however, it is actually an acronym, standing for          technology is the F-117 “Nighthawk”, which first
“RAdio Detection And Ranging”..                           saw action during the first Gulf War, with its
                                                          “bunker buster” laser guided bombs. However,
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.

                                                      8
                                                                                                                Dhaval Panchal
the nature of its “stealthy” shape, angular with             Current generation stealth planes are painted
plenty of jagged, flat surfaces, leads to                    black, and operate only at night, for obvious
aerodynamic instability, making it immensely                 reasons. This has its limitations as the enemy
difficult to fly manually, hence it cannot be flown          know, or can easily guess that bombing raids
without computer assistance. This earned it the              would be during the cover of darkness. The
nickname “the wobbly goblin”.                                question now is who knows what the future
                                                             holds? My guess is optical camouflage.
Modern stealth jets have a combination of these              After all the technology deployed in these
deflecting airframe shapes, along with materials             fascinating aircraft, the only real chance you‟d
that help with absorbing/scattering radar                    see one of them is at an air show. If not, then
signals. These are built into the composite                  you‟d better take cover! □ SPECTRUM
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




                                                                                                                Stealth Aircraft - The Future of Invisibility
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.



                                                         9
Avian Influenza, the Truth




A lot has been said in the media about avian                       What is Avian Influenza?
influenza or bird flu as we more commonly know
it and a lot of this information has been vastly        Avian influenza is an infection caused by avian
exaggerated. This article will help to put aside        influenza viruses. These flu viruses occur
the misconceptions that you may have about              naturally among birds; wild birds worldwide
the virus and its effects on humans.                    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

                                                   10
                                                                                                              Nikhil Vaghela
bird flu among poultry there is a risk to people            explored, but the risk is that they could be
who are in contact with the infected birds. The             partially effective or even useless because the
big worry though is that H5N1 could pick up                 virus‟ genetic shape will change and not be
genes from conventional human flu viruses and               recognised by the antibodies. Concerns have
mutate, making it both highly lethal and highly             already been prompted by news that a
infectious. This is because it would be a radically         Vietnamese patient has become partially
new pathogen which could be transmitted from                resistant to Tamiflu, a drug being used to
person to person which is not currently possible;           combat bird flu.
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


                                                                     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.

         Has a vaccine been found?
                                                                                                              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

                                                       11
   Stem Cells and their Potential
   Future in Medicine
   Stem Cells and their Potential
Imagine being able to make a disabled
person walk, or help return the memory of
                                                           Once embryonic stem cells have been produced,
                                                           they can be made into any type of cell through
an Alzheimer’s patient, even something                     the process of differentiation (see diagram on
   Future in Medicine
like replacing skin that has been damaged
in a dangerous accident. All of this would be
                                                           opposite page). They can then be made into
                                                           Neurons, Epithelial cells or Hepatocyes liver cells
possible through the use of stem cells. However,           for example.
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‟.



                                                             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

                                                      12
                                                                                                            Jonathan Andrews
stem cells can become any type of cell because              endless and we are only at the very beginning
they are pluripotent. Adult stem cells are                  of the road to the future of medicine.
generally limited to developing into different              □ SPECTRUM
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.

   What is the potential of stem cells in




                                                                                                            Stem Cells and Their Potential Future in Medicine
                medicine?

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

                                                       13
    Wave Particle Duality
Historically light has often been viewed as a                interference to occur there must be waves going
particle rather than a wave with Isaac Newton                through each slit? The answer is, the photon
thinking of light in this way. However a famous              acts as a wave so is affected by quantum
experiment carried out by Thomas Young                       behaviour whereby it has a probability of going
around the year 1805 brought this view into                  through either slit. The hard concept to come to
question. This was the „Double Slit Experiment‟,             terms with however is that it is considered to go
which involved shining light on two parallel slits           through both slits and a phenomenon known as
and observing the pattern created on a screen                „probability interference‟ occurs. Due to the
behind. The pattern observed was a series of                 results of this experiment for almost 100 years
light and dark lines parallel to the slits as shown          the wave theory of light was widely accepted.
below:
                                                             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
                                                        14
                                                                                                              Justin Bell
the energy of a wave E, was equal to its                  (photographic paper and photoelectric effect).
frequency f, multiplied by Plank‟s constant h             The answer is that it is either: both a wave
(~6.6 x 10E-34). E=hf.                                    and a particle; or it is something else that we
                                                          can‟t visualize, appearing to us as a particle or
The photoelectric effect is a phenomenon                  a wave depending on how we look at it. This
whereby if light is shone on a metal it can cause         strange double reality still puzzles scientists
it to ionize (lose an electron). This occurs when         today and as yet no one can justifiably claim
a photon of sufficient energy collides with an            to fully understand what light is and why is
electron and knocks it out of its orbit. According        behaves as it does. □ SPECTRUM
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

   So is light a wave or a
    particle? The answer
    depends on how we
           look at it.
amplitude). If light were to be viewed as a wave
                                                                                                              Wave Particle Duality

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

                                                     15
The Solar System




                                                                               Venus
The Solar System might not be an unfamiliar
term to most of you who study the sciences. But           Venus is a very inhospitable
try and ask yourself: How much do you know                planet for a human to stay on.
about the Solar System? Other than that there             Although it is further away from
are 9 planets (which you may say is not true)? If         the Sun, its surface temperature
you answer nothing – or nothing much, then                can reach 482°C, due to the run-
read on. Here I will unveil secrets of the Solar          away greenhouse effect, caused
System which are rarely known.                            by the atmosphere of mostly
                                                          carbon dioxide. It is hotter than
    What is the Solar System anyway?                      Mercury, and it is hot enough to
                                                          melt lead.
The Solar System is the most famous planet
system within the Universe – or at least the                    Venus rotates from east to west, so if
Galaxy so far. It has a gigantic ball of extremely               you were on Venus, the Sun would rise
hot gas, known as the Sun, as the star and the                   from the west.
centre of the system, and around it there are 9                 In a clear night, Venus is the brightest
planets which rotate around the Sun in orbits.                   star in the sky.
                                                                Venus is covered by lava flows and it has
                  The Planets                                    several large shield volcanoes.
The 9 planets – Mercury, Venus, Earth, Mars,                                   Earth
Jupiter, Saturn, Uranus, Neptune and Pluto                Everyone is familiar with the
should be very familiar to you. But how much do           planet we live on. So why bother
you know about them?                                      saying much about it?

                    Mercury                                     Earth is not a sphere, it is
                                                                 an oblate spheroid.
                   Mercury is the closest planet                Earth completes 1 orbital
                   from the Sun and it is the                    in 365.2422 days. That‟s why we have 1
                   second smallest after Pluto. It               extra day every 4 years.
                   is so close to the Sun such
                   that light only takes 19.3                           Mars
                   seconds to reach it, compared
                   to 8 minutes for the Earth.            One may say that Mars is
                                                          probably the best planet to live on
      75% of Mercury is made up of a large               other than Earth. But is it really
       iron core.                                         so? Its surface temperature is
      Even though it is the closest planet from          below zero and CO2 makes up
       the Sun, it can have a minimum surface             much of its atmosphere.
       temperature of -173 °C.
                                                     16
                                                                                                            Edmund Lam
     The highest mountain in the Solar                            Neptune
      System is located on Mars, known as
      Olympus Mons and it rises 24km in                 Neptune is the outermost gas
      height.                                           giant. It orbits the Sun every
     Mars is so far the only planet that is            164.79 years.
      suspected to have had life before.
                                                              Wind       blowing      on
                                                               Neptune is the fastest in the solar
                  Jupiter                                      system – it can travel at up to 1,200
                                                               miles per hour (typical speed of a
            Jupiter is the largest planet in the               commercial jet is 550 mph)
            Solar System, and is a gas planet,                There is a “Great Black Spot” similar to
            composed of 90% hydrogen, 10%                      the “Great Red Spot” on Jupiter, which
            helium, with traces of ammonia,                    is the size of the Earth.
            methane and water. It also has
            the most moons in the system.
                                                                     Pluto
     If Jupiter was hollow, more than 1,000
      earths could fit in it– it‟s that big!            Pluto is the smallest planet in
     There is a “Great Red Spot”, which                the Solar System. It is only the
      represents a storm that has been                  size of our moon and it is
      blowing for more than 400 years.                  the only planet which has
                                                        never been “visited” by any
                   Saturn                               spacecraft.

             Saturn is the second largest                     Pluto is not always the most distant
             planet in the Solar System. It is                 planet – for 20 years out of its 249
             famous for its beautiful ring,                    year orbit, it is closer to the Sun than
             which is the only one in the                      Neptune.
             system visible from Earth.                       Pluto is the only planet to be
                                                               discovered by an American – all the
                                                               others were discovered by Europeans.
     If there was a large enough tank filled
      with water, Saturn would float on it                  More than this – the 10th planet?
     In places near its equator, wind can blow
      at up to 1,100 miles per hour!                    On 29th July, 2005, the Solar System was
                                                        redefined. Dr. Mike Brown and his crew,
                  Uranus                                claimed that they had discovered the 10th
                                                        planet of our Solar System. It is temporarily
             Uranus is the closest of the 3             named 2003 UB313 and it is said to be the
             outermost planets, discovered              size of 1.5 times that of Pluto. However,
             between the 19th and 20th                  controversies soon arose about whether it is
             century. It is so much further             really a planet. So is it a planet anyway? You‟ll
             from the Sun than Saturn, that             have to decide yourself. □ SPECTRUM
             Uranus orbits once every 84.01
year when Saturn only needs 29.45 years.

     Uranus is tipped on its side – which
                                                                                                            The Solar System



      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.




                                                   17
Quarks and Leptons – into the world
        of ornamental garden pixies
The last decade of the nineteenth century                   by gluons, they literally stick the quarks
witnessed the birth of a new scientific era. Prior          together. Quarks give protons their charge. An
to that time, matter and electricity were viewed            Up Quark has a charge of +2/3 whilst a Down
as separate entities, with little or no relationship        Quark has a charge of -1/3. And so, in order for
to one another and the atom was considered to               a neutron to have no charge, it must contain 1
be an indivisible particle of matter. The                   Up Quark and 2 Down Quarks. Using the same
scientists of the last century so feared the                principle, a proton (a 1+ particle remember)
consequences which might flow from any                      must contain 2 Up Quarks and one Down Quark.
theoretical subdivision of the ultimate particle,           Please see table below:
the atom, that men like Büchner declared that
„divisibility of the atom would lead to a doubt of          Quark-Up                   Quark-Down
the very existence of matter itself!‟ The aim of            Charge: +2/3.              Charge: -1/3.
this article is to attempt to make sub-atomic               Protons contain two,       Protons contain one,
science accessible, not only to the members of              neutrons one.              neutrons two.
the 6th form but to juniors of the Upper school.
                                                            So, what are leptons? They are defined as
For sure, we know that the atom is indeed not               „Fundamental particles that are relatively non-
the smallest particle that composes matter.                 reactive and capable of an independent
More and more particles are being discovered                existence: electrons, muons, tau particles and
every year that leads us to exclaim what a                  neutrinos.‟ So in other words, they are a
strange world we all inhabit. For example, with             generalised word for describing sub-atomic
recent knowledge of how known particles                     particles (smaller that the atom) that can exist
behave, there is a certain probability (however             independently. The following table illustrates
small) that an object would materialise randomly            some of the particles that fall under the „lepton‟
from another part of the Universe and appear                heading:
on Earth! We know for sure that all matter in
the Universe is composed of atoms. So, what is              Electron                  Electron-neutrino
the atom? Well, here‟s a brief description:                 Charge: -1                Charge: none.
Thanks to Rutherford‟s model of the atom we                 Responsible for           Also possibly no mass.
can say without too much trouble that the basic             electricity and           They move in their billions
particles that compose it are electrons, neutrons           chemical reactions.       through our bodies per
and protons, as learnt in GCSE chemistry and                                          second!
physics. The electron, with a 1- charge can not
be split into anything simpler to our knowledge.
However, neutrons and protons can. Now we                   This table can be misleading in the sense that it
enter into a world of quantum mechanics!                    suggests that there are only 2 leptons. The
Neutrons appear in the nucleus of the atom and              leptons above are the most simple in form and
have a neutral charge (hence the name                       behaviour. The other leptons are significantly
neutron). Within the neutron are located three              more complex and need more scientific
types of subatomic particles: up quarks, down               explanations. A chart of all the leptons and their
quarks and gluons.                                          electric charges is shown on the opposite page.
                                 As    illustrated,
                                 we    can      see         Mankind has only just entered the world of
                                 three     quarks,          quantum mechanics in the last 70 years. Even
                                 two of which are           though we have a better understanding of the
                                 Down       Quarks          atom, mankind still doesn‟t have enough
                                 and    one   of            knowledge to predict the behaviour of the atom.
                                 which is an Up
                                 Quark.    These
                                                            Perhaps the most exciting development as a
                                 quarks      are
                                                            result of the modelling of these particles
                                 bound together
                                                       18
                                                                                                             Janak Bechar
behaviour is that of nuclear fusion: the process          built in France and will be ready within 10
of combining atoms to create heavier elements             years!
and in the process, releasing huge amounts of
energy. This new technology has the potential
                                                          Scientists believe that deuterium, extracted
to solve the earth‟s energy problems and
                                                          from seawater, can be used to produce
essentially, harness the power of our own Sun!
                                                          enormous amounts of energy from a
Experiments with the advanced new Tokamak
                                                          deuterium-tritium fusion reaction under huge
device, a doughnut-shaped reactor, will start in
                                                          temperatures of 100 million oC. After nuclear
July or August. If the experiments prove
                                                          fusion, the deuterium extracted from one litre
successful, China will become the first country in
                                                          of seawater will produce energy equivalent to
the world to build a fully-functioning Tokamak
                                                          300 litres of petrol!
fusion device! The ITER programme, still in its




                                                                                                             Quarks and Leptons – into the world of ornamental garden pixies
initial stages, involves Russia, Japan, the United
States, the European Union, China and the                 I trust that I have not only given you an incite
Republic of Korea. The aim of this programme is           into the world of quantum particles but have
to create a viable working prototype of the               also shown you a useful application of our
fusion reactor. A model of this is currently being        knowledge of these particles. □ SPECTRUM




                                                     19
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!

                                                      20

				
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