Eureka
moments!
 Educational resources |
Educational resources
Introduction
Eureka moments – past, present and future
Health
Inspired by insulin
Science and sex
Cunning, devious, nasty
Environment
Skippy in the limelight
I'm gonna catch me a rabbit
Buzz off
Technology
Probing new worlds
Hazy wine and crazed cats
Use the light
Eureka
moments – past, present and future
In general, science
research progresses in a series of small, incremental steps, making advances
over a period of time. However, sometimes there is a Eureka moment when
the problem is suddenly solved.
This exhibition presents
nine Eureka moments that have occurred over the past 50 years in the fields
of health, technology and the environment. But there are many problems
still to solve. One – the problem of salinity – is still waiting
for its Eureka moment.
Salinity is a major
scientific problem in Australia. It decreases agricultural production,
affects water quality, threatens biodiversity and damages roads and buildings.
There are two kinds
of soil salinity: dryland salinity (occurring on land not subject to irrigation)
and irrigated land salinity. Both occur in areas where soils contain high
levels of salt.
Much of Australia's
landscape is naturally saline – think of the great salt lakes in
our interior. Many of our agricultural lands also contain vast reservoirs
of salt, but normally these are held deep within the soil profile where
they don't affect plant growth. The problem occurs when this salt is brought
to the soil surface by rising water tables.
Remote sensing is
being used to map salt stores in the ground. These maps, combined with
data from decades of field research, are helping scientists to understand
how and where the salt is moving and to predict sites most at risk of
salinisation.
Useful sites
Salinity
– the awakening monster from the deep (Nova: Science in
the news, Australian Academy of Science)
Monitoring
the white death – soil salinity (Nova: Science in the news,
Australian Academy of Science)
Introduction to remote sensing (PhysicalGeography.net, Canada)
Salinity
mapping methods in the Australian context – conference proceedings
(17 October 2003, Australian Academy of Science)
Salinity information from each State
Discussion
questions
- How do you think
salinity decreases agricultural production, threatens biodiversity and
damages roads and buildings?
- What areas of
Australia are most threatened by salinity?
- What do you think
the terms groundwater and water table mean?
- In some areas
tree-planting is advocated as a method to reduce salinity. Why do you
think planting trees would affect salinity?
- Remote sensing
is used to map salt stores in the ground. What is remote sensing?
Activities
- Using the information
available at Australia's
salinity problem (National Action Plan for Salinity and Water Quality,
Australia), write a short paragraph explaining what salinity is and
the difference between dryland salinity and irrigation salinity.
- Write a short
explanation of the causes of soil salinity using the information available
at Salinisation
– causes and preventions (Nova: Science in the news,
Australian Academy of Science). Include the terms groundwater, water
table, recharge and discharge in your explanation.
- Educational
activities (Salinity – Australia's silent flood, Australian
Broadcasting Corporation) has activities and case studies for each of
the four episodes of the 2002 documentary series, The Silent Flood.
- Caring
for the country: Salinity of soils and water (NSW HSC Online, Charles
Sturt University, Australia) provides resources and activities for this
aspect of the Earth and Environmental Science syllabus.
- Saltwatch:
A resource book for schools (Waterwatch Victoria, Australia) has
experiments (eg, 'Capillary rise', 'Sampling surface water', 'Testing
for soil salinity') and other teaching resources.
- Queensland Department
of Natural Resources and Mines (Australia) provides two investigations
into the effects of salinity on plant growth – Effects of soil salinisation and Threshold levels for cultivated crops.
- University of Adelaide has two activities relating to salinity – Effect
of salinity on beans and Determining
soil texture.
- Sad,
salty pot plants (Country Areas Program, New South Wales Department
of Education and Training, Australia) explains how to design an experiment
to determine the effect of different concentrations of fertiliser on
plants, and the relationship to salinisation.
- The
electrical resistivity of materials (SEED, Schlumberger Ltd, USA)
shows you how to compare the electrical resistance of dry soil with
soil that has been soaked with different liquids.
- Read What
is remote sensing? (NASA, USA) and write a brief explanation of
the technique in your own words.
-
Image is everything
(University of Alabama Teaching and Learning Center, USA) is a remote
sensing unit. 'Remote sensing and digital images' has students working
in pairs to 'scan' and 'digitise' an image and 'The truth, the whole
truth and nothing but the truth' shows how ground measurements (ground
truthing) are used to double check remote sensing data.
Inspired
by insulin
Injecting insulin
is a daily routine for many. Without injecting insulin, people with diabetes
are unable to convert the food they eat into energy. Their bodies cannot
produce insulin, the hormone that transports glucose from the blood into
body cells. To treat diabetes, insulin used to be sourced from the pancreas
glands of pigs and cows. Some patients had an immune reaction to animal
insulin so researchers looked to other methods.
The insulin
that diabetics now use is an exact copy of the human hormone insulin produced
by the pancreas. John Shine, a biochemist, was the first to show
that a human gene could be copied and transferred into bacteria to produce
a biologically active product. A number of human proteins and hormones
can now be produced such as human growth hormone, immune molecules for
treating cancer and enzymes to dissolve blood clots after heart attacks.
Useful sites
Professor
John Shine interview (transcript of ABC TV's George Negus Tonight,
20 August 2003)
Professor
John Shine (Faculty of Medicine, University of New South Wales, Australia)
Genetic
engineering (British Broadcasting Corporation, UK)
Explains how to isolate and identify a gene and how to put the gene into
another organism to be cloned.
Stem
cells – gateway to 21st century medicine (Nova: Science
in the news, Australian Academy of Science)
Humanity's
heritage: The human genome and stem cells (An address by Professor
John Shine to the National Press Club, 21 July 2004)
What is diabetes? (International Diabetes Institute)
Discussion questions
- What do scientists
mean when they say that genes act like a blueprint?
- What is meant by
cloning? What kinds of cloning are there?
- What are stem cells?
- Why do diabetics
have to be careful about their diets?
- Do you think it
is better for diabetics to inject insulin that has been isolated from
a pig's pancreas or to inject insulin that has been produced by a cloned
human gene? Explain your answer.
- What other human
genes might be cloned in order to improve medical treatments?
Activities
- Desperately
seeking insulin (The University of Texas Health Science Center at
San Antonio, USA)
In this play students take on the roles of glucose, insulin, and organs
in the body to demonstrate how our bodies process sugar.
- Saving
superman – a look into stem cell research (National Center
for Case Study Teaching in Science, University of Buffalo, USA)
This case study covers the main concepts of stem cell research and therapy
and the political and ethical issues surrounding these subjects. Case
study teaching notes are
available.
- New York Times
Learning Network, USA
Science
and sex
Take one pill once a day to control
fertility. The development of the oral contraceptive pill was not the
aim of chemist Arthur Birch. He refined a chemical reaction in
1950—now called the Birch Reduction Method—that allowed the
activity of steroids to be modified. Today 70 million women across the
world take the oral contraceptive pill. It is also the preferred contraceptive
choice for 52 per cent of visitors to Australian Family Planning Clinics.
Useful sites
Arthur Birch,
organic chemist (1915-1995)
Reduction
and oxidation reactions (Chemtutor.com)
Steroids
(Elmhurst College, USA)
The pill: Myths and misconceptions (Women's Health Queensland Wide, Australia)
Discussion questions
- What is meant by
the terms contraception and fertility?
- One important use
of the Birch Reduction Method is the modification of steroids. In what
context have you heard of steroids?
- Why do you think
the expanding population poses a major challenge for our world?
- A modified version
of the hormone progesterone is the main component of the pill. What
other hormones do you know about and what do they do?
Activities
- Using library and
internet materials, find out what is meant by a chemical 'reduction'
and write a short definition.
- Oxidation:
How can it be proved? describes several experiments that illustrate
oxidation.
- Oxidation-reduction
of indigo carmine demonstrates the use of dextrose as a reducing
agent to change the colour of the indigo carmine to yellow.
- Hormones
of the reproductive system (Kimball's Biology Pages, USA) includes
information about oestrogen and progesterone and how they work. Summarise
how these hormones and their actions relate to the combined oral contraceptive
pill.
- Find out more about
steroids and write a short report on what you have learned.
- Write a short report
summarising the information available at Contraception
– past and future by Anna Glasier (Nature, October
2002).
- Sanger, Pincus,
Rock, Colton, Marker and Djerassi are other names associated with the
development of oral contraceptives. Using library and internet resources,
find out more about how each of these people contributed to the development
of the pill, and then write a short report on what you have learned.
- Human population: Fundamentals of growth and change (Population Reference Bureau, USA) provides a number of discussion questions and web resources related to the topic.
Arthur
Birch, organic chemist (1915-1995)
Arthur Birch was born
in Sydney on 3 August 1915. His interest in chemistry was evident as a
child; his grandmother apparently called him 'Professor'. He studied organic
chemistry at the University of Sydney, graduating with a University Medal
in 1936. He travelled to England for his post-graduate studies, receiving
a DPhil from the University of Oxford.
He continued his research
in England until 1952, initially at Oxford then moving to the University
of Cambridge in 1948. During this period he formulated a breakthrough
procedure that became known as the Birch Reduction – one of the
most widely used methods in synthetic organic chemistry. The procedure
used alkali metals in liquid ammonia to reduce aromatic rings. Using the
procedure, Birch made analogues of natural steroid hormones, which was
a major contribution to the development of the oral contraceptive pill.
This contribution has led to the description of him as 'the grandfather
of the pill'.
Birch returned to
Australia in 1952 to take up the position of Professor of Organic Chemistry
at the University of Sydney, but remained here for only a few years. Frustrated
by poor equipment and inadequate funding, he returned to the UK in 1955
as Chair of Organic Chemistry at the University of Manchester. He was
lured back to Australia in 1967 when the Research School of Chemistry
was established at the Australian National University in Canberra. He
was appointed as Dean of Chemistry and Foundation Professor of Organic
Chemistry, and held the latter position until his retirement in 1980.
Birch took a broader
interest in science than just his own area of research. In particular
he worked to strengthen scientific contacts between Russia and Australia.
Birch was elected
as a Fellow of the Australian Academy of Science in 1954 (president 1982-86),
a Fellow of the Royal Society in 1958 and was a Foreign Member of the
Russian National Academy of Sciences. Just before his death in 1995, the
main building of the Research School of Chemistry at the Australian National
University was named the Birch Building.
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Cunning, devious, nasty
Viruses have challenged humans
for centuries. The Spanish flu in 1918 killed 50 million people worldwide,
including Australia—more than the number of deaths in four years
of fighting during the First World War. Humans’ continual battle
with invading viruses was given new armoury when Peter Doherty,
an immunologist, described how our body’s immune system goes about
recognising virus-infected cells. This led to an understanding of how
the immune system distinguishes between the body’s own tissue and
foreign organisms—‘self’ and ‘non-self’—and
resulted in advances in vaccine development and increased understanding
about transplants.
Useful sites
Interview
with Professor Peter Doherty (Australian Academy of Science)
Peter
C. Doherty – Autobiography (Nobelprize.org, Sweden)
The
immune system (Back to Basics, Australian Academy of Science)
Nobel
prizes: Unraveling immune-cell mysteries (Science Magazine, USA)
Understanding cancer series: The immune system (National Cancer Institute, National Institutes of Health, USA)
Immunisation
– protecting our children from disease (Nova: Science in
the news, Australian Academy of Science)
Discussion
questions
- What is the function
of your immune system?
- How would you describe
the difference between natural immunity and acquired immunity?
- What are the characteristics
of viruses? Why do you think it is difficult to find drugs to control
viral diseases?
- What do you think
the term autoimmune means?
- What do you understand
about the term vaccine?
- Why do you think
some parents in the community are opposed to childhood immunisation?
Activities
- Write a paragraph
summarising the information at Vaccines
explained (Better Health Channel, Australia).
- Prepare a short
talk on how vaccination provides immunity to a disease.
- Choose a vaccine-preventable
disease and find out more about it using library and internet resources.
Combine your information with others in the class to create a table
that shows symptoms, causes, methods and patterns of transmission, treatment,
and prognosis for any of the diseases for which there is a current vaccine
available.
- Use library and
internet resources to investigate which vaccines are currently recommended
for people living in Australia and how this compares to recommendations
for other countries. Present your findings as a brief report.
- Student teams
investigate both sides of the pro- and anti- immunisation argument.
After collecting information, the class can have a debate on the question
'Is global immunisation a worthwhile objective?'.
- The
immune response (NSW HSC Online, Charles Sturt University, Australia)
provides you with information about the immune response and has a number
of suggestions to help learn more about immunity and vaccination.
- Using
balloons to teach immunology (American Association of Immunologists,
USA)
This participatory classroom demonstration can be used to show what
antibodies look like and how they combine with foreign materials in
order to eliminate them from the body. It illustrates several principles
of immunology and can be modified for a variety of audiences.
- Virus
replication (Department of Microbiology and Immunology, University
of Leicester, UK)
Learn about viruses by 'becoming' one and then answer questions about
how your virus would behave in different biological situations. You
can choose to be a polio, flu or HIV virus particle.
- Discovery School,
USA
- Operation
antibody
Students learn how the human immune system works at the cellular
level. They identify what types of cells are important in the immune
system and investigate the different mechanisms used by these cells.
- Common
vaccinations
Students learn how vaccinations work and create class posters describing
different types of vaccines.
- Immunization
(CyberSchoolBus, The United Nations)
This site provides a wide range of information concerning how global
immunisation programs are developed and implemented, and suggests number
of classroom activities.
- Immunotherapy
is treatment that uses certain parts of the immune system to fight disease,
including cancer. Write a paragraph or two summarising the information
available at Types
of immunotherapy (American Cancer Society).
- Find out more
about diseases that involve autoimmune reactions and write a short report
on your findings.
Skippy in the limelight
Kangaroos, wallabies and platypus are known internationally for being cute,
unique and a bit odd. Australia’s marsupials are also distinctive
in the information they provide genetically. We learn more about the importance
of various human genes by comparing them with those of other animals. Kangaroos
are well placed to highlight genes of biological importance. Jenny Graves,
a geneticist, is planning to sequence the first marsupial genome.
Useful sites
Interview
with Professor Jenny Graves (Australian Academy of Science)
Teachers
notes to accompany an interview with Professor Jenny Graves (Australian
Academy of Science)
Reality
CV – Jenny Graves (Women in Science Enquiry Network, Inc, Australia)
Kangaroo
– The goldilocks genome (transcript of The Science Show,
28 September 2002, Australian Broadcasting Corporation)
Fact sheets from the
National Human Genome Research Institute (National Institutes of Health,
USA)
Discussion
questions
- What are the differences
between marsupials and other mammals?
- What does it mean
when scientists say that kangaroos are our distant relatives?
- Why do you think
it might be more important to sequence a marsupial genome than a frog
genome?
- How could the
identification of special marsupial genes lead to new human drugs?
- Why do genes need
to be turned off and on at different times?
- How do you think
the Kangaroo Genome Project could help protect Australia's biodiversity?
Activities
- Build
your own DNA model (Double Helix, CSIRO, Australia) provides templates
for you to assemble a DNA model.
- Number the following
in order of their size in an organism, from smallest to largest:
genome DNA gene base chromosome
- Read The
Kangaroo Genome Project (Australian National University) and then
prepare a news report that describes the project and what it hopes to
achieve.
- Biotechnology Australia
- Extracting DNA in your kitchen describes how to extract DNA from onion cells.
- DNA sequencing provides a sequence of coloured bands from electrophoresis. Using this information, you can work out the sequence of bases in a section of DNA.
- Using a gene probe is an interactive online activity in which you can work through the steps of extracting a cell and treating the DNA in it, and then use a gene probe to find out which of the organism's chromosomes carries a particular gene.
- Read Gene
mapping and DNA sequencing (Nova: Science in the news,
Australian Academy of Science) and write a paragraph or two explaining
the difference between mapping and sequencing a genome, and the
difference between a genetic map and a physical map.
- Sequence
for yourself (NOVA, Public Broadcasting Service, USA) does a
good job of describing, with diagrams, the complex method used to
determine the sequence of bases in a genome. Upper level students
can attempt to summarise the sequencing method in their own words.
I'm
gonna catch me a rabbit
European rabbits became
a pest, then a plague and a personal enemy to Australian farmers after
being introduced for sport in 1859. Burrowing through pastoral and cropping
land, they stripped bushes of leaves and bark and left the environment
vulnerable to erosion. The population was initially kept in check by trapping,
shooting, baiting, poisoning and gassing. With no natural predator though,
they reached plague proportions. Something had to be done.
Frank Fenner was the
virologist on the team who released the myxoma virus, a virus specific
to European rabbits, into the Murray River Valley in 1950. Within two
years the rabbit population dropped from 600 million to 100 million. There
was also a subsequent increase in wool and meat production worth $68 million
due to recovered pastures.
Useful sites
Interview
with Professor Frank Fenner (Australian Academy of Science)
Teachers
notes to accompany an interview with microbiologist and virologist, Professor
Frank Fenner (Australian Academy of Science)
Frank
Fenner (transcript of ABC TV's George Negus Tonight, 17 February
2003)
2002
Prime Minister's Prize for Science – Professor Frank Fenner
(Commonwealth Department of Education, Science and Training, Australia)
A
plague on the pest – rabbit calicivirus disease and biological control
(Nova: Science in the news, Australian Academy of Science)
Commonwealth Department
of the Environment and Heritage, Australia
Dr
Laurie Twigg (run, rabbit, RUN! – the story of rabbits
in Western Australia Australian Museums and Galleries Online)
Transcript of a 2002 interview with Dr Laurie Twigg from the Vertebrate
Pest Research Services in Western Australia. Covers different methods
of rabbit control.
Australia’s
pest animals: New approaches to old problems (Science for Decision Makers, Commonwealth
Department of Agriculture, Fisheries and Forestry, Australia)
Discussion questions
- Why do you think
rabbits became plague after they were introduced into Australia in 1859?
- What does the term
'biological control' mean?
- Why do you think
there is still a rabbit problem in some parts of Australia even though
the myxomatosis was very effective in reducing rabbit numbers?
- There are many
vertebrate pest species in Australia in addition to the rabbit (eg,
fox, mouse, carp, cane toad, feral pig). Which of these species do you
think would be the most important to control? Explain your answer.
Activities
- Using the information
available at Rabbits (Invasive Animals CRC, Australia) and European
rabbit (Oryctolagus cuniculus) (feral.org.au) write a short
report explaining why rabbits are Australia's most widespread and destructive
pest animal.
- Find out more about
myxoma virus and the more recently introduced rabbit calicivirus. Write
a report comparing the two viruses, including mode of transmission and
type of genetic material.
- Use role play to
simulate a meeting of concerned people in an area where rabbits are
a problem. Representatives could include a grazier, an animal liberationist,
a geneticist, a politician, an environmentalist, a zoologist or botanist,
and a veterinarian.
- Nova: Science
in the news (Australian Academy of Science)
- How
do we get rid of pests? (Tall Poppy Campaign, Australian Institute
of Political Science) provides information
and classroom activities relating to rabbits in Australia.
- run rabbit
RUN! (Australian Museums and Galleries Online) covers the story
of rabbits in Western Australia. Using the information available at
this site, explain in your own words how rabbits affect native
plants and animals and agriculture.
- Viruses
and host evolution (Access Excellence, USA) introduces viruses and
their effects on the evolution of rabbit populations. Students then
find out more about a viral disease of their choice.
- Rabbit
calicivirus disease: Magic bullet or Pandora's box? (University
at Buffalo, The State University of New York, USA)
Students read a scenario about a proposed release of rabbit calicivirus
disease in New Zealand as a biological control, and then discuss the
questions that are provided. Teachers'
notes are available.
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Buzz
off
Outdoor living in Australia is synonymous with insects – flies,
mosquitoes and ants. Called into action during the Second World War, Douglas
Waterhouse, an entomologist, discovered the active ingredients of
insect repellent, a now permanent fixture in any picnic basket, camping
backpack and sporting bag.
Useful sites
Interview
with Dr Douglas Waterhouse (1916-2000) (Australian Academy of Science)
Teachers
notes to accompany an interview with Dr Doug Waterhouse (Australian
Academy of Science)
Biographical
memoirs of Douglas Frew Waterhouse (Australian Academy of Science)
Integrated
pest management – the good, the bad and the genetically modified
(Nova: Science in the news, Australian Academy of Science)
Crops
and pest control by James Ridsdill-Smith
(Nature and Society Forum, Australia)
Discussion questions
- What is the difference
between a repellent and a pesticide?
- What is biological
control? Why do you think biological control methods might be preferable
to using pesticides for insect control?
- Australia was
certified free of malaria by the World Health Organization in 1981).
Why do you think occasional cases of malaria are still reported in Australia?
- What do you think
is meant by the phrase integrated pest management?
- What are some
methods employed in integrated pest management?
Activities
- Bugs (Museum Victoria)
Waterhouse was an entomologist, someone who studies insects. This website
tells you all about bugs, many of which are insects. Find out about
different types of bugs in the museum's collection at Bugcatcher
(Requires Flash 6 Player). Check out the Classification
guide and try some of the Activities
on the Education page. The activities cover Prep-Year 2, Years 3-6,
and Years 7-10.
- Read the 'Pest
origins' section of Insects
as pests (University of Sydney) and then summarise the information
in a paragraph.
- Summarise the
information on malaria and its prevention available at Protozoa:
malaria (schoolscience, UK) (There is a short quiz available.)
- Malaria is characterised
by recurring bouts of fever every few days, with no significant symptoms
in between. How does this cycle of symptoms relate to the life cycle
of the malarial parasite?
- Biological
control vs pesticides (Center for Insect Science, University of
Arizona, USA) has students design and perform a controlled experiment
to assess the effects of predators and insecticides on a population
of insect pests.
- Nova: Science
in the news (Australian Academy of Science)
- Global Education
(AusAID, Australia)
- Read the case
study at To
spray or not to spray: A debate over malaria and DDT (National Center
for Case Study Teaching in Science, University of Buffalo, USA) then
discuss the questions provided. Case teaching notes are
available.
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Probing
new worlds
For millennia we explored the Universe
only by what we can see— visible light. In the twentieth century
astronomers started using other tools such as UV radiation, X-rays and
radio waves. They uncovered an invisible world. The discovery by three
engineers, headed by John Bolton, of the first extragalactic radio sources
soon after World War II revolutionised space exploration. Mapping the
skies using radio waves means we can probe more deeply into the universe.
Useful sites
Biographical
memoirs of John Gatenby Bolton (1922-1993) (Australian Academy of
Science)
From
the solar corona to clusters of galaxies: The radio astronomy of Bruce
Slee (Publications of the Astronomical Society of Australia,
2004, Vol. 21)
Vale
Gordon Stanley (by Wayne Orchiston and Bruce Slee) (Australia Telescope
National Facility, CSIRO, Australia)
Australia Telescope
National Facility, CSIRO, Australia
The
future of radio astronomy (Australian Broadcasting Corporation)
Discussion questions
- Why do you think
it is important to study astronomy?
- How would you describe
'radio astronomy'?
- What is 'outer
space'?
- Some scientists
use radio telescopes to 'listen' for signals that might have been produced
by intelligent life elsewhere in the universe. What do you think these
scientists have to consider when setting up their investigations?
Activities
- Watch the short
video, Hidden
galaxies, from the CSIRO's Australia Advances series and then write
a report to show what you have learned about radio telescopes and finding
new galaxies. (Requires QuickTime player.)
- The
one-square-kilometre telescope – the future of radio astronomy
(Australian Broadcasting Corporation)
Explores past conquests, exciting experiments and the future of radio
astronomy. Contains numerous in-text links for finding out about ideas
presented in the article. This site also has an Activities
section containing numerous suggestions for additional ways to explore
the material presented in the article, and a Teachers'
guide.
- Make
a radio image (National Radio Astronomy Observatory, USA) explains
how scientists turn radio data into pictures and provides real data
for you to produce a 'radio picture'. Another activity, Be
an interference detective, explains how you can use a small radio
to detect radio waves given off by batteries and other appliances in
your home.
- The
communications lab (AstroCappella, USA) shows you how to build and
test a parabolic-dish receiver. This is the type of system used by radio
telescopes to capture signals from space.
- SETI – the
Search for Extraterrestrial Intelligence – involves the use of
large radio telescopes to detect radio signals from other intelligent
civilisations. How
SETI works (How Stuff Works, USA) describes SETI and How
does SETI@home work? explains how you can donate some of your computer's
time to the project by downloading software available at SETI@home.
Hazy
wine and crazed cats
Your glass of sparkling white wine has been tested to ensure that it is
absolutely clear. The presence of metal atoms can cause haziness, which
winemakers test for using an atomic absorption spectrometer. In 1956 in
Minamata, Japan, cats started frothing at the mouth, throwing fits and
eventually suicided by jumping into the sea. Spectrometry revealed mercury
had contaminated the fish that the cats—and people—had eaten.
The ability to detect the presence
and concentration of small amounts of metal in any sample was made possible
by Alan Walsh’s experiments with atomic absorption. The
atomic absorption spectrometer can quickly and accurately detect what
elements are in a sample of soil, metal, water or food. They are now found
in virtually every hospital, laboratory and factory around the world.
Useful sites
Biographical
memoirs of Alan Walsh (1916-1998) (Australian Academy of Science)
Chemistry
101: Atomic absorption spectrophotometry (American Chemical Society)
Atomic
absorption spectroscopy (University of Adelaide, Australia)
Flame
atomic absorption spectrometry (Environmental Sampling and Monitoring
Primer, Virginia Polytechnic Institute and State University, USA)
Discussion questions
- Why do you think atomic
absorption spectroscopy has been described as 'the most significant
advance in chemical analysis' in the twentieth century?
- What do you think is meant
by the term 'trace elements'? Why are they important?
- Sir Alan Walsh was well
known and respected in scientific circles as the inventor of the atomic
absorption spectrophotometer. Although his invention influenced everyone's
lives, he was little known outside the scientific community. Do you
think that today's public would know very little about an equivalent
inventor? Defend your answer.
- What do you think is meant
by the terms 'emission' and 'absorption'?
- What are some ways of expressing
concentrations?
Activities
- Chemical
monitoring and management: Manufactured products are analysed (NSW
HSC Online, Charles Sturt University, Australia) provides information
about analysing the chemical composition of products. It provides several
flow charts that can be used to assist in the identification of ions
present in an aqueous sample, a case study on the monitoring of arsenic
and a simplified diagram of the equipment used in atomic absorption
spectroscopy.
- Identification
of metals by flame tests
(NASAexplores, USA) explains how to observe and identify elements based
on the color produced in a flame test.
- Choose an element whose
concentration can be measured using atomic absorption spectroscopy.
Using library and internet resources, find out how measuring the concentration
of that element is applied to a practical situation.
- Atomic absorption spectroscopy
has found important application worldwide in areas as diverse as medicine,
agriculture, mineral exploration, metallurgy, food analysis, biochemistry
and environmental monitoring. Choose one of these areas and find out
how atomic absorption spectroscopy is used.
- Absorption
spectroscopy (Kansas State University, USA) has an interactive demonstration
which allows you to observe the absorption spectra of different gases.
(Requires Shockwave.)
- One
in a million (US Environmental Protection Agency) explains how to
do a dilution series using mouthwash and then to calculate the concentration
of each dilution in parts per million.
- Parts per million (University of Nebraska-Lincoln, USA) explains
the concept of parts per million and provides instructions for a serial
dilution experiment using red food colouring that is analysed using
a spectrophotometer.
- Write a short paragraph
explaining why atomic absorption spectroscopy has been particularly
important in the analysis of trace elements. Include an example in your
discussion.
- Plants require a number
of nutrients for productive growth, including the trace elements boron,
iron, manganese, zinc, copper, molybdenum and chlorine. Using library
and internet resources, find out more about one of these trace elements
and plant growth (for example, the required concentration of the element,
why the plant needs it, symptoms that appear if the plant is deficient
or oversupplied). Write a report on your findings.
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Use
the light
Too much to download, not enough
time? Using the speed of light to transmit information via an optical
fibre led to a breakthrough in communication capacity in the early 1990s.
Allan Snyder, a physicist, explained exactly how light travels
down a fibre, what dimensions the fibre needs to be and how to convert
the pulses into information at the other end. His description simplified
an existing theory, which laid the foundation for fibre optic technology.
Useful sites
1997
Australia Prize – Professor Allan Snyder (Commonwealth Department
of Education, Science and Training, Australia)
Allan
Snyder (Tall Poppy Campaign, Australian Institute of Political Science)
Communicating
with light – fibre optics (Nova: Science in the news,
Australian Academy of Science)
How
fibre optics work (How Stuff Works, USA)
Modern
communication: The laser and fiber optic revolution (Beyond Discovery,
National Academy of Sciences, USA)
Discussion
questions
- What do you think
is meant by the term 'fibre optics'?
- Using light to
transmit information via an optical fibre led to a breakthrough in communication
capacity in the early 1990s. Before that, what methods were used to
communicate over long distances?
- In what ways has
this increase in communication capacity affected your life?
- Optical fibres
are not used just for communication. What other uses are there for optical
fibres?
- Allan Snyder, a
physicist, was studying how photoreceptors in the human eye transmit
light images to the brain when noticed the transmission properties were
similar to those of optical fibres. Today he is studying creativity
through the Centre for the Mind. What characteristics do you think enables
Snyder to work in such disparate fields?
Activities
- In 1997 Allan Snyder,
Rodney Tucker and Gottfried Ungerboeck were awarded the Australia Prize
for their contribution to telecommunications. Using internet resources,
find out more about the work of these three scientists and write a short
report.
- Nova: Science
in the news
(Australian Academy of Science) has two activities relating to fibre
optics and communication with light. Optical
fibres as 'light pipes' shows how light travels through a bent glass
rod and Illustrating
the inverse square law of radiation shows how illumination varies
with distance from the light source.
- Fibre
optics in the kitchen (The Helix, CSIRO) has do-at-home
activities that demonstrate properties of optical fibres.
- Telecommunications
(Newton's Apple, USA) provides an introduction to telecommunications
and activities on optical fibres.
- Read the information
available in the eight sections of the information kit This
busy ray: The story of communication by light beam (Telstra, Australia)
and write a short report on what you have learned.
- NSW HSC Online
(Charles Sturt University, Australia)
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