|
About the Academy
Awards
Basser Library
Education
Events
Fellowship
International
Media releases
National Committees
Nobel Australians
Policy
Reports and submissions
Publications
The Shine Dome
|
Home > Science education
BACK TO BASICS
Atoms and molecules
Atoms, molecules, water, pH (Clermont College, University of Cincinnati, USA)
In addition to information on atoms, molecules and ions, this site introduces elements (a substance made up of only one type of atom). Describes how electrons determine an element's chemical properties and its position in the periodic table (a way of organising the elements). The information on water and pH is not necessary for a basic understanding of atoms and molecules. Simple diagrams effectively illustrate concepts. You can click on highlighted words for brief definitions.
|
The Phantom's Portrait Parlor (The Atoms Family, Miami Museum of Science, USA)
Spectroscope of an atom
This animation of a single electron spinning around a nucleus conveys the idea of how much empty space there is in an atom and why people speak of an 'electron cloud'.
Teachers might like to try the activities at this site: Paper cutting demonstrates how small an atom is and Mighty molecules shows how to build molecules from gumdrops and toothpicks.
|
When you've mastered the basics, try this site:
DNA and genes
Genetic Science Learning Center (University of Utah, USA)
What is DNA?
Explains that instructions providing all the information necessary for a living organism to grow and function are present in every cell. The instructions are in the form of a molecule called DNA. The structure of DNA is represented by a ladder twisted into a spiral shape (a double helix), with each rung of the ladder represented by a pair of bases. There are four bases – adenine (A), cystosine (C), guanine (G) and thymine (T) – and A pairs with T and C pairs with G. You can think of each base as representing a letter, with the letters grouped in threes to form words and a number of words making a sentence, or a gene.
What is a gene?
Explains that genes are like instruction manuals that contain directions to build the proteins to make our bodies function.
Other topics – 'What is a chromosome?', 'What is heredity?', 'What is a protein?' and 'What is mitosis/meiosis?' – are also available. Note: All information is presented as animated slide shows that require the Flash plugin.
|
Understanding cancer series: Gene testing (National Cancer Institute, National Institutes of Health, USA)
The information is presented as a series of concepts, each of which is illustrated with a clear diagram on a Powerpoint slide. Teachers can go to 'View/print Powerpoint' to print out black line masters for overheads or can create their own slides by mixing and matching information from slides.
Explains how genes are used to make proteins that perform a wide range of functions in living cells.
Changes in a gene cause a change in the protein and its function.
The site goes on to explain how changes in genes (mutations) can cause diseases and what is involved in gene testing.
|
When you've mastered the basics, try these sites:
DNA from the beginning (Cold Spring Harbor Laboratory, USA)
Information is organised around 41 key concepts, with an explanation of the science behind each concept. Although the explanations are sometimes complex, the text is clearly written. Animations and videos add interest, but a good understanding of the basic science is needed to appreciate them fully.
The 41 concepts are divided into three sections:
Classical genetics
Covers genetics and chromosomes. Includes 'Children resemble their parents', 'Genetic inheritance follows rules' and 'Chromosomes carry genes'.
Molecules of genetics
Covers DNA, RNA and proteins, and what genes are. Includes 'One gene makes one protein', 'The DNA molecule is shaped like a twisted ladder' and 'DNA words are three letters long'.
Genetic organization and control
Covers some concepts relating to DNA that do not fit into the traditional pattern (eg, 'Some viruses store genetic information in RNA' and 'Some DNA can jump').
|
Access Excellence (USA)
The structure of the DNA molecule
Gives a history of the development of the scientific understanding of DNA: Mendel's principles of genetic inheritance; DNA as the carrier of hereditary information; and Watson and Crick's model of the structure of DNA. Uses some technical language.
DNA: Two views (graphic)
An illustration of the DNA structure that shows how the DNA bases join and ultimately form a double helix.
|
Electromagnetic radiation
MicroWorlds (Advanced Light Source, Berkeley Lab, USA)
Electromagnetic radiation
Introduces the idea that radio waves, microwaves and visible light are all examples of electromagnetic waves and differ from each other only in the length of the wave. (A diagram of two different wavelengths is included.) Explains that electromagnetic waves are also called electromagnetic radiation because the waves radiate from electrically charged particles. The full range of wavelengths is known as the electromagnetic spectrum.
Electromagnetic spectrum
A diagram of the electromagnetic spectrum showing:
- wavelengths in metres;
- their size relative to the size of a full stop on the page;
- their common names;
- the source of the radiation; and
- the frequency (waves per second).
|
The electromagnetic spectrum (Gondar Design Sciences, UK)
Explains that the visible spectrum appears when white light is shone through a prism. Two alternative ways of describing the behaviour of light – photons and waves – are introduced, then each of the different wavelengths of light is discussed.
|
Measuring the electromagnetic spectrum (Imagine the Universe, Goddard Space Flight Center, NASA, USA)
Builds on the information in the above sites. Also explains the three ways of expressing (and measuring) electromagnetic radiation – energy, wavelength and frequency.
|
When you've mastered the basics, try this site:
How light works (How Stuff Works, USA)
This site concentrates on one form of electromagnetic radiation – light. The collection of six articles clearly explains some of the complex but interesting aspects of light – 'Ways of thinking about light'; 'What is light?'; 'How do you produce a photon?'; How are colours made?'; 'What happens when light hits an object?'; and 'Why do we see rainbows in soap bubbles?'
|
Energy
|
The Energy Story, Chapter 1: What is energy? (California Energy Commission, USA)
A simple introduction to energy. Good use of everyday examples to illustrate concepts.
Background: Because the concept of energy is not particularly easy to grasp, we are providing more background information than usual.
Introducing energy
Most of us associate energy with movement. A child who is always running and jumping is said to have a lot of energy. This example contains the seeds of the whole concept of energy, for we associate energy not only with the actual activity of running and jumping, but also with the possibility of doing these things. A child who is ordinarily running and jumping but who is, for the moment, quite still, has suppressed energy or potential energy. The child has the potential to do a lot of running and jumping.
We can therefore recognise at the outset these two different sorts of energy – energy of motion (which is also called kinetic energy, from the Greek kineo, to move), and suppressed or stored energy (which we call potential energy). Potential energy can have many forms. The wound-up spring of a toy has potential energy that can be converted into energy of motion when the toy is set running. Water in a high dam similarly has potential energy that can be converted into energy of motion when we open the sluice gates of the dam and the water streams down.
One of the important things about energy is that it can be used to do things. In formal terms we call this 'useful work', but it might not be useful and it might be play rather than work! Simply making something move might be useful work, but so also could be cutting materials, stirring liquids, lifting loads or heating foods.
Conversion of energy
One form of energy can be readily converted to another. The elastic energy of a wound spring can be converted to energy of motion of a toy. The chemical energy of petrol can be converted to the energy of motion of a car, and also to heat energy in the engine. The chemical energy in an electric battery can be converted into electrical energy and then into light (in a torch) or into motion (in a toy). It can even be converted into sound energy (in a radio or a CD player). These various conversion processes are very important to scientific understanding.
Conservation of energy
One of the most important things recognised by scientists about 100 years ago was that energy is never actually created or destroyed. It simply changes from one form to another or moves from one place to another. The processes of energy conversion always tend to make the energy less easily available and less useful. All of our useful sources of energy (eg, oil, coal, spinning wheels) convert their energy to heat. Most of this heat is dissipated in air or water and we can't make any further use of it.
The phrase 'conservation of energy' is a physical fact that is now so well established that it is referred to as a 'law'. It is an entirely different thing to the exhortation that we should all conserve energy, by which we mean not waste it.
|
|
What is energy? (Energy Information Administration, US Department of Energy)
Explains the difference between renewable and non-renewable energy sources.
Background: Starting with the use of fire, many advances we associate with civilisation have come from our capacity to harness energy. Like any living thing, a human needs energy in a biological form (food) in order to carry out all the processes of life. But, unlike most other living things, we can harness energy from sources other than our food and use this energy to carry out much more than simple life processes. The extent to which we have been able to use wind, water, wood, fossil fuel and atomic energy has made impossible for use to modify our environment more than any other species on Earth. Since the Industrial Revolution, our energy consumption has increased enormously. Modern society needs vast quantities of energy.
Energy is a non-renewable resource. By this we mean that once it has been used, it is no longer in a form in which it can readily be used again, although the energy itself is not destroyed. However, we tend to refer to some sources of energy derived from the sun as renewable. This is because the amount of energy in the sun is so great and because the sun has produced energy continuously for as long as humans have existed. Indirect sources of solar energy include biomass (eg, wood) wind and wave energy, and hydroelectricity. And, of course, sunlight itself is direct solar energy. Fossil fuels (natural gas, coal and oil) also contain energy that originally came from the sun. However, fossil fuels form at such a slow rate that, in practice, they are non-renewable. What we use is not being replaced.
|
When you've mastered the basics, try these sites:
|
The Energy Story, Chapter 2: What is electricity? (California Energy Commission, USA)
Explains that electricity is the movement of electrons among atoms of matter. Also explains electrical energy in terms of a battery, a motor and static electricity. Includes illustrations and a do-at-home experiment on static electricity.
|
The immune system
Understanding cancer series: The immune system (National Cancer Institute, National Institutes of Health, USA)
This online lecture provides the user with basic information about the human immune system. The lecture demonstrates how immune cells co-operate to rid the body of unwelcome invaders such as bacteria and viruses. It also explains how malfunction of the immune system may result in allergies, AIDS or cancer.
Teachers can download the PowerPoint presentation or print onto overheads.
|
The immune system: A primer (The Body: An AIDS and HIV Information Resource, USA)
Gives a good understanding of the interactions and complexity of the immune system. Uses helpful analogies (eg, explains that our immune system must distinguish the 'fingerprints' of intruders from those of 'family members' – our own cells and molecules).
|
How the immune system fights disease (San Francisco AIDS Foundation, USA)
Uses many simple diagrams to explain the basics of how different parts of the immune system interact to defend our bodies against viruses. Goes on to explain that AIDS interferes with the body's normal immune response.
|
When you've mastered the basics, try these sites:
Cancer and the immune system: The vital connection (Cancer Research Institute, USA)
Explains how the different components of the immune system work together
to combat infection in a highly integrated way. Includes an effective animation
to illustrate the immune response.
|
Lymphatic system and immunity (Estrella Mountain Community College, USA)
Uses annotated diagrams
to give an overview of the immune response system and how the components interrelate. |
The solar system
|
Melbourne Planetarium (Scienceworks Museum, Museum Victoria, Australia)
The solar system
A brief introduction to our solar system and its origin.
Background: The solar system consists of the sun; the nine planets (including Earth); satellites of the planets; and hundreds of thousands of smaller pieces of rock and ice (asteroids and comets). The sun lies at the centre of the solar system and is the largest object in it.
Stars
Explains that our sun, like other stars, is a giant ball of glowing gas.
Background: Stars vary in size, brightness and age. Stars turn hydrogen into helium and other elements by means of nuclear fusion. In the process, huge amounts of energy are released as heat, light and other types of radiation. Our sun is a rather ordinary star, 150 million kilometres away from Earth.
Distances in the universe are so large that we usually need to use much larger units than kilometres to measure them. Astronomers use the distance that light travels in a year (at a speed of about 300,000 kilometres per second) as a convenient unit for distances – 1 light year is about 10 million million kilometres. The sun is only about 8 light minutes away from Earth, but the nearest star is 4.3 light years away.
Galaxies
Covers the Milky Way (our Galaxy) and describes the shapes of different galaxies.
Background: The sun is just one of hundreds of millions of stars that make up our Galaxy. (Galaxies are huge regions of space that contain hundreds of billions of stars, planets, glowing nebulae, gas, dust, and empty space.) Our sun is a medium-sized star about two-thirds of the way out from the centre of our Galaxy, which is shaped like a flat spiral. The estimated number of other galaxies out to the edge of what we can see with our largest telescope is about 100,000 million.
The universe
Explains how the 'big bang' theory explains the origin of the universe.
Background: By careful measurements astronomers know that the universe is expanding, so that all galaxies are moving further apart. Calculating back, they are able to determine that 10,000 million-20,000 million years ago all galaxies were packed together. Apparently at that time they were blown apart as a result of a huge explosion – the 'big bang'. This was not an ordinary explosion because space and time themselves came into existence at that moment – the phrase 'before the big bang' has no meaning.
Planets
From this page you can access information about each of the nine planets, as well as information about comets, meteors and asteroids. (Information about our moon is linked from the 'Earth' page.)
Skynotes
Monthly notes about what you can see in the night skies over Australia.
|
When you've mastered the basics, try this site:
|
The nine planets (Students for the Exploration and Development of Space, Lunar and Planetary Laboratory, University of Arizona, USA)
An overview of the solar system
Gives the relative sizes of the planets and their orbits. Also lists different ways the planets can be classified.
Background: The four planets closest to the sun (Mercury, Venus, Earth and Mars) are smaller planets and are composed of rock and metal. Four of the outer planets Jupiter, Saturn, Uranus and Neptune) are giant planets and are composed of gases. Little is known about Pluto, the planet furthest from the sun. The orbits of the planets are elliptical.
Contents
A list of links to extensive information on the planets and their moons, the sun, and smaller bodies such as comets, asteroids and meteorites. For each item there is an overview of its history and current scientific knowledge, as well as excellent photographs to illustrate different features. There are also many links from highlighted words within the text to more in-depth articles.
|
|
Welcome to the planets (Planetary Data System, Jet Propulsion Laboratory, NASA, USA)
A collection of captioned images of planets and spacecraft from NASA's planetary exploration program.
|
The structure of the Earth
|
United States Geological Survey
Inside the Earth
Describes the internal structure of the Earth (includes diagram).
Background: The Earth is a rocky planet 12,750 kilometres in diameter. Deep in its centre lies the core, which has a diameter of about 6900 kilometres. The core is surrounded by a layer of rocks called the mantle, about 2900 kilometres thick, which constitutes about 80 per cent of the planet's volume. Above the mantle lies the lithosphere, the outermost shell of the Earth. Averaging at least about 80 kilometres in thickness, the lithosphere is rigid and strong. The top layer of the lithosphere is called the crust. The lithosphere is broken up into moving plates that contain the continents and oceans.
Historical perspective
Describes Wegener's ideas about moving continents. Includes a series of illustrations showing the break-up of the supercontinent Pangaea, an important aspect of the theory of continental drift.
Background: Although it feels solid enough, our planet's rocky surface, on land and under the sea, is a restless jigsaw of slowly moving pieces. These moving pieces are called plates and the formation and movement of these plates is best explained by the theory of plate tectonics. This theory was developed in the 1960s but ideas of moving continents were first put forward as early as 1596, and in 1912 Wegener introduced the theory of continental drift. Wegener's theory was based on several observations – the remarkable fit of the South American and African continents; the occurrence of fossils and unusual geologic structures on the matching coastlines; and the evidence of dramatic climate changes on some continents.
Developing the theory
Discusses the scientific developments that encouraged the formulation of the plate-tectonics theory.
Background: The theory of continental drift became more reasonable as knowledge about the Earth's crust increased. Studies of the ocean floor showed that the oceanic crust was constantly being recycled. This awareness that the Earth's crust moved provided geologists with an explanation for the movement of continents – they are part of a 'conveyor belt' system in which the lithosphere moves over the inner part of the Earth. The observation that the oceanic crust was recycled, and other scientific observations, led to the development of the theory of plate tectonics.
Understanding plate motions
Describes and illustrates the types of plate boundaries.
Background: The place where two tectonic plates meet is called a plate boundary. There are different types of plate boundaries depending on how the plates are moving in relation to each other:
- divergent boundaries – where plates pull away from each other;
- convergent boundaries – where one plate goes under another; and
- transform boundaries – where plates slide horizontally past each other.
Some unanswered questions
Describes the forces that move the tectonic plates and poses some unanswered questions about the details of plate movement.
Background: Below the lithosphere, thermal convection currents circulate, slowly moving the partially molten mantle (as when a saucepan of soup is heated). In the process, the plates of the lithosphere move because of the sideways movements of the currents underneath.
Geologic time
Introduces the two timescales that are used to measure the age of the Earth.
Background: Time is important to a geologist. Not only time in the present and the future, but also in the past. Geological events can be placed in an order or sequence from the oldest to the youngest without knowing the actual time at which an event occurred. For example, if you were given a collection of newspapers that had the dates removed, you could place them in order from oldest to most recent by reading about the events or the people described in them. This kind of exercise enables us to determine relative time.
To learn about the rate at which geological events take place, we must be able to measure numerical time. Radioactive breakdown of certain elements in minerals can be used to measure time accurately. These radiometric dating methods produce an absolute time scale.
|
|
University of Alaska Fairbanks (USA)
Geologic time scale
Presents a table with the names and dates of the major divisions that are used to describe geological time.
Background: The Earth is approximately 4.5 billion years old. To make it easier to understand the history of the Earth over this long time period, geologists have divided all the time since the Earth was formed into four eons, which are further divided into eras, periods and epochs. The traditional form of a geological time scale depicts the oldest time at the bottom and the most recent at the top with the present day at zero.
|
When you've mastered the basics, try this site:
|
The Paleomap Project (Christopher R. Scotese, USA)
The paleogeographic method
Summarises the methods used in palaeogeography to map the past positions of the continents and the changing distribution of topographical features such as mountains and oceans.
Earth history
Presents detailed diagrams of the position of the continents and the location of other features (eg, ancient mountain ranges and active plate boundaries) for each major geologic time period – and predictions for the future.
|
|
Beyond Discovery (National Academy of Sciences, USA)
When the Earth moves: Seafloor spreading and plate tectonics
Presents an historical look at the kinds of scientific evidence that supported the theory of plate tectonics. Australian scientists like Edward Irving and Ian McDougall contributed to these scientific findings.
|
Weather and climate
|
Encyclopedia of the Atmospheric Environment (Atmosphere, Climate and Environment Information Programme, UK)
Introduction to weather and Introduction to climate
(Expanded versions of these very simple introductions are available:
http://www.ace.mmu.ac.uk/eae/Weather/Older/Weather_Introduction.html
http://www.ace.mmu.ac.uk/eae/Climate/Older/Climate_Introduction.html)
Background: Local, short-term characteristics of the atmosphere (eg, wind, temperature, cloudiness, moisture and pressure) make up the weather of a particular place. The climate can be thought of as the long-term average of the weather of a particular place.
Measuring weather and Forecasting
A very brief description of how meteorologists measure various elements of the weather and then use these measurements to make forecasts.
(Expanded versions are available:
(http://www.ace.mmu.ac.uk/eae/Weather/Older/Measuring_Weather.html
http://www.ace.mmu.ac.uk/eae/Weather/Older/Forecasting.html)
Background: Meteorologists measure temperature, winds, rainfall, pressure, humidity, sunshine and cloudiness. Using patterns of recorded weather, meteorologists attempt to predict what might happen next.
Clouds
Explains how clouds form, and describes (with illustrations) four different types of clouds. (An expanded version is available at: http://www.ace.mmu.ac.uk/eae/Weather/Older/Clouds.html.)
Background: When air rises, either because it is warmed by the sun or because it is blown over high ground by the wind, it cools down. If the air becomes saturated with water vapour, then some of the vapour condenses as it cools, forming tiny water droplets. A mass of millions of these tiny suspended droplets forms a cloud.
If the air rises slowly and gently over a whole region, then the cloud forms a fairly thin uniform layer and is called stratus cloud. If the air rises in a disorganised way, usually on a hot day, then the cloud forms as isolated cauliflower-like structures and is called cumulus cloud. Some clouds form very high in the cold atmosphere and actually consist of tiny ice crystals rather than water droplets. These are called cirrus clouds.
Rain forms when clouds are thick enough and contain enough water for the droplets to come together and form raindrops. Heavy rain usually comes from towering cumulus clouds, while light rain comes from thick stratus clouds.
Temperature
Explains how thermometers measure temperature, and the difference between the three temperature scales – Celsius, Fahrenheit and Kelvin.
Wind
A brief explanation of wind.
Background: Winds are driven by the heat from the sun, which warms the air and causes it to rise. This occurs mainly in the tropics where the sun is nearly directly overhead in the middle of the day. Where the air rises, cool air must flow in to take its place, and this is felt as a wind on the Earth's surface.
Because of the rotation of the Earth, winds move in complicated patterns, In northern Australia the winds blow mostly from the east, while in southern Australia they blow mostly from the west. On top of this general circulation pattern we find other winds associated with tropical cyclones in northern Australia or with cold fronts in the south.
All winds blow in circles. The major circulation patterns of easterly winds (in the north) or westerly winds (in the south) blow right around the Earth, carrying weather patterns with them.
Pressure
Explains atmospheric pressure, how it is measured and that air moves from areas of high pressure to areas of low pressure.
Background: Patterns of pressure are important because they are closely related to wind and rain – the most noticeable features of weather. Regions of high pressure tend to be associated with fine weather and regions of low pressure with clouds and rain. Regions of very low pressure in the north of Australia may become tropical cyclones.
|
|
Bureau of Meteorology (Australia)
Australia – climate of our continent
Outlines Australia's climate zones, compares them with other parts of the world and gives maximum and minimum temperatures and rainfall for the major cities. Maps and charts make the information more accessible.
|
When you've mastered the basics, try these sites:
|
Bureau of Meteorology (Australia)
The weather map
Explains how weather maps are prepared. Includes typical summer and winter weather maps for Australia.
Background: Weather maps show pressure patterns in the atmosphere. They are derived from measurements made each day by hundreds of observers around Australia. The lines drawn on the maps connect places with equal pressure and are called isobars.
Interpreting weather satellite images
Presents several weather satellite images and explains what some characteristic patterns mean.
Background: Weather satellites now let us look down on the Earth and photograph the patterns of clouds. These satellites are in orbit about 20,000 kilometres above the Earth's surface at the equator, at which height they take exactly 24 hours to make one orbit and so remain above the same point on the Earth's surface. The view from such a satellite covers almost half the entire Earth. A Japanese meteorological satellite positioned above the equator just north of Australia provides cloud pictures for the Australian region.
|
|
The causes of climatic change (Climatic Research Unit, University of East Anglia, UK)
An information sheet covering a number of factors that can contribute to climate variability. Includes graphs showing how the Pinatubo eruption and El Niño have affected mean monthly temperatures.
|
|
Stormsurf (USA)
Check out this site to see how weather information can be used. It presents storm and weather data for surfers, and you can even create your own surf forecast. Images accompany the text.
Weather basics
Explains that storms form as the result of an extreme difference in air pressure, driven by the movement of cold and warm air.
Satellite imagery
Explains the different kinds of images produced by satellite instruments – visible images, infrared images and water vapour images.
Atmospheric models
Explains how surf forecasters use models to predict storm formation.
|
|
![[Go to Home page]](https://webarchive.library.unt.edu/eot2008/20090115212753im_/http://www.science.org.au/images/smallseg.gif){kind=small}
