Introduction
We observe light all around us in the form of sunlight, from torches or fire, but what actually is light?
Light is not actually matter – it has no mass – so in effect it can’t be seen. We can’t hold it or smell it. We can only learn about it by how it interacts with or affects things around it.
This resource covers the basic physics that describes light, a bit of the history and philosophy of light and its applications and implications for society. There are links to critical thinking exercises and experiments that cover the concepts of absorption, reflection, refraction and diffraction to help students (and curious adults) think critically about the phenomenon of light, to potentially challenge their perceptions, and reflect on their understanding of light. The resources and activities are aligned to the years 4-9 curriculum, but there are links and suggestions to extend students’ thinking. Some concepts and activities may be suitable for younger year levels.
The content and activities are scaffolded to enable teachers to assess student learning. There are the following two broad types of activities:
Critical thinking activities to analyze and reflect on how the nature and concept of light, its implications for society, and the value of research that is underpinned by this understanding of light is being used to develop the next generation of electronic and digital technologies.
Hands-on activities/experiments that help students understand light and to consider the value, acceptability and direction of the research and technologies that will help shape their future.
Learning outcomes
By the end of the unit, students will….
- Have a solid understanding of the nature of light
- Have knowledge about the nature of light as a wave and particle
- Be able to communicate ideas, explanations and processes about light using scientific representations
- Develop an awareness of the history and philosophy that led to our understanding of light and its application to modern digital technologies
- Be able to think critically about and the social implications of how we exploit light to develop modern digital technologies
- Have the ability to apply experience from each stage of the unit to predict or develop hypotheses in novel contexts
- Be able to use evidence to generate a discussion about what is happening.
Download the pdf of the full resource with links and graphics.
Download a Powerpoint presentation for use in presenting this unit to your class
The powerpoint is targeted for years 4-6 and presents selective information from the resource on reflection and refraction
Curriculum links
The resource content and activities are linked to the following Australian curriculum codes:
Year 5.
ACSSU080 (drawing simple labelled ray diagrams to show the paths of light from a source to our eyes / recognising that the colour of an object depends on the properties of the object and the colour of the light source / exploring the use of mirrors to demonstrate the reflection of light / recognising the refraction of light at the surfaces of different transparent materials, such as when light travels from air to water or air to glass
ACSHE081 (developing an understanding of the behaviour of light by making observations of its effects)
ACSHE083 (exploring objects and devices that include parts that involve the reflection, absorption or refraction of light such as mirrors, sunglasses and prisms)
Yr 9
ACSSU182 (discussing the wave and particle models and how they are useful for understanding aspects of phenomena; investigating factors that affect the transfer of energy through an electric circuit; exploring the properties of waves, and situations where energy is transferred in the form of waves, such as sound and light)
ACSSU180 (exploring the properties of waves, and situations where energy is transferred in the form of waves, such as sound and light)
ACSHE158 (considering how common properties of electromagnetic radiation relate to its uses, such as radar, medicine, mobile phone communications and microwave cooking)
ACSHE160 (considering the impact of technological advances developed in Australia, such as the cochlear implant and bionic eye; recognising aspects of science, engineering and technology within careers such as medicine, medical technology, telecommunications, biomechanical engineering, pharmacy and physiology)
ACSHE228 (considering how technologies have been developed to meet the increasing needs for mobile communication)
FLEET researchers use light to help develop atomically thin materials and electronic circuits for the next generation of energy-efficient electronics. The motivation for FLEET’s research, outlined in the next section, is an important discussion for students to consider and it provides context for some of the experiments and critical thinking activities.
Lighting the way to a solution
FLEET works in the quantum world, which is where some of our deepest understanding yet of universe may be. FLEET researchers want to understand how the atomically thin (2D) materials they are developing behave at the quantum level to manipulate and control their useful properties. The next task is to develop ways to fabricate these materials at a commercial scale. The use and manipulation of light is crucial to FLEET researchers to help test and understand the behaviour of 2D materials and to develop novel materials of use to low energy electronics.
FLEET research and the need for the next generation of electronics
Digital technologies (anything with a computer chip) consume about 10% of global electricity and this proportion is increasing each year as demand for computation increases and we desire smarter, more powerful computing systems to be integrated into our daily lives.
Moore’s Law (though it is not really a law) predicts that the number of transistors on a computer chip would double every 18-24 months, and it was right…until now. For many years, the energy demands of an exponentially growing number of computations was kept in check by ever-more efficient, and ever-more compact silicon-based microchips. But, we can’t make the transistors much smaller without breaking some laws of physics. To learn more about the bigger picture of digitilization and energy read Nicola Jones’ article, How to stop data centres goggling up the world’s electricity.
FLEET’s aim is to develop the next generation of low-energy electronics that will enable energy-efficient computing. Find out more about FLEET’s research and the motivation for that research here.
Broader implications of light
Our understanding of light has led to the development of microscopes, microwave ovens, telescopes, X-rays, lasers, our optical fibre network that delivers all our data worldwide, sending and receiving signals worldwide via satellites (ie radio or microwaves), even development of an artificial eye. In fact, light can help describe most of the physical universe around us. As one of the most extensive carriers of information, we can study and learn about some of the smallest things such as atoms and bacteria, to the most distant and largest such as stars and galaxies. Understanding light has led us into the quantum world where some of the deepest-held secrets of the universe are being revealed. Now it is time to get our heads around what light actually is.
The rest of this resource is divided into two sections: ‘Understanding light’ and ‘Reflection, absorption, refraction, diffraction’. See links to each section below. In each section are the associated critical thinking and hands-on activities, or they are listed below. You can download the whole resource to use in your classroom – see below.
List of Activities
Understanding light
Reflection, absorption, refraction, diffraction
Activity 4. Reflection of Pepper’s Ghost
Activity 6. How to find a rainbow
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