STAGE 3 SCIENCE - LIGHT Term 2 2016

STAGE 3 SCIENCE - LIGHT Term 2 2016

Strategy:

STEM: Science, Technology, Engineering & Mathematics
STEAM: Science, Technology, Engineering, Art & Mathematics

The Australian National STEM teaching strategy 2016 is a twenty year commitment to STEM education that was endorsed by Australian Education Ministers on 11 December 2015: National STEM School Education Strategy 2016

An introduction to how to teach using STEM & STEAM| for primary school teachers.

Curriculum Source

BOS: http://syllabus.bostes.nsw.edu.au/science/science-k10/content/974/
WPS: Teaching context proposed by WPS teachers: Catchy name???

Outcomes

ST3-12MW uses scientific knowledge about the transfer of light to solve problems that directly affect people’s lives

BOS Content

Light from a source forms shadows and can be absorbed, reflected and refracted. (ACSSU080)

Students:

classify materials as transparent, opaque or translucent, based on whether light passes through them, is absorbed, reflected or scattered p1
observe and describe how the absorption of light by materials and objects forms shadows, eg building shading p2
gather evidence to support their predictions about how light travels and is reflected p3
research, using secondary sources to gather information about science understandings, discoveries and/or inventions that depend on the reflection and refraction of light and how these are used to solve problems that directly affect people's lives, eg mirrors, magnifiers, spectacles and prisms (ACSHE083, ACSHE100) p4

Rubric:

Please also see: Assessment Rubric

NOTES:

The current BOS syllabus does NOT include 'colour' as a topic… but it DOES include 'absorption'.

Understanding anything about absorption without understanding something about colour is extremely difficult to do!

How To Teach Science:

Research around the world indicates that at the end of their schooling, large numbers of students still hold many ideas, or conceptions, which are not in accord with the way that scientists understand our world.

Here are some guidelines for teaching science at school.
Here is a good example of a scientific guide for students: What is heat

There are many possible ways to help investigate, understand and predict the behaviour of things in the natural world. Here are two of the popular ways:

The Philosophical Method:

In ancient times, men indulged in philosophical argument about the natural world: often, to seek reputation and glory for its own sake. This contrasts with modern scientific enquiry, which only concerns itself with propositions and predictions that stand up to real-world test: If a proposition does not stand up to real-world test, then it either does not fall within the realm of scientific investigation or it is wrong.

The Scientific Method:

Many non-scientists continue to hijack and leverage the success of the scientific method to serve self-satisfying, non-scientific, agendas. In the world of finance for example, some people claim that accounting is 'a science'. A physicist would most likely describe such people as bankers - a homonym often more broadly applied to those engaged in similar pseudo-scientific pursuits!

The scientific method is just one definitive way of ask and answering questions; by making observations and doing experiments in the natural world.

Some people argue that there is no such thing as The Scientific Method - make up your own mind:

The generally agreed steps of the scientific method are to:

Ask a question
Do some background research
Construct a hypothesis (a guess)
Test your hypothesis by performing an experiment
Record your observations in a table of results
Analyse the data and draw a conclusion
Communicate your results in a way that others can replicate/test.
Source: Steps of the scientific method

No matter what your method is, it is important for your experiment to be a fair test:

A fair test means that you should set up your experiment so that everything is fair.

You should only change one thing at a time, and note down the results.
If you change more than one thing at a time, you can not tell which thing (variable) it was that affected the results.

Teacher background information

Atoms and molecules contain electrons: It is often useful to think of these electrons as being attached to the atoms by springs. The electrons and their attached springs have a tendency to vibrate at specific frequencies. Similar to a tuning fork or even a musical instrument, the electrons of atoms have a natural frequency at which they tend to vibrate.

When a light wave with that same natural frequency impinges upon an atom, then the electrons of that atom will be set into vibrational motion. (This is merely another example of the resonance principle introduced in Unit 11 of The Physics Classroom Tutorial.) If a light wave of a given frequency strikes a material with electrons having the same vibrational frequencies, then those electrons will absorb the energy of the light wave and transform it into vibrational motion.

During its vibration, the electrons interact with neighbouring atoms in such a manner as to convert its vibrational energy into thermal energy. Subsequently, the light wave with that given frequency is absorbed by the object, never again to be released in the form of light. So the selective absorption of light by a particular material occurs because the selected frequency of the light wave matches the frequency at which electrons in the atoms of that material vibrate. Since different atoms and molecules have different natural frequencies of vibration, they will selectively absorb different frequencies of visible light.

Visible Light Reflection and Transmission: Reflection and transmission of light waves occur because the frequencies of the light waves do not match the natural frequencies of vibration of the objects. When light waves of these frequencies strike an object, the electrons in the atoms of the object begin vibrating. But instead of vibrating in resonance at a large amplitude, the electrons vibrate for brief periods of time with small amplitudes of vibration; then the energy is re-emitted as a light wave.

If the object is transparent then the vibrations of the electrons are passed on to neighbouring atoms through the bulk of the material and re-emitted on the opposite side of the object. Such frequencies of light waves are said to be transmitted.

If the object is opaque then the vibrations of the electrons are not passed from atom to atom through the bulk of the material. Rather the electrons of atoms on the material's surface vibrate for short periods of time and then re-emit the energy as a reflected light wave. Such frequencies of light are said to be reflected.

Don't worry if it still seems a bit complicated or confusing - Light, is difficult to understand:

Can you explain what light is? All the 50 years of conscious brooding have brought me no closer to the answer - Of course today every rascal thinks he knows the answer, but he is deluding himself. (From, Catching the Light, p. ix) Source - Albert Einstein

Student Pre-conceptions - Research Findings:

When teachers use conventional textbook-based methods of instruction, only a few students were successful in changing these misconceptions. Most students, however, successfully mastered the scientific conceptions when teachers used materials specifically designed to help students overcome their misconceptions. (Author /ML)

We distinguished two different types of propositions.

Naive propositions are beliefs that are inconsistent with commonly held scientific beliefs.
Scientific propositions are consistent with scientific theory and are derived from the content of the textbook.

For example, most students view colour as a property of objects, not of light reflected by those objects.

The naive proposition, People's eyes see objects in the light can be contrasted with the scientific proposition, People's eyes detect light that bounces off of objects.

Are you interested in science but tired of the 'same-old, same-old? Then why not try something more challenging:

Challenges for scientific bankers