Unit C: Light and Optical Systems
(Nature of Science emphasis)
Overview: Our understanding of the world is based largely on what we see-both direcfly, and aided by optical
devices that improve and extend our vision. Tools such as the microscope and telescope have helped extend knowledge
in a variety of science fields, from the study of cells to stars, to studies of the nature of light itself. In
learning about light, students investigate its interactions with different materials and interpret its behavior
using a geometric ray model. As students extend their investigations, the wave model of light is introduced and
then used in interpreting colour and other electromagnetic phenomena. This knowledge is further applied in interpreting
a variety of light-based technologies and envisaging new technologies we may use in the future.
Focusing Questions: What do we know about the nature of light?
What technologies have been developed that use light, and what principles of light do they show?
Key Concepts
microscopes and telescopes
contribution of technologies to scientific development
reflection and refraction
transmission and absorption of light
sources of light
colour and wavelength
electromagnetic spectrum
images
vision and lenses
imaging technologies
STS and Knowledge Outcomes
Students will:Investigate the nature of light and vision, and
describe the role of invention, explanation and inquiry in developing our current knowledge
identify challenges in explaining the nature
of light and vision (e.g., recognize that past explanations for vision involved conflicting ideas about the interaction
of eyes and objects viewed; identijy challenges in explaining upside-down images, rainbows and mirages)
investigate the development of microscopes,
telescopes and other optical devices, and describe how these developments contributed to the study of light and
other areas of science
investigate light beams and optical devices,
and identify phenomena that provide evidence of the nature of light (e.g., evidence provided by viewing the passage
of light through dusty air or cloudy water)
Students will:Investigate the transmission of
light and describe its behaviour using a geometric ray model
investigate how light is reflected, transmitted
and absorbed by different materials, and describe differences in their properties (e.g., compare light absorption
of different materials; identify materials that transmit light; distinguish clear and translucent materials; identify
materials that will reflect a beam of light as a coherent beam)
measure and predict angles of reflection
investigate, measure and describe the refraction
of light through different materials (e.g., measure differences in light refraction through pure water, salt water,
and different oils)
investigate materials used in optical technologies
and predict the effects of changes in their design, alignment or composition
Students will:Interpret the nature of visible
light-as part of an electromagnetic spectrum-u sing the wave model of light
describe the characteristics of solar energy
as it comes to Earth in its various wavelengths and explain the significance of these different forms to humans
and the environment (e.g., infrared, ultraviolet, X-rays, microwaves, radio waves)
describe and compare how incandescent, fluorescent,
phosphorescent and biolummescent sources produce light
investigate and describe the effects of infrared
and ultraviolet light on materials, and identify related health concerns and technological applications (e.g.,
skin damage through sunburn; using fluorescent light as a tool in mineral identification)
No Longer Required
describe and explain the uses of red, green and blue as primary additive colours
(e.g., in coloured stage lights, in television)
Students will:Investigate and explain the science
of image formation and vision; and interpret related technologies
demonstrate the formation of real images using
a double convex lens, and predict effects of changes in lens position on the size and location of images (e.g.,
demonstrate a method to produce a magnified or reduced image by altering the placement one or more lenses)
demonstrate and explain the use of microscopes,
and describe in general terms the function of eyeglasses, binoculars and telescopes
explain how objects are seen by the eye, and
compare eyes and cameras (e.g., compare focusing mechanisms; compare the automatic junctions of the eye to junctions
in an automatic camera)
compare the function and design of the mammalian
eye to that of other vertebrates and
invertebrates (e.g., amphibians, fish, squid, shellfish, and insects such as the housefly)
investigate and describe the development of
new technologies to enhance human vision (e.g., laser surgery on eyes; development of technologies to extend night
vision)
investigate and interpret emerging technologies
for storing and transmitting images in digital form (e.g., digital cameras, infrared imaging, remote imaging technologies)
