MiddleSchoolPortal/Light, Optics, and Lenses

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Light, Optics and Lenses - Introduction

Remember how much you enjoyed those wacky mirrors in the fun house at the amusement park? Or the colorful geometric images in a kaleidoscope? And don’t forget the awesome images of stars, nebulae, and distant galaxies from the Hubble space telescope! Middle school students appreciate the fun these examples of the effects of light, lenses and optics represent. You can inexpensively and feasibly give students direct experience with each of these examples.

Fun house mirrors are easily made with some shiny sheet metal, or they can be purchased. Inexpensive kaleidoscopes can be purchased online or at a toy store, and Hubble images are available online. Using these perspectives to approach a study of light, reflection, refraction, and absorption will hook your students. Students can be "allowed" (read "required") to build their own fun mirrors and kaleidoscopes, as long as they are prepared to fully explain the science behind them, a la summative assessment.

Hooked on the study of light and optics, curious students may ask: Why is the sky blue? Why are rainbows relatively rare? What's the difference between regular lenses, bifocals, and trifocals? Why do telescopes make very large, distant objects appear closer (as opposed to larger) while microscopes make very small objects appear larger? What's with those round security mirrors in stores? Why is my reflection upside-down on the back of a spoon?

Physical Science Content Standard B of the National Science Education Standards encompasses transfer of energy and specifically states, "Light interacts with matter by transmission (including refraction), absorption, or scattering (including reflection). To see an object, light from that object — emitted by or scattered from it — must enter the eye." Our objective in this publication is to provide background content, resources, lessons, and activities to help you and your students meet and exceed this standard.

We begin with early investigations into the nature of light that culminated in the current understanding of the nature of light, both visible and invisible as the same physical laws apply to the entire electromagnetic spectrum. From there students are ready to explore the interaction of light with various surfaces, producing a variety of perceptible effects. Finally, students will be able to apply their knowledge through construction, critique, and assessment of their own optical devices or interpretation of optically derived data.

Other methods of student investigation could include research into, and reporting on, optical devices that extend our sense of sight, such as infrared cameras, telescopes that create images with radio waves, and night-vision goggles. If you are located near a Reserve Officers Training Corps (ROTC) facility or an armed forces base, you may be able to line up a guest speaker who can demonstrate some of these devices.

Other devices for investigation include scanning electron microscopes, cell phones, and microwave ovens. Although these devices represent a wide variety of applications, they rely on the same fundamental theories in physics that explain the behavior of "light," which we now recognize as extending beyond the visible light spectrum.

The resources in Background Information for Teachers include articles, photographs, illustrations, and simulations, some of which are interactive, that will fortify your content knowledge and support you through the instructional unit. The lessons on the nature of light and optical devices include hands-on, minds-on, and virtual activities. The National Science Education Standards section highlights the various standards that are addressed in these lessons and activities, including the history and nature of science, science and technology, science as inquiry, and of course physical science.

Background Information for Teachers

You may be wondering how to approach such an abstract concept as light with middle school students who tend to be concrete learners. The NSDL Strand Map Service provides guidance. These maps illustrate connections between concepts and across grade levels. An image of the middle grades (6-8) only part of the Waves map appears below. Clicking on a concept within the maps will show NSDL resources relevant to the concept, as well as information about related AAAS Project 2061 Benchmarks and National Science Education Standards. Move the pink box in the lower right hand corner of the page to see the grades 6-8 learning goals. Since telescopes are important optical tools used in science, we also recommend checking out the Galaxies and the Universe Map covering light and telescopes.

You may be aware that light exhibits both wave properties and discrete particle properties. The resources in this section explore and explain what is meant by these properties. It then is easier to understand why, in the context of most familiar optical devices, we can conceptualize light as rays.

Science, Optics, and You Magnet Lab scientists developed this curriculum package for teachers, students, and parents. The activities are designed to promote asking and answering questions related to light, color, and optics. The program begins with basic information about lenses, shadows, prisms, and color, leading up to the sophisticated instruments scientists use. The contents page links to optics history, teacher resources, background information, and interactive tutorials.

The Michelson-Morley Experiment This lecture describes in comprehensible detail the historic experiment that showed that light has wave properties and that no aether exists. Up to that point, aether was thought to be the medium of waves. The lecture is also available in French and Spanish. A Flashlet simulation of the experiment is included.

Light: Particle or Wave? This is a detailed explanation of the dual nature of light, complete with clear, labeled line drawings and interactive tutorials.

Science 101: How Do Microscopes Work? This NSTA journal article explains how microscopes work and how they enhance the scientific process. Available online to NSTA members at no cost; nonmembers must pay $4.99.

The Science of Light: Fun House Mirrors This page briefly describes and illustrates the laws of reflection. It includes a short section on pedagogy, relates the content to standards, and links to some Exploratorium activities.

Teacher's Guide to the Infrared This is a page from a larger web site called Seeing Our World in a Different Light and sponsored in part by NASA. It contains side-by-side standard and infrared photos to illustrate how infrared photos show heat. It describes and compares visible light and infrared light. An explanation, accompanied by photos, of how infrared cameras work is also provided.

Seeing Our World in a Different Light The aim of the Cool Cosmos portal, part of NASA’s outreach program, is to explain infrared astronomy to students and the public at large. At this web site, you’ll find classroom activities where students perform a version of the experiment in which astronomer Sir Frederick William Herschel discovered infrared light or the experiment in which Johann Wilhelm Ritter first discovered ultraviolet light. Tutorials about multiwavelength astronomy include an image gallery that shows celestial objects observed in different wavelengths and also explains the benefits of each wavelength. Be sure to peruse the Paper Products page, where you can download images.

Lessons on the Nature of Light

Light is simultaneously concrete and abstract to middle school students. It is concrete because students have direct experience with it daily. It is abstract because it is intangible. The lessons and activities in this section are designed to facilitate bridging the familiar to the abstract so that students are able to construct accurate conceptions of the nature of light.

Light, Prisms and the Rainbow Connection Students working in pairs or in small groups will predict how to make a rainbow using the materials they are given, then produce a rainbow and record the colors they see. They will also draw diagrams that show how a prism separates the colors of light. Alternative methods to demonstrate the separation of white light into the color spectrum are suggested. A link is provided to an interactive tutorial where students can explore how light refracts. A second tutorial illustrates Newton's prism experiments, showing the separation of sunlight, its component spectrum, and the recombination of the spectrum by a second inverted prism.

Angles of Reflection An interactive simulation shows what happens to light when it hits a mirror. The simulation allows the user to change the angle of the incoming, or incident, light wave and to see the corresponding reflected angle. Click on Mirror, Mirror on the Wall for an activity.

Seeing Our World Through a Different Light The aim of the Cool Cosmos portal, part of NASA’s outreach program, is to explain infrared astronomy to students and the public at large. At this web site, you’ll find activities where students perform a version of the experiment in which astronomer Sir Frederick William Herschel discovered infrared light or a version of the experiment in which Johann Wilhelm Ritter first discovered ultraviolet light. Tutorials about multi-wavelength astronomy include an image gallery that shows celestial objects observed in different wavelengths and also explains the benefits of each wavelength. Be sure to peruse the Paper Products page, where you can download images.

The Electromagnetic Spectrum: Waves of Energy According to the objectives given for this lesson, students will understand (1) that the sun’s energy is transferred to Earth by electromagnetic waves, which are transverse waves, (2) that there are eight main types of electromagnetic waves, classified on the electromagnetic spectrum according to their wavelengths, and (3) how each of the types of electromagnetic radiation is used or found in our everyday lives. This lesson would be a suitable activity for small groups.

Lessons on Optical Devices

Once students have some concept of the nature of light, they can explore optical devices and begin to conceptualize how the devices work. The resources here include optical devices students will likely encounter again in later grades; thus, an introduction to these devices in middle school is appropriate.

Liquid Mirror Lunar Telescope Scientists may have figured out a way to make a new telescope that can out-observe the most powerful space telescopes by a factor of a thousand. The secret to the design? A liquid mirror.

Sight and Light In this two-day lesson plan, students will learn about the eyeball, pupil, retina, and optic nerve and make a model of an eyeball. Included are the objectives, needed materials, procedures, adaptations, discussion questions, a rubric for evaluation, suggested reading, links to other sites, vocabulary, and academic standards. Students can click on a vocabulary word to hear its pronunciation and a sentence using the word. Teachers can create worksheets, puzzles, and quizzes. A printable version can be downloaded. Teachers can purchase the video Seeing the Light and download comprehension questions and answers.

Telescopes: Our Eyes on the Universe This illustrated article touches on the history of telescopes, profiles three types of optical telescopes, and offers a few pointers for amateur astronomers. In the history category, the article mentions the telescopes developed by Hans Lippershey and Galileo Galilei in the early 1600s. The discussions of the Hubble Space Telescope and the Next Generation Space Telescope, which is slated to follow Hubble, focus on the portion of the electromagnetic spectrum that each telescope can detect and the usefulness of observing in those regions of the spectrum. Part of the article's first page is devoted to a summary of how optical telescopes as a group work. The second page provides descriptions and simple ray diagrams of refracting telescopes, reflecting telescopes, and catadiatropic telescopes.

Exploring Microscopes In this activity, students will explore how microscopes work. Students will use three different types of microscopes to view the same image and explain their observations. An interactive Java-based simulation is included

How Does It Work? Binoculars, Periscopes, and Kaleidoscopes This resource explains how binoculars, periscopes and kaleidoscopes work. The learner will discover these instruments share similarities. In order to allow for student discovery, making the instruments first, followed by investigation into and discussion of how they work, is suggested. Thus, it may be necessary to modify handouts to exclude explanations of how the item works to begin. Instructions are included for making a periscope and a kaleidoscope.

SMARTR: Virtual Learning Experiences for Students

Visit our student site SMARTR to find related science-focused virtual learning experiences for your students! The SMARTR learning experiences were designed both for and by middle school aged students. Students from around the country participated in every stage of SMARTR’s development and each of the learning experiences includes multimedia content including videos, simulations, games and virtual activities.

Careers

The FunWorks Visit the FunWorks STEM career website to learn more about careers in Photonics.

Latest Scientific News from the New York Times

National Science Education Standards

The resources, lessons, and activities in this publication align with portions of at least three domains of the grades 5-8 content standards of the National Science Education Standards as indicated below:

History and Nature of Science Content Standard G:

Science as a Human Endeavor

• Science requires different abilities, depending on such factors as the field of study and type of inquiry. Science is very much a human endeavor, and the work of science relies on basic human qualities, such as reasoning, insight, energy, skill, and creativity — as well as on scientific habits of mind, such as intellectual honesty, tolerance of ambiguity, skepticism, and openness to new ideas.

Nature of Science

• Scientists formulate and test their explanations of nature using observation, experiments, and theoretical and mathematical models. Although all scientific ideas are tentative and subject to change and improvement in principle, for most major ideas in science, there is much experimental and observational confirmation. Those ideas are not likely to change greatly in the future. Scientists do and have changed their ideas about nature when they encounter new experimental evidence that does not match their existing explanations.
• In areas where active research is being pursued and in which there is not a great deal of experimental or observational evidence and understanding, it is normal for scientists to differ with one another about the interpretation of the evidence or theory being considered. Different scientists might publish conflicting experimental results or might draw different conclusions from the same data. Ideally, scientists acknowledge such conflict and work towards finding evidence that will resolve their disagreement.
• It is part of scientific inquiry to evaluate the results of scientific investigations, experiments, observations, theoretical models, and the explanations proposed by other scientists. Evaluation includes reviewing the experimental procedures, examining the evidence, identifying faulty reasoning, pointing out statements that go beyond the evidence, and suggesting alternative explanations for the same observations. Although scientists may disagree about explanations of phenomena, about interpretations of data, or about the value of rival theories, they do agree that questioning, response to criticism, and open communication are integral to the process of science. As scientific knowledge evolves, major disagreements are eventually resolved through such interactions between scientists.

Science and Technology Content Standard E:

Understandings About Science and Technology

• Many different people in different cultures have made and continue to make contributions to science and technology.
• Science and technology are reciprocal. Science helps drive technology, as it addresses questions that demand more sophisticated instruments and provides principles for better instrumentation and technique. Technology is essential to science, because it provides instruments and techniques that enable observations of objects and phenomena that are otherwise unobservable due to factors such as quantity, distance, location, size, and speed. Technology also provides tools for investigations, inquiry, and analysis.
• Technological designs have constraints. Some constraints are unavoidable, for example, properties of materials, or effects of weather and friction; other constraints limit choices in the design, for example, environmental protection, human safety, and aesthetics.

Science as Inquiry Content Standard A:

• Different kinds of questions suggest different kinds of scientific investigations. Some investigations involve observing and describing objects, organisms, or events; some involve collecting specimens; some involve experiments; some involve seeking more information; some involve discovery of new objects and phenomena; and some involve making models.
• Technology used to gather data enhances accuracy and allows scientists to analyze and quantify results of investigations.
• Science advances through legitimate skepticism. Asking questions and querying other scientists' explanations is part of scientific inquiry. Scientists evaluate the explanations proposed by other scientists by examining evidence, comparing evidence, identifying faulty reasoning, pointing out statements that go beyond the evidence, and suggesting alternative explanations for the same observations.

Physical Science Content Standard B:

Transfer of Energy

• Energy is a property of many substances and is associated with heat, light, electricity, mechanical motion, sound, nuclei, and the nature of a chemical. Energy is transferred in many ways.
• Light interacts with matter by transmission (including refraction), absorption, or scattering (including reflection). To see an object, light from that object — emitted by or scattered from it — must enter the eye
• The sun is a major source of energy for changes on the earth's surface. The sun loses energy by emitting light. A tiny fraction of that light reaches the earth, transferring energy from the sun to the earth. The sun's energy arrives as light with a range of wavelengths, consisting of visible light, infrared, and ultraviolet radiation

Read the entire National Science Education Standards online for free or register to download the free PDF. The content standards are found in Chapter 6.

Author and Copyright

Mary LeFever is a resource specialist for the Middle School Portal 2: Math & Science Pathways project, a doctoral candidate in science education at Ohio State University, and presently teaches introductory biology at a Columbus, Ohio local high school. She has taught middle school and high school science and is an adjunct instructor of biology and natural sciences at Columbus State Community College.

Please email any comments to msp@msteacher.org.

Connect with colleagues at our social network for middle school math and science teachers at http://msteacher2.org.

Copyright October 2007 - The Ohio State University. Last updated September 19, 2010. This material is based upon work supported by the National Science Foundation under Grant No. 0424671 and since September 1, 2009 Grant No. 0840824. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.