• Visit
    • Calendar
    • After Dark Thursdays
    • Buy Tickets
    • Exhibits
    • Museum Galleries
    • Artworks on View
    • Hours
    • Getting Here
    • Visitor FAQ
    • Event Rentals
  • Education
    • Professional Development Programs
    • Free Educator Workshops
    • Tools for Teaching and Learning
    • Learning About Learning
    • Community Programs
    • Educator Newsletter
  • Explore
    • Browse by Subject
    • Activities
    • Video
    • Exhibits
    • Apps
    • Blogs
    • Websites
  • About Us
    • Our Story
    • Partnerships
    • Global Collaborations
    • Explore Our Reach
    • Arts at the Exploratorium
    • Contact Us
  • Join + Support
    • Donate Today!
    • Membership
    • Join Our Donor Community
    • Engage Your Business
    • Attend a Fundraiser
    • Explore Our Reach
    • Thank You to Our Supporters
    • Donor & Corporate Member FAQ
    • Host Your Event
    • Volunteer
  • Store
  • Visit
    • Frequently Asked Questions
    • Calendar
      • Today
      • This Week
      • Online
      • After Dark Thursday Nights
      • Arts
      • Conferences
      • Cinema Arts
      • Free + Community Events
      • Fundraising Events
      • Kids + Families
      • Members
      • Highlighted Artworks + Exhibits
      • Special Hours
      • Private Event Closures
    • Prices
    • Hours
    • Getting Here
    • Museum Map
    • Reduced Rates & Community Day
    • Accessibility
    • Tips for Visiting with Kids
    • How to Exploratorium
    • Exhibits
    • Tactile Dome
    • Artworks on View
    • Cinema Arts
    • Kanbar Forum
    • Black Box
    • Museum Galleries
      • Bernard and Barbro Osher Gallery 1: Human Phenomena
        • Tactile Dome
          • 1971 Press Release
        • Black Box
        • Curator Statement
      • Gallery 2: Tinkering
        • Curator Statement
      • Bechtel Gallery 3: Seeing & Reflections
        • Curator Statement
      • Gordon and Betty Moore Gallery 4: Living Systems
        • Curator Statement
      • Gallery 5: Outdoor Exhibits
        • Curator Statement
      • Fisher Bay Observatory Gallery 6: Observing Landscapes
        • Wired Pier Environmental Field Station
        • Curator Statement
    • Restaurant & Café
    • School Field Trips
      • Getting Here
        • Bus Routes for Field Trips and Other Groups
      • Admission and Tickets
      • Planning Guide
      • Reservations
        • Field Trip Request Form
      • Resources
    • Event Rentals
      • Full Facility & Gallery Bundles
      • Fisher Bay Observatory Gallery & Terrace
      • Moore East Gallery
      • Bechtel Central Gallery & Outdoor Gallery
      • Osher West Gallery
      • Kanbar Forum

      • Weddings
      • Proms and School Events
      • Daytime Meetings, Events, & Filmings

      • Rentals FAQ
      • Event Planning Resources
      • Rental Request Form
      • Download Brochure (pdf)
    • Exploratorium Store
    • Contact Us
  • Education
    • Black Teachers and Students Matter
    • Professional Development Programs
      • Free Educator Workshops
      • Professional Learning Partnerships
      • Teacher Institute
        • About the Teacher Institute
        • Summer Institute for Teachers
        • Teacher Induction Program
        • Leadership Program
        • Teacher Institute Research
        • CA NGSS STEM Conferences
          • NGSS STEM Conference 2020
        • Science Snacks
          • Browse by Subject
          • Special Collections
          • Science Snacks A-Z
          • NGSS Planning Tools
          • Frequently Asked Questions
        • Digital Teaching Boxes
        • Meet the Teacher Institute Staff
        • Resources for Supporting Science Teachers
      • Institute for Inquiry
        • What Is Inquiry?
        • Watch and Do Science
        • Inquiry-based Science and English Language Development
          • Educators Guide
            • Conceptual Overview
              • Science Talk
              • Science Writing
            • Classroom Video Gallery
              • Magnet Investigation
              • Snail Investigation
            • Teacher Professional Development
            • Project Studies
            • Acknowledgments
          • Conference: Exploring Science and English Language Development
            • Interviews with Participants
            • Plenary Sessions
            • Synthesis, Documentation, and Resources
        • Workshops
          • Participant Portal
          • Fundamentals of Inquiry
            • Summary Schedule
          • BaySci Science Champions Academy
          • Facilitators Guides
          • Commissioned Workshops
        • Resource Library
        • Meet the IFI Staff
      • Resources for California Educators
      • K-12 Science Leader Network
      • Resources for Supporting Science Teachers
      • Field Trip Explainer Program
      • Cambio
    • Tools for Teaching and Learning
      • Learning Toolbox
      • Science Snacks
      • Digital Teaching Boxes
      • Science Activities
      • Tinkering Projects
      • Recursos gratuitos para aprender ciencias
      • Videos
      • Exhibits
      • Publications
      • Apps
      • Educator Newsletter
      • Exploratorium Websites
    • Educator Newsletter
    • Advancing Ideas about Learning
      • Visitor Research and Evaluation
        • What we do
        • Reports & Publications
        • Projects
        • Who we are
      • Center for Informal Learning in Schools
    • Community Programs
      • High School Explainer Program
      • Xtech
      • Community Educational Engagement
      • California Tinkering Afterschool Network
        • About
        • Partners
        • Resources
        • News & Updates
        • Further Reading
  • Explore
    • Browse by Subject
      • Arts
      • Astronomy & Space Sciences
        • Planetary Science
        • Space Exploration
      • Biology
        • Anatomy & Physiology
        • Ecology
        • Evolution
        • Genetics
        • Molecular & Cellular Biology
        • Neuroscience
      • Chemistry
        • Combining Matter
        • Food & Cooking
        • Materials & Matter
        • States of Matter
      • Data
        • Data Collection & Analysis
        • Modeling & Simulations
        • Visualization
      • Earth Science
        • Atmosphere
        • Geology
        • Oceans & Water
      • Engineering & Technology
        • Design & Tinkering
        • Real-World Problems & Solutions
      • Environmental Science
        • Global Systems & Cycles
        • Human Impacts
      • History
      • Mathematics
      • Nature of Science
        • Measurement
        • Science as a Process
        • Size & Scale
        • Time
      • Perception
        • Light, Color & Seeing
        • Listening & Hearing
        • Optical Illusions
        • Scent, Smell & Taste
        • Tactile & Touch
      • Physics
        • Electricity & Magnetism
        • Energy
        • Heat & Temperature
        • Light
        • Mechanics
        • Quantum
        • Sound
        • Waves
      • Social Science
        • Culture
        • Language
        • Psychology
        • Sociology
    • Browse by Content Type
      • Activities
      • Blogs
        • Spectrum
          • Arts
          • Behind the Scenes
          • News
          • Education
          • Community & Collaborations
          • Science
        • Eclipse
        • Studio for Public Spaces
        • Tangents
        • Resonance See & Hear Blog
        • Fabricated Realities
        • Tinkering Studio: Sketchpad
        • Exploratorium on Tumblr
      • Exhibits
      • Video
      • Websites
      • Apps
        • Total Solar Eclipse
  • About Us
    • Our Story
    • Land Acknowledgment
    • Explore Our Reach
    • Impact Report
    • Fact Sheet
    • Awards
    • Our History
      • 50 Years 1969–2019

    • Senior Leadership
    • Board of Trustees
    • Board of Trustees Alumni
    • Staff Scientists
    • Staff Artists

    • Arts at the Exploratorium
      • Artworks on View
      • Artist-in-Residence Program
      • Cinema Arts
        • History and Collection
        • Cinema Artists-in-Residence
        • Resources and Collaborating Organizations
        • Kanbar Forum
      • Center for Art & Inquiry
        • Begin Here
          • Lessons
            • Bob Miller/Light Walk
            • Ruth Asawa/Milk Carton Sculpture
          • Workshops
      • Resonance
        • About the Series
        • See & Hear
        • Past Seasons
      • Over the Water
      • Black Box
      • Upcoming Events
      • Temporary Exhibitions
      • Arts Program Staff
    • Teacher Institute
    • Institute for Inquiry
    • Explainer Programs
    • Studio for Public Spaces
    • Exhibit Making
    • Partnerships
      • Building Global Connections
        • Global Collaborations
          • Projects
          • Approach
          • People
          • Impact
      • Partnering with Science Agencies
        • NASA
        • NOAA
      • Partnering with Educational Institutions
      • Osher Fellows

    • Job Opportunities
    • Become a Volunteer

    • Contact Info
    • Newsletter
    • Educator Newsletter
    • Blogs
    • Follow & Share
    • Press Office

    • FY20 Audit Report
    • 990 FY19 Tax Return
    • Use Policy
      • Privacy Policy
      • Intellectual Property Policy
  • Join + Support
    • Donate Today!
    • Membership
      • Membership FAQ
      • Member Benefits
      • After Dark Membership
      • Member Events
      • May Is for Members
    • Join Our Donor Community
    • Engage Your Business
      • Corporate Membership
      • Luminary Partnerships
    • Attend a Fundraiser
      • Wonder Funday
      • Science of Cocktails
      • Party at the Piers
        • Event Leadership and Host Committee
    • Explore Our Reach
    • Thank You to Our Supporters
    • Donor & Corporate Member FAQ
    • Volunteer
      • How to Apply
      • Application for Internships
      • Our Contract
      • Application for Individuals
  • Press Office
    • Press Releases
    • News Coverage
    • Events Calendar
    • Fact Sheet
    • Photographs
    • Press Video
    • Press Kits
    • Press Visits
    • Exploratorium Logos
    • Recent Awards
    • Praise for the Exploratorium
    • Join Our Press List
  • Store

Masks are required for all visitors 2+. Vaccines recommended. Plan your visit  

Visitor FAQ Buy Tickets Donate Today
Exploratorium
Exploratorium
  • Visit
    • Calendar
    • After Dark Thursdays
    • Buy Tickets
    • Exhibits
    • Museum Galleries
    • Artworks on View
    • Hours
    • Getting Here
    • Visitor FAQ
    • Event Rentals
  • Education
    • Professional Development Programs
    • Free Educator Workshops
    • Tools for Teaching and Learning
    • Learning About Learning
    • Community Programs
    • Educator Newsletter
  • Explore
    • Browse by Subject
    • Activities
    • Video
    • Exhibits
    • Apps
    • Blogs
    • Websites
  • About Us
    • Our Story
    • Partnerships
    • Global Collaborations
    • Explore Our Reach
    • Arts at the Exploratorium
    • Contact Us
  • Join + Support
    • Donate Today!
    • Membership
    • Join Our Donor Community
    • Engage Your Business
    • Attend a Fundraiser
    • Explore Our Reach
    • Thank You to Our Supporters
    • Donor & Corporate Member FAQ
    • Host Your Event
    • Volunteer
  • Store
Science Snacks
Science activity that demonstrates light polarization

Rotating Light

Polarized light passing through sugar water reveals beautiful colors.

White light is made up of all the colors in the rainbow. When polarized white light passes through a sugar solution, each color’s direction of polarization is changed by a different amount. The colors change as the depth of the solution changes or as the polarizing filter is rotated.


Grade Bands: 
6-8
9-12
Subject: 
Chemistry
Materials & Matter
Physics
Light
Keywords: 
polarized light
molecules
color
NGSS and EP&Cs: 
LS
LS1
LS4
PS
PS1
PS4
CCCs
Patterns
Cause and Effect
Scale, Proportion, and Quantity
Structure and Function

  • Facebook logo
  • Reddit logo
  • Twitter logo


Tools and Materials

  • Clear plastic or glass cylinder, such as a 100mL graduated cylinder
  • Karo syrup (other light-colored corn syrups may work)
  • Two pieces of polarizing material (the lenses from a pair of polarizing sunglasses work well)
  • Any bright light source that can be held below the cylinder (an illuminated sheet of white paper, overhead projector, or flashlight) (not shown)
  • Tape
  • Optional: red and blue filters, other liquids that can take the place of the Karo syrup

Assembly

  1. Fill the cylinder with several inches of Karo syrup.
  2. Use tape to hold one piece of polarizing material under the bottom of the cylinder and hold the other over the top.
  3. Place the light source below the bottom polarizer. (In the diagram below, the light source is the illuminated piece of white paper. Click to enlarge the image.) 

To Do and Notice

Look down through the polarizing filter into the cylinder at the light source. Slowly rotate the top filter and notice the color changes in the syrup.

As you continue looking through the top filter, pour more syrup into the cylinder. Notice that the color changes as the depth of the syrup changes. See if you can keep the color constant by rotating the filter as the syrup level gradually rises.

You can perform a quantitative experiment by adding a colored filter under the cylinder. Suppose you use a blue filter. In order to see the blue as you add syrup, you must slowly rotate the upper polarizing filter. Determine the depth of syrup required to rotate the polarization of blue light by one full turn. Then try the same experiment with a red filter. With red light, a greater depth of syrup is needed.

Try a variety of transparent liquids and solutions such as honey and sugar syrup. Some are better than others at changing the direction of polarization.


What’s Going On?

Light from most ordinary light sources wiggles up and down, left and right, and diagonally. Your polarizing filter lets through only the light that is vibrating in one particular direction. In this polarized light, the light waves all wiggle in the same direction.

To understand what this means, picture waves traveling along a rope. If the waves vibrate up and down, they are vertically polarized. Vertically polarized rope waves can pass through the slots between the vertical slats in a fence; waves vibrating in other directions are blocked by the slats. If you orient a polarizing filter properly, vertically polarized light waves can pass through the filter, while waves vibrating in other directions are blocked.

The light emerging from the light source at the bottom of the tube is unpolarized. That means it vibrates in all directions perpendicular to the light’s direction of motion. The polarizing filter under the sugar solution polarizes this light so it vibrates in one direction only.

When polarized light passes through the Karo syrup, the direction of its polarization is changed. Light vibrating from to side to side, for example, might end up vibrating at a 45-degree angle. The amount of rotation depends on the depth of the syrup: The angle of rotation is proportional to the depth. It also depends on the concentration of the syrup: The more concentrated the syrup, the greater the rotation. Finally, the angle of rotation depends on the wavelength or color of the light. Blue light, with its shorter wavelength, rotates more than longer-wavelength red light.

When the white light emerges from the sugar solution, each color in the light has its own direction of polarization. When viewed without a polarizing filter, this light still appears white because our unaided eyes cannot detect the direction of polarization of light. However, when you look through a second polarizing filter, you see only the light that is vibrating in a direction that can pass through the filter. Only certain wavelengths or colors of light have the appropriate polarization. The intensity of the other colors in the light, which have different directions of vibration, is diminished. If a certain color of light has its polarization perpendicular to the axis of the polarizing filter, it is blocked out completely. (Think about the fence again. The rope waves won’t get through if they are vibrating perpendicular to the slats.) As you rotate the filter, each orientation of the rotated filter produces a different dominant color, as does each different depth of sugar solution.


Going Further

Materials that change the orientation of polarized light are called optically active materials. Some optically active solutions rotate the direction of polarization clockwise, to the right; ­others rotate it counterclockwise, to the left.

All organically produced glucose rotates the direction of polarization of light clockwise. This sugar is called d-glucose. Another sugar, called l-glucose, rotates the direction of polarization counterclockwise. It can only be made by inorganic chemical synthesis. Both d-glucose and l-glucose have the same chemical formula: C6H12O6. However, the atoms in each of these isomers are arranged in a different pattern. The left-handed sugar (l-glucose) tastes just as sweet as the right-handed one (d-glucose), but your body can’t use it as an energy source. That’s how left-handed sugars can produce sweetness without calories.

All the proteins in your body and in all organisms on Earth are made from amino acids that rotate the direction of polarization of light counterclockwise. On the other hand, laboratory-­synthesized amino acids, and amino acids found on meteorites, are made up of equal numbers of amino acids that rotate light to the right and amino acids that rotate light to the left. No one knows why this is so.



Related Snacks

Science activity that demonstrates light polarization
Polarized Sunglasses

Polarizing sunglasses cut road glare better in some positions than in others.

Science activity that demonstrates colors of polarized light
Polarized-Light Mosaic

With polarized light, you can make a stained glass window without glass.

Science activity demonstrating light polarization and stress patterns
Bone Stress

Polarized light reveals stress patterns in clear plastic.



Creative Commons License



This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Attribution: Exploratorium Teacher Institute

  • Education
    • Teacher Institute
    • Tools for Teaching and Learning
      • Science Snacks
        • Browse by Subject
        • Special Collections
        • Science Snacks A-Z
        • NGSS Planning Tools
        • Frequently Asked Questions



Connect with us!



  •   Sign up for our educator newsletter

  •   Follow #ExploEDU

  •   Teacher Institute YouTube

  •   Teacher Institute Facebook

  •  teacherinstitute @exploratorium.edu

Exploratorium
Visit
Join
Give

Pier 15
(Embarcadero at Green Street)
San Francisco, CA 94111
415.528.4444

Contact Us

  • Plan Your Visit
  • Calendar
  • Buy Tickets
  • Getting Here
  • Store
  • Event Rentals
  • About Us
  • Become a Member
  • Donate
  • Jobs
  • Volunteer
  • Press Office
  • Land Acknowledgment

Get at-home activities and learning tools delivered straight to your inbox

The Exploratorium is a 501(c)(3) nonprofit organization. Our tax ID #: 94-1696494
© 2022 Exploratorium | Terms of Service | Privacy Policy | Your California Privacy Rights |