1. Science and Data Acquisition with Vernier Probeware
Reflectivity of Light – Level 1

2. What You’ll Learn… Stuff You’ll Need…
How color affects the reflectivity of light
How to use Vernier light sensors
How to use the Vernier LabQuest interface
How to use Vernier Logger Pro software to record and analyze scientific data
Stuff You’ll Need…
Vernier light sensor probe
Vernier LabQuest interface
Computer with Logger Pro software
Soda can bottom and different colored paper
Vernier, LabQuest and Logger Pro are all registered trademarks of Vernier Software and Technology

3. Research/Documentation…
Before you start the activities in this Learning Launcher, write down what you already know about light and how it reflects off of different colors.
Record all of your experimental data.
Formulate and explain a hypothesis before you begin to record data. What do you think your experimental data will reveal? Remember – it doesn’t matter whether your hypothesis is right or wrong, only that you have a hypothesis to test.

4. What You Should Know… Light:
The light we see is made of extremely tiny particles called photons. A source of light such as the Sun gives off vast amounts of photons each second. When some of these photons hit our eyes, we see them as light.
If a lot of photons hit our eyes, we see them as a bright light. If fewer photons hit our eyes, we see dim light or darkness.
Light sensors, like the one you’ll be using in this activity work much the same way and can record the amount of light with precision. 4

5. What You Should Know… Light:
When we measure the intensity of light, we are really measuring the number of photons hitting a certain area.
There are too many photons to measure individually, so we compare the total amount of light to some standard measurement.
A foot-candle is a common measurement that approximates the intensity of light on an object emitted from a candle placed one foot away.
One Foot Candle
Your Vernier light probe will measure light intensity in units called “lux”. You can think of one lux as approximately equivalent to one meter-candle – or a little less than 1/10th of a foot-candle. 5

6. What You Should Know… What Makes Color?
Light particles travel in waves – similar to waves in the ocean. The distance between each wave is called its wavelength. Different colors of light have different wavelengths. Each wavelength is perceived by our eyes as a different color. Only a narrow band of wavelengths can be seen with the human eye. We call this the visible spectrum.
Portion of the spectrum visible to humans
Light that contains all wavelengths in the visible spectrum is colorless. You’ve probably seen how a prism divides light into its component parts: red, orange, yellow, green, blue, indigo and violet. You can remember these colors with the name Roy G. Biv! 6

7. What You Should Know…
When light waves hit an object they can be reflected, absorbed, or transmitted (allowed to pass-through).
For the most part, opaque objects (things you can’t see through) will either reflect or absorb light. Substances can absorb certain wavelengths and reflect others. When something reflects all the wavelengths in the visible spectrum, it’s seen as white. When something absorbs all the colors of the visible spectrum, it’s seen as black. When something reflects certain wavelengths and absorbs others, it is perceived as having color.
So it’s the wavelength of reflected light that gives an object its color!

8. What You Should Know… The Scientific Method
You’ve probably studied the scientific method before in other classes. But, before we start to use our Vernier probeware to collect data, let’s review it one more time:
1.  State the question you intend to answer through your research and experimentation.
2.  Form a hypothesis – a prediction of what you think you’ll find.
3.  Test your hypothesis by doing an experiment or study.
4.  Analyze your results.
5.  Draw a conclusion and report your findings.
Be sure to capture all of these steps in your eFolder to be turned in.

9. What You Should Know…
The activities in this Learning Launcher use the Vernier light sensor, the LabQuest interface and Logger Pro software on your computer.
Light Sensor
LabQuest Interface

10. What You Should Know…
Now let’s explore the Logger Pro software. It’s what you’ll use to record and analyze your experimental data.
Launch Logger Pro software. Then under the File menu, click Open and select the Tutorials folder. Click on Tutorial 1 – Getting Started and follow along with the tutorial.
To learn about using Logger Pro for the kind of data you’ll be collecting in this Learning Launcher, follow along with Tutorial 3 – Events with Entry. [Note that this tutorial uses the temperature probe. That’s okay, the process of collecting data with the light sensor will be similar.]

11. Do It! Reflectivity of Light
In this Learning Launcher, you will conduct an experiment using the Vernier light sensor to measure how color changes the amount of reflected light.
The print of the color charts on the following pages are in the Vernier Lab Tools box that you check out from Mr. Ochs.

12. Vernier Science – Reflectivity Experiments

13. Vernier Science – Reflectivity Experiments

14. Vernier Science – Reflectivity Experiments

15. What You Should Know…
Now let’s explore the Logger Pro software. It’s what you’ll use to record and analyze your experimental data. Look in the “All Applications” folder for Logger Pro.
Launch Logger Pro software.
Then under the File menu,
click Open and select the
Middle School with Vernier folder.
Click on “07 Reflect-Light Sensor.”

16. Reflectivity of Light Procedure
Create a table in your Word Document
Make sure the light sensor is set to the Lux position
Launch the Logger Pro software
Open the file in Experiment 7 from the Middle School with Vernier folder
When the reading stabilizes, record the color and the reflected light value (in lux)
Make and record readings for aluminum, black, white, yellow and blue
Color
Aluminum
Black
White
Yellow
Blue
Reflection Value in lux
Percent reflectivity in %
100%

17. Answer the following questions
Calculate the percent reflectivity of each color using the following formula.
Be sure to record your data in your table!
Value of paper value for aluminum
Which colors has the highest reflectivity? Why?
Which colors has the lowest reflectivity? Why?
Define “lux.”
What surfaces might give a a planet a high reflectivity? Explain.
Does the planet Earth have high reflectivity? Why or why not?
X 100% = % Reflectivity

18. If you finish, keep it going!
If you have extra time complete the following
How do you think the amount of reflected light affects temperature? Design an experiment using the Vernier temperature probe to find out.
Experiment with the reflectivity of various materials like glass, soil, water, etc.
Consider how the colors of clothing absorb or reflect light. Now go online to learn about traditional clothing in different parts of the world (especially those with extreme climates). Do the traditional clothing choices reflect this factor?