Reflect,+Absorb,+Shine!

toc

Title

 * Reflect, Absorb, Shine! **

Problem Scenario
I chose this experiment because I wanted to figure out what kinds of surfaces reflect and absorb the most light so I could take that into account for what colors and textures I should wear when I do physical activities outdoors. Also, it could help me decide how darker surfaces reflect and absorb light different than brighter surfaces. Someone may want to know the answer to this question if they want a place to be as warm or as cold as possible. They would choose a surface that reflects the most if they want a colder place, and a surface that absorbs the most if they want a warmer place.

Broad Question
How can sunlight reflection and absorption be affected?

Specific Question
How do different textures of surfaces affect the amount of sunlight reflected and absorbed?

Hypothesis
It was hypothesized that different textures of surfaces do affect the amount of sunlight reflected and absorbed. The pavement will absorb the most and reflect the least, the black rubber will reflect the most and absorb the least, and the black construction paper will lie in the middle of the two.

Independent Variable:
Different textures of surfaces.

Dependent Variable:
Amount of sunlight reflected and absorbed.

Variables That Need To Be Controlled:
Where the trials will be done. What time of day the trials will be done.

Vocabulary List That Needs Explanation
Reflect - to cast back (light, heat, sound etc.) from a surface. Absorb - to suck up or drink in (a liquid); soak up.

General Plan
I will conduct this experiment at school and will be borrowing a light meter from school. I will be using the light meter to measure how much light I can reflect and absorb off three different surfaces which are all 'black' colored: pavement, construction paper, and rubber. Some potential problems I may run in to are not finding time to conduct the experiment or not being able to obtain the items I need to conduct the experiment.

Potential Problems And Solutions
Can not find time and/or the materials required to conduct the experiment.

Safety Or Environmental Concerns
One concern would be damaging my test surfaces during the experiment. An environmental concern would be that I can disrupt nature during the pavement testing outdoors.

Number Of Comparison Categories:
I will be comparing three different categories: pavement, black rubber, and black construction paper.

Number of Comparison Samples:
I will be taking five samples of each surface.

Number Of Observation In Each Sample:
There will be one observation for each surface sample.

When data will be collected
March 7th, 2013.

Where will data be collected?:
The data will be collected at Kennett Middle School in and outside of Mr. Littlefield's room.

Resources and Budget Table

 * Item || Number needed || Where I will get this || Cost ||
 * Light meter || 1 || Mr. Biche's classroom || $0 ||
 * Pavement || 1 supply, 3 samples || Outside Kennett Middle School || $0 ||
 * Black rubber || 1 supply, 3 samples || Lowe's || $0 ||
 * Black construction paper || 1 supply, 3 samples || Home || $0 ||
 * Meter stick || 1 || Mr. Littlefield's classroom || $0 ||
 * Tape || 1 || Mr. Littlefield's classroom || $0 ||

Detailed Procedure
I will use a table in Mr. Littlefield's room for my data. I will use a meter stick and stand it up vertically in centimeters. I will tape the light sensor pointing toward the table to the meter stick at 50 centimeters. I will lay the black rubber below the light sensor and start collecting the data using the Labquest application. I will record data for 60 seconds, with 1 sample per second. I will do the same for black construction paper. For pavement I will go outside Mr. Littlefield's room and use the pavement there. I will find the average amount of lumens absorbed after the data is done collecting. To find the average amount reflected I will take the amount of lumens the light is giving off and subtract the amount it absorbed.

Photo List
Reflection and Absorption drawing. "Perception: Color & Luminosity -- Part II." //Perception: Color & Luminosity -- Part II //. N.p., n.d. Web. 21 Mar. 2013.

Data Table
(all are 'black' colored) || Average Amount Reflected (lumens) || Average Amount Absorbed (lumens) ||
 * Different Textures of Surfaces
 * Black construction paper || 16% || 84% ||
 * Pavement || 6% || 94% ||
 * Black Rubber || 14% || 86% ||

All Raw Data

 * Pavement Reflected || Pavement Absorbed || Paper Reflected || Paper Absorbed || Rubber Reflected || Rubber Absorbed ||
 * 201 || 6625 || 128 || 572 || 123 || 577 ||
 * 396 || 6430 || 121 || 579 || 97 || 603 ||
 * 439 || 6387 || 111 || 589 || 98 || 602 ||
 * 497 || 6329 || 94 || 606 || 87 || 613 ||
 * 431 || 6395 || 101 || 599 || 98 || 602 ||

Results
The results show that the majority of my hypothesis was correct. The pavement reflected the least and absorbed the most like expected, because rougher surfaces absorb more lumens than softer and smoother surfaces. Since I believed that the black rubber was the smoothest surface that it would reflect the most and absorb the least, but the construction paper did.

Conclusion
The conclusion was that different textures of surfaces **do** affect the amount of sunlight reflected and absorbed. Pavement, the roughest of the surfaces, absorbed the most and reflected the least amount of light which was predicted. Since the black rubber was the smoothest of the surfaces, it was hypothesized that it would reflect the most and absorb the least, but the construction paper reflected the most and absorbed the least.

Discussion
I was able to solve the experiment question but the surfaces did not affect the sunlight like I thought they would. The pavement reflected the least and absorbed the most like I predicted, but surprisingly the black paper reflected the most and absorbed the least. I think this happened because the black rubber wasn't flat throughout the whole surface. It had some bumps and was curved in some spots unlike the other surfaces. The reflection and absorption is changed if a surface does not have a 90 degree angle.

Benefit to Community and/or Science
If someone is trying to choose a place to do a physical activity they may want to do that activity on a surface that either reflects or absorbs the most light depending on how they want the temperature to feel.

Background Research
Large differences occur if light can penetrate the surface, the greater the penetration, the more absorption. The best surface for absorbing light is a rough, black surface. The best reflector is a very smooth, light-colored, metal surface. Another effect on absorption vs. reflection is the smoothness of a surface. A very rough surface has many more molecules per unit area to be hit by light. On a rough surface, a reflected photon is more likely to hit a second atom. More light gets absorbed. Light that doesn't get absorbed will be dispersed: reflected back randomly rather than in a narrow beam. The amount of light reflected depends on the smoothness of the surface. Smooth reflects better than rough. The amount absorbed depends on the color of the surface. Dark colors absorb better than light; flat black absorbs best of all. Also, the angle at which the light strikes the object has an effect on the amount absorbed and/or reflected. If the rays strike the surface straight down at a 90 degree angle, absorption is favored and reflection less favored. If the light strikes the surface at a low angle, reflection is favored over absorption. The amount of lumens the surface reflected, subtracted from the amount of lumens the sunlight contains will calculate the amount of lumens absorbed.

Abstract
How do different textures of surfaces affect the amount of sunlight reflected and absorbed? I tested three different types of surfaces on three different categories;pavement(rough),black rubber(smooth),and black construction paper(plain). I hypothesized that the pavement would reflect the least and absorb the most because I know that rougher surfaces don't reflect much light,so in theory they will absorb the most. I thought that black rubber would reflect the most and absorb the least because smoother surfaces reflect the most light. And finally, I thought that the black construction paper would not reflect as much as the rubber but would reflect more than the pavement and vice-verse for absorption. After the experiment I found that I was correct about the pavement but the black construction paper reflected the most and absorbed the least like I thought the rubber would. I used a table in Mr. Littlefield's room for all of my experiment excluding the pavement which I did outside Mr. Littlefield's classroom.