Challenge 1: Students devise a way to direct a light beam around an opaque obsticle.
Challenge 2: Students compare thier mirror based solution to a optic fiber based solution.
Challenge 3: Students experiment with a model of an optic fiber and determine the critical angle
Science TEKS Process Skills

6.2 7.2 8.2 IPC Physics Astronomy  The student use scientific methods during field and laboratory investigations.
(A) plan and implement investigative procedures including asking questions, formulating testable hypotheses, and selecting and using equipment and technology;
• Challenge 1: Students plan a mirror arrangement that will direct the beam around the obsticle and test their arrangement. They are also challenged to minimze the number of mirrors needed to direct the light from beginning to end.

8.5  The student knows that relationships exist between science and technology.
(A) identify a design problem and propose a solution;
•Challenge 1: Although the mirror arrangement directs light to a target, the beam suffers degredation and some light scatters out of the beam. Students grapple with possible solutions to these problems:
• reduce the number of reflecting elements? • clean the glass? • smoother surfaces to reduce scatter?
(B) design and test a model to solve the problem;
• Challenge 1 and 2: Students may test several alternative mirror arrangements in order to minimize the number of mirror elements and reduce scattering and beam degredation. They also compare their mirror based solution with an optic fiber based solution.
(C) evaluate the model and make recommendations for improving the model.
• Challenge 1 and 2: Through testing, students evaluate their mirror arrangements and try new arrangements.

Science TEKS Concepts
6.5 Systems may combine with other systems to form a larger system.
(B) describe how the properties of a system are different from the properties of its parts.
• Challenge 3: An optic fiber is a system of parts: core, cladding, jacket, plastic, etc. Each piece has different light transmission and refractive properties. Together, and arranged in the correct way they make a flexible fiber that efficiently guides light.

Physics
(8) Characteristics and behavior of waves (A) examine and describe a variety of waves propagated in various types of media and describe wave characteristics such as velocity, frequency, amplitude, and behaviors such as reflection, refraction, and interference;
• Challenge 3: Students experiment with an optic fiber model to discover characteristics of the fiber, like the index of refraction of the cladding and core, and the central role of refraction in relationship to the critical angle of the fiber.
(C) interpret the role of wave characteristics and behaviors found in medicinal and industrial applications.
• Challenge 2: Students investigate an optic fiber and its role in the HobbyEberly Telescope. They compare and evaluate their mirror based and optic fiber based solutions for guiding light from one place to another. • Challenge 3: Students experiment with an optic fiber model to discover characteristics of the fiber, like the index of refraction of the cladding and core, and the central role of refraction in relationship to the critical angle of the fiber.

IPC
(5) Effects of waves on everyday life
(B) demonstrate wave interactions including interference, polarization, reflection, refraction, and resonance within various materials
• Challenge 2: Students investigate an optic fiber and its role in the HobbyEberly Telescope. They compare and evaluate their mirror based and optic fiber based solutions for guiding light from one place to another. In the mirror based solution, students reflect a laser beam among mirrors to direct the beam around a barrier to a target. For the optic fiber solution, students direct the light into the fiber, which guides the light to the target. • Challenge 3: Students experiment with an optic fiber model to discover characteristics of the fiber, like the index of refraction of the cladding and core, and the central role of refraction in relationship to the critical angle of the fiber. The model is a plastic jar half full of water. At the water surface (airwater boundary) the laser beam is refrated if it meets the boundary at an angle less than the critical angle. The materials in the fiber and the model determine the critical angle.

Math TEKS
6.8 Measurement: The student solves application problems involving estimation and measurement of length, area, time, temperature, capacity, weight, and angles.
• Challenge 1 and 2: Students measure mirror angles and the distance between mirrors in order to draw a diagram of their mirror based solution. Students measure the size of the beam on the target. • Challenge 3: Students measure the angle of the laser beam inside the model optic fiber in order to determine the critical angle.

6.11, 7.13, 8.14 Underlying processes and mathematical tools: The student applies Grade 6, 7, or 8 mathematics to solve problems connected to everyday experiences, investigations in other disciplines, and activities in and outside of school.
(A) identify and apply mathematics to everyday experiences, to activities in and outside of school, with other disciplines, and with other mathematical topics; (B) use a problemsolving model that incorporates understanding the problem, making a plan, carrying out the plan, and evaluating the solution for reasonableness;
• In each challenge, students solve problems whose solutions involve the application of mathamatics.
• Challenge 1 and 2: Students measure angles and distances of mirrors, and measure the size of the beam on the target. • Challenge 3: Students experimentally determine the critical angle and measure it.
