Section H — Coach Light — Why Light Matters
This section covers Chapter 1, Lessons 1.1 through 1.4.
Part A — Vocabulary (20 points, 2 points each)
Select the best answer for each question.
1. Light is:
A) A solid material B) A kind of energy that travels through space as waves C) A type of sound D) A liquid
2. A wavelength is:
A) The distance from one wave peak to the next — for light, this decides color B) How tall a wave is C) How long water has been in a glass D) The same as height
3. Visible light is:
A) Light that you can see — wavelengths from about 380 to 700 nanometers B) Any light that exists C) Light that is dangerous D) Sound that you can see
4. Ultraviolet (UV) light is:
A) The same as visible light B) Light with wavelengths shorter than violet — your eyes cannot see it, but it affects skin (vitamin D, sunburn) C) Light that comes only from light bulbs D) The same as infrared
5. Infrared (IR) light is:
A) Visible red light B) Light with wavelengths longer than red — your eyes cannot see it, but you can feel it as warmth C) The same as ultraviolet D) A type of radio wave we cannot detect
6. A rod is:
A) A type of fishing tool B) A light-detecting cell in the retina that works well in dim light C) A type of bone D) A cell only found in plants
7. A cone is:
A) An ice cream holder B) A light-detecting cell in the retina that works in bright light and lets you see color C) A cell in the brain D) A part of the lens
8. An ipRGC is:
A) A bone in the eye B) A third class of retinal cell that does not contribute to vision but detects light to set your body clock C) The same as a rod D) A vitamin
9. Lux is:
A) A type of car B) A unit that measures how bright the light is at a surface C) A vitamin D) The same as a calorie
10. The SCN (suprachiasmatic nucleus) is:
A) A part of the eye B) A small cluster of brain cells that acts as the body's master clock C) A muscle in the chest D) A bone in the skull
Part B — Concept Comprehension (20 points, 2 points each)
Select the best answer for each question.
11. A water molecule, an electron, and a wavelength of red light all have one thing in common, which is:
A) They all taste sweet B) They are all extremely small physical things, much smaller than anything your eyes can directly see C) They are all visible D) None of the above
12. Visible light covers wavelengths of approximately:
A) 50 to 100 nanometers B) 380 to 700 nanometers C) 700 to 1,000 nanometers D) 1 to 100 millimeters
13. Direct sunlight at noon is roughly:
A) 100 lux B) 1,000 lux C) 50,000 to 100,000 lux D) The same as a typical living room
14. A typical living room with the lights on is roughly:
A) 50 to 200 lux B) 5,000 lux C) 100,000 lux D) Brighter than the sun
15. Compared to a bright office, direct outdoor sunlight is roughly:
A) About the same brightness B) About 100 to 1,000 times brighter C) Half as bright D) Always darker
16. The eye has three light-detecting cell types — rods, cones, and ipRGCs. The job of ipRGCs is:
A) Color vision B) Sending a time signal to the body clock, not contributing to vision C) Replacing rods that wear out D) Tasting
17. Light has two jobs in your body. They are:
A) Heating and cooling B) Vision (so you can see the world) and timekeeping (so your body clock knows the time of day) C) Hunger and thirst D) Memory and sleep
18. Looking directly at the sun:
A) Is recommended every morning B) Can cause permanent retinal damage (solar retinopathy) in seconds — never do it C) Is fine if the sun looks "soft" D) Helps your circadian system
19. Your body clock can be set well by:
A) Standing outside in the morning with your eyes open, looking around the world — NOT by staring at the sun B) Looking directly at the sun for as long as possible C) Always staying indoors D) Avoiding all sunlight
20. Coach Light's main message at Grade 6 is:
A) Light is just for seeing B) Light has two jobs — vision and timekeeping — and most kids have never been told about the timekeeping job C) Stare at the sun every morning D) Only adults need to think about light
Part C — Application (30 points, 6 points each)
Write 2-3 complete sentences for each question.
21. Explain in your own words why water and light are similar in one way (both are physical things you experience every day) and different in many others. Use one specific fact about each from the chapter.
22. Use the lux table from Lesson 1.3. A sunny day at noon is about 100,000 lux. A typical office is about 500 lux. About how many times brighter is the sunny day? Show your math.
23. Describe what ipRGCs are and why their discovery changed scientists' understanding of the eye. Use language from Lesson 1.2.
24. Safety recognition. A video tells you to "stare at the rising sun for several seconds every morning to set your body clock." Why is this dangerous? What should you do instead?
25. Coach Light says light has two jobs in your body. Name both, and explain why the same beam of light can serve one job well and the other badly. Give one example of when the two jobs disagree (like a bright phone screen at 11 p.m.).
Continue to Section I — Coach Water.