I'm updating some poorly written lab activities for an online physics class that I have been given, and I am going through the experiments and doing them myself to better write them. I came across this one, and I have no idea what the results are supposed to be. It comes after the chapter on diffraction, which covers interference patterns, why interference patterns indicate that light is a wave, diffraction, diffraction patterns, and Huygen's principle. Here (everything in blue) is the text that the students are given: Observing Light Waves You’ll answer the following research question: • Which light behaviors does the wave model explain? Procedure 1. Using a thin needle, poke a tiny hole in the center of the paper. Stand at about 1 m from your screen. Shine the flash light through the whole onto the screen. What do you see? Move the paper screen slowly toward the flash light and back toward the screen. Observe what happens. What light phenomenon do you observe here? Explain. 2. Using the same needle, poke two more holes in the paper so that all the three holes make a triangle with a side of about 0.3 cm. Shine the flash light through the holes onto the screen. What do you see? Move the paper screen slowly toward the flash light and back toward the screen. Observe what happens. What light phenomenon do you observe here? Explain. 3. Organize all of your data in a chart. Record and explain all of your observations in as much detail as you can. 4. Evaluate your data by creating a data analysis focused on light waves. To do this, be sure to answer the following questions: • Why is the wave model of light most appropriate to explain your observations? • What wave behaviors did you observe? I understand that lasers make diffraction patterns through a pinhole, but flashlights don't seem to. It doesn't seem to be a pinhole camera since they aren't looking at a discernable image, just the light of a flashlight. And I have no idea what they are doing with the three holes in a triangle shape - I can't find any lab activities online that are similar. When I did it myself I found nothing interesting with one pinhole - just a large circle of light - and with three I could see that it was brighter where the circles overlapped but that's it. Am I missing something? Should there be more notable results? Or could the point just be that the students should point out that diffraction causes the image to be bigger than the pinhole? Can anyone shed some light on the purpose of the three pinholes arranged in a triangle? Does anyone have any suggestions for updating this activity? (Note that this is for an online class where we don't provide students with materials; we are limited to household materials. I wouldn't even want to require a laser pointer because if they don't have one, we're kind of stuck; though it could be used as an optional addition.) Any advice on this is appreciated!