Diffraction has many uses, from measuring the smallest distances known to humank

Diffraction has many uses, from measuring the smallest distances known to humankindLinks to an external site. to putting pretty lights on your houseLinks to an external site.. However, it is a very particular thing and its uses are often very niche. To work around this I’m going to provide more direction than normal for this week’s discussion… We are going to specifically investigate “iridescence” also known as “interference coloration” in animals.
Iridescence can be defined as “a lustrous rainbowlike play of color caused by differential refraction of light waves.” In animals it is what we might call “shiny” or “colorful,” especially when the colors shimmer and change from different viewing angles and different light. It doesn’t only have to be shiny/sparkly it can also sometimes appear as a plain/flatter color. A great example of this are blue-jays! They are brown in terms of pigmentation, but they are covered in interference barbs that refract constructive interference for blue light- making them appear blue!
You will pick an animal type from the following list:insects, birds, fish, reptiles, cephalopods, mammals (there’s only one mammal that I know of though!)
Once you have picked your animal category, go find an example of an animal from that category that displays iridescence.Name which animal you have picked for the discussion.
Describe in what ways the animal creates iridescence.
Describe why the animal creates iridescence- obviously this part will be up for debate among the biologists.
This initial reply is worth 5 points and is due May 3, 2024.For example, if I were to pick the common raven:The common raven (Corvus corax) has tiny keratin feather barbs that are ordered specifically to cause light interference from sunlight (sourceLinks to an external site.). Because of this ravens might look black from one angle, but will have a green blue iridescence from another angle. This is theorized to allow them to blend in with stormy or night skies as a means of increasing their survival. It also might be the case that their iridescence is just a stepping stone evolutionarily from a matte color to a full rainbow shine (sourceLinks to an external site.).
Reply to at least one other student to discuss their example.Search around and find a student who has picked a shiny animal you would like to see a picture of.
Search online to find a photo of the shiny animal in question.
Reply to their post with the best/shiniest picture you can find of their animal.Be sure to cite where the photo came from, either by providing the link or stating the website/organization where it was found.For example, with my raven from above, someone might reply with:
Source: RedditLinks to an external site.
This reply is worth 5 points and is due May 5, 2024.
Ensure you are subscribed to the discussion, so you remember to come back and view the replies to your post!
Grading: This discussion is due by the end of the day on May 5. You may post after it is due, however if you are late there will be a 10% penalty per day, up to a maximum of 50% off for over 5 days late. (That is, if you are 5 or more days late, you can still participate for half credit.)
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