Why Some of the Rainbow Is Missing
If you look closely at a rainbow made from sunlight (e.g. through a prism or an actual rainbow), you’ll notice that some of the colors are missing. It turns out that these absent colors (called Fraunhofer lines) have something to do with the types of elements that are present in the Sun (and the Earth’s atmosphere). Dr. Joe Hanson explains in the video above.
Over 200 years ago, scientists were looking at sunlight through a prism when they noticed that part of the rainbow was missing. There were dark lines where there should have been colors. Since then, scientists have unlocked the secrets encoded in these lines, using it to uncover mind-boggling facts about the fundamental nature of our universe and about worlds light-years away.
Science is fascinating…Fraunhofer lines can tell us something about objects and processes all along the Powers of Ten scale, from the inner workings of the atom to the composition of the Earth’s atmosphere to how quickly the universe is expanding or contracting.
If you’d like to check out the missing parts of the rainbow for yourself, you can make this DIY spectroscope using a CD or DVD and a few other items. (via the kid should see this)
Comments
Hello! In order to comment or fave, you need to be a current kottke.org member. If you'd like to sign up for a membership to support the site and join the conversation, you can explore your options here.
Existing members can sign in here. If you're a former member, you can renew your membership.
Note: If you are a member and tried to log in, it didn't work, and now you're stuck in a neverending login loop of death, try disabling any ad blockers or extensions that you have installed on your browser...sometimes they can interfere with the Memberful links. Still having trouble? Email me!
In order to comment or fave, you need to be a current kottke.org member. Check out your options for renewal.
This is the name that'll be displayed next to comments you make on kottke.org; your email will not be displayed publicly. I'd encourage you to use your real name (or at least your first name and last initial) but you can also pick something that you go by when you participate in communities online. Choose something durable and reasonably unique (not "Me" or "anon"). Please don't change this often. No impersonation.
Note: I'm letting folks change their display names because the membership service that kottke.org uses collects full names and I thought some people might not want their names displayed publicly here. If it gets abused, I might disable this feature.
If you feel like this comment goes against the grain of the community guidelines or is otherwise inappropriate, please let me know and I will take a look at it.
This thread is closed for new comments & replies. Thanks to everyone for participating!