Tag Archives: rainbow

Rainbows III

Updated movie following Arne’s advice.

When I asked for feedback on the rainbow movies the other day, Arne had a pretty good idea for how one of the explanations could be made more intuitive. I have other people’s comments still in the queue and I’m working on them, this is still very much in the trial & error phase… And unfortunately it’s in german, which I didn’t realize until I had uploaded it.

But please do keep the comments coming, I will include them eventually!

Secondary rainbows

Sometimes you get lucky and see a double rainbow. But how does the second rainbow form?

On my first 17th of May in Bergen, Ellen invited me to her home for a traditional dinner, which was exceptional. And as a bonus we got to see a double rainbow over Store Lungårdsvann!

Screen shot 2014-07-11 at 6.16.13 PM

Double rainbow in Bergen on May 17th 2011

The outer rainbow is the so-called secondary rainbow, and as you can see the colors in the secondary rainbow are reversed, with red being on the inside and blue being on the outside.

Having watched my explanations in the textbook-style movie or in the short movie collection, is the sketch below enough information for you to make sense of how a secondary rainbow forms?

If the sketch isn’t clear – what additional information would you need to make sense of the sketch?

Here comes the movie in case you’d like to watch it:

I have yet a newer version of the rainbow movies as well as the one pictured above ready for you, but I thought I’d give you a bit of a break from rainbows and talk about something else for a while. But we’ll be back to rainbows soon, promise!

Rainbows and refraction II

Taking the same graphics as in this post, but presenting them differently.

In the previous post, I presented a screen cast explaining, in a very text-booky way, how rainbows form. Today, I am using the same graphics, but I have broken the movie into six individual snippets.

I’m starting out from the schematic that concluded last post’s movie and ask  five questions that you could ask yourself to check whether you understand the schematic:

Ideally I want to link the other five of the movies into the one above, but I haven’t figured out how to do that yet, so here you go for the answers:

What do you think of this way of presenting the material? Do you like it better than the textbook-y movie? I’m curious to hear your opinions!

For both this and the other way of displaying the material, I am toying with the idea of adding quizzes throughout the movies, in a programmed learning kind of way. But considering all the pros and cons, I haven’t made a final decision on it yet. What do you think?

Rainbows and refraction

Why is a rainbow always red on top and blue at the bottom?

We always talk about prisms and refraction and stuff, but be honest – would you be able to explain the order of colors in a rainbow without pausing and thinking first?

Screen shot 2014-07-13 at 3.34.19 PM

Rainbow. Picture taken in Laufenselden in 1996

As I said the other day, I am currently experimenting with screen casts. This is my very first attempt – I didn’t write a script so it is pretty chaotic, I have a cold (which you can hear from my voice), my handwriting sucks, the movie is, at 4 minutes, about twice as long as I wanted it to be – it is not perfect and I will certainly modify it before using it in teaching. But I would be very interested in your feedback so I can improve it!

As you noticed, this is a very textbook-y screen cast. I’ll present an alternative model for the same topic in my next post.

P.S.: As you might have noticed from the watermarks in the video, I have continued experimenting with screen cast programs and am currently using Doceri. And I am very happy with it!