Tag Archives: diffraction

Diffraction and reflection of waves

Last night, we saw really nice wave phenomena on the Schlei in Schleswig.

Do you see the waves being diffracted by the pier in the picture below?

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Waves are coming in from the right (see the three lines on the right in the picture below) and at the head of the pier they get bent around (all other lines).

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Now look at the line on the very left. What happens where that wave hits the pier?

This.

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Awesome criss-crossing of wave crests!

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An annotated picture of what happens below: The red lines show the incoming original wave crests, and the green lines show the wave crests of the wave that got reflected by the shore.

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If all those lines are a tad confusing, thankfully a ducky in a fairly wave-less spot made a single wake which also got reflected on the sea wall:

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Same picture as above, this time with the original wake marked in red, and the reflected wake marked in green:

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Nice evening, isn’t it?

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And since everybody else is asleep, I put together some short video clips into a movie for you:

What I learned from the movie-making? I need to take longer footage and practice my editing-skills! :-)

Waves on Aasee in Münster. By Mirjam S. Glessmer

Wave hunt expedition. You don’t need to live close to the coast to observe all kinds of wave phenomena!

A 1.5 hour walk around a lake — and 242 photos of said lake — later I can tell you one thing: You definitely don’t need to live close to the coast in order to observe wave phenomena!

The idea to go on a “wave hunt expedition” is actually not mine (although it definitely sounds like something I could have come up with!), it’s Robinson’s idea. Robinson had students go on wave hunt expeditions as part of their examination, and present their results in a poster. I was so impressed with that, that I had to do it myself. Obviously. So the second best thing about work travel (right after the best thing, again, obviously!) is that I find myself in a strange place with time on my hand to wander around and explore. Not that Münster might not have been a nice city to explore, but the lake…

Anyway. I only want to show you 53 out of the 242 pictures. I was going to annotate all of them so you actually see what I mean. And I started annotating. But since I am giving a workshop tomorrow (which is all prepared and ready, but I do need my beauty sleep!) I only drew the key features in the pictures, and you will have to come up with the correct keywords all by yourself (have your pick: refraction! diffraction! fetch! interference! :-)) So click through the gallery below and see first the original photo and then one that I drew in. Do you spot the same stuff that I saw, or what else do you see? Let me know!

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If you think it would be useful to see all those pictures with proper annotations and descriptions at some point please let me know. I might still be excited enough to actually do it, who knows…

P.S.: I actually really enjoy work travel for the work parts, too. For example, I went to a great workshop in Dortmund earlier this year to learn about a quality framework for quantitative research, and that workshop was amazing. And a week ago, I went to Stuttgart for a meeting with all the fellows of the Stifterverband für die Deutsche Wissenschaft, which was also great. And now I am giving this workshop in Münster, that I am actually really excited about because I managed to condense pretty much all I know about “active learning in large groups” into a 2.5 hour workshop. Just so you don’t get the wrong idea about my priorities. Obviously water comes first, but then work is a very close second ;-)

Diffraction of light

Today I’m playing with the sun.

As I mentioned in the sun dog post already, I recently went on the ferry from Kiel to Gothenburg. And I had plenty of time to watch the sun rise and set.

One thing that kept me entertained for quite a while is to squeeze the sun through the imaginary eye in the mast:

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As the sun moved behind the mast (or as I moved in front of the mast, whatever), the sun seemed to get pinched in while passing.

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Watch the video below to see the whole thing in action:

Also highly entertaining: Watching how the sun eats into my finger tips as I bring them together in front of the sun:

Kids. If you try this at home, please make sure you only look at the sun on the display of your camera, never look directly into the sun…