Tag Archives: wave watching

Some #friendlywaves from Berlin

My friend Alice is currently in Berlin, and as one does when visiting Germany’s capital city: She’s wave watching!

I can only say: I approve! That’s what I always do there, too (exhibit 1, exhibit 2).

And knowing that I always like the challenge, she sent me a #friendlywaves picture. Meaning a picture of waves that she would like me to explain.

We aim to please… So here we go! (gif of the original Insta story above, individual pictures for easier viewing below)

Clearly this was done as an Instagram story and not designed to be posted on my blog, and I am not quite sure if it works. Please let me now what you think!

Experimenting with Insta stories for my wave watching scicomm

Inspired by the absolutely brilliant job that Kati is doing for my project GEO-Tag der Natur, I have recently started experimenting with “Insta stories” on the topic of wave watching.

Insta stories, for those who aren’t familiar with them, are a special type of post on Instagram that only stays visible for 24 hours (unless you save them as highlight, in which case they can be watched until you decide to delete them). They are usually used to give quick glimpses into what’s going on that day, and can be anything from random snap- or screen shots to elaborate stories. The latter is what Kati has been doing for GEO-Tag der Natur — she tells cute and engaging short stories about different topics, using photos and video clips, which she combines with fun gifs to make them even cuter (if you have an Instagram account you can watch them in the highlights of our account).

So that’s what I have been trying to do, too.

My first attempt is posted below — except that what I post below doesn’t contain the links and gifs and stuff, because it turns out that while you can export stories from Instagram, I couldn’t convert them into a format that my blog or vimeo would accept and still keep the gimmicks (original version here). But I still like the format of telling a story. What do you think?

The feedback I got on that story was super positive, so I decided to do it again.

Since my second Insta story contained so many cute gimmicks, I didn’t even attempt to export it, but wrote a separate blog post using the same videos and pictures (But you can watch the story — including the cute gimmicks! — here).

(And then, when writing this blog post, I realized that if I did a screencast, I could that then convert into something my blog accepts. Duh! So below you can watch my story the way I see it when logged into my account — including how many people watched it and all the buttons that I could click to edit and exit etc.. In the future I should probably just do the screencast from a different account to give you a cleaner view…)

By this point, it started bugging me that I was putting effort into Insta stories but that I didn’t have a good way to use them on my own blog (remember, I hadn’t come up with the screencast idea yet). I like having full control over hosting the stuff I don’t want to disappear, and I don’t like telling the same story twice for different platforms (although I realize that customizing stories for each platform and thus audience is always good advice).

So the next story didn’t use fancy gimmicks (except on the last slide), and I could export the pictures and combine them into the .gif you see below.

Mmmmh, I like that!

Except now I am thinking I should still do an English gif for my blog and keep the German one to my Instagram. Which, again, feels like a lot of work for something that I want to do in random pockets of time like on my commute, not as a real task. So my next story was a language-free one:

So in the end it turns out that classical gifs work quite well for transporting my stories. Not nearly as cute as they could be, but maybe that’s ok?

What do you think? What style of Insta story would you like to see more of?

Option A: Give me cute little gimmicks like ducks on surfboards and ladies jumping into pools!

Option B: GIFs work well and I don’t need all the cutesy gimmicks

Option C: Other. Please elaborate! :-)

A pilot ship making waves, and what happens to the waves over time

This is the story of a pilot ship, merrily sailing along on a beautiful day, making waves.

Since it’s windy and Kiel fjord is a little choppy, the waves break and both side of the V-shaped wake with the pilot ship at its tip are visible. See the foam of the breaking waves? And in the middle of both sides of the V, visible as a lighter-colored stripe, there is the turbulent wake where the ship’s propeller has set the water into chaotic motion.

Both constituents of the wake — the V-shaped feathery waves and the turbulent wake — stay visible for quite some time after the ship has passed!

Can you spot the one side of the V approaching the shore?

A little while later, the pilot ship returns. nice bow wave (where its bow is breaking the water apart) and all. Also note the wave field inshore of the floating wave breaker — it is a lot calmer than on the outside!

But not for long. The pilot ship is making waves!

The V-shaped wave keeps spreading, one of its sides coming closer and closer to the wave breaker.

Wow, now it’s there! Can you imagine what it will do to the floating wave breaker, and what that in turn will do to the wave field inshore?

Below, you see that the V-shaped wake is now so wide that one end is reaching the edge of the wave breaker, which is already moving almost violently in the waves.

And the moving wave breaker now produces waves of its own, radiating away from the wave breaker, towards the shore.

See how those waves propagate further and further towards the shore and form a crisscross pattern with the waves that come in through the gap between wave breakers?

That was a nice wave watching break! :-)

Wave watching on Schwentine river

Surprise! I did some wave watching yesterday!

Ok, let’s start with something simple to warm you up: A duck’s wake.

And wind waves (coming in from the top right) hitting a patch of moss on the side of this little pier, and then radiating away as half circles.

Here is a movie of that because it’t pretty cool, actually.

Are you ready for the cool stuff? A water strider making waves in the movie below! It hops happily on the water, and every time it lands, capillary waves radiate outward from its point of impact.

And in the movie below, there is another water popping up after a couple of seconds. But what I find fascinating about the movie below: In the beginning, there are these smooth waves running through that were created by a breeze further upwind on the lake. But over the course of the movie, the texture of the surface changes: It gets rougher and ripples appear as the breeze moves in where I am filming. So within half a minute the lake looks substantially different!

And below a movie clip that should be used in physics classes because it illustrates so nicely that waves transport energy, not matter. How do we see that?

Can you spot the long waves going through right to left, and the small ripples that seem to, if anything, move from left to right? (Not true, that’s an optical illusion! They are moving right to left, too, only so much slower than the longer ones)

But if water was moving with the longer waves, the small waves would have to be transported with it, just riding on the other wave field. Clearly that is not the case! And that’s because only energy and the shape of the waves is transported, not the actual water the waves consist of.

And below is the picture that I would use to open my hypothetical wave photography exhibition with. Or maybe have it printed in a size to fill a whole wall if I ever had to furnish a large house.

Wave watching on Brodowinsee

What do you do the night before the most important three days of your whole work year? Yep — some wave watching with friends!

On Thursday night, we went to cool down and relax after preparing for GEO-Tag der Natur all day long. Don’t these images make you feel much more calm instantly?

And look at the waves in the atmosphere that only become visible because, as air is moved up and down by the waves, conditions change such that clouds form in the troughs but disappear at the peaks of the waves. Contemplating these things is so relaxing to me! Especially when looking at them both in the sky and in their reflection on the water.

And if you look carefully at the picture above, you see tiny little wave rings in the lower right corner. That’s small fish touching the lake’s surface from below, creating disturbances that propagate away from where the surface was deformed.

Other things make similar pattern, albeit on a larger scale. My colleagues K and K, for example, are creating wave rings, too. Theirs are much larger and propagate all the way across the lake!

And thanks to K&K’s waves, the reflections of the atmospheric waves on the water becomes even more interesting as they are deformed by surface waves on the lake.

Is there any better way to calm down any worries you might have?

And, btw, the GEO-Tag der Natur turned out a blast. I’ll update you on that once I’ve had A LOT OF SLEEP! Until then — go and do some wave watching! :-)

Wave watching in Kleinwaabs — and my first real Insta story!

So today (and tomorrow and the day after) is the big event that I have been working towards all year in my not-so-new-anymore job: The GEO-Tag der Natur! If you are curious about what’s going on there, check out our Instagram account @geo.tag.der.natur that Kati is doing an amazing job with!

As you can imagine, the weeks running up to this weekend were quite busy and a little stressful, too. So last Sunday I went to the beach to hang out with friends and do some wave watching! Because nothing has a more calming effect on me than watching water…

For example below we see nicely the effect of the wave (and wind) breakers on the wave field. In the lee of the wave breaker, the water is completely calm, whereas towards the right of the bay waves form and grow larger and larger.

And below we see a pretty cool “diffraction at slit” example: Straight wave fronts reach the slit between two wave breakers, and as they propagate through the slit, they become half circles.

But to relax and get my thoughts away from my job, I tried something new: I created and posted my first ever Instagram story! I’m not quite sure it’s my format, but I definitely had fun! What do you think? Would you like to see more of those? (I only just realized the story is in german and my blog in English. Posting anyway… Would anyone like to see this kind of stuff in English? Then please let me know and I’ll see what I can do…)

(P.S.: Since I made this for Instagram, the format of the video was optimized for viewing on a mobile phone. Therefore it looks crap embedded in a blog. But some you win, some you loose…)

What do you do to relax and get your mind off of work? Wave watching and posting about it on social media? Have you ever tried that? Or what else would you recommend?

Watching a V-shaped wave widen over time

Yesterday we looked at a very cool wake that Nena sent in as a #friendlywaves, today I have a nice gif for you to illustrate one of the points that I was trying to make.

We are looking out of a porthole at a ship sailing past. And the further the ship sails, the wider its V-shaped wake becomes at a fixed position.

Picture by Arnt Petter Både, used with permission

Nena sent me some #friendlywaves from Lago Maggiore

This is a #friendlywaves challenge, where I try to explain other people’s wave photos and they tell me how I did.

I love it when my friends see waves, think of me, whip out their cameras, take pictures, and send them to me! In this case, Nena even used a telephoto lens and took the amazing pictures below that she allowed me to share with you!

They are the perfect example for talking about wakes when a ship doesn’t just go straight ahead. Because, of cause, ships going straight ahead are the easiest case, like the one we see below.

Picture by Nena Weiler, used with permission

Here, we see the two different constituents of a wake: The turbulent wake that is the white stripe right behind the boat, that turns blue a little way behind the boat but stays a lighter color than the surrounding water.

And then there is the V-shaped wake with the boat at its tip. This V-shaped wake consists of very many individual waves that are fairly short in the direction parallel to their crests, and that are shifted slightly so the further away from the boat you look, the wider the V opens. I usually call this the “feathery” wake, since it consists of all these little “feathers”, but since I need the “feather” image for something else today, I’ll just call it the V-shaped wake here.

Now when the boat takes a turn, this messes up the structures of the waves making up the V-shaped wake (or makes them more interesting, depending on your point of view). Below, the boat has taken a right turn, which you can see from the turbulent wake that starts right behind the boat as a white stripe that then changes color to a lighter blue than the surrounding water (with a darker stripe to each side, and then the V further out).

Picture by Nena Weiler, used with permission

Now looking at the individual waves of the V-shaped wake, we see that they get bunched up on the right side of the boat’s trajectory, while they are getting fanned out on the left side.

Now imagine the boat’s trajectory as the shaft of a feather. If you have ever bent a feather, you will have observed that on the side the shaft is bent towards, the individual barbs (I looked this up: barbs are the little thingies that spread outwards from the feather’s shaft) get bunched together, while on the other side they fan open.

So far, so good. Still with me?

Now what happens as time goes on is that the V opens up — the two sides move away from each other. We don’t usually notice this because we are used to focussing on the wake relative to the ship rather than to some fixed vantage point. But if we looked at a fixed point while a ship going past, we’ll see the wake spreading over time until one side of the V reaches us.

Picture by Nena Weiler, used with permission

And this spreading of the V is what’s making interpretation of the picture below a little difficult. The picture below is showing almost the same part of the ocean as the one above (see the little white and blue moored boats in the bottom right corner of the lower picture? They are the same boats that are visible at the left of the bottom right corner above), only a little later. During the time between the two pictures, the ship moved further towards the bottom left corner, but also the wake spread further apart.

Above, you see that some “barbs” start running into each other (the ones where the bend is strongest, where there is foam on breaking waves because the waves suddenly become a lot steeper due to interference). So some time later, they have grown longer and are now crossing each other, which leads to the checkerboard pattern located right inside the bend of the boat’s trajectory. If you follow the V-shaped wake from the boat backwards, you can still make it out, even though it’s been deformed by the ship turning around.

Picture by Nena Weiler, used with permission

Tell me, Nena, is your family happy with this explanation? :-)

GEO-Tag der Natur making waves on Parsteiner See.

Remember I did this for work?

We ended up with pretty cool pictures, like this one:

And as I was standing in the water, guess what I was doing? Taking pictures of the ring waves propagating away from my feet! :D

And I find it so amazing how you can start a wave train moving away from you, and then just have it grow bigger and bigger and completely calm in the middle.

That’s the stuff that makes me happy :-)

One last picture, because it’s just sooooo beautiful!

Feathery wake approaching! #WaveWatching in Kiel Holtenau

A week ago already, Frauke and I went on an evening walk in Kiel Holtenau. Beautiful wave watching to be done there as always! Here you see the one side of a ship’s V-shaped wake approaching our vantage point. You can see the individual “feathers” of the wake: Short wave crests, all parallel to each other, but slightly shifted to the side to form a straight line (well, two straight lines to form a V with the ship at its tip, but the other side of the V is not visible on this picture).

And this is what it looks like when the wake has moved past us: Looking on the back of the feathery shapes. The ship that made all these waves has long sailed away.