Category Archives: hands-on activity (easy)

Using coffee in a talk on kitchen oceanography

I have been a bit quiet on here recently, because I had so many exciting projects going on that I did not manage to document them in real time (well, not on here anyway, but partly on my Insta).

One of those projects is on #KitchenOceanography with coffee, where I have compiled a lot of interesting experiments into a postcard. And the postcards arrived yesterday! (Thanks, Vanja, for picking them up!)

My super cool new postcards in front of the first slide of my presentation, because I had to take a picture when they arrived and that was the only background available :-D

Juuust in time for the “Hammer talk” presentation that I was scheduled to give at the Geo department of the University of Oslo. Where — you guessed it — I invited people to play with coffee!

Lots of things happening in coffees everywhere!

And I was so excited to see how well people played, and how beautiful the stratifications turned out!

Diffusive layers formed by double-diffusive mixing in a milk-coffee mixture

Here is even an internal wave on the stratification!

Thanks for coming and for playing! :)

Our presentation at #FieldWorkFix: “An interactive mobile adventure on coastal protection”

This summer I had a fun little side project: I was co-supervising a Bachelor thesis in geography at Kiel University! Janina Dreeßen, with Katja Kuhwald as her main supervisor, did an excellent job, and I am presenting her work at the #FieldWorkFix conference today. If you can’t join later, here are my slides and what I’m planning to say. Enjoy!

Janina’s task was to create a learning opportunity on coastal protection for 16-year olds in a school setting, to run it with some students from her target group, and to do a preliminary evaluation of how it worked. And that’s what I want to present here (of course she also did a review of both the subject of coastal protection, and the literature on how students learn with digital media and on excursions, but that’s beyond the scope of this presentation).

The learning outcomes that Janina focussed on were

  • to be able to name which coastal protection measures exist close to the students’ homes (i.e. on a specific part of the German Baltic Sea coast),
  • to recognising those coastal protection measures “in the wild” and understand their functioning, and
  • to explain why there are rules in place to protect dunes etc, and what the rules are.

Because of Covid-19 regulations in Germany this spring, we wanted to create something that could be done outside, and socially distant.

We decided to create a virtual scavenger hunt using the app Actionbound that provides the platform and an easy drag-and-drop interface to create interactive mobile adventures. Actionbound serves as a virtual guide to different locations, which you can navigate to following an arrow or looking at a map, and you can prescribe whether the mobile phone’s GPS actually has to show that a location has been reached (within a couple of meters) for the scavenger hunt to continue, or whether you trust your players to find it, or you can also allow to skip it.

Within the app, you can provide media related to, and released at, specific locations: Movies, sounds, pictures, texts; so there is a great potential to use this in teaching. Actionbound scavenger hunts are also interactive experiences, as it is possible to create quizzes using multiple-choice questions, ask for free text answers, or media uploads. All of these can be made compulsory (so you can’t continue the scavenger hunt unless you respond) or voluntary, so they can be skipped.

Actionbound runs on the participants’ own smartphones, and scavenger hunts can be downloaded in advance and played offline, if data usage is restricted or the network in the region might be a problem.

The person who creates a scavenger hunt is provided with usage statistics: How many people played, how long they played, what they answered, the files they uploaded, those kinds of things.

Playing a scavenger hunt using Actionbound is free for players. Creating scavenger hunts is free for private use (so great if you want to just test it!), but for educational or commercial use, you have to buy licenses. We were lucky as we could get a free educational license under the umbrella of GEO-Tag der Natur, which bought licenses and distributed them for free to people creating scavenger hunts to be played on the topic and within the timeframe of that larger project (no coincidence here, that’s my project and Janina’s idea was a perfect match for what we were looking for :-)).

The design of our scavenger hunt was guided by our interpretation of the self-determination theory by Deci and Ryan (e.g. 2000, but many more). This theory suggests that learning is optimal when it is intrinsically motivated, and that in order to feel intrinsic motivation, three basic needs have to be met: autonomy, competence and relatedness.

Autonomy means that we need to feel that we have control over our behaviour, that we have choices that we can make in whatever way we please. Obviously in a school setting, there is always going to be external constraints, but the more we can give students ownership over what is going on, the more likely they are to feel motivated.

For our scavenger hunt this means that, where possible, we provide different options for how tasks can be done (and I will give an example of that later).

We do want everybody to reach specific waypoints and look at different things along the way, but we give participants flexibility for how exactly they reach those waypoints (there is an obvious way, but they can also do detours on the way if they like), and how they organise their time. We do that for example by letting them know when they have reached the mid-way point and what type of larger tasks are still ahead of them, so they can estimate how much time they will need to get back to the starting point, and decide when and where they would like to take their breaks.

Below, you see a map of the area we were focussing on: We start out in location (1), then students head to stations 2 to 11, and then everybody meets up at station (12) in the end, to drive back to school together. On this tour, students see many features that are relevant to coastal protection, some of which you can probably spot from this satellite picture: We see for example the marina, the slip hook which contains a nature reserve, sand banks offshore off the coastline, a dyke, and groynes.

We do want to know whether students recognise relevant features along this tour that they’ve been introduced to earlier, so one task was for example to take and upload a picture of the “spit hook” — a term that they were likely not familiar with before and where they had to make the transfer from the map above to the feature you see in the pictures below. It was visible on all pictures students submitted, although better on some than on others.

Back to basic needs that need to be fulfilled in order to feel intrinsic motivation! The second basic need, the feeling of connection, we try to address by letting students work in small groups of 2 to 4. Within those groups, we foster a sense of belonging by starting the scavenger hunt off by asking them about their personal experience with extreme(-ish) events.

This, for example, shows a relatively common (as in about once a year) event in Kiel, the next bigger city to where this scavenger hunt is located, that students doing this tour are likely familiar with: Storm surges in the Baltic Sea often lead to roads close to the water being closed and flooded, and waves breaking over the sea walls. Damages to sea walls can regularly be seen (also because it takes years before they are being repaired), and booms to close roads off with with “road closed due to flooding”-signs are permanently installed, so students should have some personal experiences and prior knowledge that can be activated. Talking about personal experiences and sharing stories about them is a good way bond with others.

The third basic need that must be fulfilled is a feeling of mastery, which we tried to ensure both by scaffolding our tasks and by making sure that students could make choices that would allow them to show their strengths.

For example, the last task of our scavenger hunt was to create a movie about a coastal protection measure of their choice, in whatever format they chose. They were given this task at the farthest point out, so they could walk back past all the coastal protection measures they had seen on their way out, contemplating the task, and then use free time towards the end to implement it.

I expected students would submit something that looks like what we show here (although that’s my incredibly adorable and smart three year old niece and not a 16 year old student): building structures on the sandy beach, maybe discussing the design criteria behind them, and then maybe making a large wave to show how it breaks (or doesn’t break) the structure.

Here is one example of a movie that was uploaded (and other examples include someone sitting on a bench, talking about coastal protection in a story-telling sort of way), that was clearly thoroughly thought-through and produced: The movie shows a person walking down a dyke towards the sea. As she is walking, a narrator talks about how dykes protect settlements from storm surges. The camera follows the person walking down the dyke as she crosses a street and starts stepping on the dunes, where the narrator (who is now also visible on camera) steps in and tells her to stop, and explains how there are rules in place to protect the dunes. He then also points out other coastal protection measures that are visible in the distance.

So now we are coming to our conclusions. Throughout this process, and testing this scavenger hunt on a 10th grade geography class, what did we learn?

Generally, things worked really well. Being able to deliver inputs at specific locations without students following a guide around gave them a feeling of autonomy which they seemed to enjoy, and we were positively surprised by the quality of most of the artefacts we collected via the app. Despite (or maybe even because of) it’s game-like appearance, Actionbound turned out to be well suited for use in a school context, although the effort of creating a scavenge hunt is not inconsiderable. In our case, we created a scavenger hunt that can be played by many different school classes over months or even years, and the effort needed to set something like this up might be more realistic than if it is just done for use with one single class.

Using self-determination theory to guide development was also useful for us, because it reminded us to include elements beyond the classical tasks of “read this, then answer the question to show us that you understood what you read”. Including elements of gamification made it fun and memorable, but did hopefully not distract from learning.

But another thing we learned (which we had also been advised before, but I guess this is something everybody needs to learn for themselves): test, test, and test again! It is frustrating if, for example, “dog” is the expected and accepted answer to the question of who is not allowed in the dunes, and “dogs” then isn’t counted as correct, or even looses you points. Those kind of things we only caught when testing with the school class, but would ideally have caught earlier.

And then we were very lucky with the weather — this might not have been fun if it hadn’t been warm and sunny, and we did not have a backup plan!

One thing I would try and implement more next time is to have students really do something at the location they are at — not just observe, but actually either collect something that they bring home to analyse later, or have them work on an artefact that stays in this location and that other groups can build on (giant sandcastle? wall painting? …?). Because now for us it was great that students could see the coastal protection measures “in the wild”, to scale, interacting with the ocean (albeit on a calm day), but I would like to strengthen that connection with the actual physical location even further in the future.

One last thought: I would really like to do a similar thing as co-creation in the future, where students design scavenger hunts to teach other students about a topic they first did some research on themselves. That would a) be a great way to document their own learning (instead of e.g. writing a report), and b) likely lead to scavenger hunts that are even better tailored to that specific target group, and even more fun to do. Actionbound has that option already implemented, and I think that could be great!

But that’s for another time.

Thanks, Janina and Katja, for this fun project! :)

Molecular diffusion at different temperatures (involving tea bags and some convection)

I thought I had posted the picture below some time in winter already, but when I recently searched for it, I couldn’t find it. So either I didn’t post it, or I didn’t post any sensible search terms with it, in any case: It’s useless. So here we go again.

Below you see two tea bags that were placed into cold (left) and hot (right) water at the same time. On the left, the tea is sinking down in streaks, while at the same time on the right everything  is completely mixed through and through, showing how molecular diffusion depends on the temperature. Which is why we usually make hot tea.

Funnily enough, as I was about to write this blog post and had the picture already open on my laptop, I felt thirsty and decided to prepare a cold brew tea, which you see in the picture below. Here again you see the tea spreading from the tea bag, but it comes out in those plumes and only slowly diffuses throughout the whole carafe.

This would of course be easier to see had I chosen a white background, but since I am still so touched that my friends showed up at the train station with a flower and a flag on Friday, and also since this is literally the spot I put the tea down after I had prepared it, you get to enjoy a view of my flower and flag!

Also that fake flower on the left makes for really interesting reflections on the carafe. Especially the top two that are joint in the middle!

Can your favouite beverage tell you what your reseach as an ocean scientist should be on?

A “fortune teller” for #WorldOceanDay! What would you work on if you were an ocean scientist? And if you are an ocean scientist — are you doing the work you were destined for? ;-) Your favourite drink can give you the answer!

Click on the image below to download a printable .pdf, and find out!

I would really appreciate it if you could give me a 3-minute feedback (click here!) so I can improve future versions of the “fortune teller” as well as my science communication in general!

Coffee in #KitchenOceanography

For some reason my workflow regarding all things #KitchenOceanography and #WaveWatching changed at the beginning of this year. I started editing frames on the pictures I’m posting on Instagram, and, since I was most likely doing this on my computer anyway, scheduling the posts through a program on my computer, which meant that I was typing captions on the computer, too, writing a little more. But somehow that meant that I had already written everything I wanted to write about the pics and didn’t feel the urge to blog later, so … I didn’t. Until now, that is!

Here is a collection of my Instagram posts on coffee in #KitchenOceanography!

[photo] Coffee cup in which two counter-rotating eddies form because Mirjam @meermini is blowing across the cup. The eddies become visible because the circulation disrupts a surfsce film caused by cream in the coffee

Enjoying your lazy first morning coffee of the year (or already back from your New Year’s morning walk, but forgot to take pictures — what’s wrong with you, 2021?)? Then it’s a perfect opportunity to look at wind-induced currents in your coffee! Gently blow across the cup and observe how two counter-rotating eddies develop. This becomes especially clear if you take milk in your coffee (or something else that creates a surface film). Enjoy!

Maybe not The Best Thing about morning coffee, but definitely very important: Observing what happens when you pour milk or cream in! Here the cold milk is denser than the coffee, so it sinks down to the bottom of the glass (it would probably even shoot to the bottom of the glass if it was the same density as the coffee since it’s coming in with a lot of momentum). Hitting the bottom, it shoots along the curved rim of the glass and up in these cute little turbulent billows. But eventually, it will settle on the bottom of the glass, forming a denser layer under the less dense coffee — that’s what we call a stratification, both in density and in coffee&milk. And it’ll stay like that for a little bit, until other processes come into play. So stay tuned for those :-D⁠

Actually, not only internal waves, but also current shear!⁠ When you pour milk into coffee, the milk will form a layer at the bottom of the coffee. Similarly to when you poured the coffee in and it surface leveled out, the surface of the milk wants to level out. And similarly to the waves that you probably observed initially on the coffee when you poured it in, waves appear on the interface between milk and coffee. Except that these waves have larger amplitudes, move more slowly and persist for longer. That is because the density difference between milk and coffee is orders of magnitude smaller than that between coffee and air. Those waves are called “internal waves”.⁠ And what we see in the pic, too, is that the milk layer is moving relative to the coffee layer, therefore the wave crests are being pulled into these sweeping strands. Pretty awesome!⁠

My sister & nieces made this mug for me for Christmas. Isn’t it just perfect together with the swirl in the last bit of my coffee? I’m considering making this my logo and profile pic and EVERYTHING because I think it is Just. Perfect.⁠

I’ve been playing around with different glasses and different ways of lighting them in order to get clearer pictures of the things I want to point out: The behavior of the fluids, not reflections on the side walls of the tanks I am using. At least here there are only two stripes where the light is reflected? And the internal waves on the interface between milk at the bottom and coffee on top come out quite clearly. Even from this photo you can see how dynamic the system is!⁠

Again, there is a milk layer at the bottom of the coffee. And those mushroom-y milk fingers appear when the milk is warming up and its density is thus decreasing. As it gets less dense than the coffee, the stratification becomes unstable and milk starts rising until it reaches a level of its own density.⁠

Today there is some interesting surfactant on my coffee. It might be due to oils in last night’s tea that I didn’t clean off, or maybe it’s the cream (but I would think that that’s the little blobs of oil you see). In any case, the surface film behaves in very interesting ways: It is showing us a front in the coffee, with lots of small instabilities on the front! The front must be related to me drinking from the mug somehow, but I’m not sure how. Thanks to the surface film, we also see convection occuring in the top left, where we get all those small-scale structures in the color, lighter areas indicating convergence zones where the surface film gets pushed together, darker areas where it is pulled apart.

A little while ago I posted a picture of the front you see in my coffee here. And what I did then was twist the mug a little bit: I wanted the front to be in the picture more nicely together with the little boat. BUT: exciting things happened (predictably): As I was twisting the mug, it did not behave as a solid body together with the coffee. Rather, it twisted while the coffee was not! And this created shear between the sidewalls of the mug and the coffee, which is what we see all around the edge: shear instabilities breaking into eddies! And all that due to inertia of the coffee.

About #KitchenOceanography

At the end of last year, I did a poll on Twitter, asking what people would like to see more of in 2021: Kitchen oceanography, wave watching, teaching & scicomm tips, and other things. And 2/3rds of the respondents said they wanted more kitchen oceanography!

So obviously my strategy was to do a photo shooting and prepare … Instagram posts (did I mention I asked that question on Twitter? Yeah. Don’t ask me about the logic behind that). Anyway, below is the beginning of that series (which, on Instagram, is not posted consecutively, in case you are wondering about how often people want to see me grinning at the exact same experiment…). Enjoy!

[photo & text] Mirjam @meermini cheering with a glass filled with clear water, with a green ice cube floating in its green melt water on top of the clear layer. In the foreground a second glass with a green ice cube in it, this time floating in completely green water. Text on the photo says "Cheers to the new year" and "#KitchenOceanography"

So people tell me they want to see more #KitchenOceanography. Get ready for 2021, I come prepared! Carrying a non-alcoholic experiment with me (doesn’t look like it, does it?). Can you tell which of the glasses contains salt water and which fresh water? Both were at room temperature before I put in the (now mostly melted) ice cubes… Happy New Year! May your 2021 be full of curiosity and new experiences!

[Photo and text] Mirjam @meermini pointing at a glass in which a green melt water layer is spreading from a green ice cube over clear water. The text says "Observation. Discovering oceanography everywhere. #KitchenOceanography"

What do I love so much about #KitchenOceanography? Discovering oceanography EVERYWHERE. . When people think of oceanography, they think of endless oceans, weeks and weeks at sea on research ships, something that feels remote and unconnected to their everyday lives. But for me, it is anything but! And #KitchenOceanography is a great tool to bring the ocean and a normal everyday life closer together, both for myself and others. The concept of #KitchenOceanography is simple: you use what you find at home to simulate oceanic processes. Usually this involves some kind of “tank” (anything from a tupper ware container to the wine glass as in the picture), obviously water (usually varying temperature or salinity to change density), food dyes (or anything that can safely be used in food storage containers and that can act as coloring, e.g. dark red fruit juice, black coffee, …). And then you put it together, observe, and relate the physics happening in your kitchen to the things that happen on much larger scales in the ocean. Fun! #KitchenOceanography works really well as a fun activity at home, but is also a great tool in teaching, both in-person and remote. Over the next couple of posts I’ll tell you how and why to use it, and give you plenty of ideas for #KitchenOceanography experiments, so please check back!

[Photo & text] Photo of Mirjam, grinning stupidly at the camera while holding green ice cubes over two glasses full of water. Text in the photo says "Excitement. Right before the experiment. #KitchenOceanography

It might not be immediately obvious to you why I am grinning stupidly at the camera in the picture above, while holding green ice cubes over two glasses full of water, so let me explain. I am about to drop the two ice cubes into the two glasses of water. But those two glasses are not filled with the same stuff. Even though it’s water at room temperature in both, one is fresh water and the other one is salt water at approximately a typical oceanic salinity (e.g. 35g of salt per liter water, or 7 tea spoons per liter). When the ice cubes are dropped into the water, they’ll both melt (in fact, they have already started, which is why I had green finger tips for days after this picture was taken). But they won’t melt in the same way. I’ve done this experiment dozens of times, alone or with people from preschool age to professional oceanographers, so I know what will happen. But what I don’t know is what EXACTLY it will look like, and what I might discover for the first time, or see more clearly than before. Even though the experiments are simple, there is ALWAYS something new to discover, because even such a simple system is still chaotic. Plumes of melt water will never look exactly the same, nor will the condensation on the glass. Discovering all those small featuers and contemplating the physics behind them makes me happy, and it’s easy to engage most people once they get over the “you are looking at two ice cubes and two plastic cups!?” threshold and actually start observing, questioning, and trying to explain, which is why #KitchenOceanography is such a great tool in teaching & outreach!

Photo & text: Mirjam @meermini holding two green ice cubes over two glasses of water, grinning stupidly into the camera. Text says "Eliciting. What do you think will happen next? #KitchenOceanography"

Eliciting! . #KitchenOceanography is a great tool in teaching and outreach of ocean and climate topics, because we are using a simple system — one that people think should be easy enough to intuitively understand. But this is often not the case for many reasons, one being that many people have “misconceptions” about physical processes: ideas that they formed and that worked well to explain their observations until now, but that aren’t correct and that will break down in the context of the physics we are trying to teach. . But in order for those misconceptions to be changed into correct understanding of physics, they first need to be brought to light and be made conscious. . For example by asking: In front of me you see two glasses, one filled with salt water, the other with fresh water, both at room temperature. If I drop the ice cubes in, which one will melt faster, the one in fresh water or the one in salt water? . At this point, it is not important that students give the correct answer, but that they articulate their beliefs. And what happens next? Look out for my upcoming “confront” post!

Photo & text: Mirjam @meermini holding up two wine glasses which she looks critically at, both with green ice cubes floating in them. One glass contains clear water with a thin green layer on top, the other glass contains green water

Confronting! In my previous “eliciting” post, I talked about the importance of realizing WHAT it is that we believe about how the world works. But what if our beliefs are wrong? Then, #KitchenOceanography is a great tool to confront a prediction of what SHOULD happen with what actually DOES happen. It’s surprisingly difficult to observe something that is not what we expect to observe! But when we manage to make observations that contradict what we expected to see, we come to the “confronting” step: Realising that there is a conflict between our interpretations of the world and how the world really works. So what now? Look out for my upcoming “resolving” post!

Mirjam @meermini holding two wine glasses, filled with green ice cubes melting in water, towards the camera. Text says "Resolving! How can you explain your observations?"

Resolving! . In previous posts, we have eliceted a misconception by asking what we believe would happen in an experiment and making predictions about the outcomes. We then confronted our prediction with an actual observation. . Now we need to somehow resolve the cognitive dissonance — what we thought should happen did not happen — and build new, correct ideas about physics into our belief system. This happens best by explaining how things fit together, either to others or to ourselves (I think the main reason I like blogging and social media is because it forces me to explain things to myself, thus helping me to understand them better!). . So this is where we talk through what we observed, what did happen, how we can explain it, what might have happened if the boundary conditions had been different. Another thing that’s great about #KitchenOceanography is that in many cases, it is very easy to test what happens when you change the boundary conditions: You CAN force the ice cubes to the bottom of the glasses and observe what happens, you CAN add salt to the water before making the ice cubes, you CAN change the water’s temperature. And then observe what happens, and see if it fits with what we expected to see. . Of course, once we get playing with #KitchenOceanography, we easily get stuck with it, changing one thing, then the next. So if you use this in teaching, be aware that it will — and should! — take a lot longer than just running an experiment once, and then moving on. But, since the experiments are so easily done with household items, students can always continue discovering outside of class, too; no fancy lab needed! Perfect! :)

Published in Oceanography: How to Teach Motivating and Hands-On Laboratory and Field Courses in a Virtual Setting

One of the few “behind the scenes” shots of me taking #WaveWatching pictures! See the super awesome current right at my feet? :-D⁠⠀
⁠⠀
Similar to kitchen oceanography, I believe that wave watching is a great tool in education and outreach, especially during times where activites have to be socially distant. My article “How to Teach Motivating and Hands-On Laboratory and Field Courses in a Virtual Setting”, where I am elaborating on both, just came out in Oceanography, the official magazine of The Oceanography Society. Check it out at https://tos.org/oceanography/article/how-to-teach-motivating-and-hands-onlaboratory-and-field-courses-in-a-virtual-setting⁠!

Glessmer, M.S. 2020. How to teach motivating and hands-on laboratory and field courses in a virtual setting. Oceanography 33(4):130–132, https://doi.org/10.5670/oceanog.2020.417.