[annotated photo] Photo of water flowing over a weir, annotated with arrows showing particle velocities

Testing the new particle tracking app “Flow on the Go”

Leave a reply

The new particle tracking app “Flow on the Go” became available for testing on iOS yesterday. And it is SO AWESOME!!!

The idea is that particle that are advected in a flow can be used to visualize a flow field (similar to what we did when we were at the 13-m-diameter rotating swimming pool in Grenoble, where we added particles with neutral density to the tank in order to track currents). So the app latches on to something that it recognized as “particle” and then displays arrows as it follows that feature from frame to frame. Pretty amazing, isn’t it?

(If you are impatient, scroll to the second-to-last video of this post for my best example, otherwise stay with me as I walk you through different scenarios…)

First, I tested with movies I already had on my phone, for example storm waves in Kiel. Which might not be the nicest test case as wave crests break and thus new “particles” appear, but then vanish in a trough behind another wave etc.. So even though the app tracks them, it all seems a bit messy. The movies always start with a short glimpse of the original movie and then the tracking begins…

 

Then, I tried the “soap protects you from Corona” demo that my adorable nieces are presenting for you. There is water on the plate sprinkled with pepper (or something), and they dip their fingers in with a little bit of dish soap, break the surface tension, and the particles all get pushed to the edge of the plate. (Spoiler alert: Kids’ hands — no matter how cute — will be recognized as particles…. :-D)

 

At this point I decided that it was definitely time for my parents and me to go for a walk to film some flows.

Below: Laminar flow towards the edge, then turbulent flow at the bottom. Interesting observations here (beside the super cool flow field that is captured surprisingly well): Where there is a lot of foam and everything appears white, it’s not easy for the app to find “particles” to trace. And when reflections on the water move (like the handrail when there are waves) that looks like “particles” to the app.

 

Here is one example where there are plenty of bubbles passing by on the other side of the river (which are tracked very nicely) and my dad threw in some leaves on our side so there were particles that showed the recirculation. Nice! (No idea what the app sees in the top left corner, though)

 

Then I had the brilliant idea to film the large scale flow field with lots of bubbles in it. But, as you, dear reader, will probably have guessed already, the reflected trees are the much more dominant signal. That’s what happens when you film tons of things and only process them afterwards…

 

But here is a very nice example for you: Fast, laminar flow upstream of the weir, then a waterfall, a submerged hydraulic jump and turbulence at the bottom. Nice!

 

Back home, I decided I wanted to test some tank experiments. Below I’m first showing a couple of seconds of the original “thermal overturning circulation” movie (because I knew my hands would mess up the particle tracking when I’m dripping dye into the tank) and then cut to the processed one.

I thought that this was one of my better movies with few reflections on the tank, a nice background, etc.. Turns out: Still waaaay too much going on! Reflections on the glass, shadows on the wall behind it as we are watching… I’m sure there are settings in the app that would lead to much better results (if I knew how to use it) but for now I know that using the app is a little more difficult than I thought.

 

In any case, I think it’s a brilliant app, and I am looking forward to playing with it some more and figuring out how to use it best! There are so many settings that I haven’t figured out yet, so I know what I’ll be doing over the next couple of days… ;-) And I can’t wait to use it on our DIYnamics rotating tank experiments!

Mind-set interventions

1 Reply

Two years ago, I was really into daily writing in my bullet journal. I used it to plan out my day, week, month, year, but also to set goals and reflect on how I was doing achieving them. During that year I felt really efficient, accomplished, capable, and it definitely felt related to all that reflection and goal-setting going on. In 2019 I continued, but not with the same regularity, and this year I’m only on page 40 of my 2020 bullet journal. But as I felt frustrated about not moving towards a specific goal a little while ago (and, in fact, effectively moving away from it), I decided that it was time to bring out the bullet journal and write down what I wanted, and why. I instantly felt better and more motivated, and this reminded me of an article that I had wanted to blog about for a while now. Because even though I don’t know if bullet journaling is what really helps me stay on the track I want to be on, or if there are other mechanisms at play, there is good evidence that short, written exercises can help students transform their mindset and achieve more.

What is an academic mind-set, and why does it matter?

What is referred to as the “academic mind-set” is a collection of core beliefs around how capable someone is and how relevant the effort that person puts into something is for their bigger picture, both related in an academic context. So for example students might believe that their intelligence and capabilities are static (“I am just too stupid for maths”) or alternatively, that anything can be learned if you just put your mind to it and enough effort into learning it. Or students might believe that they are learning for the teacher or to achieve a certain grade, rather than because they are actually learning something that will improve their own lives (or those of others).

Obviously some of those beliefs are more conductive to learning than others, and therefore the idea is of academic mind-set interventions is to change beliefs to help students become more successful in their academic lives, for example by helping them see that intelligence is not fixed but rather a matter of training, helping them develop a “growth mindset”. Or recognizing that classes — no matter how boring — might be a useful tool to bring them closer to what really matters to them, which helps give them a sense of purpose. If those beliefs are successfully addressed through interventions, that can change how students react to challenges that come their way because they interpret for example effort not as a sign of weakness but rather as a sign of effort that leads to learning. Ideally, this leads to a “positive viciuos circle” where they recognize more and more how true those beliefs are because they are becoming more successful academically. And whether this works on a large scale was tested in the article I want to tell you about:

Paunesku et al. (2015): Mind-set interventions are a scalable treatment for academic underachievement.

In the article, Paunesku et al. (2015) describe how academic-mind-set interventions can increase academic outcomes even when they are administered online and not specifically targeted to the students’ individual contexts. That way, those interventions become easily applicable everywhere and are not only available to students who are likely advantaged already, e.g. those where the parents and/or school invest extra time and money into their development.

In this case, high school students participated in two 45 minute sessions online (which is really not a lot of time in the big scheme of things!) and both interventions showed a positive impact. And, it turns out, that students who received both interventions (in contrast to one intervention and one control treatment) did not show greater benefit than from just one intervention (So if we wanted to do an intervention with our class, we wouldn’t even need to commit to twice 45 minutes).

Growth-mind-set interventions

One of the 45 minute sessions was dedicated to “growth-mind-set interventions”, designed to help students recognize that their intelligence can increase when they work hard on difficult tasks, and that the difficulty they are having is the opportunity for growth and not a sign that they are not good enough.

For this intervention, students read an article on how the brain can grow through hard work. Additionally, students did two writing exercises: Summarizing the article in their own words, and then writinga letter to a student who felt not smart enough to do well, and advising them on what they could do, based on the article the students had read.

Sense-of-purpose interventions

The second 45 minute session dealt with a “sense-of-purpose intervention”. This was done by first asking students to reflect briefly about their vision of a better world, and then helping the students reflect on what meaningful goals beyond themselves they could, and and would want to, contribute to if they learned a lot in school, and how schoolwork could help them there. This intervention is designed to help students stay motivated during boring or frustrating times because they are working towards a bigger goal.

Intervening online; and should we try it, too?

The interventions discussed in the article were specifically designed to work well online: They targeted only one single core belief each, they took only very little time, and they could be done with standardized materials because they used common stories and science concepts, i.e. they did not require tailoring to the specific course or context. This makes them — or something similar — a viable tool in other instruction, too. Seeing that having two interventions didn’t yield larger gains than just having one, I would tend to do something along the lines of the second intervention: Have students describe their vision of an ideal world, and then write about how studying will let them contribute to making it become a reality.

Granted, this research was done on highschool students and is more of a proof-of-concept than a blueprint that we can copy. But I still think that we could have our students do something similar. There is a lot of research on how applying learning to students’ lives is a really important step in the learning process, and reflecting about how that learning is contributing to their lives is one part of that. And if they grow their academic mind-set and are thus more successful even beyond the specific course we are teaching, how awesome would that be?

Even just thinking about writing about my vision for the world and how my learning of new things can open up ways I can contribute to making that vision become a reality makes me feel motivated and like the world is opening up to all these exciting new possibilities that I can’t wait to get started with. Can you feel it? I think it would be amazing to give this to our students!

—

Paunesku, D., Walton, G. M., Romero, C., Smith, E. N., Yeager, D. S., & Dweck, C. S. (2015). Mind-set interventions are a scalable treatment for academic underachievement. Psychological science, 26(6), 784-793. [link]