Today we are doing the melting ice cubes experiment in fancy glasses, because Elin is giving a fancy lecture tonight: The Nansen Memorial Lecture of the Norwegian Science Academy in Oslo! Cheers!
We each had green ice cubes in our glasses, but one of our glasses contained fresh water and the other one salt water, both at room temperature. Can you figure out who got which glass?
This time lapse might give you a clue…
To read more about this experiment, check out this blog post!
Now that I have introduced the new tag “kitchen oceanography: food related” to my blog, it’s time to add a couple new posts to that category. And today I have a fun post for you!
But first, what does “kitchen oceanography” even mean?
It’s pretty apparent why “kitchen oceanography” is a great alternative to regular tank experiments: because you can do it with stuff you have at home rather than needing access to a lab with a tank, and then a lot of water, salt, dye, other resources to conduct the experiments. Doing kitchen oceanography, we use a minimal amount of resources.
But the second, even larger benefit to me is that you can do these kinds of experiments and observations basically everywhere and at any time. So you can fit in a quick session of kitchen oceanography while sitting in front of the fire place on a skiing trip with friends, or while doing the dishes with your godchild. And you can inspire others who might not have access to labs to still do cool oceanography experiments, at home or wherever they like!
Apparently, the biggest predictor of future interest in STEM topics is whether people as kids often cooked with their parents! No literature source for this, but that’s what my educational research colleagues next door told me… So playing in the kitchen, whether on kitchen oceanography or with food, is a good thing!
Observing boiling eggs might not sound like a super exciting activity to engage in, but sometimes it is. Last year we did observe interesting foam pattern when boiling eggs (I still can’t explain where the foam is coming from! Can you?).
Foam pattern in a pot of boiling eggs. P.S.: The “black egg” sings different songs to let me know how hard-boiled my eggs are at any given moment. I love this because they are songs I learned from my godson and it always reminds me of him and his family :-)
The pattern in the foam show the convection pattern of the boiling water around the eggs which act as obstacles. Water is raising from the bottom of the pot to its surface, bringing up foam. But the eggs are located so close below the water’s surface that the circulation above them (if there is one) is pretty much disconnected from the convection happening all around the eggs.
But then if you throw out the water…
Limescale deposits at the bottom of an empty pot after boiling eggs in it
But then the next cool thing happens when you throw out the water: There are limescale crystals on the bottom of the pot! And, interestingly enough, they show the former locations of the eggs. And I think they are forming in exactly those spots because just as there is (hardly any) circulation above the eggs, the circulation below is also inhibited, water has longer residence time (because it isn’t whipped away by convection) and those crystals can form.
An alternative explanation might be that there is more limescale below the eggs because calcium carbonate gets dissolved from the egg shells and gets deposited as limescale right below the eggs because the concentration is highest closes to the eggs.
Which explanation do you think is more likely? Or do you have another one entirely?
What is the impact of this blog? And who am I writing it for?
Those are not questions I regularly ask myself. The main reason I started blogging was to organise all the interesting stuff I was collecting for my introduction to oceanography lecture at the University of Bergen in one place, so I would be able to find it when I needed it again. And I wanted to share it with friends who were interested in teaching oceanography or teaching themselves.
Another of the reasons why I blog is that I notice a lot of exciting features in everyday life that relate to oceanography and/or physics, that other people would just walk past and not notice, and that I would like to share the wonder of all those things with others. And noticing all this stuff is so much FUN! The blog “gives me permission” to play, to regularly do weekend trips to weirs or ship lifts or other weird landmarks that I would probably not seek out as often otherwise.
But the other day I was browsing the literature on science blogging in order to come up with recommendations for the design of what is to become the Kiel Science Outreach Campus’ (KiSOC) blog. I came across a paper that resonated with me on so many levels: “Science blogs as boundary layers: Creating and understanding new writer and reader interactions through science blogging” by M-C Shanahan (2011). First, I really liked to see the term “boundary layer” in the title, since it brings to mind exciting fluid mechanics. Then second, I read that the boundary phenomena I was thinking of were really where the term “boundary layer” came from even in this context. And then I realised that I have had “boundary layer” experiences with this blog, too!
So what are those boundary layers about? Well, in fluid mechanics, they are the regions within fluids that interact with “something else” — the boundary of a flow, e.g. a pipe, or a second fluid of different properties. They are a measure for the region over which temperature or salinity or momentum or any other property is influenced by the boundary. But the same construct can be used for social groups, i.e. in my case oceanographers and non-oceanographers. (You should, btw, totally check out the original article! Her example is even more awesome than mine)
But here is my own boundary layer experience: My sister sent me an email with the subject “double-diffusive mixing” and a picture she had taken! My sister is not an oceanographer, and I wasn’t even aware that she associated the term “double-diffusive mixing” with anything in particular other than me writing my Diplom thesis about it and probably talking about a lot. But that she would recognise it? Blew my mind!
Turns out what she saw is actually convection, but it doesn’t look that dissimilar from salt fingers, and how awesome is it that she notices this stuff and thinks of oceanography?
Day 1. The remaining pink soap starts making its way up through the refill of clear soap.
Obviously I asked for follow-up pictures:
Day 2. A lot of the pink soap has reached the top, passing through the clear refill.
Day 3. All of the “old” pink soap is now on its way up through the clear refill.
And I had another boundary layer experience recently: A sailor on the Norwegian research vessel Håkon Mosby with many many years experience at sea had seen my book and told me that he now looks at waves in a new way. How awesome is that? That’s the biggest compliment my book could get, to teach something new about visual observations of the ocean to someone who looks at the ocean every single day!
Anyway. Reading this article made me think about how happy both those boundary layer experiences made me, and that maybe I should actually start aiming at creating more of those. Maybe not with this blog, that I kinda want to keep as my personal brain dump, but there are so many different ways to interact more with people who would potentially be super interested in oceanography if only they knew about it… I guess there is a reason why I am working the job I am :-)
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Shanahan, M. (2011). Science blogs as boundary layers: Creating and understanding new writer and reader interactions through science blogging Journalism, 12 (7), 903-919 DOI: 10.1177/1464884911412844
In my last post, I showed you the legendary overturning experiment. And guess what occurred to me? That there is an even easier way to show the same thing. No gel pads! (BUT! And that is a BIG BUT! Melting of ice cubes in lukewarm water is NOT the process that drives the “real” overturning! For a slightly longer version of this post check this out).
So. Tank full of luke warm water. Red dye on one end. Spoiler alert: This is going to be the “warm” end.
Now. Ice cubes on the “cold” end. For convenience, they have been dyed blue so that the cold melt water is easily identifiable as cold.
A very easy way to get a nice stratification! And as you see in the video below, awesome internal waves on the interface, too.
And because I know you like a “behind the scenes”:
I took this picture sitting on my sofa. The experiment is set up on the tea table. The white background is a “Janosch” calendar from 15 years ago, clipped to the back of a chair. And that is how it is done! :-)
What is wrong with this picture?
Random wall somewhere between Mölln and Hamburg
Don’t you guys make your parents stop the car when you drive by newly built walls in random villages somewhere when they are a perfect example of what the Paranuss-Effekt (Brazil nut effect, or granular convection, for all you non-german-speakers) does NOT look like?
For comparison, this is what it SHOULD look like:
My emergency snacks. Why is it always so hard to get the sunflower seeds out of a jar of mixed nuts?
Yep. Granular convection!
Another one of those days where I kinda wish I had taken at least some meteorology at some point (only “kind of” because I wouldn’t want to miss any of the stuff I actually took…). But on my way to work I saw the clouds below:
The internet says they might be cirrocumulus undulatus clouds.
In any case, the wavy clouds started to disintegrate into cirrocumulus-like clouds.
But whatever they were, they were very pretty!
Meteorologists out there (Torge! :-)) – what kind of clouds were they and why did they form?
Don’t you just love lava lamps?
I got a lot of weird looks when I excitedly told people about two years ago that I had just bought a lava lamp. But what’s not to love about them? Plus they are great for teaching. These days kids don’t know them any more, so they are missing out on a really nice mental image of how convection works. Be it in the Earth’s mantle or in the ocean…
“Lava” flow.
When I moved into my new flat, for the first week I only had an inflatable air bed and my lava lamp in my living room (oh, and a lot of boxes of course). So I have spent a lot of time looking at how the flow changes over time.
Today, all I want to share is this 9 minute movie of the lava lamp. But I’m working on a post where I’m discussing the temporal development of the flow. Sounds interesting? Stay tuned! :-)