Tag Archives: foam

Foam pattern when hard-boiling eggs

Today we have foam patterns again, but of a very different kind than usually:

I don’t know if I have just never noticed before (I can’t really imagine I would have missed that?), if it never happened when I have boiled eggs because I always boil my eggs with more bubbles and hence more turbulence, or if French eggs are just different from german eggs?

But living in this shared flat in Grenoble is proving to be quite educational. Not only have we learned that you should never wash eggs because that destroys some protective layer of “hen juice” (technical term coined by Nadine), we also learned that a peanut and a salted peanut have different names in French (l’arachide vs la cacahouètte), and that there are cheeses with a layer of ash in them.

But anyway, I don’t think it’s foam that comes off the eggs, I think it’s coming off the bottom of the pot. Because if those bubbles are raising up from the bottom, that would explain why there are more bubbles around the edges of the eggs (when they had to move around the eggs to get to the surface) than in between, and that there is hardly any foam above the eggs? Or what do you think?

And then, of course, we are learning all the cool oceanography stuff, too, and you can read all about it over on Elin’s blog!

Burning foam

One weekend, my godson’s family took me to the Explorado Duisburg, Germany’s largest museum for kids. And one thing we learned there was to make foam that you can ignite in your palm! (Although, to be fair, they didn’t tell the kids what they put in, I had to walk up on the stage and ask ;-))

Watch the movie to see how much fun my godson’s mom and I had once the kids were asleep!

Of course we repeated the experiment with the kids the next day, too. So much fun :-)

Foam stripes parallel to the coast.

On my way to Heligoland the other day I noticed a phenomenon that I found really intriguing and that I should probably be able to explain. I first saw it on the screen of the boat’s web cams when we were about to leave the port of Hamburg. Unfortunately I could, at that point, only take a photo of the screen (but see how I excited I was to actually take a photo of the screen? ;-)).

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Can you spot what I mean? Yes, that foam stripe running pretty much parallel to the pier! The place where it bends is right in front of our boat, which you see the railing off as that white stuff at the bottom of the screen).

But then, on Heligoland, I saw it again and became even more intrigued. Right in front of the place I stayed at, you could see it looking down the coast to your left…


…and to your right!


Here we can also see the stripe bending at some point, but here again the bend coincides with a change in the coast line. Similarly to what we saw in the port of Hamburg above, the stripe stays at more or less the same distance from the coast, so it is parallel while the coast is straight, and bends out when there are obstacles (like the catamaran above or the rocks below).


So how do we interpret the whole thing? I am not quite sure. I seem to have a very vague recollection that it should have something to do with half a wave length of the dominant wave, and foam collecting in a node point. And that makes sense intuitively. Except that I have several (ha! understatement of the month) minutes of video footage of the above, and I cannot for the life of me spot anything that would explain the stripe. If it is a node point, it is a very well-disguised one and I am surprised the foam can find it!

But there must be something different about that location than about all the other places closer to or further away from the coast. Any ideas, anyone?

Foam stripes on the water.

Sometimes you need to look at the bigger picture to understand what is going on, especially when looking at phenomena on the water.

My dad recently sent me the images below from Schleswig: Weird foamy stripes on the water.

They don’t really make a lot of sense until you look at it from a different angle:


Now you see how the foam is forming in the waves all over, but that only some of that foam makes it through the gaps in that floating pier, forming a stripe behind every single gap. Cool, isn’t it?

What I found also really interesting in one of the pictures was this:


The different wave fields upwind and downwind from the pontoons. On the upwind side (right side of the picture above), you see really choppy water. On the downwind side, though, close to the pontoons, the water is pretty calm, and only with increasing distance from the pontoons waves start to build again. And we can see that the waves at the far left of that picture are still a lot smaller than those coming in on the right side, just right of the pontoons!