Vanishing Ink

I've got another science conundrum for you. It's not quite as mysterious as the last one, but more amusing, really. It's (drum roll please) The Case of the Vanishing Ink.

For my current course, I'm supposed to be following a particular kind of journal-writing practise, one that involves putting on a Baroque music CD, lighting a candle, and then introspecting for half an hour by cello warbles and candlelight. Great - I love Baroque, and adore candlelight. So I thought I'd get out something a bit special for the purpose: I have a pack of floating candles that I bought a couple of years ago and never used yet; they're shaped sort of like fat lenses and are meant to be floated in pretty dishes while softly illuminating their surroundings. Seeing as the bag of candles sat in the broom closet through two hot summers (we usually have at least one week when the temperatures go well above 30°C), they melted out of shape and stuck together. But I thought they might still be useful.

I got out a little plexiglass dish, filled it with water, and dropped a candle in. Purty. But, I thought, how about making it a bit more interesting? I could colour the water, I thought. Not having my watercolours handy, I reached for the nearest colouring agent, which was a cartridge of blue ink from my fountain pen. So I dropped in about four or five drops, and watched it swirl around the water. Lovely, deep royal blue colour. I lit the candle, and started my first piece of journalling. Then I looked at the candle dish again. Hmm, I thought the water had been darker blue. Ah well. Back to writing. Another look at the dish - is it just me, or is the water getting paler by the minute? No, it's not just me. After half an hour or so, the water had gone completely clear:

Now, that kind of ink (Pelikan Royal Blue, if you must know) usually fades over time, anyway, especially if it's left in the sun; I knew that. But to disappear completely, and in such a short time? That's just weird. But it happened. Twice. I recoloured the water after it had gone clear, and again, the ink totally faded in an hour or so. I don't know - maybe it would eventually reach its ink saturation point and stay blue? But I'm not going to try it out; those ink cartridges are imported all the way from Germany and I don't want to waste them on having them fade away in the water. The candle looks pretty enough bobbing in clear water.

Life, the Universe, and Mysteriously Vanishing Ink. Science is a strange thing.

Very Mysterious

See this picture? It's a mystery. One of those "name that object" ones. What? You think it's an ice cube tray? Well, yeah, that was moderately obvious. No, I don't mean the tray. I mean those strange and vaguely improper-looking spikes sticking out of the ice cubes. Do you have any idea what they are? I sure don't.

Those spikes just started appearing on my ice cubes this summer. I really have no idea what does this. Well, okay, I have some idea, a guess. Incidentally, they're not drips from the top of the freezer; that was my first thought, and I checked if there was anything dripping. But you see how they're pointing in all different directions; if they were stalagmites - or is it stalactites? - they'd be straight up and down. Perpendicular, like the gothic architecture ("This is a peh-fect exah-mple of an ice spike of the ah-citechture of the peh-pendicular period."). But they're not. The front one, in this case, is at a 45° angle, at least; no drip could be causing that. And after I used up these particular spiky ice cubes to impart a pleasing chill to my preferred summer beverage (I like iced tea, American style - just brew some tea and dump it on ice cubes. Takes the spikes off in no time flat, and is marvellously cooling. Aaaah.), I made more ice cubes, and every once in a while, they'd throw out these spikes again. And every time, they'd be pointing off in all direction at weird angles.

So here is what I think those spikes might be: I figure they're eruptions from the ice cube's core. The other day, I opened the freezer to get some more tea chillin' materials, and there was a loudish crack from the ice cube tray. Several of the ice cubes had split down the middle and just about jumped out of the tray, and there were a couple more of those spikes sticking out of the cubes. See, I think what happens is that when the ice cubes aren't 100% frozen, and someone opens the freezer (which happens more frequently at this time of year; see "iced tea" above), the still-slightly-warmer water in the core of the cube expands, and gets shot out through a tiny hole in the layer of ice covering the cube. And then it must, I don't know, flash-freeze or something, to form these spikes. I wouldn't have thought this was possible, but there's the evidence, right here in my freezer. And it's the most logical explanation I can come up with.

The funny thing about this is that quite probably, if you tried to replicate this phenomenon in your chemistry lab's lunch kit freezer, you wouldn't be able to. There's likely some weird combination of conditions that's in place in my freezer, or even in that particular spot in my freezer (eight inches from the left on the top shelf beside the ice cream and in front of the dish of lemon juice), which, together with the prevailing atmospheric conditions and the fact that Venus and Jupiter appeared together in the early morning sky for several weeks, created ideal ice cube spiking scenarios.

None of this really matters, does it? I just thought it was curious. And those spikes look decorative, don't they?

Life, the Universe, and Ice Cube Tray Mysteries. If you can think of a better explanation than mine, do tell.

Addendum Jan. 4, 2016: The mystery has been solved! What we're dealing with is ice spikes, and here is the Wikipedia article that explains how they're formed: https://en.m.wikipedia.org/wiki/Ice_spike (the article wasn't written until a year or two after this blog post, that's why I couldn't find anything about it online). Finally, a solution!