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Reply	Anonymous says: The bubbles are gas that was dissolved in the liquid water but precipitated out on freezing. Not sure why the pattern formed but probably due to the direction from which the ice formed in the vessel - as ice floats, gas bubbles would be trapped under the ice layer. As the ice layer gets thicker and more bubbles precipitate out, they could form lines through the thickness like this.  (no votes) Tags: technology, domestic science, human body.
	posted on 2009-02-04 21:04:00 | Report abuse

Reply	David Rice says: This is based on simple science. Most water has air dissolved in it. As the water freezes the air is forced into bubbles (air does not freeze at the same temperature as water). This creates white patterns in the water. These patterns are determined by the way in which the water frezes. The water probably froze from the top down, and these bubbles moved up, following the curve of the growing lump of ice. The air is inevitably trapped by the ice, and are preserved in these curious tubes. I would surmise that this formation is fairly hard to achieve all the same.  (no votes) Tags: technology, domestic science, human body.
	posted on 2009-02-08 05:58:00 | Report abuse

Reply	Anonymous says: Why on earth would you ask NewScientist when you could ask John Richfield?  (no votes) Tags: technology, domestic science, human body.
	posted on 2009-02-09 21:40:00 | Report abuse

Reply	P. Harrowell says: I love this picture! The water in the mug froze from the outside. As the water froze, the dissolved air was excluded from the region now filled by ice - a crystal is generally a lot less accommodating when it comes to guest molecules. As the concentration of air builds up at the ice-water interface, the air forms bubbles. That's why none of the air tubes make it to the surface - the surface had to freeze enough to begin generating bubbles. Anyway, now comes the good bit. The ice continuous to freeze around the bubble, forming gas-filled pores in the ice surface. These act as ideal nucleation sites for the next bubbles to form and the ice grows around these as well. The tubes are the result of this sequence of bubbles forming on the sites left by the previous bubbles. The curve in the tubes tracks the changing direction of the ice front as it grew into the centre of the mug. The concentration of tubes in the middle is the result of all the remaining air in the liquid being forced into bubbles as the last bit of liquid froze.  (no votes) Tags: technology, domestic science, human body.
	posted on 2009-02-24 04:06:00 | Report abuse

Reply	Martin says: Hi Brian. The answers on here are 100% correct - it is air bubble coalescing as the ice formed. But being born and growing up in Stellenbosch and Cape Town, there is an additional chemical force at play too....Cape Town, and Somerset West's water, is some of the cleanest in the world, often rivalling the best mineral water for taste and purity. One of the best ways of proving waters purity is on fact a freeze test, to see what kinds of gunk as well as how much air is present in the water. This is a not often used test, but it does in fact have an ISO standard associated with it. (Learnt about that at the University of Stellenbosch, Dept. Food Science)The waters of the Western Cape are remarkably pure, very particulate free, and very sterile, but have a definite acid/base moeity that gives them increased flow, and higher solubility.The pattern is a classic example also of ice crystalisation at low rH (relative humidity - the Cape rarely gets over 22 degrees rH) and gradually on a hot summer's day...  (no votes) Tags: weather, technology, unanswered, domestic science.
	posted on 2009-03-04 02:29:00 | Report abuse

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