Over a number of years several different people have told my that when making ice cubes it is better to fill the trays with hot water than cold water since the hot water will freeze quicker. The usual explination is that when the water starts cooling the hot water will cool down faster, due to the temperature differential, and the dropping temperature of the hot water will catch up and pass the dropping temperature of the cold water. As if the temperature dropping has some kind of inertia that keeps it dropping at a faster rate. My own thought is that the drop in temperature is strictly related to the differential of the temperature of the water and that of the freezer, so that as the hot water cools down the rate of cooling will slow and the temperature of the hot water will not catch up since the cold water had a 'head start'. Has this concept ever been tested in a controled situation or is it just passed of as silly? Is there some mechanism of heat transfer that can procede with a kind of inertia that will allow the hot water to catch up with the cold water before it freezes?
PS, I have no means to test this myself, and like some scientific ideas it sounds just crazy enough to be true.
Thankyou Dingfod and Vivisectus, the article was interesting and it states that science doesn't know why it sometimes happens. The mention of impurities and gas disolved in the water as possible contributors leads me to the question 'What happens with water that is as pure as possible and with as much gas removed as possible?' If the impurities or the gas is the cause then it should not occure with pure, gas free water. Any ideas?
Based on the article it is also probable that it might not happen in the freezer making icecubes?
Ding's link is down, so I don't know what it says, but we had this discussion recently and a few people ran their own experiments. It seems the hot water thing only works in older freezers, not modern frost-free ones. Also, even in one of those older freezers, if you put in a hot and a cold tray at the same time the cold tray will still freeze first.
What seems to be happening is that in older freezers the thermostat gets covered in frost, and the temperature stays pretty stable. But when you put in a container of hot water, steam melts some of the frost and the thermostat registers a higher temperature, so the compressors kick on sooner and run longer, which makes the temperature in the freezer get lower and stay lower for a longer time than if you'd put in a tray of cold water.
It's just fooling the freezer into working harder to freeze your ice cubes, not any property of hot water that makes it freeze faster than cold.
Thats a good idea, just do it in the fridge. Glad I didn't follow my knee jerk instinct when I first saw the OP though and post some stuff about calorimeters and lawrs of thermodynamics.
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Over a number of years several different people have told my that when making ice cubes it is better to fill the trays with hot water than cold water since the hot water will freeze quicker. The usual explination is that when the water starts cooling the hot water will cool down faster, due to the temperature differential, and the dropping temperature of the hot water will catch up and pass the dropping temperature of the cold water. As if the temperature dropping has some kind of inertia that keeps it dropping at a faster rate. My own thought is that the drop in temperature is strictly related to the differential of the temperature of the water and that of the freezer, so that as the hot water cools down the rate of cooling will slow and the temperature of the hot water will not catch up since the cold water had a 'head start'. Has this concept ever been tested in a controled situation or is it just passed of as silly? Is there some mechanism of heat transfer that can procede with a kind of inertia that will allow the hot water to catch up with the cold water before it freezes?
PS, I have no means to test this myself, and like some scientific ideas it sounds just crazy enough to be true.
Perhaps you could just start drinking your whiskey without ice. That way you would not have to wait so long.
__________________ You can always trust a person in search of the truth, but never the one who has found it. Manly P. Hall