Wikipedia:Reference desk/Archives/Miscellaneous/2010 November 30

= November 30 =

Harry Potter film location
In the Harry Potter movie that recently came out, Harry and Hermione are on the run and end up in some pretty neat locations. One of the locations was rather unusual and I'd like to know more about it. The location looks over a valley but what made it interesting were the rocks that they were standing on. Think of a large sheet of rock that is hit with a gigantic hammer so that there are thousands of cracks running throughout. But the cracks aren't jagged and sharp. They've been rounded off so that you're left with all these sort of rock islands with round edges and each rock is only separated by a couple inches from the one next to it. For those who've seen the movie, it was the location where H & H had decided to go to Godric's Hollow. Does this sound familiar to anyone? I've looked through the images at IMDb but didn't see any of this location. Thanks, Dismas |(talk) 06:05, 30 November 2010 (UTC)
 * Wait, no. I found a pic of the scene:   Thanks for any info, Dismas |(talk) 06:07, 30 November 2010 (UTC)
 * In films, it can be hard to tell matte paintings and such from the real thing, especially nowadays. ←Baseball Bugs What's up, Doc? carrots→ 07:16, 30 November 2010 (UTC)
 * Looks kind of like pillow lava. Compare with 161.222.160.8 (talk) 07:49, 30 November 2010 (UTC)
 * It reminded me immediately of The Burren in western Ireland. A limestone landscape that has been eroded by rain over millenia, all those clints and grikes look similar to the HP scene. Here [] is a selected picture. Richard Avery (talk) 08:13, 30 November 2010 (UTC)
 * It's limestone pavement all right, but it appears to be filmed near Malham Cove rather than The Burren. See here.  Ka renjc 09:43, 30 November 2010 (UTC)
 * Agreed; look at this. The imdb page lists the Yorkshire Dales National Park (which Malham is within) amongst the locations. Alansplodge (talk) 09:50, 30 November 2010 (UTC)
 * There's no doubt that it was Malham Cove, I recognised it the moment I saw it in the film. Mikenorton (talk) 10:22, 30 November 2010 (UTC)

Thanks all! The Malham Cove article even mentions that filming took place there. Dismas |(talk) 10:27, 30 November 2010 (UTC)

Hot ice?
Mother always said that hot water freezes quicker than cold; was she right?--Artjo (talk) 12:07, 30 November 2010 (UTC)
 * Hot water, no - but there is some research that shows that warm water can freeze faster than cold water. The reasons still seem to be debated, but it's often suggested that in a still environment like a freezer, the warm water has stronger convection currents that result in uniformly faster heat transfer. See Mpemba effect, which covers this fairly well, and also this article which goes into quite a bit of detail. ~ mazca  talk 12:16, 30 November 2010 (UTC)

Great thanks, answered quicker than frozen!--Artjo (talk) 12:33, 30 November 2010 (UTC)


 * Fascinating. I'm still not fully convinced. But the implication of that article is that with warm water you're liable to end up with smaller cubes. There's no fooling mother nature. But there's a better reason to start with cold water, which is that the hot-water pipes are more likely to have various kinds of gunk in them, and less palatable for consumption, which is why in cooking it's normally recommended to run your saucepan full of cold water and bring it to a boil. And even with cold-water pipes, it's typically recommended to run the water about 30 seconds before consuming any of it. ←Baseball Bugs What's up, Doc? carrots→ 14:56, 1 December 2010 (UTC)
 * Shouldn't this be in the Science Ref desk? My understanding is (or was?) that hot water has slightly less oxygen than cold water.  (Right?)  So given a hot water pipe and a cold water pipe side by side, when a hot water pipe freezes, there is less room for the freezing water to expand, and the pipe sometimes bursts, while the cold water pipe does not.  (Leading some to believe that hot water freezes first?)  I'd be skeptical of any research that indicates that warm water freezes faster than cold water.  They both need to reach 32°, and it seems obvious that the cold water would get there first....  Kingsfold   (Quack quack!)  17:16, 2 December 2010 (UTC)
 * Cold or hot, water expands 5-10% when it freezes and would probably break either of your water pipes. Googlemeister (talk) 20:17, 2 December 2010 (UTC)

Switching off the refrigrator
Is it a good idea to switch of the fridge daily for a few hours to save electricity during winters? I am told that frequent switching of the fridge wil result in some loss of the gas filled in it. Can anyone give me a detailed answer?Sumalsn (talk) 15:27, 30 November 2010 (UTC)
 * Ask yourself about the value of saving a few pennies of electricity cost vs. the potential risk to yourself and your family from food spoilage. ←Baseball Bugs What's up, Doc? carrots→ 15:40, 30 November 2010 (UTC)


 * It shouldn't save energy. Fridges have thermostats in them, so they already don't run when they're already cold.
 * (Of course, if you leave it off long enough you'll save energy and your food will get warm.)
 * The second part of your question will require a mechanic to answer, but I can't imagine why it would lose refrigerant. APL (talk) 15:54, 30 November 2010 (UTC)


 * You would be better of making sure it is properly defrosted and that the coils behind has any fluff vacuum off them. Switching off will only cause it to run for longer when you switch back on again. The compressor in domestic fridges are sealed inside the sump so nothing will leak out simply because its off. . If your the very reincarnation of Jack Benny, then leave a metal container of water outside overnight  to freeze then put that in the fridge. You might need to add a little salt to get the temperature down to 5 Centigrade (40 F) but it might help to raise a laugh from your neighbours. --Aspro (talk) 15:58, 30 November 2010 (UTC)
 * Yea, if you don't need a freezer, in many areas you could probably go one step farther and not use your fridge at all during the winter months. Some combination of leaving stuff on the windowsill and keeping portable coolers cold with icepacks frozen outdoors would probably be adequate for many people.  (A little labor intensive, though.) APL (talk) 16:06, 30 November 2010 (UTC)


 * (ec)APL's cogent comment farther up reminds me of the old joke about having a truckload of parakeets and the truck being overweight, so "we have to keep half of them flying". ←Baseball Bugs What's up, Doc? carrots→ 16:07, 30 November 2010 (UTC)


 * Scientifically, that could be feasible if the truck was such that air could pass in large quantities to and from the birds wings from outside the truck. It would not work for an enclosed cargo area though.  Googlemeister (talk) 20:11, 2 December 2010 (UTC)


 * I think in parts of Scandinavia they have a cupboard (closet I think in American-english) with the outside uninsulated, that serves as a fridge. 92.28.247.40 (talk) 16:25, 30 November 2010 (UTC)


 * Many older residences in Northern California have a kitchen cabinet adapted for keeping vegetables. The shelves are wire, to facilitate air circulation, the inside door is solid, and there are screened vents to outdoors at the top and bottom. Not as good as a refrigerator, but cheaper, and reasonably effective in our mild climate. PhGustaf (talk) 16:52, 30 November 2010 (UTC)


 * The culinary term for these storage cupboards or rooms is Larder--Aspro (talk) 17:31, 30 November 2010 (UTC)
 * Which, along with its root word lard, come from Latin, for fat or bacon. It's fair to say that if one's diet had substantial lard in it, the cost of electricity should be the least of their worries. ←Baseball Bugs What's up, Doc? carrots→ 17:38, 30 November 2010 (UTC)
 * Lard! This saturated fat issue has been over-hyped by the vegetable oil industry. Saturated_fat. The worst thing about having a large a pot of lard in the larder is if it falls off the top shelf and lands on one's toe -that really hurts!--Aspro (talk) 18:31, 30 November 2010 (UTC)


 * I haven't seen anyone mention the fact that whatever rise in temperature that occurs due to the fridge being turned off/unplugged, you'll have to make up for once you turn it back on/plug it back in.  The best way to save energy is likely just not opening it as often to keep as much of the cold air inside.  Dismas |(talk) 17:41, 30 November 2010 (UTC)


 * Aspro did in his first comment, although the reason was implied. --Saddhiyama (talk) 17:43, 30 November 2010 (UTC)


 * Whatever you do, don't empty the fridge out, unplug it, and leave it alone with its doors closed for months. Mold will run riot, deliriously happy, inside the refrigerator.  Comet Tuttle (talk) 19:31, 30 November 2010 (UTC)
 * If the mold is in the dark, where does the energy come from for its growth? 92.28.247.40 (talk) 20:21, 30 November 2010 (UTC)
 * A mold can sit in the dark, eating food, and exist quite happily, just as you or I could. Molds are fungi, and one of the distinguishing characteristics of a fungus (differentiating it from plants) is that it does not have chlorophyll and does not use sunlight for energy. —Steve Summit (talk) 20:30, 30 November 2010 (UTC)
 * Absolutely. I moved into an apartment once where the idiots had turned off the power and left the fridge door closed. Eek. I should point out that while I did not observe any mold, the fridge smelled like seriously spoiled milk. ←Baseball Bugs What's up, Doc? carrots→ 19:36, 30 November 2010 (UTC)
 * I can go one better (or worse) than that:--Aspro (talk) 20:41, 30 November 2010 (UTC)


 * Two points:
 * Theoretically, switching off a fridge for a while would save energy (though this does not make it a good idea!). Yes, when you switch it back on, it's going to have to cool down again, but the energy it takes to do that will be generally be less than the amount of energy that would have been required to keep the fridge fully cold for the duration, counteracting the inevitable heat leakage.  The argument is the same as the one which refutes a widely-held urban legend, namely that turning off your heat when you're not at home during cold weather wastes energy, because of the extra work your furnace has to do to heat the house back up when you return.  (On the contrary, turning off the heat saves energy, of course.)
 * Speaking of urban legends, the one about fridges being damaged by turning them off is a doozy. It might have had some credence a hundred years ago for some completely different refrigeration technology, but for a modern refrigerator, it's nonsense.  Turning off a refrigerator, or unplugging it, is no different in its effect on the fridge's internal components than the normal on/off cycling which the thermostat does all the time.  Presumably the fridge doesn't damage itself when it turns itself off, so it won't be damaged when you turn it off, either. —Steve Summit (talk) 20:42, 30 November 2010 (UTC)
 * But with your point one, if you turn your refrigerator off longer than it would have cycled itself off anyway, your food will get warm. APL (talk) 22:41, 30 November 2010 (UTC)
 * What I would add to 'point one' is that when it comes to things like ice-cream (which also has a high specific heat capacity) it can still be below freezing but will be spoilt if it raises above -12 C. In fact I think it might need to stay below -16 C.--Aspro (talk) 21:07, 30 November 2010 (UTC)
 * Yes? Since a fridge stays above freezing, ice cream kept in it for any great length of time will be spoilt anyway. A fridge that went below freezing would be faulty, and turn salad to mush. Turning it off won't change a fridge's inability to store ice cream properly. You are thinking of a freezer. 86.161.108.241 (talk) 13:02, 1 December 2010 (UTC)
 * Don't be disingenuous. One of the most common meanings of the word 'refrigerator' is a stand-up combination appliance containing compartments both above (refrigerator) and below (freezer) freezing.  Go ahead, do a Google Image search on 'refrigerator' &mdash; you'll be lucky to get one fridge-without-freezer appliance in the first couple of pages of hits.  See also synecdoche.  TenOfAllTrades(talk) 14:31, 1 December 2010 (UTC)
 * The formal term I used to hear was "refrigerator-freezer", indicating the combination, but nowadays the typical "refrigerator" also has a "freezer compartment" - even many of the little boxy refrigerators you find in hotel rooms. Hence the normal usage "refrigerator" (or "fridge") is assumed to also have a freezer compartment. ←Baseball Bugs What's up, Doc? carrots→ 14:48, 1 December 2010 (UTC)
 * For what it's worth, 86.161 isn't alone in thinking "refridgerator" refer only to above-freezing coolers. To use the word "fridge" to describe something that keeps food below freezing would be extremely odd where I live (England). The OP might (or might not) think the same way. Vimescarrot (talk) 18:20, 1 December 2010 (UTC)
 * "Fridge" might be an Americanism, and might derive from the brand name "Frigidaire" as much as from "refrigerator". ←Baseball Bugs What's up, Doc? carrots→ 18:38, 1 December 2010 (UTC)
 * Note that according to EO, "refrigeration" can refer to freezing as well as cooling. ←Baseball Bugs What's up, Doc? carrots→ 18:40, 1 December 2010 (UTC)
 * Note also that the Frigidaire corporation sells freezers separately, but that all of their products labeled just-plain "refrigerator" also appear to have freezer compartments. ←Baseball Bugs What's up, Doc? carrots→ 18:44, 1 December 2010 (UTC)
 * In my experience, the freezer compartment of those little mini-fridges is worthless for storing icecream as it is barely below freezing. Googlemeister (talk) 20:15, 2 December 2010 (UTC)

Exterior mirrors
Are there such things as mirrors designed for exterior use? I would like one or two to put next to a skylight in a flat roof, to blot out an ugly view and direct more light down the skylight. They could have other uses too - I'm intregued by the idea of building a grotto in my garden so that I can be outdoors without the traffic noise. Thanks 92.28.247.40 (talk) 18:50, 30 November 2010 (UTC)
 * Unless you enjoy seeing the sun in the mirrow, you might be better off to get some of those reflector things that photographers use in outdoor settings to add extra light to the subject. File:Photographing a model.jpg They're kind of like mirrors but with less likelihood of blinding you. ←Baseball Bugs What's up, Doc? carrots→ 18:56, 30 November 2010 (UTC)
 * Nah, Perhaps he wants the sharp, high contrast lighting you get when the sun is shining into your window. (As happens naturally from time to time without the need for mirrors.)
 * You probably want something designed for garden use. This is an example : APL (talk) 19:04, 30 November 2010 (UTC)
 * I presume that those fish eye mirrors they put on the road side so that cars coming out of a driveway or road can better see who's coming are designed for exterior use. I don't know if that's what you want though. Nil Einne (talk) 20:49, 30 November 2010 (UTC)
 * They are convex mirrors. 92.28.247.40 (talk) 22:25, 30 November 2010 (UTC)
 * Yes fish eye mirror redirects there but I forgot to link it Nil Einne (talk) 04:15, 1 December 2010 (UTC)

Thanks, although I don't see why seeing the sun in a mirror would be any worse than seeing it directly. The advantage of a mirror rather than a white wall is that the mirror should be invisible and make it appear that you are instead looking at the sky or whatever. The acrylic garden mirror looks good, and perhaps its possible to buy the acrylic sheeting directly from somewhere without the big mark-up in price. 92.28.247.40 (talk) 20:19, 30 November 2010 (UTC)
 * It wouldn't be worse, it would be just as bad. ←Baseball Bugs What's up, Doc? carrots→ 20:27, 30 November 2010 (UTC)


 * Glue some of these onto a board of your choice. --Aspro (talk) 20:50, 30 November 2010 (UTC)