Wikipedia:Reference desk/Archives/Miscellaneous/2009 May 14

= May 14 =

awkward question
does anyone how to solve this???????! 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + 9 + ... - 99 - 100

(i know the answer is 100 cos i did it with some simple extensions and calculations, what i'm asking for is a way to solve it in the shortest simplest mathematical way) thanx —Preceding unsigned comment added by 122.50.137.100 (talk) 09:33, 14 May 2009 (UTC)


 * Easy, take the first two numbers added together, and keep adding 4 (up to 9+10), then multiply by 5, and add 5. Simple.--KageTora - (영호 (影虎)) (talk) 09:52, 14 May 2009 (UTC)
 * KageTora, note that there is no equals sign. It's a series, not a sum. --Polysylabic Pseudonym (talk) 09:56, 14 May 2009 (UTC)


 * The pattern ++-- does seem to repeat. The ellipsis seems to indicate that the pattern repeats. So write the numbers 1 to 100 and follow the pattern you gave. 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + 9 + 10 - 11 -12 ... - 99 - 100 --Polysylabic Pseudonym (talk) 09:55, 14 May 2009 (UTC)


 * Yes, 4 and 5 are the most important numbers in it. That's a hint.--KageTora - (영호 (影虎)) (talk) 09:57, 14 May 2009 (UTC)


 * And then I wake up and read the question. You solve it by either summing the entire series (where numbers increase by 1 each time, and the sign changes from + to - and vice versa every two numbers) or you note that the pattern gives an obvious answer where after every first "-" the answer is zero, and after every second one it is minus whatever digit we're up to. The answer is certainly not +100. --Polysylabic Pseudonym (talk) 10:10, 14 May 2009 (UTC)


 * Also there is a mathematics reference (WP:RD/MA) desk which might be a bit more appropriate --Polysylabic Pseudonym (talk) 11:56, 14 May 2009 (UTC)


 * It comes out prettier if you start with -0, and get zeroed lines from there:

- 0 + 1  + 2  - 3 - 4  + 5  + 6  - 7 - 8  + 9  + 10 - 11 - 12 + 13 + 14 - 15 - 16 + 17 + 18 - 19 - 20 + 21 + 22 - 23 ...
 * --Sean 15:14, 14 May 2009 (UTC)

And, of course, the end answer is '0'.--KageTora - (영호 (影虎)) (talk) 23:53, 14 May 2009 (UTC)


 * ... if you stop at -99. The final term in the original question, however, is -100. Gandalf61 (talk) 09:07, 15 May 2009 (UTC)

Physical Training
Hello, I just saw the SEALS training videos, which looked damn hard. Are there other training units from some military (not necessarily from US) which are even harder? What kind of physically challenging things do they have to do? - DSachan (talk) 13:55, 14 May 2009 (UTC)


 * You might want to look at United Kingdom Special Forces and links off of it (e.g. Special Boat Service and Royal Marines - both of which are known for intense training regimes. 194.221.133.226 (talk) 14:02, 14 May 2009 (UTC)


 * There is a large number of special forces groups around the world (List of special forces units). Which ones are the "hardest" is probably a point of view issue, especially since there is an "our country is best" component. -- 128.104.112.117 (talk) 14:06, 14 May 2009 (UTC)

Cos i'm nice here's links from those links Royal Marines recruit training and Special Boat Service. No idea whether that is more than United States Navy SEALs but I wouldn't fancy doing any of it! 194.221.133.226 (talk) 14:07, 14 May 2009 (UTC)
 * Any SEALs trainee here, who spends the rest of his training time editing wikipedia? - DSachan (talk) 14:21, 14 May 2009 (UTC)

There are specialty "soldier forums" like this one [] that could perhaps better answer your question. Acceptable (talk) 00:07, 15 May 2009 (UTC)

EU fines Intel; why does Intel pay?
So the EU has just fined Intel $1.5 bn for anticompetitive practices, like they've done with Microsoft in the past. I don't get the jurisdiction issue, though. What compels Intel (or Microsoft, or other US-based companies) to pay up? I can't fathom much reason aside from a goodwill desire to maintain the current business relationship, but it also seems as though there's an opportunity for the company to make the EU flinch (well, for Microsoft anyway; I'm not sure Intel has quite the perception of irreplaceability). There's quite a rabbit hole of move and countermove options here if the fine isn't compulsory. Note: while there's a discussion to be had about whether or not the EU could switch en masse to Linux, AMD, or what have you, that's not really the question I'm interested in (and certainly not the zealotry magnet I'm interested in). &mdash; Lomn 15:37, 14 May 2009 (UTC)
 * If they refuse to pay, eventually the EU will simply seize their European assets & accounts, plus they'll lose the European market. In the end, the European market matters more to Microsoft/Intel than those companies matter to Europe. —Preceding unsigned comment added by 194.171.56.13 (talk) 15:45, 14 May 2009 (UTC)


 * Agree with the above, although it would technically be possible for a company like intel to just flip the EU the bird and ignore the fine, it would almost certainly cost far more then the fine. 65.121.141.34 (talk) 16:00, 14 May 2009 (UTC)


 * How about sources for the above? Particularly with Microsoft, what "European accounts and assets" are there to be subject to seizure?  I tend to agree with the risk/reward of paying the fine, even if the nationalist in me would like to see who would break in a game of chicken.  However, I can reach such speculation of my own accord. &mdash; Lomn 16:06, 14 May 2009 (UTC)


 * See lien. A lien is a right, enforceable only in equity, to have a demand satisfied out of a particular fund or specific property without having possession of the fund or property on a debt.  A government is able to impose a lien.  The EU operates in the same way.  So they can seize properties or funds of Intel for non-payment, if there are properties or funds of Intel that are within the reach of the EU people who do that sort of stuff.  65.121.141.34 (talk) 16:21, 14 May 2009 (UTC)
 * Microsoft, as with any multinational, will have subsidiaries in several European countries which will have significant assets that can be seized. They could avoid that by quickly moving all their assets out of Europe, but that would require withdrawing from the European market. That would cost them far more. --Tango (talk) 16:24, 14 May 2009 (UTC)


 * Thanks guys. &mdash; Lomn 18:09, 14 May 2009 (UTC)


 * Also, if Intel or Microsoft just "skipped town" and didn't pay, the EU would probably contact the US State department or the Justice department after a while and invoke one of the multitude of mutual assistance and legal cooperation agreements. Hillary's job is probably quite interesting enough without.71.236.24.129 (talk) 05:37, 15 May 2009 (UTC)

company based tariffs ?
The above question about Intel getting fined by the EU made me think of a question. Is it within the power of companies to impose their own tariffs on trade to certain foreign countries? IE, could Intel decide to hike the price of all their good exported to EU countries (and only EU countries) by say 10% in order to make the citizens of the EU pay their fine for them? 65.121.141.34 (talk) 16:04, 14 May 2009 (UTC)
 * I don't know about the legalities in this case. Or how high they could hike it before retailers simply bought from non-EU wholesalers. But see Regional lockout. That's rather relevant. APL (talk) 16:13, 14 May 2009 (UTC)
 * If they increase their prices more people will buy their competitor's products. They will already be charging the amount that maximises their revenue, that's how prices are determined. --Tango (talk) 16:21, 14 May 2009 (UTC)
 * It is common for companies to charge different prices for their products in different countries. Cars are a good example, which can vary in price even between the US and Canada. However if they raise prices much they will find other people importing them from one place to another. Especially if your product is easy to ship, like computer chips. DJ Clayworth (talk) 17:46, 14 May 2009 (UTC)
 * Absolutely possible. Companies can price their products however they want from territory to territory.  US drug companies encounter controversy for this, because they're in sort of a no-win PR situation.  If they sell an HIV drug to African distributors for the same price as they sell it to American distributors, they're pilloried for not making the drug available to the poor.  If they discount it to the African distributors, the American consumers bitch that they're being taken to the cleaners.  Tempshill (talk) 19:19, 14 May 2009 (UTC)


 * As a matter of private law, it is valid for a company to discriminate amongst its customers. These are not really "tariffs" but simple price discrimination. Domestically, though, there could be anti-discrimination law constraints on the basis on which the company can discriminate. For example, "we charge them more because the standard of living in Norway is higher" is fine, but "we charge them more because we don't like the looks of them damn Aryans" could well be illegally discriminatory.
 * International trade law might get involved if there is some kind of governmental role in this: e.g. by its act or omission the government is supporting, mandating or condoning discriminatory trade behaviour. This would depend on the interpretation of the nature of the measure: e.g. is it dumping? --PalaceGuard008 (Talk) 00:25, 15 May 2009 (UTC)


 * The problem (both with Intel and Microsoft) is not that they priced their product in a particular way - it's that they did so while abusing their near-monopolistic status. When you are a near-monopoly, you have to moderate your business behavior so as not to use that position to push your competitors out of the market.  I was surprised that Intel got hit with a larger fine than Microsoft - but I haven't been following the action too closely.  Incidentally - Intel are being sued for similar infractions in the USA, Korea and Japan - and they already lost a similar case brought about by AMD in US courts in 1992...so don't jump to the conclusion that this is something new - or that the Europeans are in any way unusual in this regard. SteveBaker (talk) 03:15, 15 May 2009 (UTC)

Pentland South Pole Expedition
'What brand & type of tent was used during the Pentland South Pole Expedition by Sir Ranulph Fiennes?'

I've searched already a lot about this one; I've sent e-mails, got response, but not the answer to my question. I really can't find it. I hope someone can answer this for me. 91.180.4.26 (talk) 17:47, 14 May 2009 (UTC)

Validity of Soviet passports
For how long was a Soviet international passport valid? Someone told me it was 20 years, so a few would still be in date now. If so, can they still be used for travel? 86.130.134.9 (talk) 18:10, 14 May 2009 (UTC)


 * This link at the US State Department website says Soviet passports are no longer valid. This link from the Canadian immigration service is interesting, talking about people within Russia still using Soviet "internal passports".  Tempshill (talk) 19:25, 14 May 2009 (UTC)
 * The first link only mentions official and diplomatic passports, not ordinary ones. Thanks for the reply though. Re the second link, I wonder how a new internal passport necessarily contains a triple-six - surely if it was only in the serial number and the court finds that a reasonable concern, it could instruct OVIR to generate a new one. 86.144.112.84 (talk) 23:54, 14 May 2009 (UTC)

How to disarm a bomb
I've seen this done so many times on TV and in the movies that I've become interested in learning the theory of how to do so. I don't suppose there is a night class in bomb disablement at my local college - do I have to joint the military or law enforcement to learn the techniques? Also, why do bomb makers use different color wires (cut the red one, no the blue one!)? —Preceding unsigned comment added by 75.36.216.233 (talk) 18:20, 14 May 2009 (UTC)
 * Most sizable police agencies have a special force known as a "Bomb Squad" which speciallizes in Bomb disposal. Unfortunately, this is not the sort of training which is availible to the general public, as its the kind of advanced training you get AFTER you are already a member of the military or part of a police force.  There's just not the demand necessary to teach classes on this stuff to the general public.  Its sort of a specialized job requirement, such that you usually need to have the job before you need to be taught how to do it.  I certainly have never been around a bomb long enough to be able to disarm it.  Also, it should be noted that the kind of bomb that usually gets disarmed in the movies, the one with the convenient little clock which ticks down the time till detonation, does not really exist.  Most bombs are fired by proximity triggers of some sort, which require a person to move the bomb; or they are activated remotely, such as by a cell phone.  The whole rediculous plot element of giving the cops a nice convenient clock to tell them how long they have to foil your nefarious plot is entirely illogical once you think about it.  Bombs are meant to blow up and kill people.  If you are the Evil Midnight Bomber What Bombs at Midnight you don't want to really make it that way... --Jayron32. talk . contribs  18:36, 14 May 2009 (UTC)
 * That's on the list of things not to do if you are en evil overlord. Number 15. DJ Clayworth (talk) 21:13, 14 May 2009 (UTC)
 * Certainly they don't lean over the bomb with a pair of wire cutters agonizing over whether to cut the red wire or the black wire (it's the RED wire stupid!) - generally, these days they'll either try to safely detonate it or gently melt the explosives so that they flow away from the detonator...and of course they have robots for doing most of the dangerous work. SteveBaker (talk) 19:28, 14 May 2009 (UTC)
 * I don't think anyone wants to hear "I took a couple of night classes - I'll have a go at disarming it". DJ Clayworth (talk) 21:13, 14 May 2009 (UTC)


 * If you have a look at this Austrian terrorist, you may discover an unpleasant way to "disarm" a bomber  (he blew off his hands with a self-made explosive device on arrest). --Cookatoo.ergo.ZooM (talk) 21:14, 14 May 2009 (UTC)

The British Army's preferred technique is to drive in a remote-controlled "robot" which eventually disintegrates the bomb using a super-high-pressure jet of water. The water jet is generated by a small explosion in a gun-barrel-like metal tube. This blasts the component parts of the bomb apart before it can go off - I believe the detonator is often triggered during this process, but by the time it explodes it's no longer connected to the main charge of explosive. Note that the wheelbarrow robot pictures in the article is a primitive early model - they're a lot more high-tech now. 93.97.184.230 (talk) 22:10, 14 May 2009 (UTC)


 * You might find interesting the article Danger UXB and the DVDs of the Brit miniseries of that name, and the factual book on which the series was based, Hartley, A.B. (1958), "Unexploded bomb, a history of bomb disposal." London: Cassell. Bombs dropped by different sides had different methods required for de-fusing. They often had features intended to kill the bomb-defuser. Simply exploding them is not always the chosen method, since that might destroy major transportation centers, commercial centers, or cultural treasures. British experts in defusing German unexploded bombs were not familiar with defusing unexploded British bombs as they advanced into formerly German-held territory, and some died in the effort. WW2 bombs often had electrical detonators as well as clockwork. Modern bombs made by terrorists or nuts might have anti-tampering features to cause detonation if the battery leads or other leads are cut. But I will not provide any helpful hints for the bombmakers. Edison (talk) 03:17, 15 May 2009 (UTC)
 * Lord, it's a good show, but you've got to have some nerves of steel to watch it. I just couldn't take it. If it had been one of those shows where you know, "oh, the heroes will always be fine"... but it's not! Aiiieee.... --98.217.14.211 (talk) 13:46, 15 May 2009 (UTC)
 * While I was living in Germany they occasionally uncovered unexploded bombs and munitions from WWII when doing construction work. They'd clear everyone out of the area or tell people to stay indoors and bring in the bomb disposal squad. You can't just put a bunker-buster in a box and detonate it, so they will defuse it on the front-loader shovel or in the construction ditch where it is.  They also have aerial photographs and a to-do list of known areas that still need to be cleared.  They have special training in the types of explosives and devices they are likely to encounter.  When some idiot builds a bomb somewhere the design specs are distributed to parties on a "need to know" basis.  So if someone comes up with an unusual design or someone uses the same design as had been used in a previous case the law enforcement/international channels will provide their local bomb disposal teams with the information.  In the time of cheap and common remote sensing and wireless equipment building a bomb with a timer may look ludicrous.  That doesn't mean that people who don't/didn't have access or sufficient skills wouldn't.  The bomb at the Olympics in Atlanta for example used a timer.  So did an unexploded suitcase bomb found in Dresden, Germany.  If you don't mind raising suspicion there are reportedly sites that explain how to build bombs and once you know how they're made and how they work, you might be able to figure out how to disarm them.  Otherwise you'll just have to get a new job :-)71.236.24.129 (talk) 06:24, 15 May 2009 (UTC)
 * WW2 bombs often had clockwork so they would detonate some time after the air raid, apparently as a method of killing fire and rescue personnel as well as bomb disposal crews. Per the Hartley book, the clockwork sometimes stopped, often when the mechanism started to press on the trip for the detonator, because of the additional resistance. The smallest jarring, years later, could start it ticking again, and the time until detonation would obviously be very short. Lifting the bomb out of the ground would ba a prime way to start it ticking. Nearby construction work, or even a heavy truck driving by could suffice to jar the clockwork enough to set it off. There does not seem to be any period of years after which a bomb or artillery shell is no longer explosive, even gunpowder filled shells from the 1860's or from previous centuries. Edison (talk) 18:22, 15 May 2009 (UTC)
 * I admit that it occasionally gave me the creeps to know what I had been walking past or in some cases on top of. There is some merit to the phrase "Ignorance is bliss."  It is amazing how fast one readjusts to a known danger potential one can't do anything about though.  71.236.24.129 (talk) 08:28, 16 May 2009 (UTC)

With gay male couples is it common for one to be the 'top' and one to be the 'bottom' or is 'switch' often the way it is done?
I can't find this answer in Wikipedia, looked up gay sex, but I was wondering whether it is the norm for gay male couples for each partner both to give and receive oral and anal sex at different times? They must both have a penis, therefore it stands to reason that both partners in the relationship would want to use them...--I&#39;ve Never Been to Me (talk) 18:21, 14 May 2009 (UTC)
 * While it is certainly possible to have "roles" whereby one partner "gives" and the other "receives" it is not the only method of sexual stimulation availible. There are several options availible to gay men (69, or frot, or mutual masturbation) whereby both partners take an equal and simultaneous role in stimulating their partner.  --Jayron32. talk . contribs  18:28, 14 May 2009 (UTC)
 * Is your question referring to swapping roles during a single session of intercourse, or over the time of a relationship? 90.193.232.41 (talk) 20:39, 14 May 2009 (UTC)
 * Over the time of a relationship.--I&#39;ve Never Been to Me (talk) 21:53, 14 May 2009 (UTC)
 * In my (unfortunate lack of) experience, the concepts of roles vary between couples. In relationships where anal sex is common (not all are such), if one of the men is a larger, more aggressive man (i.e. a bear or something like that), and the other is more effeminate, the roles of top and bottom tend to be more fixed. If the relationship is between two men of more equal masculinity (definition left deliberately vague), it is more likely that roles are less fixed. Historically, more fixed roles have been the norm, but the modern gay movement is more likely to have fluid roles. Citation needed there, but it does seem to go hand in hand with the deconstruction of gender roles, etc. that come with the postmodern movement. Steewi (talk) 01:14, 15 May 2009 (UTC)


 * Sorry, but I do like the reference to "hand in hand"!--81.170.40.155 (talk) 12:45, 15 May 2009 (UTC)


 * User:Stewi has it about right - except for the assumption about masculine men being tops, which is simply a (porn-promoted?) stereotype. It is generally not possible to predict, and in any gay bar you will see many couples in which both men are equally masculine or feminine. The majority of gay men claim to enjoy both roles, although a significant number have a preference for one - so it really depends on the couple. Most younger couples "flip" depending on mood, in my experience.YobMod 14:26, 15 May 2009 (UTC)

this sux man —Preceding unsigned comment added by 61.95.140.188 (talk) 10:54, 16 May 2009 (UTC)
 * Well... who does that is kind of part of this question, yes? Steewi (talk) 01:38, 18 May 2009 (UTC)

largest lake in scotland?
--72.73.71.233 (talk) 19:59, 14 May 2009 (UTC)


 * List of lochs in Scotland may be useful to you. --Cookatoo.ergo.ZooM (talk) 20:03, 14 May 2009 (UTC)


 * You should note that while List of lochs in Scotland has Loch Ness as the largest in volume Loch Lomond is larger in surface area.G8briel (talk) 20:10, 14 May 2009 (UTC)


 * "The freshwater Lake of Menteith is the only natural body of water called a "lake" in Scotland."--86.25.195.160 (talk) 09:01, 15 May 2009 (UTC)


 * O RLY? What do they call Lake Winnipeg in Scotland? —Tamfang (talk) 05:05, 16 May 2009 (UTC)
 * Lake Winnipeg isn't in Scotland. We'd call foreign lakes lakes (or loughs or whatever that body of water is commonly known as) but such bodies of water actually in Scotland are lochs, apart from the Lake of Menteith. AllanHainey (talk) 11:25, 21 May 2009 (UTC)

magma energy source
In Russia they got a hole that was 7 miles deep or perhaps more on the Kola peninsula and it was very hot at the bottom. If you got all the way down to magma, you would have a great energy source right? Throw some water on it and you have steam. So the trouble is getting down to magma because they kept breaking their drill and it was only a 1/4" bit anyways. So here is an idea.  have a nuclear reactor go into a meltdown at the bottom of a mine.  With all that heat energy, you will melt your way through the crust and reach magma right?  Aside from all the radiation and stuff, would that work, or would your meltdown cool too fast?  65.121.141.34 (talk) 20:10, 14 May 2009 (UTC)


 * Our Nuclear meltdown article suggests this unusual 'drill' would stop as soon as it hits the water table. Tempshill (talk) 20:30, 14 May 2009 (UTC)


 * PS: Kola Superdeep Borehole is the hole you're mentioning.  Tempshill (talk) 20:32, 14 May 2009 (UTC)
 * Even if you melted your way to the magma, you wouldn't have a hole, would you? You'd have a massive pool of melted rock. Once it cools, it's going to be exactly as it was before - but presumably, unusable, since you've just melted down a reactor. 90.193.232.41 (talk) 20:37, 14 May 2009 (UTC)


 * Well the thought is that the magma you cool will sink because it is heavier and new magma would replace it. There are probably a lot of holes in this idea, but maybe its good enough for a movie?  Some sort of intentional China Syndrome. 65.121.141.34 (talk) 20:42, 14 May 2009 (UTC)


 * There is no magma ocean. Most of the Earth is a solid (see: rheid, Earth's mantle) all the way to the Earth's core.  Magma, i.e. regions of liquid rock, only occurs when you have the combination of relatively high temperatures and relatively low pressures.  Yes, geothermal energy can use hot rock at great depths, but it relies on hot solid rocks and is unlikely to use magma as an energy source.  Dragons flight (talk) 20:51, 14 May 2009 (UTC)


 * Wow, I was always under the impression that the mantle was liquid magma. If it is more or less solid (obviously there would be pockets of magma or else we wouldn't have volcanoes), then that idea would not work in anything but a B grade movie.  Guess you never stop learning.  65.121.141.34 (talk) 21:01, 14 May 2009 (UTC)


 * It is a very common misconception, and one I am happy to rid you of. :-)  Dragons flight (talk) 21:19, 14 May 2009 (UTC)


 * Mantle (geology) says the outer core is liquid. Doesn't that qualify as a magma ocean?  Tempshill (talk) 22:12, 14 May 2009 (UTC)


 * Magma is liquid rock. The outer core is liquid metal and hence not magma.  Dragons flight (talk) 23:08, 14 May 2009 (UTC)


 * Besides which, the outer core is a tad further down than 7 miles. Try 1,800 miles: there is no available technology that can drill down to anything approaching that depth. Nobody has yet succeeded in drilling even all the way through the Earth's crust to the mantle, and not for want of trying either.  Sp in ni  ng  Spark  01:17, 17 May 2009 (UTC)
 * The hard part of drilling a big hole isn't getting down through all the rock, it's getting the rock back up and out of the hole (which you need to do if you are going to have a hole at the end). --Tango (talk) 21:25, 14 May 2009 (UTC)


 * What you're talking about is Geothermal power - but you don't need to go that deep to get it. There are plenty of entirely viable geothermal power stations around the world - and in some places, people even have geothermal power for their individual homes.  It's not even a particularly new idea - there is a geothermal power plant in California that's been running effectively for almost 50 years! SteveBaker (talk) 03:03, 15 May 2009 (UTC)


 * As for drilling deep, you might enjoy reading David J. Stevenson's semi-serious proposal to send a probe to the center of the earth in an enormous drop of molten iron: . --Sean 13:22, 15 May 2009 (UTC)


 * True, but those are mostly small plants, and do not involve magma. This would have presumably been a huge hole, and one you could cite wherever the power was needed.  65.121.141.34 (talk) 13:27, 15 May 2009 (UTC)


 * Well, the plants aren't huge - but that's because they don't need to be. Unlike gas, coal, hydro or nuclear - you don't need a large plant to get the economies of scale.  If you include the geothermal energy used for heating and cooling as well as for electricity production, geothermal energy production exceeds wind power and comes close to solar power.  It's definitely not some weird experimental thing.  As I said before, there are plants that have been producing power solidly for 50 years.  They don't involve magma because that's a silly idea.  Firstly, you either have to drill ridiculously deep or build your power plant close to an active volcano.  Secondly magma is so hot that you'd need extremely exotic technology to use it.  It's much easier to drill much shallower holes into merely hot rocks and convert water to steam to drive a turbine.  Thousand to fifteen hundred degree magma is going to melt your pipes and do all sorts of other mischief - with not much benefit compared to mere one to two hundred degree rocks which will let you use normal steel or copper pipes and conventional steam turbines.  Siteing these plants near natural hot springs means that you can get the temperatures you need with very traditional drilling rigs.  Another problem is that one bore-hole isn't enough - as you extract heat from the material, it cools off and in the case of your magma is going to cause a solid lump of cooled rock to form around the bottom of your pipe.  In more conventional geothermal plants, you drill many holes (because it's fairly cheap to do so) - and when one cools off too much, you can switch to another one while the heat builds back up again in the first one.  Considering the massive effort it would take to drill the first hole to the depths you're considering - this hardly seems like a productive way to go! SteveBaker (talk) 16:01, 15 May 2009 (UTC)
 * In Britain, some houses have their own individual deep borehole and heat the house from geothermal energy, or at least the earth's warmth. There are plans to have more of these. 78.146.17.231 (talk) 18:14, 16 May 2009 (UTC)
 * Why the distinction between "geothermal energy" and "the earth's warmth"? Surely they are exactly the same thing, by definition? --Tango (talk) 01:36, 17 May 2009 (UTC)
 * I don't think those bore holes are anywhere near deep enough to use geothermal energy, they probably rely on the heat capacity of the soil (earth) to maintain a more constant temperature all year round. --antilivedT 19:08, 17 May 2009 (UTC)
 * Plus who's going to pay for the power plant you scrap each time you sink a new hole? They aren't exactly cheap either.71.236.24.129 (talk) 00:02, 16 May 2009 (UTC)
 * With existing geothermal plant, they don't shut down the plant when the hole goes cold - they just use a different hole drilled nearby. Remember that modern drilling rigs can drill at an angle - so the bottom ends of the bore holes can be quite far apart. SteveBaker (talk) 03:57, 16 May 2009 (UTC)