Wikipedia:Reference desk/Archives/Miscellaneous/2007 August 15

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August 15

Mosquito Repellent

If I were to spray mosquito repellent on say, a door, would that discourage mosquitos coming into the home if the door were open? aznshorty67 00:55, 15 August 2007 (UTC)

Probably not. It would keep them from biting the door, though. You'd be better off with something like a citronella candle or a mosquito coil if you want to repel them from a broader area. - Eron ^Talk 01:04, 15 August 2007 (UTC)

See the DEET article. Mosquito repellent doesn't actually repell mosquitos so much as making it so they no longer bite. --Mdwyer 01:35, 15 August 2007 (UTC)

You can buy a mosquito attractor. It's about the size of a small portable barbecue and it emits a smell that mosquitoes can;t resist. You can put that in an unused corner in your backyard and it will trap and kill the mosquitoes. Acceptable 01:10, 15 August 2007 (UTC)

I see, thank you aznshorty67 00:55, 16 August 2007 (UTC)

Polish Translations

How does one say the following phrases in Polish?:

1. "May I go to the bathroom miss?"

2. "You are the frosting on my cake"

3. Where is the subway station?"

Thanks a lot. Acceptable 01:08, 15 August 2007 (UTC)

According to http://www.poltran.com :-

1. Może (maj; majowy) idę do łazienki przepuszczają (być nieobecnym)?
2. Wy jesteście cukier (cukrowy) uwieńczający (uwieńczanie; stający na czele; świetny) na moim ciastku
3. Gdzie jest stacja (miejsce) metro?

"Frosting" and "Icing" refused to translate, so I used "sugar topping" there. Exxolon 01:14, 15 August 2007 (UTC)

I would definitely ask this question on the languages help desk! Automatic translation services are notoriously bad. If you ever suspect that they actually work, take the Polish it generated and tell it to translate it back to English again! SteveBaker 03:41, 15 August 2007 (UTC)

...and when you do that, you get:

1. Can (may; to be there for bathroom) go miss (absent <absentee>)?

2. You are sugar topping (sugar) topping (; becoming at the head; on my cake topping)

3. Where is station (place) subway?

Well - I guess you need to leave out the stuff in brackets in the Polish - then you get:

1. Can it for bathroom go miss?

2. You are on my cake sugar topping.

3. Where is station subway?

Yeah - definitely go talk to the folks on the Language desk. SteveBaker 12:27, 15 August 2007 (UTC)

And I want to know what sort of conversation would involve those three phrases :) Lemon martini 14:53, 15 August 2007 (UTC)

Should I re-post this question on the Language Desk? If not, how should I transfer this question over there? Acceptable 20:38, 15 August 2007 (UTC)

I would just ask it again over there. SteveBaker 22:14, 15 August 2007 (UTC)

This question has been answered on the Lang Desk. Using an automatic translator was a bad idea, although "Maj idę do łazienki nieobecny" (Month of May I'm going to the bathroom absent.) is hilarious. — Kpalion^(talk) 20:21, 16 August 2007 (UTC)

computer energy

if i were to leave the computer on the whole day (about 12 hours), would that save more energy than turning it off when i'm not using it? (i turn it on and off around 6 times a day...i guess every 2 hours).

Turning it on every 2 hours sounds like a pain. How long is it on per cycle? Unless you are constantly turning it on and off, and waiting for it to do a cold boot-up, you would probably save some energy any time it is off. I do not think the energy used in starting it up would exceed the energy it would use being left on in general. But the energy cost must be balanced against productivity and lost life-time of the computer. The down side of the energy savings is that you would lose productivity if you have to wait for it to boot up every time you need to use it. It makes sense to turn a computer off at the end of the business day, so it is off perhaps 15 hours out of every 24 as well as weekends, from the energy saving point of view. I would not turn one off when going to lunch. A computer's life may be reduced by each turn off and turn on cycle, especially if it has a cathode ray tube display. The computer and monitor may fail sooner if turned on and off one or more times each day than if left on continuously. The more times a day you turn it on and off, the fewer months of service you can expect from it. Many modern computers go into a "sleep" mode if there are no keystrokes for a period of time, thereby extending battery life for a laptop, and reducing kilowatt hours of electricity used per month for a desktop computer. Edison 02:39, 15 August 2007 (UTC)

Thanks for the advice, I'll keep this in mind.

You will undoubtedly save energy by turning it off. But we all know that long reboot times are a pain - so do the best you can: Set up the computer with all of the power saving stuff turned on - and manually turn off printers, monitors and other stuff when you aren't using them. Those things power up very quickly - so you don't really have an excuse to leave them on. If you have a bunch of power outlets driving stuff like USB peripherals, powered speakers, etc - put all of those onto one multi-way power outlet so you can turn them all off and on with one switch. SteveBaker 03:38, 15 August 2007 (UTC)

Ehm, 6 x 2 = 12. That means no off time at all (you'd be turning it off and then on again immediately). Or do I misunderstand something? DirkvdM 03:57, 15 August 2007 (UTC)

I believe the OP is saying they turn it on, use it, and turn it off again every two hours. --Masamage ♫ 04:04, 15 August 2007 (UTC)

Or maybe donate your computer and electricity to something like Folding@home? --antilived^{T | C | G} 05:25, 15 August 2007 (UTC)

Turning the printer off and on again uses a lot of ink as it recharges.

I seem to recall a figure that if you're not using your computer for an hour or more, it's always more energy efficient to turn it off. Otherwise, you can try standby etc which can use a bit less electricity. Standby is quick to recover. See this page, though I'm a bit skeptical about how little energy standby is using on that page. --Wirbelwindヴィルヴェルヴィント (talk) 15:29, 15 August 2007 (UTC)

I believe theres a sort of power saving sleep mode you can invoke on most computers (in control panel under power management). This will spin down the drives and put the monitor into standby. I personally would not switch on and off every 2 hours as you dont know how the surges and thermal cycling are going to affect the various bits of the computer.(apart from the annoyance of waiting for boot up and entering PW s etc etc) --SpectrumAnalyser 17:05, 15 August 2007 (UTC)

Quotation Question

Who is credited with the quote "God be in my head and in my understanding; God be in my eyes and in my seeing; God be in my mouth and in my speaking; God be in my heart and in my thinking; God be at my end and at my departing"?Vafille 02:49, 15 August 2007 (UTC)

I haven't found a who, but a what: the Sarum Primer, "a collection of prayers and worship resources developed in Salisbury, England, during the 13th century." Most references I have found point to that as the source (although my copy of Voices United credits the words to a 1514 Book of Hours). - Eron ^Talk 03:04, 15 August 2007 (UTC)

Sounds like a version of St Patrick's Breastplate to me. Since the original is in Latin, there is some variation between English versions. Skittle 18:20, 15 August 2007 (UTC)

Actually, I think that it's a different source. We do have an article on the Sarum Primer, as part of the Sarum Rite. Hornplease 11:06, 18 August 2007 (UTC)

Thanks so much for the information!!Vafille 02:46, 16 August 2007 (UTC)

Truthtellers.org charges ADL is promoting the destruction of Christianity

Is there a article on this religious group ? They're the one that flat out accuses the ADL of promoting matter to have Christians declared criminals under some kind of "hate crimes" laws. Seen the matter on rense.com, which takes the reader to their website. Troll, Spammer ?! Hell fucking NO! 65.173.104.223 02:56, 15 August 2007 (UTC)

Are they a "hate group", like the KKK ? 65.173.104.223 03:05, 15 August 2007 (UTC)

OK - who are the protagonists:

• http://Truthtellers.org is one of several web sites of the National Prayer Network (NPN) - an unashamedly anti-Israeli/anti-gay Christian group - we don't appear to have an article about them - but their web site makes it pretty clear what they are about. Ted Pike (for whom we do have a stub) is their director. Their website is full of (what seems to me) 'fringe' stuff that most mainstream Christians would probably not support. Notably, the site includes a strenuous effort to get the US hate-crime laws repealed.
• ADL is the Anti-Defamation League (for whom we have a substantial article) who have a general 'anti-hate' mandate - notably, they are defenders of Jewish people against discrimination.

So - to try to answer what our OP asks, ADL is attempting to use the hate-crimes laws to try to deal with NPN - NPN claims the laws are limiting their free speech (which presumably means that they'd like to say things that would be considered illegal under those laws). Is it the case that ADL is trying to get Christians declared criminals under the hate crimes laws? Yes - it certainly appears so. Not all Christians - just the members of NPN. However, just because NPN claim to be Christians doesn't necessarily mean that they aren't criminals if they are indeed breaking the hate crimes laws. Are NPN breaking the hate crimes laws? Well, there is certainly a goodly amount of hate there - whether it reaches the level of illegality is for the courts to decide. SteveBaker 03:30, 15 August 2007 (UTC)

Actually, Steve, that's not true -- the ADL is not trying to ban hate groups. The bill at issue (H.R. 1592 and S. 1105) increases the penalty for crimes that are already illegal when hate of a particular group is the motive. A ban on hate speech or hate groups would violate the First Amendment. -- Mwalcoff 22:39, 15 August 2007 (UTC)

Good point - although NPN definitely claims that these laws violate the first amendment. I agree with you. It's all kinda nonsensical though - if the law did violate the constitution then NPN would have nothing to fear from it since a quick appeal to the Supreme Court would get the law wiped off the books in no time flat. But there is so much bullshit on that site, it's hard to know where to start in on the illogic of it all! SteveBaker 14:15, 16 August 2007 (UTC)

It appears that Ted Pike's father Claude, the original anti-Semite in the family, was instrumental in the creation of the National Day of Prayer, hence the name of the NPN. They do seem a little over-the-top crazy. I don't know how much worse it is than some of the stuff I hear from Pat Robertson at 3am, though. Hornplease 11:01, 18 August 2007 (UTC)

Camera Repair

I need to have my Minolta SLR Model 450 si repaired. Is there a list of repair stations?

There is usually a list like that in the back of the manual. If you don't still have that, it would help us to get you a good answer if you'd tell us which city you live in. SteveBaker 03:45, 15 August 2007 (UTC)

Minolta is out of the camera business, so the list in the manual is probably out of date. However, under this page you should find what you want. --Anonymous, August 15, 2007, 04:28 (UTC).

Or, just take your camera to your nearest reputable camera store. If they can't repair it, they should be able to tell you who can. --Richardrj ^{talk email} 04:34, 15 August 2007 (UTC)

Power wire avoidance

What is the term for the large balls that are put onto power lines so that low flying planes, cranes, etc. see them and can avoid hitting the lines? Dismas|^(talk) 05:26, 15 August 2007 (UTC)

Wire markers or marker balls. See Google Answers --Mdwyer 06:40, 15 August 2007 (UTC)

Power line markers?[1]--SpectrumAnalyser 17:12, 15 August 2007 (UTC)

Coca Cola poster

I'm trying to find an image of a Coca Cola poster, WW2 vintage, one of a series showing US troops drinking a coke with civilians in various war theatres. The one im after shows soldiers with a New Zealand Maori in front of a Meeting House. Thanks. Mhicaoidh 05:50, 15 August 2007 (UTC)

See here, towards the bottom of the page. There's a high res version here. --Richardrj ^{talk email} 08:19, 15 August 2007 (UTC)

Thanks! Mhicaoidh 11:12, 15 August 2007 (UTC)

Hee hee, they're comparing tattoos! That's awesome. --Masamage ♫ 19:18, 15 August 2007 (UTC)

Camoflauge etiquette

Is it improper for civilians to wear military clothing during wartime? Not military issue clothing but store bought clothing? And not for the purpose of hunting, etc. but for fashion statement only? So I guess the full range of the question would be: Is it improper for a civilian to wear store bought military style clothing for fashion reasons during wartime? Thank you!

No. --Lucid 08:19, 15 August 2007 (UTC)

No². Lanfear's Bane

NO, but why?

Generally not, but don't go overboard; Michael Jackson got into trouble for wearing British military medals in court.[2] Laïka 09:43, 15 August 2007 (UTC)

It would certainly be improper to wear clothing (or anything else) which suggested you were a soldier, when in fact you were not. DuncanHill 09:59, 15 August 2007 (UTC)

For the same reason that it's not improper to wear sunglasses when it's not sunny? Or wearing wellies when it's not muddy? Capuchin 09:45, 15 August 2007 (UTC)

Why do people wear sunglasses whn it isn't sunny? I would walk into things if I did. DuncanHill 09:59, 15 August 2007 (UTC)

I have a pair of urban camouflage trousers. I think they are sweet, and by sweet I mean totally awesome, and have no qualms wearing them during times of war. I probably wouldn't wander through Basra wearing them, though. Neil ム 10:43, 15 August 2007 (UTC)

Some military clothing may cause offense or even be illegal in some countries - although I don't imagine this is what you have in mind. As has been suggested, don't go overboard and be sensitive to the feelings of other people, and you should be alright. Gandalf61 11:35, 15 August 2007 (UTC)

Military camouflage#Military camouflage in fashion and art may be of interest. --Richardrj ^{talk email} 12:22, 15 August 2007 (UTC)

Actually not just Nazi's uniforms but it is illegal to wear camoflauge uniforms in some countries. Malaysia is one [3] and from my Google searchs a number of African and Carribean countries as well. Very likely elsewhere as well, especially where the is a history of guerilla warfare (in Malaysia I suspect it originates predominantly from the communist insurgency). What counts as a camoflauge uniform will likely be somewhat difficult to define. Usually if it's openly sold in the country in question in many shops it would be acceptable but of course that wouldn't be an excuse if it is illegal. And it's rather likely that in war time the law will be much more vigiriously enforced. And if you are in an active combat zone I agree it would be foolhardy to wear camoflauge clothing for fashion reasons Nil Einne 12:56, 15 August 2007 (UTC)

As a matter of pure etiquette (relating to personal etiquette) - I would suggest that if you feel even slightly uncomfortable about wearing an item of clothing - you shouldn't. That you are asking this question suggests that to me. If it was not a question of personal interest then I can only say that wearing camo may suggest or imply implicit support of 'military lifestyle' which includes war unfortunately.83.100.174.137 16:33, 15 August 2007 (UTC)

Real army surplus is less 'distasteful' (my opinion) that fake army fashion clothing - it's also usually better quality, cheaper, (more honest). Apologies if I've added opinions that weren't asked for or wanted.83.100.174.137 16:38, 15 August 2007 (UTC)

Mia Michaels got into trouble on an episode of So You Think You Can Dance a few weeks back, for wearing a Marine dress uniform jacket. The show had to issue an apology. Corvus cornix 23:38, 15 August 2007 (UTC)

Speaking from a U.S. perspective: Camo clothing has become such a part of civilian culture that I wouldn't think anyone was insinuating they were active or prior military simply by wearing it. If someone started adding things like rank, unit insignia, name tag, etc. then I would certainly look askance at them. That would almost be like "claiming" a military background. Those with an actual military background would not wear their uniforms except on-duty, official travel or for certain official functions. In most countries, anyone wearing a fully-decked out uniform as casual wear is either a soldier violating regulations or a wannabe who is "claiming" an honor they haven't earned. A stripped-down (no rank, no name tag, etc.) camo uniform, however, wouldn't even get a blink from me. It is very common in today's culture. 152.16.59.190 05:39, 16 August 2007 (UTC)

The follow-up question (b the OP, I presume) is pretty weird. Does one have to come up with reasons why something is not distasteful? First someone would have to say why it would be distasteful and then others might respond to that. As to why people wear them, like the anon three posts up said, it's strudy clothing and cheap. Ideal for teenagers with an active lifestyle. Ironically often the sort that would never want to join the army (where others tell you what to do). As a Canadian girl once told me, it's a way to get her tax-money back. DirkvdM 19:01, 17 August 2007 (UTC)

Bug Identification

These two insect species are strange to me, but no doubt common to the locals. What are they?

Bug A was observed in rural Iowa, at a gas station, at night: http://www.plaft.net/bug_a.jpg

Bug B was crawling around in the grass in a field in Ohio, and went catatonic when I poked it with a plant stem. It came back to life about 10 minutes later and wandered on its way. Sorry for the picture quality, but please note the sturdy front legs: http://www.plaft.net/bug_b.jpg

Thanks. By the way, what's the best procedure for using "temporary" pictures on WP? Back in the day we just embedded external images, but this is apparently no longer allowed. I hesitate to upload these useless files to WP or Commons, but don't have a good place to host them.

In answer to your last question, you can upload them to an image hosting site such as Imageshack, and post the links here. --Richardrj ^{talk email} 10:09, 15 August 2007 (UTC)

Bug A looks like a mole cricket. No clue on bug B. ---Sluzzelin talk 11:32, 15 August 2007 (UTC)

I agree that A is a mole cricket, and B looks like a cicada pupa. --Sean 14:11, 15 August 2007 (UTC)

Ah, thanks! Cicada pupa should've occurred to me, and I was going to mention that Bug A (the cricket) did indeed look like it was outfitted for digging. Also, when we were photographing it, it kept trying to tunnel under my friend's shoe. Very interesting creatures.

when...

will the M16A2/A4/A3 be replaced by another rifle in the United States military (specifically the Marine Corps)? --MKnight9989 13:42, 15 August 2007 (UTC)

See M16_rifle#Future_replacement. Short answer: not soon (unless you count the M4 Carbine). --Sean 14:19, 15 August 2007 (UTC)

Checkouts

Why do American checkout people stand ? In Europe checkout people sit.86.200.7.107 14:46, 15 August 2007 (UTC)DT

Because jobs in this country are specifically made to keep me from being able to do them --Lucid 14:51, 15 August 2007 (UTC)

Er, do you live in the US without the ability to stand, or in Europe without the ability to sit? --Sean 21:15, 15 August 2007 (UTC)

I think the difference is that in most US supermarkets the checkout staff bag the items for you - and in some they unload and reload your shopping cart too. In the UK (at least), they expect you do to that yourself - hence the staff can sit. SteveBaker 15:55, 15 August 2007 (UTC)

Note - in smaller supermarkets in the UK they stand.83.100.174.137 16:28, 15 August 2007 (UTC)

In the bigger supermarkets in the UK, they tend to now ask if you would like any help bagging your groceries up, and if you do, they press a button and someone comes along (not the checkout person) and helps. In Tescos they now have to ask, even if you're just buying some gum and a packet of crisps. I always say yes just to annoy them and cock a snoot at the Man. Neil ム 08:40, 16 August 2007 (UTC)

They tend to stand in smaller shops because they usually have more than the one job. But why should not an operator load shopping whilst sitting ? In some UK shops there are moving belts that deposit the purchases directly into shopping bags.90.4.255.188 14:19, 16 August 2007 (UTC)DT

I have traveled around the world quite a bit and thinking back, I can indeed only remember people standing at US checkout counters. Though not always, if memory serves me well, such as when the bagging person is not the same person as the cashier. I regularly had words with those baggers, first telling them that I'd rather bag my things myself (so that I know what's where), then insisting that I really preferred doing it myself and then shouting that they should keep their hands off my stuff. Which resulted in first puzzled and then scared looks. The concept of people bagging their own shopping was totally alien to them. Note that the US is the only country in the world where this is done. That I know of, anyway. With the possible exception of Canada. DirkvdM 19:17, 17 August 2007 (UTC)

Here in Texas, if there is a separate person doing the bagging - they'll carry the stuff out to your car, put it into the trunk for you and take the cart back if you ask...often they'll offer to do that even if you don't ask. That's probably the same throughout the USA. SteveBaker 01:37, 18 August 2007 (UTC)

canning okra

While canning my pickled okra I noticed the garlic that I added has turned a blue color. My question is why did it turn blue and is it safe to eat?

This website [4] says you are still good to go and that "The garlic is still perfectly safe to eat" and it sounds funky. Have it with some blue milk. Lanfear's Bane

What is pickled okra, and in which part of the world is it commonly found? Plasticup ^T/C 17:55, 15 August 2007 (UTC)

Okra? Skittle 18:01, 15 August 2007 (UTC)

Which has been pickled? DuncanHill 18:19, 15 August 2007 (UTC)

Now you've gone and got me craving some. Off to the store. Edison 23:29, 15 August 2007 (UTC)

That looks so gross. Plasticup ^T/C 03:07, 17 August 2007 (UTC)

Mmmmm, okra. Wonderful stuff. Either fried in cornmeal or stewed with beans and tomatoes. Awesome. (I sound like Homer Simpson.  :) ) Corvus cornix 23:40, 15 August 2007 (UTC)

Cheese cake!? A cake of chesse!? Perry-mankster 08:35, 16 August 2007 (UTC)

Cheesecake is indeed a cake made from cheese, I'm just about to eat some too:) DuncanHill 14:18, 16 August 2007 (UTC)

 :-) Skittle 00:31, 20 August 2007 (UTC)

Butterswim

I'm on holiday by the sea. Earlier I was in my father's boat and I saw a butterfly fluttering a few inches above the water. This was reasonably far out so it didn't merely fly over it a little en route to some other destination. What the hell could it have been doing? Vitriol 18:03, 15 August 2007 (UTC)

Many species of butterflies migrate, some of them over long distances across bodies of water. Marco polo 18:30, 15 August 2007 (UTC)

Your language suggests to me that you are English, so you might have seen a painted lady butterfly. This article has information on their autumn migration, which would take them across the English Channel on their way to North Africa. Marco polo 18:43, 15 August 2007 (UTC)

For airplanes, flying just above the surface of water can be quite an energy saver. Forgot what it's called (somewhat like hydrofoil, but based on an airplane in stead of a boat). But I'm not sure if the same effect would work for butterflies because they fly in a very different manner. DirkvdM 19:24, 17 August 2007 (UTC)

More likely the winds at higher "altitudes" would buffet the butterfly off course. They aren't particularly strong and the surface's calming influence on even the slightest breeze would, I am sure, be most welcome. Plasticup ^T/C 19:08, 19 August 2007 (UTC)

Agincourt (1901)

I think one of my Dad's relatives was on the Agincourt, which was in Dorset on the 1901 census. I would like to know what sort of boat was it? —Preceding unsigned comment added by 212.50.171.152 (talk • contribs)

I think the vessel in question is this one, which was located in Portland as a training ship in the year in question. Originally an ironclad battleship, I have no idea what kind of condition the ship was in while being used for training purposes. Carom 18:32, 15 August 2007 (UTC)

She formed part of the HMS Boscawen training depôt, and there is some further information, including pictures of her at the time, here [5] DuncanHill 20:54, 15 August 2007 (UTC)

And this site has some more information about training ships of the time, [6] DuncanHill 21:00, 15 August 2007 (UTC)

Head-on collision with two cars

Suppose two identical cars with 2 clone drivers collided with each other head-on, each traveling at a speed of 100 km/h. Would the impact that the two driver feel be equal to the impact of them driving into a solid wall at 200 km/h? This is what I intuitively think, but several driving instructors told me that the impact would be like as if driving into a solid wall at 400 km/h, citing something to do with physics. However, I am skeptical about this. Which, if any, of the viewpoint is correct? Thanks. Acceptable 20:33, 15 August 2007 (UTC)

Simplistically, it would be like hitting a wall at 200 km/h, not 400, since it's only the relative motion that matters. That said, hitting a solid wall is a different enterprise to hitting a car (which can crumple, deflect sideways, etc.), so it would be closer to the truth to say the impact would be like hitting a stationary car at 200 km/h. --Sean 21:20, 15 August 2007 (UTC)

No, it would be like hitting a (rigid, unbreakable) wall at 100 km/h. If the two cars crumple in exactly the same way (they won't, of course, but it's a decent first approximation) then no point of either car will make it past the plane of the impact point. Exactly as with the solid wall. --Trovatore 21:23, 15 August 2007 (UTC)

Or here's another way to see it: In the two-car case, you have the kinetic energy of two cars, each going 100 km/h, dissipated in the mass of two cars. In the one-car-rigid-wall case, you have the kinetic energy of one car going 100 km/h, dissipated in the mass of that one car (because a perfectly rigid body dissipates no energy at all in a collision). So it works out the same on a per-car basis. --Trovatore 21:34, 15 August 2007 (UTC)

I agree with Trovatore (Acceptable, Sean and the driving instructors are all wrong!) - it's most definitely like hitting a wall at 100kph. There is a simple answer and a MUCH more complicated answer - and your driving instructors are picking the complicated one and failing to understand the full consequences of that decision. I'll try to explain - but it's gets horribly complicated very fast!

• SIMPLE ANSWER: The total energy that has to be dispersed by crumpling metal is twice as high when two cars collide (if both are travelling at 100kph) than if one car hits a totally immobile brick wall at 100kph - but the crumple distance is also doubled and so is the amount of bent metal at the end (which is where all that kinetic energy went) - so the accelleration is the same when two cars collide at 100km/h versus one car hitting a wall at 100km/h. So no - driving into another car with both going at 100km/h would be the same as driving into a wall at 100km/h. (In fact, no wall is going to perfectly fail to absorb any energy - so you'd probably be fractionally better off hitting the wall in the real world).
• UGLY RELATIVE MOTION ANSWER: The relative motion argument is another perfectly valid way to look at it - but you have to be utterly consistant about that. So from the point of view of a frame of reference that's moving at a uniform speed of 100kph towards you: You are initially rushing towards that frame of reference at 200kph and the other car is stationary (compared to that frame of reference) - then you collide - but then both cars continue on at 100kph - the frame of reference didn't stop moving. So your speed (in that frame or reference) went from 200kph to 100kph - so you lost 100kph and it's no worse than driving into a brick wall at 100kph in a stationary frame of reference.
• DRIVING INSTRUCTOR ANSWER (which is bogus): I suspect these guys read that kinetic energy is mass times the SQUARE of the velocity (that's true - if you hit a brick wall at twice the speed - you'll take four times the amount of damage - so drive slowly!). So they reason that the kinetic energy at double the approach speed is four times higher. But then they make the mistake of picking the other car's frame of reference, instead of having two cars, both with energy (E) given by E=(Mass x 100kph x 100kph) - they assumed that this was the same thing as one car moving at twice the speed (Mass x 200 x 200)...which is 4E. But that's only allowed if you take the 'UGLY RELATIVE MOTION ANSWER' - and in that case, the car doesn't lose all of it's kinetic energy - it only loses enough to drop its speed from 200kph to 100kph (3E) - and (critically) in this rather strange frame of reference, the other car GAINED kinetic energy because it starts off stationary and winds up moving backwards at 100kph, gaining -E in the process. The resulting energy (2E) is then shared between the two cars - so (as if by magic), each car has to dissipate exactly 1E of damage...just the same as it was if you pick a less mind-bending stationary frame of reference.

PHEW!

So - the instructors weren't off by a factor of two (as Acceptable thought) but by a factor of FOUR. I would be quite surprised if you manage to convince them of that. SteveBaker 22:08, 15 August 2007 (UTC)

A head-on collision between two cars travelling at 100mph would obviously be the same as hiting a wall at 200mph. SteveBaker wrote:" So from the point of view of a frame of reference that's moving at a uniform speed of 100kph towards you: You are initially rushing towards that frame of reference at 200kph and the other car is stationary (compared to that frame of reference) - then you collide - but then both cars continue on at 100kph - the frame of reference didn't stop moving." This is not correct. When the frame of reference is the other car, the reference frame NEVER moved. It's you that's travelling toward the second car at 200mph and colliding with a stationary car. I think you are abit confused about frame of reference concept. 192.53.187.183 20:43, 16 August 2007 (UTC)

As a practical matter, however, there's always the possibility the other car is much more solidly built and/or heavier than your own, in which case you will likely be in the car for which it sucks the most. 151.152.101.44 22:14, 15 August 2007 (UTC)

Of course - but the OP stated that the cars are identical. SteveBaker 14:03, 16 August 2007 (UTC)

Of course, if God forbid you ever have to make the choice between the two, there's a strong argument to be made for the brick wall. The consequences for you are the same, but there's some other poor shmo who won't have to die. And maybe God'll give you a little rhythm on one or two of those taking-his-name-in-vain things. Naturally that's speculation as Wikipedia cannot give spiritual advice. --Trovatore 22:21, 15 August 2007 (UTC)

Interestingly, everyone in my old high school was taught in driver's ed to aim for a telephone pole if you were about to crash, because a telephone pole would allegedly slow your car down more gradually than a brick wall, or a tree, or another car. 151.152.101.44 22:40, 15 August 2007 (UTC)

That's a sort of "double or nothing" strategy, though, because cars have an unfortunate tendency to be cut apart by trees, poles, etc. And if you happen to be in the area of the cut or are ejected as a result of the cut, you'll probably die. Around here, teenagers unfortunately prove this out every year.

Atlant 23:03, 15 August 2007 (UTC)

Aiming for the pole is lunacy, as it would concentrate all of the force into a much smaller area of your car, rather than spreading it across your entire crumple zone. Exxolon 00:19, 16 August 2007 (UTC)

Ejected? With a seat belt on? --Anon, August 15, 23:26 (UTC).

Strangely enough, a lot of the really bad drivers in the world are also the ones who don't seem to wear their seatbelts. Perhaps it has to do with the amount of EtOH in their bloodstreams? Or is it the testosterone??

Atlant 12:22, 16 August 2007 (UTC)

You need to aim for something soft...duh. The energy from the collision needs to be soaked up somehow, and the plan is for it not to be your body - or bits of the car that could stick into your body. A brick wall is better than a moving car (just fractionally) - and it certainly saves some other driver from harm - but a parked car would be an EXCELLENT choice because you know it's designed to crumple and absorb energy. It's hard to say about things like poles and trees because you don't know precisely how you'll hit them and what the consequences to the dynamics of the car might be. But in any case, your number one goal is to shed speed - that means standing on the brakes and hoping the ABS will do it's thing. With most cars, if you are braking hard, you certainly don't want to be steering - so the idea that you have a choice as to what to hit is somewhat nebulous. SteveBaker 14:03, 16 August 2007 (UTC)

EDIT: I understand now. Thank alot everyone for clearing this up for me =) Acceptable 12:15, 16 August 2007 (UTC)

Apparently there is a good reason why the driving instructor is teaching pimply-faced teens to drive instead of teaching physics at MIT. StuRat 04:04, 17 August 2007 (UTC)

Yes - but it is actually somewhat subtle - I mean, several of us got it wrong - and I had to work up quite a mental sweat to explain why "doubling the speed quadruples the kinetic energy" didn't mean that the instructors were right. These guys have grasped the important (and counter-intuitive) fact that if you drive twice as fast, your crash will be four times as bad. That's true - and certainly something to think about when zipping along the freeway at three times the speed you might drive in town (== 9 times the amount of damage!). But it was the application of that fact to the head-on collision case that caused their argument to come apart - and you can easily understand why - because that's where most of us tripped up. SteveBaker 18:09, 17 August 2007 (UTC)

Peru Earthquake

This just happened. it was a 7.7 quake. Sources incl. FOX News. Not much is known at this time about what happened, such as casualties and damage. 65.173.104.223 00:06, 16 August 2007 (UTC)

Can this be placed in that article ? 65.173.104.223 00:07, 16 August 2007 (UTC)

I just turned the tube on when I saw this on the news. 65.173.104.223 00:09, 16 August 2007 (UTC)

It is not a reference desk matter. If you want to start an article on it, go ahead. --Tagishsimon (talk)

Someone else and I tried to in the Peru article, only it was removed. This quake is a MAJOR news story. 65.173.104.223 02:57, 16 August 2007 (UTC)

Personally I'm not sure whether it would technically count as something that belongs in an encyclopedia article about Peru (although perhaps it does), but it would certainly be worth considering on WikiNews. Confusing Manifestation 03:43, 16 August 2007 (UTC)

And, of course, if there's enough information on it then there could easily be an article on 2007 Peru Earthquake. Confusing Manifestation 03:44, 16 August 2007 (UTC)

It would belong in Geology of Peru (if this shows up red, can someone write it please?) DuncanHill 11:07, 16 August 2007 (UTC)

It is big enough to deserve its own article, and indeed it has its own article. Plasticup ^T/C 12:26, 16 August 2007 (UTC)

lemon law

How many times do I need to take my car back to the dealer for the same problem? I think I have a lemon. It's been back five times. What is the limit. I always thought it was three. Am I correct? —The preceding unsigned comment was added by 4.179.106.89 (talk • contribs) 21:27, 15 August 2007 (UTC)

Are you in the US? Looking at the articles on Lemon laws and the Magnuson-Moss Warranty Act, it isn't clear that there is a set limit. It probably depends on where you are, the terms of the warranty, etc. - Eron ^Talk 01:55, 16 August 2007 (UTC)

You could try reading the law, although individual states have their own laws as well. Someguy1221 01:58, 16 August 2007 (UTC)

The laws vary HUGELY from one state to another - some states have no useful lemon laws at all - it's also not enough that the car went in some number of times. If the car goes in for a different problem each time - and if the dealer manages to perfectly fix the problem each time - then it may not be a lemon - but if the same problem recurs - or if the dealership simply can't fix it - then that's a different matter. But we're getting close to providing legal advice here - which we're not allowed to do - so check the laws in your state, and get a lawyer if you don't understand them. SteveBaker 13:53, 16 August 2007 (UTC)

I say we change the name of this law.I feel this casts a slur upon my person :) Lemon martini 11:25, 18 August 2007 (UTC)