Wikipedia:Reference desk/Archives/Miscellaneous/2013 February 15

= February 15 =

Was Xena inspired by roman or Spanish princess

 * I remember reading in older article on Wikipedia that the TV character Xena inspired by roman or Spanish princess but this info was deleted. Who did I read about? Venustar84 (talk) 05:22, 15 February 2013 (UTC)
 * Maybe not a princess, but Bellona was the Roman goddess of war, who usually was portrayed as wearing armour. --TammyMoet (talk) 10:10, 15 February 2013 (UTC)

Perhaps this "real Spartan Princess was a little inspiration: http://en.wikipedia.org/wiki/Arachidamia Venustar84 (talk) 07:55, 16 February 2013 (UTC)

UK bus routes
Wondering if anyone knows where I could go to look up possible bus routes between Portsmouth, Hampshire and Swindon, Wiltshire? The stagecoach bus website is being particularly unhelpful in the matter, I can only look up information about routes I already know and their maps cover each town individually, so I would have to know every place the route passes through already and then look each of them up individually.

86.15.83.223 (talk) 12:44, 15 February 2013 (UTC)


 * www.transportdirect.info has various on-line journey planner tools. One route that it suggests is National Express route 300 to Salisbury, then Wilts & Dorset route X5 to Swindon. Gandalf61 (talk) 13:04, 15 February 2013 (UTC)
 * You can also try National Express directly for routes, times, fares etc. Stagecoach tend to provide local bus services; for cross-country routes in the UK we would normally talk about "coaches". AndrewWTaylor (talk) 14:23, 15 February 2013 (UTC)
 * I'm wondering if the OP is hoping to take advantage of a senior citizen's bus pass. (I'm certainly aware of people making moderately long journeys on local buses for free by using this, changing several times and accepting that it will take an age). He may want to try traveline.info which is run by a consortium of local government and industry bodies. The search facility allows you to input a starting point and destination and what types of public transport to include - so you can, for example, choose to search for (local) bus journeys only and exclude (long-distance) coach journeys. The journey appears to be do-able just by local bus (via Southampton and Salisbury) at certain hours of the day, but be prepared for it to take around 6 hours. (Mind you, including long-distance coaches doesn't knock much off the time at all, though train journeys - via Southhampton and Reading - take it down to around 2 1/2 hours). The journey is around 70 miles by the shortest route (which is not the route any of the public transport uses), so that's an impressive 12 miles an hour!). Valiantis (talk) 02:30, 16 February 2013 (UTC)
 * Travel line (South West) is useful for planning public transport. CS Miller (talk) 19:45, 17 February 2013 (UTC)

Songwriting
Heyy em in music we've got to make up a song on the keyboard for our important assessment and i'm pretty stumped for ideas, it has to have the chords in this order: C,C,C,C,F,F,C,C,G,F,C,C. I'm not very good at keyboard so it has to be simple and sound great it can't already exist and it has to use a combination of white and black notes, I'd prefer for it to have a pop style, anyone give me ideas/song for my assessment lesson??? Please help really stuckxx <3 :)  — Preceding unsigned comment added by Lucy8D (talk • contribs) 18:00, 15 February 2013 (UTC)
 * As a rule we don't help people with their homework. If you have specific questions about the composing process, we might be able to help. Rmhermen (talk) 18:16, 15 February 2013 (UTC)
 * Don't know if it helps you, but that chord sequence is a twelve-bar blues. Blues melodies are normally written using the notes of the minor pentatonic scale. --Nicknack009 (talk) 18:23, 15 February 2013 (UTC)
 * Blues scale may be a useful article to read as well. Just experiment with notes from the blues scale in C, based on the chords. Keep experimenting until you find something that sounds good. --Tango (talk) 21:45, 15 February 2013 (UTC)

destroying documents.
My question is: I've got lots of confidential documents that I need to destroy. I don't have a paper shredder and I'm not sure I'm comfortable shredding them in my workplace. How else could I destroy all this confidential data? Identity theft is no joke! Lamb Ham Jam Man (talk) 18:38, 15 February 2013 (UTC)


 * How much documents do you have and how much are you willing to pay?


 * If you're not willing to spend $15 then you can manually shred them.


 * If you're willing to spend $15 then you can afford a paper shredder.


 * If you have a large amount of documents then you can google "shredding service" and find professionals who will shred it for you.Dncsky (talk) 18:51, 15 February 2013 (UTC)

Have you heard of gasoline and matches?  Captain Screebo Parley! 18:56, 15 February 2013 (UTC)


 * Large amounts of paper are surprisingly difficult to burn; the air cannot get between the sheets leaving large lumps of unburned paper with singed edges. It requires some effort to break up the paper masses so that they burn properly. In addition, there may be legal constraints on burning rubbish, especially in built-up areas - there certainly are in the UK. Finally, petrol/gasoline and matches are a risky combination, either diesel or paraffin/kerosene are less likely to have unintended consequences. Alansplodge (talk) 21:36, 15 February 2013 (UTC)


 * Thank you all for your help so far. I have been thinking - perhaps I could put them in a pot on the stove and fill it with water and bring it to the boil whilst stirring them, and then putting the compacted mass of pulp in the paper recycling bin. I am keen to recycle them (which is why I am not too keen on burning them) but would this destroy all the data? Thank you Lamb Ham Jam Man (talk) 21:43, 15 February 2013 (UTC)


 * Just buy a cheap shredder... --Tango (talk) 21:47, 15 February 2013 (UTC)


 * Sometimes I will do the following, with bills and such:


 * 1) Tear off any critical info, like account numbers, my birth date, social security number, etc. These are then torn into tiny pieces and disposed of in separate trash containers (to prevent anyone from taping them back together).


 * 2) The remainder can be recycled normally. StuRat (talk) 22:20, 15 February 2013 (UTC)


 * Perhaps it would help if we understood your objection to a shredder. Is it the noise ?  Some are quieter than others, of course. StuRat (talk) 22:17, 15 February 2013 (UTC)


 * It is funny but until you mentioned it I never realised I had a problem with shredders. But actually they do make me edgy at times. I think it is ever since seeing that film where Whoopi Goldberg gets sucked into one. I always worry it will happen to me. Lamb Ham Jam Man (talk) 15:02, 16 February 2013 (UTC)
 * They really are quite safe. A finger won't fit in the slot.  I suppose a tie might, but the shredders I've seen aren't nearly strong enough to strangle you.  You'd just pull the shredded tie back out. StuRat (talk) 17:08, 16 February 2013 (UTC)


 * Additionally, the one I have has the switch right on top. It has three positions, Reverse - Off - Forward.  So just slapping the switch will result in either turning it off or (as is often the case with me) turning it on reverse and your tie or important document is spit out.  And yes, not even my nephew's fingers could fit, though I haven't tried.  Dismas |(talk) 16:34, 17 February 2013 (UTC)


 * Yea, they're not like a wood chipper, which really can ruin your entire day. StuRat (talk) 01:11, 18 February 2013 (UTC)


 * In Jumpin' Jack Flash (film), it's only a part of her dress that gets shredded - she wasn't in any personal danger from the machine. And the shredders I've used and owned have jammed at the slightest thing - so there isn't much real chance of even that being a problem.  Paper burns very nicely (without gasoline) if you just crumple it up and feed a few balls into the fire at a time.  Dumping an entire slab of paper in at once is less effective. SteveBaker (talk) 14:57, 18 February 2013 (UTC)

Stopping a moving car with a machine gun
Suppose someone is driving towards me at 60 km/h in a regular sedan, say a Toyota Camry or a Honda Civic. In my possession is an M2 .50 caliber machinegun. Suppose I am trained in using the weapon and have an infinite supply of ammunition, how long (in terms of the car's stopping distance) would it take me to stop the car that is driving towards me head-on?

I heard anectodally that the .50 caliber BMG round that the M2 fires can destroy a car's engine block. Still though, wouldn't the car still coast towards you even with the engine block destroyed? Is the car's stopping distance more or less the same as it would be as if the driver had just taken his foot off the gas? Or would the impact of the bullets help slow the car down some appreciable amount? Acceptable (talk) 22:19, 15 February 2013 (UTC)


 * .50 BMG describes these rounds, they can be fired by a person so I doubt firing a machine gun with them at a car would affect its momentum much but BB Gun describes a similar problem. Dmcq (talk) 22:28, 15 February 2013 (UTC)
 * Argh! You beat me to the ob.xkcd reference. Darn!! SteveBaker (talk) 02:34, 16 February 2013 (UTC)


 * A base-model 2012 Honda Civic sedan going 60 km/h (16.7 m/s) has a momentum of 19,700 kg*m/s. A .50 BMG round fired from a M2 Browning has a momentum of 37.4 kg*m/s.  Assuming a totally inelastic collision and ignoring the added mass of bullets sticking to the car, a simple conservation-of-momentum calculation says that it would take 527 rounds (total mass 22kg, so ignoring the mass is justified) to bring the car to a stop, or about a minute of firing.  Deceleration is about 0.3 m/s/s, and the car will travel about 500 meters after you start firing -- easily within the range of a M2. --Carnildo (talk) 22:52, 15 February 2013 (UTC)


 * You're allowed to ignore the added mass regardless, since otherwise you'd be somehow creating new momentum. Someguy1221 (talk) 02:42, 16 February 2013 (UTC)


 * All of that assumes the car was traveling in neutral and was otherwise not hindered in its ability to roll. In reality, if the transmission was engaged then there's good chance of a seized engine block, which would cause the car to lock its wheels and come to a stop much sooner.  There's also likelyhood of bullets and/or shrapnel damaging the tires or axle to much the same effect.  -- Jayron  32  04:25, 16 February 2013 (UTC)


 * I'm a bit surprised that a person can withstand the force needed to stop a car going at 60 mph within a minute. I gues they're just standing up to the battering rather than actually trying to accelerate the car. Dmcq (talk) 18:33, 16 February 2013 (UTC)


 * Considering that the US Army issues armor-piercing incendiary (API) rounds in most deployments, I would expect the car to pretty much disintegrate and go up in flames. I once took out a three foot diameter tree with standard ball ammo when we had a target system failure and the rangemaster told us to expend all ammo so he did not have to count it for turn-in[Yet another anecdote]. --— Gadget850 (Ed) talk 19:03, 16 February 2013 (UTC)


 * Carnildo's answer is probably the ideal one, but wouldn't most of the energy go into generating heat and rending the car's body rather than backwards thrust? μηδείς (talk) 23:23, 16 February 2013 (UTC)


 * The momentum has to be conserved regardless of what happens to most of the energy. The momentum can be transferred to the air, or to the earth via the car's tires, but beyond that the car is required to accelerate in reverse. Actually, since momentum is directly proportional to velocity, rather than to its square, it's possible for >99% of the energy to go one place and for >99% of the momentum to go somewhere else. Think about say, when a plane lands on the ground; nearly all of the plane's momentum went into the Earth, but the Earth's kinetic energy barely budges. Someguy1221 (talk) 02:53, 17 February 2013 (UTC)


 * The energy of the momentum is conserved, but the bullet acts as a wedge, transferring some of that energy to forcing the material of the car body apart sideways and heating it as well. If the it were entirely conserved as forward momentum you'd be getting the heating and rending of the metal for free on top.  The only source of energy in the bullet to rend and heat the car is the total momentum--some of it must be converted and be lost to pushing the car backwards. μηδείς (talk) 19:53, 17 February 2013 (UTC)


 * The law of conservation of momentum is a very powerful tool for solving this sort of problem. It lets you ignore issues such as how much energy gets turned into heat, or your wedge effects.  Conservation of momentum requires that any momentum change of part of the car be balanced by a momentum change in the other direction by something else.  Either the momentum change has a component parallel to the travel of the bullet (in which case it's contributing to the slowing of the car), or it doesn't (in which case you need to move another part of the car in the opposite direction).  It's impossible to "redirect" momentum to act in another direction.


 * The "heating and rending" does "come for free": momentum is directly proportional to velocity, while kinetic energy is proportional to the square of velocity. In an inelastic collsion, the kinetic energy of the combined object is less than the sum of the kinetic energies of the original objects, so the extra energy needs to be carried off somehow -- and it happens by the deformation and heating of the objects involved. --Carnildo (talk) 22:42, 19 February 2013 (UTC)


 * Stopping a moving car with a machine gun is quite easy:


 * 1) Ensure that you're in a Hollywood movie.


 * 2) Make sure bad guys are in the car, in which case the car will inexplicably flip over, as if it had hit a hidden ramp, and burst into flames. (If good guys are in the car, the bullets will bounce off, making impressive sparks). StuRat (talk) 20:01, 17 February 2013 (UTC)

I think something that's adding to the awe of the minute calculation above is the (conveniently) overlooked issue of how far a car going 60kph travels in one minute -- I'm no mathematician, but that's a kilometer according to my calculations, which is a pretty long distance. The car would then have to be more than a kilometer away for the shooter to stop it in time from collision.  DRosenbach  ( Talk 19:56, 18 February 2013 (UTC)


 * I covered that in my calculation: the car travels about 500 meters from the time you start firing, assuming no outside forces other than the machine gun (distance subject to variations in the actual firing rate of the gun). --Carnildo (talk) 22:42, 19 February 2013 (UTC)

List price or only price?
Hello there, I have just come up with two different pricing system in amazon.com. For example: this book has two pricing, List Price: $24.95 and Price $16.47. I want to order this book (along with other books) via local book store in my country. The book store accept the order of books and deliver them to customer within customers specified time period. Before placing the order I want to be sure which pricing system I should mention to local book store (so that they can not deceive me). I noticed that Barnes and noble follow the same structure with slight difference in pricing. Thanks.--180.234.93.75 (talk) 22:24, 15 February 2013 (UTC)


 * The "list price" is the Suggested Retail Price, which is the most it should ever cost (with some rare exceptions). However, I consider the discounted price to be the "real" price, and the SRP to be the "rip-off" price.  Also note that delivery charges may be extra.  I suggest you first see the price at the bookstore, then, if it's higher than the price you can get on Amazon or elsewhere, mention this to them, and they might lower their price to match. StuRat (talk) 22:38, 15 February 2013 (UTC)


 * These aren't "pricing systems", they're just prices. "List price" is a suggestion from the publisher, and nothing more. In a free market (where something like the Net Book Agreement doesn't apply) then a bookseller can sell the book for whatever they want. So the local store can charge you what it likes, and not charging you what Amazon (with its efficient cost structure and negotiating power) does isn't "cheating" you, it's just different. -- Finlay McWalterჷTalk 22:39, 15 February 2013 (UTC)


 * Amazon is notorious for charging different amounts for the same book depending on who you are and what books you've bought before. Prices also go up and down on their site automatically depending on how popular the books are - and their 3rd party resellers frequently use dynamic pricing to compete against each other or undergo subtle price fixing.  Check out this blog post about someone who discovered a well known, common science text book selling for several million dollars due to this kind of nonsense.  His tracking and analysis of how this came about is quite revealing.  So using Amazon as a guide is a highly dubious thing! SteveBaker (talk) 02:32, 16 February 2013 (UTC)


 * You do realize the blog post is about third party vendors selling their own items through Amazon, not Amazon's own prices? Saying that Amazon itself is notorious without a source for the claim is defamatory.


 * The OP may want to check out abebooks.com and the buy option at google books which gives other listings. μηδείς (talk) 04:07, 16 February 2013 (UTC)


 * Perhaps, before you accuse me of such behavior, you'd be kind enough to actually read what's in the link I posted? It says: "I learned that Amazon retailers are increasingly using algorithmic pricing (something Amazon itself does on a large scale)". SteveBaker (talk) 07:21, 16 February 2013 (UTC)


 * Your claim "Amazon is notorious for charging different amounts for the same book depending on who you are and what books you've bought before" is not supported, and the only evidence the blogger gives is of two third party vendors, not any notorious actions by Amazon itself. μηδείς (talk) 19:51, 16 February 2013 (UTC)
 * 
 * 
 * ...many others. SteveBaker (talk) 15:09, 18 February 2013 (UTC)


 * Not that I like to argue with you, Steve, but that first link (from 2008) seems to simply be a consumer who didn't understand how the Amazon marketplace works. They weren't really getting different prices, and certainly weren't getting dynamic prices adjusted according to their account history. Maybe in 2008, the Amazon Marketplace didn't have the handy sort option "lowest to highest (including p&p)", which makes this sort of thing trivial to spot? 86.163.209.18 (talk) 23:28, 21 February 2013 (UTC)