Wikipedia:Reference desk/Archives/Science/2009 June 28

= June 28 =

Power Press
I want to know the type of air compressor used in the Pneumatic power generator in a Power Press Machine.I will be very grateful to any one who can give me an actual working method of a Power Press Machine....I would like to have the description of all the components in the machinery which drives the Power Press. —Preceding unsigned comment added by 121.246.174.130 (talk) 02:54, 28 June 2009 (UTC)


 * There are lots of power press machines. This lists some of them and their manufacturers, who have the information you want. Cuddlyable3 (talk) 13:08, 28 June 2009 (UTC)
 * they dont give me the working...only the information about its material is given —Preceding unsigned comment added by 121.246.174.130 (talk) 17:07, 28 June 2009 (UTC)

What in the world is this creature?
http://www.youtube.com/watch?v=Bv6cqUpqelc&feature=related

^ I'm referring to the gigantic crustacean depicted in the above film. It looks to be some sort of lobster, but it might be a crayfish, or something else, for all I know. I'm really curious, this thing is HUGE. —Preceding unsigned comment added by 75.148.127.194 (talk) 03:30, 28 June 2009 (UTC)


 * There are literally hundreds of species of lobster in the world; judging by the lack of large claws, this may be a variety of Spiny lobster or "Rock lobster", of which, according to our article, there are at least 45 different species. Our article mentions a 3-foot, 26-pound rock lobster as the record, so this wouldn't even be close to that.  My guess is this is an 8- or 9- pounder, certainly large but no where near unheard of... --Jayron32. talk . contribs  04:00, 28 June 2009 (UTC)


 * Actually, looking at the video again, it may be a species of true lobster rather than spiny or rock lobsters. Reviewing our articles, true lobsters are distinguished by the having claws on the first three sets of walking legs; while rock lobsters do not have these.  This appears to be a species of true lobster based on that, however our article list 48 known species of true lobster; there are only articles on a dozen or so of these, and only pictures of 3-4.  It's certainly not a "Maine lobster" or other American or European lobster, but I can't narrow it down more than that.  --Jayron32. talk . contribs  04:10, 28 June 2009 (UTC)


 * Looks like a Rock lobster, Panulirus ornatus to be specific. Richard Avery (talk) 07:42, 28 June 2009 (UTC)


 * Well, there ya go... --Jayron32. talk . contribs 12:24, 28 June 2009 (UTC)


 * If you're into large crustaceans - check out the largest...one of my favorite animals - the Coconut crab. SteveBaker (talk) 00:29, 29 June 2009 (UTC)

Virtual Gravity
I'd like to live comfortably aboard a space station for the remaining 60 or so years of my life. The space station I imagine is a very long cylindrical rod rotating about its central axis to achieve that biologically-approved 9.8 m/s/s constant acceleration. The human cargo would be on the lowest level of the spinning rod where the gravity is virtually earth-like. My question is: how long does that rod of a space station have to be so that the entire height of a 6' human would be subjected to within 1% of 1g gravity? Follow-up question: is a differential of 1% of 1g over a human body acceptable for human biology to thrive very long-term? (This is not a homework assignment, I promise. I'm watching 2010 and the spinny thing they have going on their craft is so short it would seem to only achieve a gravitational nightmare.) Sappysap (talk) 04:39, 28 June 2009 (UTC)


 * The artificial gravity effect is proportional to the radius of rotation, so a 600' long rod should do. I think the human body would do just fine with a differential much higher than 1%. Dauto (talk) 05:41, 28 June 2009 (UTC)


 * A quick googling landed me on this page which suggests you may want a rotation period of 30 seconds or more (2 rpm) or you have a good chance of getting dizzy. The page has a link to a handy calculator for space station designers. A radius of 225 meters gives 1 g at 2 rpm. 62.78.198.48 (talk) 09:57, 28 June 2009 (UTC)


 * You are describing an O'Neill cylinder, I believe. (WP:WHAAOE) --Tango (talk) 17:37, 28 June 2009 (UTC)


 * From your description, the length is irrelevant. A shape like a bicycle wheel like 1940's science fiction space stations makes far more sense, or two or more habitats connected by long cables to a central hub about which they rotate. The radius or distance from the axis and the rotation rate creates the virtual gravitation. I believe that a gravitational differential between head and toe would create vertigo if you sat down or bent over. The rotation period would be unrelated to dizziness unless you were looking outside a window, since you would otherwise be unaware of it. Edison (talk) 03:18, 29 June 2009 (UTC)


 * The question was a bit unclear. Sappy first said the rod was rotating "around its central axis", which would mean spinning like an axle or drive shaft; in that case the radius or diameter of the cylindrical rod would be the relevant dimension.  But then he or she asked how long it would have to be; that would be the relevant dimension if it was spinning end-over-end like a propeller blade, and I'm guessing that this is what he or she had in mind.  (Of course, the bicycle-wheel space station includes the end-over-end rod as a component, and gives a much larger area at full "weight", i.e. the full perimeter of the wheel, than the rod alone)


 * If the 1% g variation that Sappy requested is taken as definitive rather than the estimated rotation speed posted by 62, then Dauto's logic in calculating a length of 6/1% = 600 feet is correct, but it applies to the radius of the circle of rotation, not the diameter. So a rod-shaped station rotating end-over-end would have to be 1200 feet long if built symmetrically.  It could be made shorter by building it with a large mass at one end, so the center of mass would be closer to that end.  For a bicycle-wheel design, you want a diameter of 1200 feet.


 * It's also possible that the negative effects of dizziness would disappear after some time spent in the facility. When astronauts first enter free-fall, they get that horrible sensation of falling - they feel sick - all sorts of bizarre sensations afflict them - but after a few days, they get over it and it all seems perfectly natural.  It's possible that the dizziness due to coriolis in an overly small spinning craft would subside after a few days and you'd learn to expect things not to fall in a straight line, etc.  SteveBaker (talk) 04:36, 29 June 2009 (UTC)


 * A Science Channel series, something like "Escape from Earth" discussed such artificial gravity for a very long distance space trip, like th Gliese 581c, and showed a centrifuge on Earth as a prototype. Strangely, the person's head was at about the pivot point, and only at the feet was normal gravity. This did not cause any strange feeling in the person, but moving his head around caused vertigo. I would strongly vote for 2 or more capsules a long distance apart, twirling about the central axis. An elevator could allow visiting back and forth. Edison (talk) 03:19, 30 June 2009 (UTC)


 * Yes - I agree. You stick all of the motors and fuel tanks and other stuff you don't need during the trip into one 'pod' and the people and their food and recycling stuff in another - set them spinning using a counter-rotating flywheel in the "hub" of the machine and then let centrifugal force unwind a pair of long cables between the two.  You can power the flywheel electrically from solar panels - so it's easy to alter the spin rate and the diameter of the rotation of the crew quarters at any time during the mission without consuming valuable reaction mass.  The cable only has to be strong enough to support the weight of the spacecraft under 1g of normal earth gravity - so a fairly slim steel cable ought to suffice.  A small, motorized cable climber would allow astronauts and other items to travel between crew quarters, hub and propulsion pod - or you could use a soft, inflatable tube to connect the two pods and stick a rope ladder inside to allow people to move between the two pods.  When you need to accelerate the spacecraft - or to keep it from spinning while (say) the earth-to-orbit shuttle docks with you, you use the energy stored in the flywheel to slow the rotation rate as you reel the cables back into the hub - then you only have to endure zero-g while the craft accelerates or as you take on supplies.  You can scale the system up or down by connecting multiple such systems together by attaching them at their hubs.  Flimsy structures such as solar panels, zero-g experiments, telescopes and communications gear that needs a stable platform can be attached to the hub and kept from spinning with a second flywheel.  This seems like a relatively simple prospect - and I'm a little surprised that we aren't already doing this kind of thing - given the health risks to astronauts who man the ISS in free-fall over long periods. SteveBaker (talk) 12:43, 1 July 2009 (UTC)

UFOs in my bathroom
Every evening, I have lots of small insects in my bathroom: they're unidentified and flying, so I'd like help with identifying these UFOs in my bathroom. Their feet grip very well — they can hang onto a vertical mirror without problem — and when they're on the mirror it's plain that they're insects. They're shaped somewhat like grasshoppers, and they can jump very suddenly: in a fraction of a second, one jumped from one side of the sink to the other, before I could even realise what was going on. Colour is a pale green; size is quite small, with the largest ones being perhaps 5mm and the typical one being perhaps 2mm. They appear to be interested in the flourescent bathroom light (in the same fashion as moths are). My location is in western Ohio; any ideas what this species/these species are called? Nyttend (talk) 04:47, 28 June 2009 (UTC)
 * I couldn't tell you the species from your description. Your easiest bet would be to catch a few and take them to your local university. Alternately get a camera with a macro lens and take a few photos. Yesterdays POTD (a scorpion) was found in the shower. Noodle snacks (talk) 06:06, 28 June 2009 (UTC)
 * Katydids maybe? Nymphs can look like miniature versions of adults in some species.- 71.236.26.74 (talk) 07:22, 28 June 2009 (UTC)
 * check out leafhopper --Digrpat (talk) 11:39, 28 June 2009 (UTC)
 * I think that they're some sort of leafhopper: I couldn't find anything there that looks like them exactly, but the general body shape and description fits quite well. Definitely not katydids, and sadly there are no universities or other scholarly things around here.  Nyttend (talk) 13:30, 28 June 2009 (UTC)


 * Wonderful section heading, by the way (in large part because it is quite appropriate to the question). Hard to skip reading at least a little...  Chapeau!  --Scray (talk) 19:41, 28 June 2009 (UTC)

Digital cameras - more pixels useless due to camera shake?
It is now possible to buy a camera giving a 5 megapixels photo for £25 or $41 (compare with the reconditioned 1.3MP camera I paid £80 $132 for from a discount retailer four or five years ago). 1) Does camera shake mean it is pointless having so many pixels? 2) In other words, are they just a sales gimmick? 3) And might they just be software-interpolated from the true hardware resolution? Camera shake will be even worse as many cameras no longer have an optical viewfinder and are thus held far less stabily. 4) Do these cheap cameras tend to have wider-angle lenses than similar cameras a few years ago? Thanks. 78.147.242.96 (talk) 11:24, 28 June 2009 (UTC)


 * Actually, most cameras now have stabilizers which hold the image steady even if your camera shakes a little bit. --Jayron32. talk . contribs  12:22, 28 June 2009 (UTC)


 * 1) The extra pixels are not pointless unless your camera shake is always so violent that the resolution within every frame is degraded in every direction to the 1.3MP level or less. Camera shake correction aims at recovering the full resolution. 2) Caveat emptor. The extra pixels are real but you are getting just under 2x increase in linear resolution. Enlarged prints will look slightly better. 3) Digital cameras with optical viewfinders are readily available. Many people prefer to use the LCD viewfinder that can also show menus, camera status and previously taken pictures, and they do not necessarily hold the camera less steadily in that viewing mode. Disadvantages of LCD displays are that they add to battery drain and they may not be easy to see under bright light or for long-sighted users. 4) Most cheap digital cameras now have 3x ratio zoom lenses. I think they tend to have narrower-angle views because A) the digital image sensors are smaller than typical film sizes such as 35mm, and B) it is relatively expensive to build a good wide-angle lens but very cheap to obtain a reduced-resolution telephoto effect by in-camera digital processing. Cuddlyable3 (talk) 12:43, 28 June 2009 (UTC)


 * To your question 1, the answer is "no", because camera shake can be prevented or reduced by using a tripod and/or increasing the shutter speed (where possible). To your question 2, the answer is "to a degree". In order to have a high pixel count camera, you need to have good enough optics to match the imager resolution, and you cannot compress the output image too heavily. I don't know if the situation has changed recently, but I've looked at pictures (5 to 7 megapixels) taken with cheap cameras several years ago, and was quite disappointed. When you enlarge the pictures enough to be able to see individual pixels, you'll see very noticeable fuzziness and annoying artifacts. Basically, the picture quality does not commensurate with the pixel count. --173.49.12.134 (talk) 15:28, 28 June 2009 (UTC)


 * You can solve the camera shake problem with a tripod or other camera-stabilizer, but the lens is also very important, and there is no good way to compensate for a low-quality lens. Looie496 (talk) 16:25, 28 June 2009 (UTC)


 * A major problem is that for the small CCD sensors of most consumer cameras, adding resolution also adds more random noise, or, to be more precise, the smaller and smaller areas dedicated to each pixel become more and more sensitive to the (basically) constant noise floor. I've seen reviewers that put the best trade-off between resolution and noise for current compact cameras (with 4.5 by 3.5 mm CCDs)  somewhere between 5 and 6 megapixels, and who claim a noticable degradation for larger resolutions. --Stephan Schulz (talk) 22:14, 28 June 2009 (UTC)


 * When viewed 1:1 full sized photo from these high-resolution point-and-shoots is just disgusting, all the details smoothed to lumps of colours. --antilivedT 01:00, 29 June 2009 (UTC)
 * Well, to be fair "1:1" would be 4.5*3.5 mm (or, if you are generous, 36*24 mm ;-). --Stephan Schulz (talk) 10:27, 29 June 2009 (UTC)
 * Not true. The pixels on my LCD monitor are bigger than the pixels on my digital camera. --203.129.49.222 (talk) 12:38, 29 June 2009 (UTC)
 * I have a 12MP pocket camera and I very rarely take purely hand held shots unless the light is very good. I always try to brace myself when taking a photo, most of the time I put my camera against a light or sign post, fence, corner of a building, anything. If there is nothing around you can squat down and put your elbow on your knee. If you absolutely must take a hand held shot not squatting down, instead of extending your arms out, press them tightly against your body, you don't have to look into the view finder once you get the hang of point and shoot and with digital you can check as soon as you've taken the shot to make sure you framed well. Vespine (talk) 23:47, 28 June 2009 (UTC)
 * In an emergency, you can reduce camera shake simply by holding something heavy in the same hand as the camera. But the amount of blur that camera shake causes depends a lot on shutter speed.  For short shutter times (in bright light), shake is much less critical.  So finding a camera with a more sensitive detector array and a bigger lens (which allows more light in) will all help to make those extra pixels earn their keep. SteveBaker (talk) 00:22, 29 June 2009 (UTC)
 * Bracing your elbows against your chest can help steady the camera while still allowing you to see the LCD screen (you may have difficulty if you want a use a viewfinder, though). --Tango (talk) 00:50, 29 June 2009 (UTC)
 * In short, no - because in direct sunlight and other bright settings, the shutter speed is so fast that the camera shake is negligible, even handheld at 10 or 20 megapixel resolution. So it's useful. As for upscaling, I would consider that false advertising of the worst kind and I would hope no one would stand for it - the camera ought to advertise its actual sensor resolution. I don't know much about the typical angle-of-view of cheap lenses, but I'd expect a 35mm-equivalent focal length of about 50mm, which is the typical "as people see" focal length. Dcoetzee 04:33, 30 June 2009 (UTC)
 * In bright conditions, without any zoom whatsoever, it's usually OK. A lot of photos are taken in conditions that don't satisfy those two requirements though. Tiny, dense, high megapixel sensors also tend to suffer from extreme noise at higher ISO speeds or over long exposures, so again they're less useful in lower light / faster motion situations. And as mentioned above, at a point you can't really gain any extra resolution out of it (or at least not enough to justify the pixel increase), just more noise which smooths out in a larger view but up close is completely useless. -- Consumed Crustacean (talk) 04:51, 30 June 2009 (UTC)

''In the next part of this comprehensive tutorial on the art of photography our resident team will address composition techniques, lens cleaning and how to identify the exposure button on your camera. Links will be provided to every one of each poster's holiday snapshots since this is relevant to the OP's question.'' Cuddlyable3 (talk) 10:41, 29 June 2009 (UTC)

Why do some people appear to age less than others?
Cher for example still looks much younger than the typical 63 year old, both in face and body. What are the actual ressons for this in practice? Regarding her face - I expect she's had a facelift, has dyed hair and/or a wig. But regarding her body - does staying slim and exercising really make you age less than others? 78.147.242.96 (talk) 12:15, 28 June 2009 (UTC)


 * Genetics + LOTS of plastic surgery + money + fitness = Cher. --Jayron32. talk . contribs  12:21, 28 June 2009 (UTC)


 * http://www.officialcherfanclub.com/ invites one to send a message of up to 600 characters about "just about anything" to Cher. I stay slim and exercise but I am nothing like Cher. Thank you for your interest. Cuddlyable3 (talk) 12:55, 28 June 2009 (UTC)
 * I do not imagine that La Cher is an expert on Gerontology. 78.149.197.193 (talk) 15:06, 28 June 2009 (UTC)


 * When your career rides on you being in shape and looking good, you tend to stay in shape and look good. It's not like she has worked in a cubicle her whole life and tries to exercise on the weekends.
 * In any case, YES, exercising regularly and avoiding excess pounds does make you look a LOT younger than your contemporaries who do not. (It doesn't mean you will necessarily live longer or be healthier, mind you, but in terms of looks, definitely a factor.) You can see this rather dramatically in class reunion photos when people get to be around 40 — those who really take care of themselves on a regular basis (regular exercise multiple times a week, no obesity) easily look a decade younger than their peers who do not. In my experience. --98.217.14.211 (talk) 19:51, 28 June 2009 (UTC)


 * On another hand, when my dad lost a lot of weight, at age 63 (when I hadn't seen him in a couple of years) he "suddenly" looked much older – because he was no longer baby-faced. —Tamfang (talk) 09:53, 22 July 2009 (UTC)

Additionally make-up, a with-the-current-style hair-cut and wardrobe can help reduce ones apparent age enormously. ny156uk (talk) 22:02, 28 June 2009 (UTC)

1) Makeup. Did you ever see photos on the cover of tabloids of celebrities as they look when they walk out of the house in the morning to pick up the newspaper, compared to how they look with the lip gloss, concealer, and eye shadow? 2) Photoshop. They remove blemishes and wrinkles, and trim the tummy and tush, and remove wattles from the neck. Edison (talk) 03:13, 29 June 2009 (UTC)

I would add Diet and General Lifestyle as two important factors. Eating McDonalds 5 times a week or going to a quality grocer will no doubt influence the ageing process. A simple thing like sleeping with a window open would also help reduce the toll of decades, I should imagine. Vranak (talk) 19:02, 30 June 2009 (UTC)

Halogen
why iodine posess a very high electroposetive character though other halogen are highly electronegetive?Supriyochowdhury (talk) 15:56, 28 June 2009 (UTC)
 * According to our electronegativity article, Iodine has a Pauling electronegativity of 2.66, which is higher than carbon (2.55) and hydrogen (2.2), so I wouldn't say it was electropositive. The validity of those values might be questionable though, as I've been told that hydrogen and carbon have electronegativity values so close that it's unsure which is more electronegative than the other. (reference: someone with a PhD in organic chemistry) --Mark PEA (talk) 16:04, 28 June 2009 (UTC)
 * After looking at the article futher, it appears by the Allen scale that iodine is less electronegative than carbon (but still higher than hydrogen). Although chlorine is only a tiny bit more electronegative than carbon, so you can't say "all other halogens are highly electronegative". --Mark PEA (talk) 16:05, 28 June 2009 (UTC)


 * I'm not sure what you're asking. Iodine is fairly electronegative. Among the halogens, it's less electronegative than Bromine, but more so than Astatine, which is what you would expect. This can be attributed to the larger atomic radius. --Pykk (talk) 08:04, 29 June 2009 (UTC)

The reason why iodine is less electronegative than the other halogens is because its atomic radius is bigger and it has more electron shells between its nucleus and valence shell (which cause electrostatic shielding), so there's less electrostatic attraction between the nucleus and valence electrons. Hope this answers your question. Clear skies to you! 76.21.37.87 (talk) 01:28, 30 June 2009 (UTC)

Toyota High Performance Engines.
a While ago I stumbeled onto a web page that had a picture history of High performance and multi-valve Toyota engines. They ranged from 4 to 12 cylinders I think it was. All shapes and sizes. For the life of me I cannot find it again. I have looked everywhere on the net but to no avail. Can you maybe assist?

Regards, B —Preceding unsigned comment added by Benniebarnard (talk • contribs) 15:59, 28 June 2009 (UTC)


 * Wikipedia has a great history of Toyota, ranging from the Toyota AA to the Prius. Most of the articles actually have pretty good descriptions of the mechanical and engine particulars.  Nimur (talk) 01:43, 29 June 2009 (UTC)

Is this site what you're looking for? http://www.geocities.com/MotorCity/Pit/9975/dataBySubject/EnginePix.html SteveBaker (talk) 02:10, 29 June 2009 (UTC)

Nope, not this one, it had HD pictures with exelent detail. If my memory serves, it was a simular list and had more competition type engines.196.25.43.75 (talk) 05:53, 29 June 2009 (UTC)
 * Plenty of Toyota engines here and here. - KoolerStill (talk) 09:59, 29 June 2009 (UTC)

Some nice ones here!!! The articla I saw had quite a number of wide head multivalve headed motors and manny of them had more than one sparkplug per cylinder. This made me think that they must have been for the motorsport market. Injected, sidies, downies,,,the lot!196.25.43.75 (talk) 05:05, 30 June 2009 (UTC)

Need help identifying an animal skull from northern Alberta
The skull shown in the image below was found in the boreal forest of northern Alberta, Canada. A local informant suggested it might be a fox and a search of images for the red fox (Vulpes vulpes) seems to confirm this identification except for one feature: the teeth. It looks more like a juvenile deer to me -- mule deer (Odocoileus hemionus) are fairly common in the area, white tailed deer (O. virginianus) less so.

If anyone here can help identify this skull that will be appreciated. Eco ant (talk) 17:00, 28 June 2009 (UTC)
 * It is almost certainly a deer skull. The dentition is that of a herbivore and the zygomatic arch is indicative of a ruminant. However, telling the exact species is tricky at best and impossible at worst. Have a look at some skulls here; many are simply identical. Fribbler (talk) 17:44, 28 June 2009 (UTC)
 * Thanks Fribbler. I'll consider it a species of deer.  The external site you give is quite interesting.  Eco ant (talk) 19:53, 28 June 2009 (UTC)
 * Fribbler probably right, not a fox, and its a herbivore.Polypipe Wrangler (talk) 14:01, 4 July 2009 (UTC)

Mini hang glider
Would a hang glider measuring approximately 580mm x 420mm, be able to carry a 500 gram mass across a distance of about 20 metres? If so, how high up would it need to be launched from? 86.166.46.34 (talk) 17:01, 28 June 2009 (UTC)
 * Is this a homework question? TastyCakes (talk) 17:47, 28 June 2009 (UTC)


 * It doesn't look like a homework question. For one thing, the problem is too underspecified for the second part to be answered precisely. --173.49.12.134 (talk) 19:22, 28 June 2009 (UTC)


 * Are you assuming still air? Thermals make a big difference for full size hang gliders.  Widn would make a difference.  RJFJR (talk) 19:21, 28 June 2009 (UTC)


 * The shape of the glider, as well as any initial momentum (if allowable), would also make a difference. I think the answer to the first question is obviously yes. If not, any glider that fits the description will come down almost vertically when launched from the outer edge of the atmosphere. And that's just most counterintuitive. --173.49.12.134 (talk) 19:29, 28 June 2009 (UTC)


 * We have to be a bit careful here. Small details of the rules matter!  I recall that my son won a paper airplane "distance" contest at our company picnic some years ago by (in the first round) folding the paper so many times that he made a solid needle-like structure with zero lift but very little drag...but won the finals by taking the sheet of paper and scrunching it up into a tight ball which "flew" a lot further than the competition simply because he could throw it harder and it had a lot less drag than the competition.  (The rules changed the following year!)


 * So - if you start at the top of a tall enough structure and throw the thing hard enough - your 500g mass will certainly travel 20m with no "glider" at all. No matter the design of your glider, it's always going to be possible to provide a high enough launch speed to make the mass travel the desired distance...especially if the launch height can be arbitarily high.


 * Hence, the answer (within the limits of what you ask) is "Yes". But since I strongly suspect that's not what you really want to know - we have to ask: "At what speed can the glider be launched?" - are you going to toss it by hand?  Could you rig up a high speed bungee-cord launcher?


 * May I recommend this web page: - which discusses the critical matters of "wing loading" and "span loading".  These equations allow you to calculate a lot of the parameters of your design.  As a short-cut, we could look at our Wing loading article which indicates that a typical "hang glider" has a wing loading of around 6.3 kg/m2 - meaning that to support 500g with that kind of a design, you might need 0.5/6.3=0.08 m2 of wing area...and you have 580mm x 420mm = 0.24 m2...so your wing loading is around 2.1 kg/m2 - which seems pretty good. However, airspeed also has a big impact on lift...your model hang glider will probably fly a lot slower than the real thing - so it needs a lower wing loading.  Again, check the equations in Wing loading...if this is a school project - then there is much to learn there - and I probably shouldn't do that for you.


 * SteveBaker (talk) 00:11, 29 June 2009 (UTC)

Evolution of desperation
What makes people react negatively to a display of one's desperation? It seems that even though desperation is the last attempt at correcting something (and I suppose it's natural) people would rather not 'rectify' it (someone else's desperation, of course). Does this follow the pattern that the 'weakest become weaker' and so desperation must be annulled? 94.196.190.79 (talk) 18:45, 28 June 2009 (UTC)


 * Are you sure that all people react in this way? This could easily just be a cultural thing—whereby desperation is associated with weakness, and weakness is shameful. There's no reason to necessarily assume that evolution has shaped this response (would it have had a differential effect on reproduction rates? probably not). --98.217.14.211 (talk) 20:57, 28 June 2009 (UTC)


 * People learn from experience that getting involved with people who are desperate often means giving a lot and getting nothing in return except trouble. If people were capable of offering an equivalent return for meeting their needs, they wouldn't be desperate. Looie496 (talk) 21:04, 28 June 2009 (UTC)

Fresh milk
What are the risks of drinking milk straight from the cow (directly from the udders) in comparison to drinking it unpasteurised after it's been milked and stored for a day or so (in a fridge)? Vimescarrot (talk) 19:13, 28 June 2009 (UTC)
 * Not many nowadays probably - see pasteurised. It does sound a bit kinky and you might get kicked though. Dmcq (talk) 19:32, 28 June 2009 (UTC)
 * Well, i dare say that depends a lot on what cow we are talking about. If you mean a cow raised on an organic farm then probably not much, but I don't think you could pay me enough to drink milk straight from the udder of a cow raised on RBGH. Wow!!! I just had a look at that article for the 1st time in a few years and it looks like all the bovine growth hormone stuff is on the way out! Last time I read about it, it looked like monstanto was winning with all the litigation against organic farmers and stuff. Well done, that's fantastic.. Vespine (talk) 23:57, 28 June 2009 (UTC)
 * Tuberculosis has been transmitted by raw milk . Edison (talk) 03:10, 29 June 2009 (UTC)
 * Interesting. Thank you. Vimescarrot (talk) 18:40, 29 June 2009 (UTC)


 * I grew up on a farm. As a child, this was common practice.Either squirting it from the udder into our mouths or from the Milking bucket, steaming like smoke on water! These cows grazed the open fields though!! The only hormones they got was their own !!196.25.43.75 (talk) 15:08, 30 June 2009 (UTC)


 * Abraham Lincoln's mom died from fresh milk, though she would not have been saved by refrigerating it for a day. The cow had eaten White Snakeroot and she got milk sickness.  --Sean 21:42, 30 June 2009 (UTC)
 * A small chance of brucellosis too. Catching tuberculosis used to be mostly from just being around the cows, you dont have to drink the milk. Whole dairying families used to have TB. Leptospirosis is a possibility too. Polypipe Wrangler (talk) 14:18, 4 July 2009 (UTC)

Calories in a pound of fat
If I want to lose a pound of weight I need to have a caloric deficit equal to the energy content of a pound of my fat. How many (kilo)calories is that? RJFJR (talk) 19:18, 28 June 2009 (UTC)


 * Fatty tissue does also contain other things than fat, and storing and releasing fat will also cost some energy, so weight to calories is not one to one, but for the question see food energy. If you want to lose your pounds easily, why not go to London stock exchange? 93.132.184.56 (talk) 19:26, 28 June 2009 (UTC)


 * Fatty tissue as mentioned contains a lot of water. The guide often used is 3000 calories will give about a pound in body weight (but far less weight of actual fat) however I cannot find a particularly reliable source for it. --BozMo talk 20:01, 28 June 2009 (UTC)
 * Had a look at food energy which says 3500 but the references are very weak (mainly websites selling diet products which should not make WP:RS) --BozMo talk 20:09, 28 June 2009 (UTC)
 * The standard value I've seen is 4000 KCal per pound of pure fat, but I don't have a ref at hand. Looie496 (talk) 20:56, 28 June 2009 (UTC)
 * One of the references is Health Candada which I don't think they are selling diet products. See page 45. 93.132.184.56 (talk) 21:00, 28 June 2009 (UTC)
 * The kcal/g listed in the Health Canada document is for dietary fats such as vegetable oil. The calories in a pound of body fat is less, since adipose tissue doesn’t consist of pure fat.  Red Act (talk) 21:32, 28 June 2009 (UTC)
 * The American Dietetic Association counts as reliable source that doesn’t sell diet products. And the “American Dietetic Association complete food and nutrition guide” lists the 3500 calorie figure.   Red Act (talk) 21:22, 28 June 2009 (UTC)
 * Cellular respiration produces 2880 kJ per mole of C6H12O6 (i.e. glucose, not fat). That translates to 1730 Calories / pound of glucose.  As noted above, fat is a higher density storage medium, so there will be somewhat more Calories per pound of dry fat.  Dragons flight (talk) 21:05, 28 June 2009 (UTC)
 * The 3500 kilocalorie figure has come from a variety of reliable sources over several decades. Others may be original research. Edison (talk) 03:08, 29 June 2009 (UTC)
 * However, eating 3500 kilocalories less (over whatever period) does not guarantee you will lose any weight at all. Most diets of any kind will give you a loss of 1 to 2.5 lbs in the first week just in water loss. The fat already on you needs to be broken down and used as energy, which is not likely to happen from eating 3500 Kcal less in one week. - KoolerStill (talk) 10:14, 29 June 2009 (UTC)
 * Are you sure? Not true. Sensible weight lose diets suggest resticting ones diet to 500 Calories less per day (compared to typical needs) is the best way to permenantly lose weight, and this gives the 3500 in a pound of fat per week. In fact such a diet in an overweight person is likely to cause much more weight loss! A 500 calorie restriction not only causes weight loss, it is used as a "control" diet in scientific papers to compare the result of restricting different food groups or adding suplements, YobMod 12:01, 29 June 2009 (UTC)

RJFJR, you might like to download the book The Hacker's Diet. It has a lot of stuff like that in it. There should be a download url in the article. 208.70.31.206 (talk) 05:41, 3 July 2009 (UTC)

Tiredness after a meal
What are the physiological and biochemical mechanisms that make us tired after a meal? This happens to quite a lot healthy people, I'm not looking for medical advice. I'm not satisfied with the "all blood is in the belly" stuff because when you do exercises a lot of blood is in your muscles and when you do, err, something else, a lot of blood is in some other body part without you feeling tired at all. 93.132.184.56 (talk) 19:20, 28 June 2009 (UTC)


 * I feel tired when I exercise... --Tango (talk) 20:57, 28 June 2009 (UTC)


 * I don't. I sometimes feel tired afterwards but it's different tiredness from what I experiences after a heavy meal. Especially, the brain isn't tired after exercises. 93.132.184.56 (talk) 21:05, 28 June 2009 (UTC)


 * If you feel tired when you exercise, you are not exercising enough.174.3.103.39 (talk) 08:57, 30 June 2009 (UTC)


 * It could be that 'lack of alertness' is being interpreted as 'tiredness'. A fairly reductionistic view would be that the parasympathetic nervous system is fully active whilst the sympathetic nervous system is pretty much fully inactive. In my opinion I'm not tired after a meal, only very heavy ones (like at Christmas or when going to a restaurant which serves huge portions and one forces oneself to eat it all since one paid money for it). --Mark PEA (talk) 21:39, 28 June 2009 (UTC)


 * Yes, that's it. It's just a different mode of operation. There is a long forgotten time where I was more acquainted with these things, I'll have to have a new look on these. Thanks a lot! 93.132.184.56 (talk) 22:06, 28 June 2009 (UTC)


 * You should get your food packed. Ask for a box.  Don't get the servers to pack it for you.  Their hands are dirty, and most of them leave out a lot of food.174.3.103.39 (talk) 08:59, 30 June 2009 (UTC)


 * As a side note, it’s perfectly OK on Wikipedia to say “having sex” instead of “err, something else”, and “penis” instead of “some other body part”. Wikipedia has a “no censorship” policy, and has articles like vulva that go way beyond avoiding euphemisms. Red Act (talk) 21:54, 28 June 2009 (UTC)

Yeah, but euphemisms are funny :)

Ben (talk) 22:01, 28 June 2009 (UTC)


 * You were a little faster than me. Thats what I think. 93.132.184.56 (talk) 22:06, 28 June 2009 (UTC)


 * A large meal, high in carbohydrates, can cause a rise in blood sugar, especially in diabetics or those who have impaired glucose tolerance. Very high blood sugar can cause drowsiness. I've also read that some chemical in turkeys ("tryptophan?") an cause drowsiness.  Edison (talk) 03:04, 29 June 2009 (UTC)
 * Actually, turkey isn't that high in tryptophan, as this BMJ article notes. The consumption of any heavy meal can cause drowsiness due to the reduction of blood flow/oxygenation to the brain, as that article also notes (although its references are missing). Gwinva (talk) 05:03, 29 June 2009 (UTC)


 * The "turkey-tryptophan-tiredness" link is typical cargo cult pharmacology. The logic goes along the lines of: Melatonin = sleepy chemical. Melatonin is synthesized from serotonin, which is synthesized from 5-HTP, which is synthesized from tryptophan. Turkey contains tryptophan, therefore, the drowsiness after Thanksgiving/Christmas must be due to tryptophan. Unfortunately this doesn't take into account: the bioavailability of tryptophan when eaten as a constituent of turkey, the time it would take for the tryptophan to reach the brain, the time it would take for the tryptophan to be converted to 5-HTP then 5-HT, the fact that melatonin is only synthesized when certain frequencies of light are not hitting the retina, and probably some other things (enzyme/transporter competition, plasma protein binding, etc).
 * Alternative medicine has exploited this and marketed 5-HTP and melatonin as natural sedatives. I haven't read much into it but it appears melatonin may have some efficacy in age-related insomnia (which is supposedly caused by decreased synthesis in later life ) --Mark PEA (talk) 11:48, 29 June 2009 (UTC)
 * Ooohh! "Cargo cult pharmacology" - I love that phrase! I will be stealing it in the future! SteveBaker (talk) 12:48, 29 June 2009 (UTC)
 * So if I s build a simulated pharmacy counter in my basement, will a Walgreen's truck driven by John Frum deliver a load of drugs? That is what Cargo cult pharmacology would be about. The sleepiness after Thanksgiving dinner probably has much more to do with a carbohydrate overload raising bloodsugar, than with turkey tryptophans, agreed, Edison (talk) 03:10, 30 June 2009 (UTC)
 * I completly agree with Mark PEA about not making such biochemical guesses as biological systems don't react simply nor linearly. It is similar to most of the science behind vitamin supplementing "We need tiny amounts of vitamin X to live --> eating huge amounts of vitamin X will give extended-life/super-powers", which is clearly non-scientific, but such claims are everywhere.
 * 5-HTP definitely has some effect - more like being mildly stoned rather than a sedative imo - but this does not mean tryptophan would do anything similar (large amounts could inhibit the enzyme, shunting tryptphan into deamination, for example).YobMod 09:31, 30 June 2009 (UTC)

Can anybody identify this beetle?
Hi. Just wondered if anybody could identify this beetle, please? It fell down my chimney tonight, flew around the room a bit, and then just sat on the floor. It was generally very lethargic. I am in London, UK. Thanks Chalk House (talk) 21:18, 28 June 2009 (UTC)


 * Thought of a cockchafer first but then found Amphimallon solstitialis. 93.132.184.56 (talk) 21:28, 28 June 2009 (UTC)


 * Thanks. It certainly looks very similar to a Cockchafer, I wonder if the head of the Amphimallon solstitialis might be a bit too hairy. I uploaded a couple more pics that might be helpful . Thanks again Chalk House (talk) 22:13, 28 June 2009 (UTC)


 * There are more species like that but wikipedia is a bit short in articles and pictures on that. Btw, we are not to give legal advice but, the animal on the last two pictures doesn't look very healthy. If I were you I would not show that lest you'll get sued by some PETA activists. 93.132.184.56 (talk) 22:37, 28 June 2009 (UTC)


 * Thanks. Are there any other internet resources you know about that I could search? Don't worry about the beetle (whatever it is) it was just very lethargic, as I said, hardly moving for long periods of time. When I released it, it wandered off very slowly. Not sure if the fall down the chimney did it some harm though. Chalk House (talk) 01:06, 29 June 2009 (UTC)


 * You might like to try here, Richard Avery (talk) 06:59, 29 June 2009 (UTC)


 * I can tell you that in German a cockchafer is called a May Bug (Maikäfer literally), while Amphimallon solstitialis is called a June Bug. Both for good reasons. So, I guess you've got an Amphimallon. Of course they might occur in the UK at different times than on the continent. Amphimallons are also quite a bit smaller than Cockchafers. 195.128.250.104 (talk) 23:23, 30 June 2009 (UTC)

Can a chimpanzee really commit suicide?
Our article on Michael Jackson's pet chimpanzee, Bubbles, claims that this chimpanzee attempted suicide but was rushed to the hospital and saved. The cited sources are this and this. Can a chimpanzee really commit suicide? If yes, how exactly would a chimpanzee make such an attempt? A Quest For Knowledge (talk) 22:15, 28 June 2009 (UTC)


 * By making a noose out of his tyre swing? Just a thought. --Kurt Shaped Box (talk) 22:38, 28 June 2009 (UTC)


 * We don't describe chimpanzee suicide methods on the Ref Desk, sorry. Impressionable young chimpanzees could be reading. --98.217.14.211 (talk) 22:55, 28 June 2009 (UTC)
 * That is probably a result of lazy journalism. Notice that the Telegraph prefaces it with "according to reports..." which is is a large red flag when considering reliability of a statement. There is a lot of utter nonsense written about Michael Jackson, and this sounds like utter nonsense to me.
 * As to whether a chimp could commit suicide or not, depends very much on how you define "suicide". It could certainly kill itself, but its unlikely it could do so with the premeditated intention of ending its life. That would demonstrate an awareness generally thought to be beyond hon-human animals, even chimps. Thats not to say that animals do not regularly kill themselves in what we might consider "suicidal missions" (think bee or worker ants defending their queen), but those are not really suicide because the intent is not death, instead death is just the inevitable consequence. If Bubbles really did almost take his own life, then it was almost certainly without intent. Rockpock  e  t  23:10, 28 June 2009 (UTC)

For the purposes of my question, let's define suicide as intentionally killing itself for the goal of ending its life. A Quest For Knowledge (talk) 01:35, 29 June 2009 (UTC)


 * I'll have to think more about this "intent", i mostly agree with the above, but, i don't know, we've seen primates exhibit a lot of behaviour that was previously thought to be purely human, altruism is one that comes to mind.. As far as pure method goes, the easiest way for a monkey would surely be to just climb to a high place and jump. Vespine (talk) 00:03, 29 June 2009 (UTC)


 * I'm not sure suicide is beyond non-humans. My understanding is that dolphins are considered to be a species that occasionally commits purposeful suicide. --98.217.14.211 (talk) 01:13, 29 June 2009 (UTC)


 * Depression is a well documented problem in pets. In extreme cases loss of appetite can lead to the animal becoming too weak and dying of related causes. e.g. 71.236.26.74 (talk) 02:38, 29 June 2009 (UTC)


 * Dolphins and whales have been known to intentionally beach themselves, and in some cases even re-beach themselves after "helpful" humans returned them to the water. Death is an inevitable consequence of doing that (barring intervention) but it is unclear how much awareness and intent the animal may have.  I would note that some animals that do this do seem to be ones that were recently abandoned or dealing with the grief of a lost mate, etc., and to the extent human analogies makes sense could easily be considered depressed.  Dragons flight (talk) 06:40, 29 June 2009 (UTC)


 * Suicide would require a concept of self commonly called metacognition. Whether or not non-human animals have this concept of self is debatable... --Jayron32. talk . contribs  03:03, 29 June 2009 (UTC)


 * My opinion is that the article is not remotely true. What is a hospital going to do with a chimp?  The staff is not equipped or knowledgeable in the area of treating a chimp.  65.121.141.34 (talk) 13:18, 29 June 2009 (UTC)


 * Given the context, "hospital" could easily mean veterinary hospital. Dragons flight (talk) 15:56, 29 June 2009 (UTC)


 * It would have to be seriously specialized. Maybe a zoo would have the stuff.  65.121.141.34 (talk) 19:23, 30 June 2009 (UTC)

Naturism
Are there any known health issues or studies with naturism apart from extra exposure to sunlight? (not looking advice) ~ R.T.G 22:20, 28 June 2009 (UTC)


 * At least you don't have to fear pickpocketing. 93.132.184.56 (talk) 23:10, 28 June 2009 (UTC)


 * It's gonna depend dramatically on where you're doing it. Naturism in the antarctic is certainly going to come with health issues! SteveBaker (talk) 23:45, 28 June 2009 (UTC)
 * Indeed. I think most problems are going to be down to the fact that you are extremely exposed. What you are exposed to (sun, heat, cold, wind, sand, etc.) will depend on where you are. --Tango (talk) 23:48, 28 June 2009 (UTC)
 * It can be very unhealthy for men who are geese herders. The birds tend to snap at things. Edison (talk) 03:01, 29 June 2009 (UTC)
 * I'm never going to be able to look a geese the same way again... --Tango (talk) 05:56, 29 June 2009 (UTC)


 * Well now, woo, we get Mediterreanean sun in winter and hailstones in summer, occasionally (Irish south Atlantic) but nothing is found in this case about normal room temperature except - extra sun exposure = Vitamin D. ~ R.T.G 06:17, 29 June 2009 (UTC)
 * If you live in an area with Gnats or Mosquitoes you'd offer oh so much more opportunity for them to shout "lunch". Encountering a patch of Stinging nettle, Poison oak or Poison ivy may also put a significant damper on things. 71.236.26.74 (talk) 08:58, 29 June 2009 (UTC)

The OP is owed an apology for the nervous jokes that their question has evoked instead of rational answers.

See Naturism and Issues in social nudity for some issues. Typical issues concern hygiene precautions for sitting on shared towels, and debate on whether naturist venues should have rules to keep an even male-to-female balance.

Clearly there are studies because the search keywords naturism survey study got 44 500 hits. Examples: Cuddlyable3 (talk) 10:22, 29 June 2009 (UTC)
 * Mark Storey 'Children, Social Nudity and Academic Research' Nude & Natural magazine, 23.4 Summer 2004; Children, Social Nudity and Scholarly Study has copious references.
 * Political activist Nikki Craft researched child molestation within the movement. A critical website.
 * Heliotherapy - Research News and Information


 * It's something you wouldn't think of so easy. ~ R.T.G 22:21, 29 June 2009 (UTC)

Rechargeable batteries with no shelf life?
Are there any rechargeable batteries that have no shelf life, meaning they will never die out and you can keep using them indefinitely? ScienceApe (talk) 23:50, 28 June 2009 (UTC)
 * No battery will work indefinitely. Rechargeable battery has a nice list of technologies with expected cycle and shelf life. Vespine (talk) 00:12, 29 June 2009 (UTC)
 * Old-fashioned Lead/Acid car batteries that had to be topped up with acid once in a while as a part of routine maintenance could be drained dry and stored for very long periods. People who maintain ancient antique cars in factory condition rely on this fact - and some of them have batteries that go back to the very early days of motoring.  However, the need to refill them in order to use them - and drain them again for long-term storage may not be the kind of thing our OP is thinking of.   In terms of buying rechargable batteries for your camera or whatever - I don't think there are any technologies out there that give you what you'd like to have. SteveBaker (talk) 01:55, 29 June 2009 (UTC)
 * In my experience they were topped off with water, not acid. As for long term storage, there were "dry charged" batteries which sprang to life in a charged condition when the battery (with no liquid inside") initially had the sulfuric acid solution added to it. Batteries I am familiar with only have a few hundred charge/discharge cycles in their life under ideal conditions. Deep discharge decreases the life of some. Discharge or charge at too high a rate decreases the life of some. Always leaving on trickle charge and never discharging lowers the amp hours of nicad batteries. Failure modes differ among different battery chemistries.Edison (talk) 03:00, 29 June 2009 (UTC)


 * Modern drivers have no clue how much hassle owning a car before the 1970's really was! The idea of maintaining (or ever repairing) a car battery is completely alien to us these days!


 * The battery contains lead plates and sulphuric acid - but in the age before sealed batteries - they were vented to allow hydrogen gas to escape (if the vents got blocked - the battery would explode - or crack, spilling concentrated acid everywhere). Unfortunately, those vents also allowed the liquid in the battery to evaporate.  It was important to keep the acid concentration within some range in order to get enough power from the battery.  So as the liquid evaporated, you'd initially be able to do a top-up with distilled water and keep the thing working - but if you did that enough times, the pH of the liquid would gradually increase and the battery would get weaker and weaker.  Hence, at longer service intervals, you'd stick a hydrometer into each cell in turn and adjust the acid levels to get them back to the correct value.


 * Handling that concentrated acid wasn't something you'd be expected to do on your own - so you'd generally rely on a garage to do that for you on your regular service/oil-changes - which is probably where you got the idea that you only needed to add water. The owner's manual for my 1963 Austin Mini says that you have to top up the battery with distilled water on a WEEKLY basis (!!!) - and measure the specific gravity and adjust acid levels according to specific chart every 6,000 miles.  It also talks about flushing out the battery and replacing all of the fluids "as needed".  I just looked this up in the (rather quaint) 'schedule of charges' book for my 1963 Mini.  It says that the dealership will charge you 4 shillings for doing a hydrometer test and topping the cells off with distilled water but the cost would rise to 5 shillings and 4 pence if it was necessary to add acid - I didn't see a price for a complete battery flush.  Needless to say, my '63 Mini has a modern sealed-for-life battery...I'm not messing around with concentrated sulphuric acid! SteveBaker (talk) 04:10, 29 June 2009 (UTC)


 * As someone who has messed around with concentrated sulfuric acid (in a lab setting), why not? I have a distinct memory of trying to move a few milliliters in a syringe, only to discover it it had reacted strongly and eaten into the syringe during the few moments during which I was trying to do the transfer.  Also the very high heat of dilution could be a serious nuisance.  Wow!  That's a red link?!?  Dragons flight (talk) 06:51, 29 June 2009 (UTC)


 * Mostly along the lines of rechargeable batteries for electronic devices like laptops, handheld games, and such. The chart is interesting. Looks like Lithium-titanate battery is promising. Has a shelf life of 20 years if that chart is correct. I'm not really sure what those categories mean though. What category determines how long the battery will last on a full charge? ScienceApe (talk) 03:01, 29 June 2009 (UTC)
 * I just got my first ever sealed battery this year; the early ones were reputed to have high danger of exploding.(But a conventional one did explode on me. The acid must have been fairly dilute, because, while it burned holes in my clothing, there was only minor damage to exposed skin. Handling the acid is only a problem when topping it up).
 * Dragons flight, redlinks are links to articles that don't exist. You were looking for exothermic reaction. - KoolerStill (talk) 10:52, 29 June 2009 (UTC)


 * No, we ought to have a specific article discussing the heat of dilution (also called the enthalpy of dilution) for various substances and its physical origins similar to heat of formation, heat of combustion, heat of vaporization... A one line comment in exothermic reaction isn't even a suitable redirect target.  How many other concepts in physical chemistry are not yet documented I wonder?  Dragons flight (talk) 15:51, 29 June 2009 (UTC)


 * This question needs a link to low self-discharge NiMH battery. These don't last for ever but at least they are an improvement on standard NiMH. --Heron (talk) 20:47, 29 June 2009 (UTC)

"As someone who has messed around with concentrated sulfuric acid (in a lab setting), why not?" -- I handle concentrated sulfuric acid on a regular basis, and I can tell y'all, it's something that really requires special training and lots of experience. That stuff is so corrosive that if you get just a little bit of it on your skin, it can burn your skin to a crisp (and I mean completely blackened like an overdone hamburger) within seconds! And if it splashes into your eyes, well, that will surely ruin your eyesight for life. Plus, it quickly dissolves almost all metals (including your car's bodywork, engine block, anything like that). And to top off the list of hazards, its dilution is extremely exothermic, so the only way to dilute it is to very slowly add the concentrated acid to the water, with vigorous stirring; if, by terrible mistake, you add the water to the acid (and that includes if you've spilled some of the acid and try to wash it away with water), it starts bubbling and splashing all over the place and might even burst the container! No, handling concentrated sulfuric acid is definitely not something that the average person can do without endangering himself/herself and anyone else who might be standing too close. 76.21.37.87 (talk) 02:15, 30 June 2009 (UTC)
 * Lead acid batteries use dilute sulfuric acid as electrolyte. It is not all that concentrated, although I would not care to have it on my skin or clothing. The adding of acid or the "flushing" with fresh acid solution is not something I have heard of as part of the maintenance of substation battery banks or car batteries, From cradle to grave, distilled water was the only fluid generally added. When that no longer sufficed, it was time to buy a new battery (or cell). What was the supposed mechanism for sulfuric acid escaping the battery, so that more acid needed to be added? Only if you have turned over the battery and accidentally spilled out the electrolyte would there be occasion to add more acid . Edison (talk) 03:04, 30 June 2009 (UTC)
 * That's certainly most people's experience - you'd top up the battery with water (every week!!) and when you put your car in for a service, they'd add acid if necessary - so it's perfectly possible that most people didn't realise that this was a part of the service. But the 1963 Mini Owner's Manual - and the "Scedule of charges" for their car dealerships doesn't lie.  You're supposed to check the specific gravity in each cell every 6,000 miles - and add acid if necessary.  Failure to do that would mean that you were probably tossing out a perfectly good battery.  But as I said, in the 1950's and early 1960's, people would still repair faulty batteries - you could even replace the lead plates in them (they are listed in the 1963 Mini's spare parts catalog) - so there was really never a reason to completely throw one away - although doubtless many people did.  Some of the more fanatical classic car owners out there still use the original battery that came with the car as further proof that their car is in factory condition. SteveBaker (talk) 13:20, 30 June 2009 (UTC)
 * You have a good ref for that being part of the maintenance for that car's battery, but it seems to be the exception. Water is lost from electrolysis at the end of the charge cycle, or from evaporation. Acid and lead remain in the battery. Unless acid somehow leaves the battery, no acid needs to be added. Was the acid in that battery absorbed into the structure somehow, or was the goal to remedy sulphation of the lead plates? Only water needs to be replaced, absent spillage. Like the older source I cited above, a Google search shows numerous sites over several pages saying "Never add acid" to a lead acid battery . One site discusses remanufacturing a cell, and replacing the chemistry as part of that process. Remanufacturing, maybe. Maintenance, definitely no. Edison (talk) 14:15, 30 June 2009 (UTC)