Wikipedia:Reference desk/Archives/Science/2008 December 13

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December 13

Calc-sinter ???

In looking up an answer for the Travertine question above I came across the above page. I googled it and came up with dictionary links most of which went back to our page. I'm beginning to seriously doubt that such a term is in actual use in English. The page seems to have been translated from the German (Kalk-) Sinter page. That one's o.k. but I think what they are talking of is tufa or limestone (a limestone cave would be called a Kalksteinhöle in German.) Could s.o. with a geology background plse. see if this is a valid term. 76.97.245.5 (talk) 00:16, 13 December 2008 (UTC)

It's in Webster's Online [1]. DuncanHill (talk) 00:22, 13 December 2008 (UTC)

And here's an example of its use by John Davy. [2]. DuncanHill (talk) 00:23, 13 December 2008 (UTC)

Not exactly current usage then. The Webster mentions Calcite. Would you think that is the modern term for it or are the two terms merely related? 76.97.245.5 (talk) 02:40, 13 December 2008 (UTC)

Not all Calcium carbonate minerals are calcite - depends on the crystal structure. DuncanHill (talk) 22:09, 13 December 2008 (UTC)

I found this confusing, so I asked this question on the talk page for calcium carbonate. --Scray (talk) 03:20, 15 December 2008 (UTC)

I have asked a similar question at Mindat.org (the website, not our page about it), there are many very knowledgeable people there. DuncanHill (talk) 03:31, 15 December 2008 (UTC)

Excellent! --Scray (talk) 03:40, 15 December 2008 (UTC)

I respectfully suggest that follow-ups go to the question I asked on the CaCO3 page (link above). --Scray (talk) 03:42, 15 December 2008 (UTC)

• and the answer is................................... a calcareous tufa! DuncanHill (talk) 14:05, 15 December 2008 (UTC)

Small children and names

Is there a reason why young children sometimes have trouble realizing there can be two people with the same name? A classic example might be the child who is upset because some other child in his or her class has the same name. Is it a feeling of uniqueness, that they fear not being special anymore? Or, is there something that actually makes them think, "Wait, this can't be right, there can only be one of 'x' in the world." (Such as the child I read about who was, admittedly, much younger, about 20 months. He was holding his comfort object, happened to open a drawer where his mother stored 3 more just like it for when one needed washed...he closed the drawer very slowly and didn't open it for weeks, as if he thought, "This drawer causes anomalies worthy of Star Trek."Somebody or his brother (talk) 00:47, 13 December 2008 (UTC)

I wonder how it might relate to the Lacanian concept of the "mirror stage"? It first happens between six and 18 months so that's about right – it involves ego-structuring, mastery, the Imaginary and the Real, the "thing" as symbolic object Das ding an sich. There's nothing to say it doesn't continue. There was an earlier observation by Henri Wallon. But I like the Star Trek anomaly best, Julia Rossi (talk) 09:10, 13 December 2008 (UTC)

When you consider all of the other things that a child has to learn - this is really one of the more minor ones. That the sound "apple" is actually a label for a thing - is a tough thing to just "realise"...but then to realise that it stands for a whole class of things - where the label "Mummy" doesn't. Then you have to know that "Mummy" when you say it means something different than when your friend says it...but when your mummy says it, she can either be talking about herself or HER mother. This is insanely complicated. That there can be more than one person with the same name is really just a small subset of the overall problem. SteveBaker (talk) 02:58, 14 December 2008 (UTC)

What's the cause of an inability to distinguish an actor from a character?

Do people who are unable to distinguish the two suffer from some inability to distinguish fantasy from reality? From the question I asked about the Wii earlier, I considered immersion one possible reason; but, one is not actively participating in a television show or movie, except in the case of trying to solve a mystery. Besides, it seems like there would be more of this problem if it were *only* immersion causing it. this isn't just a question about seeing actors only as capable of playing a certain role, of course, but of thinking the actor *is* the character.Somebody or his brother (talk) 01:13, 13 December 2008 (UTC)

It seems to me the answer to this, if there is one, must be multi-faceted. One facet might be "how many different characters has the person in question seen the actor play?" E.g., if someone's only knowledge of Lisa Kudrow is in the role of Phoebe on Friends, they may not distinguish the personalities of Lisa and Phoebe. If they have seen Lisa in multiple roles, they likely will see her quite differently. CBHA (talk) 02:17, 13 December 2008 (UTC)

Agree – publishers of TV magazines don't help when they write in-universe stuff about "soap" characters "tying the knot" on the show for example. Though it doesn't relate exactly to the mentally you ask about, see also Typecasting (acting). Julia Rossi (talk) 09:14, 13 December 2008 (UTC)

It must have something to do with learning and experience. For example, in my grandparents village in the first few years the TVs were introduced, everyone freaked out when they saw an actor in a movie who had already died in another movie. After that however, they get accustomed to it. --131.188.3.20 (talk) 19:24, 13 December 2008 (UTC)

The phenomenon you describe is not quite limited to TV actors. A name is just one part of how we identify an individual. If you meet s.o. at a party you may refer to that person as the girl/guy who was at Jo's party, when talking about that individual. New family members are often referred to as Bob's wife, Meg and Mel's baby etc. for quite a while. Equally actors will be referred to within the context that we know them from, even when we see them in a new setting: Isn't that that guy from NYPD blue? In the evolution of our social interactions it's always been important to know where in the hierarchy to place someone. Sorting out two different identities for one individual has just not come into the picture until most recently. 76.97.245.5 (talk) 21:36, 13 December 2008 (UTC)

It's not surprising when you consider all the effort the producers of a TV show or movie put into making people believe the actors really are the characters. Those people who aren't too bright tend to fall for it. StuRat (talk) 22:40, 13 December 2008 (UTC)

I'd add the habit of critics (which I think has declined in the last thirty years) of referring to characters by the actors' names. — At age 5 or so, I understood the concept of actors, but not stunts; and wondered about all those people who got shot on Superman: how did they get paid? —Tamfang (talk) 09:21, 14 December 2008 (UTC)

I remember watching one of the Jaws movies when I was about the same age and thinking that they must've chosen actors who were already dying of cancer or AIDS or something to feed to the shark for real. I shared my theory with a friend at school the next day and he commented something along the lines of how "it couldn't be people with AIDS - because that would make the shark ill". --Kurt Shaped Box (talk) 20:41, 15 December 2008 (UTC)

Actors on soap operas in the 1950's have said that people would sometimes harass them when the saw them on the street for bad things their character had done. Cluelessness, immaturity and stupidity seem to be operative factors in thinking that the actor who played Superman 'was' Superman when he played a different role, or that Sarah Michelle Gellar was like the scheming soap opera character Kendall Hart she played before playing Buffy the Vampire Slayer. Yet there were marketing campaigns which sought to make just such a real connection, such as movie ads which shouted "Sean Connery IS James Bond." Typecasting can limit the roles an actor is offered after he is identified with a particular sort of character, so an actor whose first major role is a good guy may look hard for bad guy roles, and contrariwise, to avoid this career limiter. Edison (talk) 21:06, 14 December 2008 (UTC)

Or, to put it differently: there's a huge difference between actually being unable to tell the difference between the actor and the character and simply not bothering to do so. In a nutshell, I guess you could distill the whole thing down to "people are kinda dumb". It's simplistic, but it's still pretty much true...

I think this phenomenon reaches a kind of an apex with wrestling fans, who often don't seem to be at all motivated to distinguish between the performer and the character, and the fact that the WWE doesn't really encourage anyone to do so probably doesn't help any. In fact, even Wikipedia's wrestling articles often seem to confuse the storylines and the people, especially when it comes to injuries, lawsuits, and all of the other drama surrounding the WWE; it's often impossible for a reader to know whether a description of a specific event refers to something that actually happened or whether it's just a part of the show, because the articles often don't even acknowledge that such a difference exists. -- Captain Disdain (talk) 04:06, 15 December 2008 (UTC)

In many cases there may be no way to know if a particular WWE action was carefully choreographed or done in anger, only the participants may know, and they aren't telling. (And, even if they tell you an event was real, you can't really believe them.) StuRat (talk) 20:12, 15 December 2008 (UTC)

Soap opera actors in the UK still regularly get hassled by idiots in the street. Especially if they play (or played - this can go on for years afterwards) a rapist, wife-beater or paedo on the programme. The actors who play doctors in Casualty and Holby City have also stated in interviews that people will run up to them screaming for help if there's a medical emergency wherever they happen to be at the time - *instead* of calling an ambulance. --Kurt Shaped Box (talk) 20:46, 15 December 2008 (UTC)

One hears that actors who portray criminals on "unsolved crimes" shows get reported as fugitives. That's a bit more forgivable; the events shown are real, though what the viewer sees is a reconstruction. —Tamfang (talk) 22:16, 28 December 2008 (UTC)

Schrödinger's Particle Accelerator

My little cat, Mr. Cuddlypants, is sound asleep on his cot. The cat on the cot happens to be the terminal focus of bundles of protons sent hurtling at 99.999999% the speed of light by a gargantuan particle accelerator. I'm in bed gazing at the little cot, and only just realized the presence of the particle accelerator. Should I bother to get up and move Mr. Cuddlypants or just turn over and go to sleep? Sappysap (talk) 01:21, 13 December 2008 (UTC)

So what's the question? Would high speed protons be harmful to a cat? The answer to that is almost certainly "yes" (assuming there is a significant number of them). Protons are charged, so would be a form of ionising radiation, which at the very least risks causing cancer. At those kind of speeds, though, the energy alone would be harmful. The cat would probably be vaporised by any significant number of protons at that speed. --Tango (talk) 01:38, 13 December 2008 (UTC)

No, it's a reference to the the cat in this thought experiment, which can be considered neither alive nor dead until observed. --Bowlhover (talk) 04:42, 13 December 2008 (UTC)

Thats Schrödinger's cat, I don't think Sappysap is Schrödinger. Not to mention Mr. Cuddlypants has a very well defined state with little quantum uncertainty. Mr. Cuddlypants is asleep on his cot rather than maybe dead in box. I think Tango's explanation is reasonable.--OMCV (talk) 05:56, 13 December 2008 (UTC)

I know what Schrödinger's cat is, but I don't see a connection to that beyond the presence of a cat and the name "Schrödinger" in the section header. --Tango (talk) 14:24, 13 December 2008 (UTC)

Although I have a cat I don't know whether I'd be willing to move it out of a particle accelerator. Although I do love my cat, I love myself more. A better bet would be to try and get it to move itself (shouldn't really be a problem with most cats) and if that fails well start looking for a new cat Nil Einne (talk) 12:16, 13 December 2008 (UTC)

According to the LHC article, dumping all of the stored protons (which would happen if you suddenly stuck your cat in the middle of the beam) would result in the release of 362 MJ, or the same as burning 8 kg of oil. Given that the protons are moving at 99.999999% the speed of light, and that the ring is "only" 27 km in circumference, the beamline would empty in about 90 microseconds. Mr. Cuddlypants would probably be flash-boiled instantly. However, I doubt your reaction time would be fast enough to save him from his fate. (I wouldn't roll over and go back to sleep, though. I'd probably crack a window first - I can't imagine vaporized cat would smell all that good.) Note this assumes that the accelerator vacuum chamber terminated directly at your cat. Having to pass through air and walls would probably dissipate a lot of the energy before it reaches the cat. Also note that it depends on how many protons the accelerator is putting out. The LHC will use 3×10¹⁴ protons - smaller accelerators would use less. Theoretically, it would be possible to build a very small accelerator whose beam would produce only a mild warming sensation. I'd still stay out of the way, though, due to radiation-induced DNA damage.) -- 128.104.112.113 (talk) 22:46, 13 December 2008 (UTC)

Actually, Mr. Cuddlypants would probably survive (not counting radiation damage, cancer, or other long-term effects). It is rather hard to stop ultra-relativistic particles, and even if you dump it into a solid object, that 300 MJ would be deposited over several meters. In fact, most of the energy is deposited not at the initial contact, but a few meters further in after each ultra-relativistic initial particle is converted into a shower of mildly-relativistic daughter particles (1 particle at 99.99999% c is less dangerous and far harder to stop than 1000 particles at 99% c). Incidentally, a loss of beam containment at a particle accelerator will usually not deposit enough energy into the beam line wall to actually damage the accelerator (though it can make an audible thwwump sound). So, assuming Mr. Cuddlypants is a normal size for a cat, and he has the privilege of being the first thing the beam hits, he will probably receive much less than 1% of the total beam energy and come away singed but intact. Dragons flight (talk) 00:08, 14 December 2008 (UTC)

If Mr. Cuddlypants is in the target zone of a particle accelerator, then he must be in a hard vacuum. So he's not sound asleep at all - he's stone dead. Probably quite happy chasing Norwegian Blues in cat heaven, so I wouldn't disturb him if I were you. Gandalf61 (talk) 13:52, 15 December 2008 (UTC)

Faster means lower pressure?

Isn't the Coandă effect just an example of viscosity? Further more (ignoring the Newtonian component) is it best to say lift results from low pressure on the top of an airfoil as described by Bernoulli's principle or does the airfoil experience drag from the viscosity of the air which pulls on the top of the wing. That is to say does the outer or inner surface of the top of the wing experience force? Although both forces are in the same direction surely it possible to distinguish defamation resulting from a push from inside versus a pull from above. Which side of the metal is having more force exerted on it?--OMCV (talk) 05:06, 13 December 2008 (UTC)

Not exactly. Viscosity is due to cohesion, that is the property of a substance to stick to itself. The Coanda effect is due primarily to adhesion, the property of different substances to stick to each other... --Jayron32.talk.contribs 22:15, 13 December 2008 (UTC)

Specifically, it's the unique case of "dynamic" adhesion in a fluid, which probably does involve some amount of cohesion as well, because any individual molecule of the fluid is not adhering to a specific site on the surface. Instead, the net effect of adhesive bonds of individual molecules at the surface drag other fluid molecules through cohesion towards the surface, while at any given instant no particular molecule is really stationary. It's more of an aggregate effect of many simple behaviors interplaying together, so it's hard to uniquely attribute it to a single physical property like "cohesion" - (compare, for example: in the classic fluid equation, there is a term which directly relates to cohesive forces, so you can point to that part of the equation and say without error that "this is what accounts for cohesion/intermolecular forces"). Nimur (talk) 16:12, 14 December 2008 (UTC)

Determining the sex of a seagull?

Is it possible to visually determine whether a seagull is male or female? Without seeing it mating or laying an egg I mean. --84.66.45.248 (talk) 13:31, 13 December 2008 (UTC)

Its easy. If you see two seagulls walking down the beach, and one is going "Sqawk sqawk SWAWK" and looking annoyed, while the other one is just walking away silently; the first is the female... --Jayron32.talk.contribs 22:11, 13 December 2008 (UTC)

Sounds like you got that email, too. StuRat (talk) 22:28, 13 December 2008 (UTC)

Our resident seagull expert, User:Kurt Shaped Box, should be around to answer that soon. StuRat (talk) 22:28, 13 December 2008 (UTC)

Hokay. The following is true for Herring/LBB/GBB gulls. It may not be true for all gull species. Pretty much the only way of visually sexing them is to observe two gulls that are obviously paired-up when they're stood close together. Most of the time (I'd say eight times out of ten), the male gull will be longer and wider than the female - perhaps with a longer skull, shallower slope to the forehead and a chunkier beak (this is not always obvious, or even noticeable at all). Beyond that, it's almost impossible to determine the sex unless you physically have the gull in your hands - females have (as you might expect) a wider pelvis (not that I'd know what I was supposed to be feeling for if I was to do that...). In an area where the gulls are well-fed and relatively safe from predators, there will probably be loads of undersized adult gulls that were originally the 'runt of the litter' and gulls which are basically fat, which complicates things somewhat. --Kurt Shaped Box (talk) 23:48, 13 December 2008 (UTC)

Pills

I happened to observe this characteristic about pills, and it caused me to wonder. In my (limited) experience, most prescription pills come in an oblong-shape. Some pills (such as aspirin), however, come in a round/circular shape. Is there any reason at all -- scientific? financial? -- why the maker of a pill would select one shape over another? Thank you. (Joseph A. Spadaro (talk) 15:54, 13 December 2008 (UTC))

Not a very good source but it makes some good points: http://www.nowfoods.com/?action=itemdetail&item_id=40088 —Cyclonenim (talk · contribs · email) 18:03, 13 December 2008 (UTC)

You've completely lost me... what does a 12oz packet of Apple Fibre have to do with anything? Was that the wrong URL, by any chance? --Tango (talk) 18:35, 13 December 2008 (UTC)

Definitely the wrong link... fixed now. —Cyclonenim (talk · contribs · email) 19:08, 13 December 2008 (UTC)

Ah, that's a far more relevant link, thank you! --Tango (talk) 19:10, 13 December 2008 (UTC)

Thanks ... but I am still lost. That link is a compare/contrast of tablets versus capsules. My question was about round-shaped tablets versus oblong-shaped tablets. Any clarification? Or did I miss something in the above link? Thanks. (Joseph A. Spadaro (talk) 21:56, 13 December 2008 (UTC))

Don't know why they're shaped that way, but the oblong ones are sometimes called caplets (a portmanteau of capsule and tablet). -- 128.104.112.113 (talk) 22:00, 13 December 2008 (UTC)

This is a WAG, but my speculation is that the shape is purely for identification purposes; the wider variety of shapes and colors allows for easier differentiation between different medications. Without looking it up, you can probably easily identify a pill such as Advil (oblong brown cylander) or Viagra (blue diamond) or the like. The shape probably serves little purpose beyond that... --Jayron32.talk.contribs 22:10, 13 December 2008 (UTC)

That's correct. And, since early pills got their choice of shapes and colors first, we ended up with a simple white, round pill for aspirin. At the rate at which new (and often questionable) drugs are approved, we will soon be up to plaid and paisly dodecahedrons. StuRat (talk) 22:20, 13 December 2008 (UTC)

StuRat ... are the pill makers required to select a unique shape/color? From my memory, all the pills I have ever taken were essentially white and oblong, although perhaps of different size. (Joseph A. Spadaro (talk) 23:43, 13 December 2008 (UTC))

I believe they are required to make each drug have a unique appearance, but this includes text labels on the pills. So, they could make them all white, round pills, with unique labels, if they wanted to. However, they also want something that's easy to market, and "the new, purple pill" is far better than "yet another round, white pill that looks just like an aspirin". StuRat (talk) 04:43, 14 December 2008 (UTC)

• There aren't enough distinguishable shapes and colors for it to make sense to have a rule that every pill must be different, even within a single country. But in addition to the marketing issues, it's just good sense for them to look as different as possible so that people will be less likely to confuse one drug with another once the pills are out of the containers. --Anonymous, 05:35 UTC, December 14, 2008.

Its also become a branding thing. Major companies want their pills to be readily idenitifiable for branding purposes; so even if they didn't HAVE to choose a unique combination and stick to it; many do because its an easy branding techinque. I suppose Viagra could be made as a small, white, flat round pill, but its far better, from a marketing point of view, to make yourself stand out against the rest of the crowd... --Jayron32.talk.contribs 03:15, 14 December 2008 (UTC)

There are a couple of practical points. One is, as mentioned on that page about tablets vs. capsules, that some pills are designed to be cut into halves or even quarters. In that case a flat shape is desirable, a disk or square; or for halves, a long narrow shape with straight sides also works. I've had to cut elliptical pills in half for myself and it's a pain. Also, different shapes have different ratios of surface area to volume. So if you're preparing to manufacture a drug and it doesn't dissolve as fast in the stomach as you'd like it to, you want to make sure the pills are thin and flat rather than something close to spherical. Conversely, if your pill requires an expensive coating, go the other way and save a bit on the cost. --Anonymous, 05:44 UTC, December 14, 2008.

Another practical point is that it can't have any sharp corners that could poke you while swallowing. When they have a shape that normally would have sharp corners, like a square, all the corners are rounded off. StuRat (talk) 21:35, 14 December 2008 (UTC)

A capsule provides lots of practical benefits. If your dose is a casing full of lots of small bits (loose grains) as opposed to a packed solid, it's easier to build that in a capsule form. One might want to do this to speed dissolving (once a thin outer shell dissolves, there's a huge surface area). It can also be used similarly to a coated tablet, in which the outer shell protects a chemically fragile drug until it passes through the stomach. By having lots of bits, it's easier to customize many doses from a few stock bits (different amounts of a drug can be measured easily, or different combinations can be made, all without complex equipment) instead of needing to handle loose powders. Also, it's easier to construct such a thing (fitting two closed-ended gelatin cylinders together snugly vs two larger flatter curved discs). Unfortunately, capsules can be easy to open as well, which can lead to tampering problems, which probably sped design of capsule-shaped things for branding that aren't actually capsules in construction. DMacks (talk) 09:16, 14 December 2008 (UTC)

Thanks for the input ... this was very helpful. (Joseph A. Spadaro (talk) 00:17, 15 December 2008 (UTC))

Ocean floor water temperature

What is the average temperature of water at the bottom of the ocean, in particular the bottom of Challenger Deep? —Preceding unsigned comment added by 89.167.221.3 (talk) 16:46, 13 December 2008 (UTC)

Away from deep trenches, the bottom zone of ocean is the Abyssal zone, according to that article, "The abyssal zone has temperatures around 2 to 3 degrees Celsius, but 13-15°C in the Mediterranean Sea." In trenches, you get into the Hadal zone, but that article doesn't mention temperature. According this this book, the temperature at the bottom of pacific trenches ranges from 1.1C to 3.3C. --Tango (talk) 17:13, 13 December 2008 (UTC)

Doesn't that match the temps at which water is the most dense ? Not a coincidence, I bet. StuRat (talk) 22:12, 13 December 2008 (UTC)

It roughly matches the temps at which fresh water is the most dense, I don't honestly know much about the density of salt water... (or even what the salinity is at those depths). --Tango (talk) 23:33, 13 December 2008 (UTC)

It is a good thought. Freshwater is most dense at 4 C. Unfortunately it is also wrong. Water containing as much salt as the ocean actually increases in density without reversing all the way down to its freezing point, around -1 C. The strange little density inversion shown in freshwater goes away when you add enough salt. It is true though that deeper waters are usually colder because colder water is denser (assuming the salinity stays constant). Dragons flight (talk) 03:00, 14 December 2008 (UTC)

The freezing point of ocean water is -1° C ? I thought it was more like -18° C. StuRat (talk) 04:30, 14 December 2008 (UTC)

That sort of temperature is correct for water that is saturated with salt. Seawater is nowhere near saturated, although the correct freezing point is nearer −2°C than −1. --Anonymous, 05:45 UTC, December 14, 2008.

And upwelling and convection create non-equilibrium conditions. I'm not sure what magnitude those effects cause in a trench as deep as Challenger Deep, but as a general rule, it is safe to say that the most dense water stays at the bottom only at steady state equilibrium. Nimur (talk) 16:25, 14 December 2008 (UTC)

ESPVR curve shift

Hi:

Which way would the End Systolic Pressure Volume Relationship (ESPVR) curve shift, left or right, after Ca++ channels are blocked by Ca++ blockers?

Thanks.

74.12.39.128 (talk) 17:46, 13 December 2008 (UTC)

The ESPVR is shifted by inotropy, and calcium channel blockers are negative inotropes. Here's an illustration (fig 2.14 on page 27): [3]. The cardiovascular physiology article has relevant links for those interested in more info. --Scray (talk) 20:30, 13 December 2008 (UTC)

TOOLS/HARDWARE IE:Europian style "cup hinges".

Hello and thank you for considering my request.I am a some what experienced carpenter but my when it comes to cabinet work my skills are seriously lacking in some respects.Modern hardware is one of those areas.I have designed and created a door for a certain client and to keep the hinges hidden and create an "inset",as opposed to an "overlay" or "half overlay",appearance I'm using the cup hinges.I got them at my local big box but they didn't come w/ instructions. My home library mentions them in several of my books but none of them offer a clear,with measurements and everything,"how to" to installing them.I went on line to the manufacturer ,they are brand name,but wile they offered templates and jigs for using their products I couldn't find any instructions.Perhaps one of y'all could offer some help or even know a source that I can get the "instructions" I seek.I'll be conducting some experiments this wknd. but am still looking forward to what other help and "how-to" information is out there.Any and all suggestions will be greatly appreciated.Thank you.RCW —Preceding unsigned comment added by 76.68.73.149 (talk) 18:16, 13 December 2008 (UTC)

My gut instinct tells me it may be better to telephone the manufacturer and ask to have instructions emailed/faxed to you. Exxolon (talk) 19:09, 13 December 2008 (UTC)

If you told us the mfr and model or scanned the item and included a picture we might be able to provide more help. Edison (talk) 20:39, 13 December 2008 (UTC)

Also try to explain how you would like to use them. Are you certain the type you got is suitable for creating an "inset" look? Meanwhile you might want to see if you have these things available (or can borrow them) to make your life easier: a Forstner bit and one of these things [4] (mobile drill stand / drill guide?) not necessarily this make. You can do without, but it will take a lot more fiddling.76.97.245.5 (talk) 21:03, 13 December 2008 (UTC)

Also try asking at the big box store where you bought it. StuRat (talk) 22:08, 13 December 2008 (UTC)

A standard router can be used to create the recesses for the fitting. Much better: You also get standard drill bits for the round recesses in every hardware store (well, in Europe, which may require a spot of expensive shopping). As opposed to Forstner bits, they have the advantage that you can only drill to the required depth. The hinges you can get in any IKEA store in two types (angle of opening 125 degrees or 153 degrees for slide out / roll out bits behind the front cover) costing about € 3.00 to € 4.00. They also stock air brakes which can be clipped onto the hinges to make the door close gently without a bang.

BTW, we have no article on cup hinges but one on Martina Hingis. Unfortunately it does not say anything about what size cups she wears and it certainly does not mention any hinges in her underwear. --Cookatoo.ergo.ZooM (talk) 01:52, 14 December 2008 (UTC)

I'd go for the spade bit at Drill bit and trawl google 1.how-to's[5]; and 2. images[6]. Apart from the excellent tips in this thread, I'd find someone with a like cabinet in their kitchen to see how it all works and balances if you're a 3D kind of person when it comes to kinetic objects. Julia Rossi (talk) 07:19, 14 December 2008 (UTC)

@Cookatoo: What we have on Euro/cup hinges is well "concealed" in hinge and kitchen cabinet. A hinge sinker bit might be a bit harder to come by than a Forstner if OP isn't in Europe. A Forstner with a drill stand or jig works almost as well if you use a stop for the depth and watch that things don't get clogged. I tried a hole saw with mediocre results. As I mentioned you don't have to use the tools I recommended, but it helps. (I tried with and without and would forgo the pain anytime.) @Julia Have you tried using a spade bit for this? If we are talking solid wood I wouldn't necessarily say no, but if OP is trying to use that coated particle board that modern kitchens sometimes use, then I wouldn't want to risk using a spade bit and end up with a mess of frayed rims and broken off pieces. For my part I would also worry that the center piece might puncture the cabinet door by the time my hole has sufficient depth, there isn't all that much material left between the bottom of the hole and the front and spade bits tend to have long centers. My router wouldn't work to position those holes for the hinges. The drill stand (BTW Craftsman makes one like that, too and I have seen other brands.) comes with a piece to adjust the depth to which you can drill and you can mark the position on the rim, so you can drill the next holes with the same measurements and don't have to futz around with a jig. That speeds things up tremendously if you have 10 doors (2 holes each) You can clamp the holder to the door so that that you get perfectly positioned, straight down holes every time. Euro hinges are not forgiving when it comes to the angle of the hole wall. OR: A bit off and things won't fit or will wiggle loose. The video in Julia's first link should explain what you need to do to install the hinges. (In "Dead-Flat Assembly Table" Scroll down and click on where it says Step 3 "Installing Euro style hinges".) I'm still not sure how you get the inset to work [7], because you need room for the door to swing open. Lipped door would work, because the pivot point of the corner would be outside the frame. I think there are special Euro hinges for inset doors, but AFAIK the standard ones are usually for full or half overlay. Hope this helps. 76.97.245.5 (talk) 09:22, 14 December 2008 (UTC)

Good point about the materials. I was fixated on "carpenter" and "cabinet" making = wood, so yes: what 76.97.245 said – and the whole mass production thing. :) Julia Rossi (talk) 09:28, 14 December 2008 (UTC)

You are best to get the templates. Go to a good hardware store and they sell drill bits specifically for making the hole NOT a hole saw but more like a large router bit (35mm). One looks like this in use http://www.rockler.com/product.cfm?page=1633 It is not possible to give you reliable instructions without seeing the cupboard and the hinge. ~ R.T.G 02:02, 17 December 2008 (UTC)

Freezing hot water

Why does hot water freeze faster (assuming that what i heard is true)? --212.120.246.219 (talk) 19:48, 13 December 2008 (UTC)

See Mpemba effect 93.132.189.30 (talk) 19:52, 13 December 2008 (UTC)

Chemical depilatory

Since most chemical depilatory brands (Veet, Nair) seem to be alkaline (tell me if I'm wrong), it would seem to me that something like vinegar could neutralize the residue after use and help prevent burns. there are commercials neutralizers on the market--are they just slightly acidic solutions to do the same thing? EdwinHJ | Talk 20:59, 13 December 2008 (UTC)

If you are asking if vinegar is safe and effective to prevent burns after the use of a depilatory, I believe that would fall under the category of medical advice, which the reference desk doesn't give. Sorry. Talk to your doctor or a pharmacist(US)/chemist(UK) instead. -- 128.104.112.113 (talk) 21:57, 13 December 2008 (UTC)

In the UK you would want to talk to a pharmacist. DuncanHill (talk) 22:05, 13 December 2008 (UTC)

Without wanting to give any extra medical advice, I only want to note that those commericial neutralizers are likely buffered solutions; as such they are probably MUCH safer than using an unbuffered acid, such as straight vinegar, to neutralize the depilatory cream. But as noted, if you are experiencing problems, please seek medical advice from a professional... --Jayron32.talk.contribs 22:03, 13 December 2008 (UTC)

To explain that point further - if you just add acid - you won't know whether you've added too much or not enough. You could even make matter worse. But these buffer solutions are mixtures of chemicals that resist change in pH - so they'll just exactly cancel out any imbalance between acid and alkali. This would obviously be much safer...and that's probably what the commercial neutralizers are. SteveBaker (talk) 02:47, 14 December 2008 (UTC)

Acetic acid is a fairly weak acid, though, and in a dilute aqueous solution essentially acts as a simple buffer. In particular, normal household vinegar (up to 10% or so acetic acid) is perfectly safe to apply to skin on its own. One would generally not expect the addition of an alkali to make it less so. —Ilmari Karonen (talk) 06:25, 14 December 2008 (UTC)

Wouldn't you also have to watch what kinds of Salt (chemistry) you end up with if you neutralize an alkaline base with an acid??76.97.245.5 (talk) 09:35, 14 December 2008 (UTC)

Not to mention the aesthetic implications of spreading vinegar on your head. Nimur (talk) 16:58, 14 December 2008 (UTC)

... or anywhere else one might be removing hair. Nimur (talk) 16:59, 14 December 2008 (UTC)

Dissolved salts exist in solution as separate ions: they essentially act only as proton donors and acceptors, while the net neutralization reaction is simply OH⁻ + H⁺ → H₂O. Pretty much the only way (assuming no other types of chemical reactions occur) in which the resulting salt might have an effect different from that of its component ions is if it precipitated out — but nearly all acetate salts are highly soluble in water, so this is unlikely to happen with acetic acid. —Ilmari Karonen (talk) 06:23, 19 December 2008 (UTC)

Temporal Fenestra

Most mammals have one unbroken opening that the eye and the mandible fit into, but humans don't, they seem to have a bone separating the eye hole and hole for the mandible. What am I missing? Clarified: What was the advantage to having this bone, and what where the transitional stages of having it and not having it?24.77.21.240 (talk) 23:26, 13 December 2008 (UTC)

What do you mean by "What am I missing?" If you clarify, your question is more likely to ge answered.--Archaeopteryx (talk) 03:05, 14 December 2008 (UTC)

I would guess they are asking why there's a difference. Or, more scientifically stated, "what conditions cause there to be an evolutionary advantage to humans having this bone which other species lack". StuRat (talk) 04:24, 14 December 2008 (UTC)

Okay, I was too ambiguous there, and yes, that basically is my question. 24.77.21.240 (talk) 05:11, 14 December 2008 (UTC)

Looking at temporal fenestra I can't help but wonder if what you were missing was the search window in the side bar? Although the physiological explanation given is said to be speculation, I doubt that we could do any better than the experts. (The article also states that mammals do not have temporal fenestrae.)76.97.245.5 (talk) 10:22, 14 December 2008 (UTC)

It also states that "The presence and morphology of the temporal fenestra is critical for taxonomic classification of the synapsids, of which mammals are part." That would seem to imply that mammals have temporal fenestra. —Preceding unsigned comment added by 24.77.21.240 (talk) 17:57, 14 December 2008 (UTC)