Wikipedia:Reference desk/Archives/Science/2009 August 23

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August 23

A moth I saw when I was a kid...

The critter was about an inch long, with a bulky abdomen, coloured reddish-orange on top and light grey beneath - it was also rather 'furry looking'. However, by far the most striking characteristic of the moth was that its head and 'snout' closely resembled that of a Red Fox (but smaller, obviously). It even had the pointed 'ears'.

I was actually about to squash the thing - but ended up running away scared (hey, I was only about 6 years old at the time!) after seeing its unusual and striking face. This was more than 20 years ago now and I can't really give you any more specific details (other than that I lived in NW England at the time).

So, going on what little I've told you - does anyone have any suggestions as to what species I might've seen? --Kurt Shaped Box (talk) 02:01, 23 August 2009 (UTC)

The Smerinthus cerisyi [1] looks like it has the face of a red fox on it. Could that have been it? Red Act (talk) 04:13, 23 August 2009 (UTC)

Na. It definitely didn't have large antennae like that. Just to clarify, the moth I saw didn't have faux foxlike eyes and features on its wings - it's actual (real) head and face looked like that of a fox... --Kurt Shaped Box (talk) 23:44, 23 August 2009 (UTC)

Chinese Egrets! -- Where to report rare bird sightings for East Asia?

Out birdwatching here in NE China this morning I'm 98% sure I came across a small group of Egretta eulophotes (aka Chinese / Swinhoe's Egret).

Because they're a rare bird to begin with (est. ~3000 remaining) and I spotted them outside their common range, I'd like to report the sighting.

I managed to take poor but evidence-worthy photographs by using my binoculars as a crude lens for my digital camera. Does anyone know who I should contact about this? The Audubon Society is largely absent from China, as far as I know...

image collage link (125kb jpg version) - http://www.drewsjournal.com/JUNK/Egretta-eulophotes.jpg

image collage link (1.5mb PNG32 version)- http://www.drewsjournal.com/JUNK/Egretta-eulophotes.png

38.100.141.141 (talk) 02:03, 23 August 2009 (UTC)

You could directly email the authors of this paper (or similar scholarly papers on Chinese Egret conservation). [2] [3] [4]. These papers list a correspondance author (with email contact), who are presumably Chinese egret specialists. It's likely that the author is intersted in the breeding range of this bird; and may know more specifically about who in the community you could contact. You could also try contacting one of the editors for the respective journals. Nimur (talk) 03:29, 23 August 2009 (UTC)

Healing machines

I have this memory, either from my own imagination or something I read in the distant past, of a machine that had some type of bionic ability to heal and repair itself. FYI, this was a shaceship hull. This was not done by robots according to programming, nor guided by an artificial intelligence, but rather the nature of the material itself. The hull was like a living non-sentient creature, but definitely had been engineered. Does this concept have a name that I could research more? Thanks - Draeco (talk) 02:36, 23 August 2009 (UTC)

A lot of rubbers and polymers ("plastics") have been engineered to self-seal holes and punctures. We have an article on tires that do this. Similar material has been worked on for aircraft fuselages and fuel-tanks: self-sealing fuel tank. Nimur (talk) 03:22, 23 August 2009 (UTC)

There was talk that the Transhab would be made of self-healing materials, but I can't find any references that its prototypes actually were. Perhaps that was one of the many parts of the Transhab concept that didn't pan out. (Though it might still be a good idea.) APL (talk) 04:13, 23 August 2009 (UTC)

You might be remembering Vorlon ships from Babylon 5. See Vorlon#Spacecraft. 67.122.211.205 (talk) 05:54, 23 August 2009 (UTC)

Lots of science fiction in the past ten years has used the concept of "nanomachines" as a means of introducing self healing ships and/or self healing bodies. The Old Man's War series by John Scalzi makes heavy use of this idea, as does lots of recent sci-fi. --Jayron32 06:02, 23 August 2009 (UTC)

Another sci-fi example is the ship in the Farscape series. StuRat (talk) 08:42, 23 August 2009 (UTC)

Though Leviathans like Moya were sentient. -- 128.104.112.102 (talk) 17:09, 23 August 2009 (UTC)

That true. Are we excluding the bodies of sentient beings from the list of self-healing materials ? StuRat (talk) 15:21, 25 August 2009 (UTC)

Not necessarily, although the OP mentioned that the example being sought "was like a living non-sentient creature" (emphasis added), so I thought it was worth mentioning. -- 128.104.112.102 (talk) 21:58, 25 August 2009 (UTC)

"self healing material" seems to be the right search term, nothing more technical than that. See also Self-healing material.83.100.250.79 (talk) 12:32, 23 August 2009 (UTC)

I recall reading a science fiction book where the ship's hulls were a crystal of some sort where kinetic energy caused them to repair. It reminded me of Piezoelectricity. -- JSBillings 01:25, 24 August 2009 (UTC)

Motor learning and tools

Is there an article specifically about the phenomenon of motor learning with tools? Actually I'm thinking about the phenomenon where, with experience, most car drivers seem to drive as though the car were an extension of their body; a sudden need to swerve or brake is in fact reflexive; and control of the steering and speed are pretty much automatic (and are even conducted during those periods of time where you zone out and then "snap out of it" a few miles later, having driven on automatic pilot that whole time). Our motor learning article is surprisingly brief. Tempshill (talk) 04:05, 23 August 2009 (UTC)

Crooks and Gibson (1938) - A Theoretical Field-Analysis of Automobile-Driving - "Steering, according to this hypothesis, is a perceptually governed series of reactions by the driver of such a sort as to keep the car headed into the middle of the field of safe travel." There's no shortage of modern studies, either. Models of driving behavior: a review of their evolution (1994) - "More recent models have incorporated a hierarchical control structure, which assumes concurrent activity at strategic, maneuvering, and operational levels of control. At the same time, automaticity has emerged as a central construct in cognitive psychology. All activities are assumed to combine fast, automatic components with slower, more deliberate, controlled processing." Nimur (talk) 04:13, 23 August 2009 (UTC)

Those look excellent though I don't have access to read anything beyond the synopses. I guess I should ask whether there's a Wikipedia article about same. Tempshill (talk) 04:32, 23 August 2009 (UTC)

Exercise making someone more drunk?

As I read the "Does exercise make people less drunk?" question from several days ago, I was curious — is the following story I've heard plausible, or was it a hoax? According to a story that I've heard, part of the Lost Sea Cave in Tennessee was used as a speakeasy during Prohibition in the USA, and because the modern tunnel wasn't yet constructed, the patrons could only access the cave by a (still usable) steep rock staircase. Some patrons would consume large amounts of alcohol without becoming tipsy, but as they attempted to leave, the decreasing air pressure as they climbed to a higher altitude (I really don't know how tall the stair is, but my memory from ten years ago says perhaps over 100 feet) would somehow make them more drunk, and a few consequently fell back down the stairs. Nyttend (talk) 04:21, 23 August 2009 (UTC)

Change in air pressure during a 100ft ascent is negligible so that theory is probably rubbish. What is more likely is that alcohol absorption is a gradual process - this especially true if you had food beforehand. This, coupled with the increased circulation and thus absorption from exercising and maybe a bit of liquid lost due to sweat can increase blood alcohol concentration quite quickly (but then this is purely speculation). --antilived^{T | C | G} 10:23, 23 August 2009 (UTC)

Yes, it's not plausible that altitude would have any effect here. One of the things that alcohol most seriously impairs is the ability to balance, but it is also impaired by fatigue -- so, combine the two, and ... Looie496 (talk) 15:53, 23 August 2009 (UTC)

At higher altitudes, however, the change in air pressure would have a significant effect. That's why pilots are strictly forbidden from drinking while on duty -- even if you take just one drink at sea level and then climb to 8,000 feet, it can have the same effect as having three or four. So a pilot who's just slightly buzzed when first getting into the cockpit would be passing-out drunk by the time the plane reaches 8,000 feet.

That said, an ascent of 100 feet would not have a significant effect on how drunk you get. What prob'ly happened was that the physical exertion involved in climbing the stairs would increase the rate of circulation, which in turn would speed up alcohol absorption -- plus loss of water due to sweating, which increases the BAC significantly -- plus the effect of fatigue adding to the effect of alcohol on the brain -- and there you have it. 98.234.126.251 (talk) 23:44, 23 August 2009 (UTC)

Known precision of the nuclear force binding energy constant

Richard Dawkins, discussing the fine tuned universe in The God Delusion, writes, "Martin Rees, in Just Six Numbers, lists six fundamental constants, which are believed to hold all around the universe." Dawkins continues

An example of Rees's six numbers is the magnitude of the so-called 'strong' force, the force that binds the components of an atomic nucleus: the nuclear force that has to be overcome when one 'splits' the atom. It is measured as E, the proportion of the mass of a hydrogen nucleus that is converted to energy when hydrogen fuses to form helium. The value of this number in our universe is 0.007, and it looks as though it had to be very close to this value in order for any chemistry (which is a prerequisite for life) to exist.

This caught my eye because

1. hey, it is a dimensionless constant!
2. it exactly equals the fine structure constant (when you only consider a single significant figure).

Wikipedia discusses it in Proton–proton chain reaction#Energy release and in Dimensionless physical constant#Martin Rees's Six Numbers, but in both cases only gives a single significant figure. (Rees's book is only available via snippet view at Google Books, so I don't know if he discusses the value further.) How precisely is this constant known?

(N.B. this is a question only about the value and definition of a physical constant, and not an invitation to discuss cosmogeny.) -- Thinking of England (talk) 04:43, 23 August 2009 (UTC)

Just compare the mass of 4 protons with the mass of a alpha particle. A more precise value is 0.0068500 Dauto (talk) 06:40, 23 August 2009 (UTC)

Above I forgot to include the energy realeased from two electrons that get coverted to the much lighter neutrinos. When that is included you get the figure 0.0071224. Dauto (talk) 06:58, 23 August 2009 (UTC)

OK, I was being dense and thinking there was more to the definition than what was given in Dimensionless physical constant#Martin Rees's Six Numbers. So if we take the mass of the alpha particle, proton, and electron as m_α = 4.001506179 u, m_p = 1.007276466 u, and m_e = 0.000548580 u, then ε = 1 - m_α / (4 m_p + 2 m_e) = 0.007120446 which is reassuringly distinct from α = 0.007297352 (and from 0.007000000 -- I'll change the "ε=0.007" in Dimensionless physical constant#Martin Rees's Six Numbers to "ε≈0.007". D=3 I can accept, but I was troubled by ε being singled out of the five remaining constants for an equal sign.) Thanks. -- Thinking of England (talk) 07:49, 23 August 2009 (UTC)

software programming

what is difference between java & Asp.net —Preceding unsigned comment added by 58.68.8.187 (talk) 07:20, 23 August 2009 (UTC)

We have articles on Java (software platform) and ASP.NET, which may be of help. --Cookatoo.ergo.ZooM (talk) 08:20, 23 August 2009 (UTC)

if you require more explanation you should ask the question on the computing desk ! 83.100.250.79 (talk) 12:29, 23 August 2009 (UTC)

Streamlines and streaklines

Hi,

I've had a look through the article and my textbook, but still not sure on the difference and why they only coincide when flow is steady. Because if the streamline is calculated instantaneously, wouldn't it take into account the unsteady nature of the flow and hence end up being the same as the streakline?

Is the difference that a streakline takes into account the "history" of the flow whereas the streamline doesn't? For example, say the flow flow is unsteady, and initially it could be described as a straight line (ie the streamline was linear). But then at t₁ the streamline became parabolic. Then at t₂ it became linear again. Would the consequent streakline be a straight line followed by a parabolic section followed by a straight line?

Thanks, --Fir0002 11:56, 23 August 2009 (UTC)

Steamline is given as a snapshot of the flow (synchronous), so every point of the flow line represents a different fluid element. A streakline follows a fluid element and plots its path. Two different things. For instance, you could have all the fluid elements following similar tracks. It is possible that at some given time all of them would be moving along the same direction (say northward), but then as each element follows its track at a latter time they could be all moving eastwards. At any given time the streamlines would all be straight lines since all the fluid elements are moving towards the same direction, but the streaklines would all be curved since each element is changing the direction of its motion. Dauto (talk) 16:52, 23 August 2009 (UTC)

OK I think you're basically agreeing with my second paragraph. The streamline is the mathematical model of the flow at any point in time. The streakline is a "recording" of the path a particle takes in a given timeframe. But just so I have this clear I'd like to know what would happen in this example.. We're looking at unsteady flow. At t₀ the streamline is a straight line due north. At t₁ the flow changes and now the streamline is a straight line due east. The flow changes again at t₂ and thereafter the streamline is again a straight line due north. The streakline over that period would look something like this, correct? --Fir0002 11:06, 25 August 2009 (UTC)

Yes, that's correct. And the streamlines would all be straight lines for any given time, so they do look very different from the streaklines. Dauto (talk) 17:33, 25 August 2009 (UTC)

How to cross a river safely while hiking - portable boat?

What would be the best practical solution to being able to cross small placid rivers say 20 or 30 feet wide while hiking? Constraints include that a raft cannot be made as the materials are not available. Swimming is unsuitable as I'd get wet and cold, especially in non-summer seasons. Any portable boat would need to be light enough and compact enough to be carried. Surely inventors have considered this problem though the centuries. I'm looking for a genuine solution that I can either buy or make fairly easily. 78.149.186.253 (talk) 13:05, 23 August 2009 (UTC)

How about one of those swimming pool floating/lounge chairs that comes in (and thus is able to fit in) a remarkably small cardboard box? 69.140.12.180 (talk) 13:43, 23 August 2009 (UTC)Nightvid

...or an inflatable raft. DRosenbach ^{(Talk | Contribs)} 13:44, 23 August 2009 (UTC)

No serious hiker would carry a heavy boat through an entire hike to cross such a small stream. You just wade across. If the current is too strong you may have to use ropes for safety. 75.41.110.200 (talk) 13:47, 23 August 2009 (UTC)

A "Serious" hiker would take local conditions into account before making a decision. He already said he's hiking in "non-summer". He could be trying to cross a ten foot deep river in below-freezing weather for all you know. APL (talk) 05:05, 24 August 2009 (UTC)

The navigable rivers I have in mind are too deep to wade, with lots of water-weeds to get dangerously entangled in. Plus I'd rather not get wet and cold. 78.149.186.253 (talk) 14:14, 23 August 2009 (UTC)

I think you'll have to be prepared to get a bit wet. You can buy a floating backpack (Google it) which acts as a flotation device, even when fully laden. Just get undressed and throw your clothes into it, swim across, then dry yourself and get dressed. I saw one featured on TV a few weeks ago but I can't find a link to the exact brand at the moment.--Shantavira|^{feed me} 14:37, 23 August 2009 (UTC)

It sounds like what you're looking for is the smallest Packraft you can find. I've never used one myself so I can't vouch for any particular kind.

Incidentally, if you're hiking in a group only one person has to get wet. You can set up a simple rope bridge pretty quickly if there are trees nearby. APL (talk) 15:31, 23 August 2009 (UTC)

Wow, check out this one [5]. I wouldn't have thought they could make a boat this tiny still be useful. I've carried tents heavier than this boat. Bit pricey, though. Perhaps something like this[6]. I imagine you'd make your life a lot easier if you also packed a small bicycle pump.APL (talk) 15:43, 23 August 2009 (UTC)

The "standard" solution to this problem is to find a downed tree that lies across the stream. Where are you going to be hiking, where you find small placid rivers 20 to 30 feet across that are too deep to wade? Looie496 (talk) 17:42, 23 August 2009 (UTC)

Where are you that you have 20 to 30 feet wide rivers that are shallow enough to wade? 78.147.147.139 (talk) 19:58, 26 August 2009 (UTC)

A Klepper canoe might be useful. 98.234.126.251 (talk) 23:49, 23 August 2009 (UTC)

Or, for a small river, two people crossing arm-in-arm may make it easier. Warning. Having to cross a small river, many people look for a spot where the flow is weaker and the water is less deep, which in principle is not a bad idea. Such a point is often found in the outer side of a bend (a convexity of the river): but the opposite side, the inner side of the bend (the concavity of the river), is, for the same reasons, the spot where the flow is stronger and the water is deeper. In panic, they try to go ahead and reach the bank, making the situation worse. --pma (talk) 18:31, 25 August 2009 (UTC)

I think you are mistaken - the current is more intense on the outside bend. 78.146.255.137 (talk) 21:34, 27 August 2009 (UTC)

I think the weight-cost of carrying around the necessary scuba gear and air tanks would make that method impractical. 78.147.147.139 (talk) 19:58, 26 August 2009 (UTC)

'Level' as a point or a span

A periodontal colleague of mine insists that her goal is to "reduce clinical attachment level." Now, clinical attachment level being the level on a tooth at which the gingiva attaches, with periodontal disease resulting in loss of attachment over time so that the gingiva attaches to the tooth at a progressively more apical (towards the tip of the root) location along the surface of the root with time, a periodontist attempts to get the gingiva to stop receding (at least) and gain attachment, thereby reducing the net loss of attachment over time. I insist that my colleague is confusing CAL, because it can stand for both clinical attachment level and clinical attachment loss, but she insists that they are synonymous, so that when an initial examination reveals 7 mm of attachment loss and post-operative results exhibit only 5 mm of attachment loss, she has "reduced the clinical attachment level." I tell her she may have reduced the net loss, but the level is the spot of attachment, not the displacement span between initial level prior to disease and the current level after disease/therapy. DRosenbach ^{(Talk | Contribs)} 14:54, 23 August 2009 (UTC)

Have you a question? Cuddlyable3 (talk) 19:56, 23 August 2009 (UTC)

Haha...yes. Can level refer to a displacement between levels, or is it strictly a fixed point, based on the above soliloqy? DRosenbach ^{(Talk | Contribs)} 21:50, 23 August 2009 (UTC)

From my understanding of your description, the clinical attachment level would have "risen by 2 mm" after the surgery, whilst the clinical attachment loss would have been "reduced by 2 mm". "Level", as you point out correctly, is the "plane" of the gum´s surface surrounding the tooth, whilst "loss" (or, possibly, "gain", if such a periodontal phenomenon exists) is the distance by which this level decreases (or increases). I must add, however, that the semantics of clinical terminology are not necessarily identical to the meaning of the words in colloquial English. --Cookatoo.ergo.ZooM (talk) 22:10, 23 August 2009 (UTC)

Southwest Pacific islands

Okay, this may be patently obvious, but I don't know what I should call it, plate tectonics, or shallow seas or a subducted Atlantis or... anyway, look at a map or globe, there are random islands in the middle of all oceans, but the only really big concentration is in the southwest Pacific. It's not where two plates meet, and they're not big or spectacular in terms of the ring of fire, but there sure are a bunch of them. Any answers as to why the islands are clustered there, and not in other corners of the Pacific or in the Atlantic or Indian? Chris (クリス • フィッチュ) (talk) 16:38, 23 August 2009 (UTC)

Actually most of those islands you are talking about are located at where the australian plate meets the pacific plate. So your statement that " It's not where two plates meet" is not accurate. Most of the islands that are not located at plate boundaries, such as the Hawaiian islands, are caused by hot spots. Dauto (talk) 17:07, 23 August 2009 (UTC)

Also see Zealandia (continent) which is a microcontinent split off the Australian continent, dozens of millions of years ago, that includes quite a few of the islands. Graeme Bartlett (talk) 22:24, 23 August 2009 (UTC)

History of mind uploading

Right now I'm involved with an on going debate over some OR in the quantum mysticism article. In the process an interesting question was raised "is there an example of the idea of duplicating or copying consciousness before 1957-1962 in either philosophy of sci-fi?" I found these two "early" examples but I assume they are not the first.

• Clarke, Arthur C. (1956). City and the Stars, The. Spectra. ISBN 0553288539.
• Neumann, John Von (2000). The computer and the brain. Yale University Press. ISBN 9780300084733. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help) which was also prepared in 1956 and first published in 1958.

My question is: what is the first example of the idea of Mind uploading.--OMCV (talk) 16:42, 23 August 2009 (UTC)

Hmm. The concept of moving a mind to a different physical "body" is probably older than civilization, but the concept of doing so by copying data might not be much older than the sources you mention. If Asimov had been familiar with such an idea, he probably would have written about "uploading" human minds to the positronic brains of his robots, but I don't recall such a theme in any of his stories. Looie496 (talk) 18:36, 23 August 2009 (UTC)

The djinni was loaded mind-and-body into the lamp of Aladdin in ancient arabic folklore. I might use the expression "download" rather than "upload". Cuddlyable3 (talk) 19:51, 23 August 2009 (UTC)

November 1956: The Last Question (a short story by Isaac Asimov) talks about the minds of all of humanity becoming a part of "Multivac" - a gigantic artificial intelligence. SteveBaker (talk) 19:53, 23 August 2009 (UTC)

Thanks for the comments, I'm going to have to read The Last Question soon.--OMCV (talk) 02:18, 24 August 2009 (UTC)

In defiance of copyright, the story is hosted by the Multivax website; that site also has other derivative and original commentary related to the story. Nimur (talk) 08:07, 24 August 2009 (UTC)

Please note that I didn't say it was a good story! (But at least it's short). SteveBaker (talk) 22:44, 24 August 2009 (UTC)

Three questions about potato

1. Does a potato have a skin, or is the surface of a potato just dried and oxidised potato matter due to exposure (as found in onions)

2. It is said that the 'stolon' from which a potato grows is a sort of enlarged lateral root. I have seen the root vessels in primary root crops such as carrot, but not in a potato. Is there a root system to be seen inside a potato when cut? (It seems uniform) - A picture?

3. Does the potato grow from the outside surface, or something else?83.100.250.79 (talk) 19:15, 23 August 2009 (UTC)

My understanding is that potato skin is a kind of cork-type tissue made of suberin. --Sean 21:26, 23 August 2009 (UTC)

Decaying stew

Potato, carrot, onion, parsnip, swede, gravy, and beef.

How often can I reheat this daily before it becomes dangerous or inedible, and why will it become so? Vimescarrot (talk) 19:20, 23 August 2009 (UTC)

If you heat it to boiling, I don't see why you couldn't keep doing it indefinitely. The vegetable matter will gradually turn to goo, but there shouldn't be any harmful consequences unless you take it to absurd extremes, and even then I don't see what the harmful consequences would be. Looie496 (talk) 19:26, 23 August 2009 (UTC)

If you heat it to boiling frequently enough, it will last forever. See Perpetual stew. Red Act (talk) 22:00, 23 August 2009 (UTC)

Hiroo Onoda claimed to have killed a cow about once or twice a year; and preserved it by boiling a beef stew once a day, every day, until the meat ran out a few weeks later. This is debatably quite unhealthy; but he was in a survival situation. "If we left the carcass as it was, the rain and the crows would reduce it to a skeleton, but the remains would tell the enemy where we were. After we cut the cow up, therefore, we moved the carcass along a mountain road to as distant a point as possible... For the first three days, we would have fresh meat, broiled or stewed, two times a day. Presumably because of the meat's high calorie content, as I ate, my body temperature climbed until I felt hot to the soles of my feet. It was hard to breathe... On the fourth day, we piled up as much meat as possible in a pot and boiled it. By heating this up once every day and a half or two days after that, we kept it from spoiling, and the flavor held up for a week or ten days. While we were eating the boiled meat, we dried what was left for future consumption. We called this dried meat 'smoked beef.' ... From one cow, we could make about 250 slices of smoked beef. By eating only one slice a day, we could make the meat last for about four months." (No Surrender, chapter "Jungle Life", 1974). His biggest complaint was the flavor - the gruelish soup was very unappealing, but by adding some "magic medicine" (a tiny amount of briney sea-water for salt), he and his comrades found it palatable. Nimur (talk) 22:19, 23 August 2009 (UTC)

This is great! I KNEW about the perpetual stew and master stock idea, but for some reason i let my fiance convince me that you shouldn't reheat soup more then once. We always fridge our soup and only reheat the portion we need, but sometimes we waste some if we reheat too much.. Now I'll know better.Vespine (talk) 02:37, 24 August 2009 (UTC)

Are going to listen to your fiance or to some random anonymous internault? Dauto (talk) 04:45, 24 August 2009 (UTC)

FWIW, I have often (during the last 30 years) kept such a stew going for weeks to months with no ill effects. If you're willing to trust random internet advice, some tips are:

1. use a saucepan or pot with a closely fitting lid, and big enough to initially make a volume more than twice what you're going to eat in one sitting;
2. once you've ladled out a serving, replace the lid and don't lift it until the next time you start to heat (to minimise incoming bacteria/mould spores);
3. keep the outside of the pot, and the inside surfaces above stew-height, as clean as possible;
4. try to reboil no less frequently than every other day, but don't worry about any minor surface scum/growth, which the boiling will neutralize;
5. bring to the boil slowly with stirring and bottom scraping (to avoid a burnt bottom layer) and then simmer for at least 20 minutes;
6. during each reboil, add further washed raw vegetables, diced or sliced small, equal to the volume you ate last time in the order of their need for cooking, thus ensuring the presence of non-gooey components;
7. avoid over-dryness by adding water and/or soup when necessary (canned cream of tomato makes an excellent base stock);
8. thicken up with gravy powder or instant soup powder when necessary and if available; add pre-cooked meat such as mince or canned (and diced) meatballs from time to time;
9. use pre-cooked canned vegetables such as baked beans, chopped tomatoes or sweetcorn if and as convenient;
10. don't add all the new ingredients in one go, so as to avoid cooling too far below simmering level.

It's not Cordon Bleu, but it works for me. Note that the above assumes only one or two consumers, eating together; for a large enough household, instead of periodic reboiling it might be more convenient and more hygenic to keep the pot/cauldron simmering continually. 87.81.230.195 (talk) 12:47, 24 August 2009 (UTC)

"...don't worry about any minor surface scum/growth" ? Ewww ! If you see mold on it, toss it out. Molds can release toxins that aren't neutralized by boiling. Another hint: don't use any cream soups or milk, as that will tend to cause scorching at the bottom and/or boiling over. To end up with a reasonable amount of sodium, combine fresh veggies (containing little or no salt) with soups, canned vegetables, etc. (which often have way too much salt). You can also put something spicy in, like salsa, instead of making it salty. And, if you serve with salty crackers, then the stew doesn't need to be as salty. StuRat (talk) 21:46, 24 August 2009 (UTC)

I'm curious Stu. You aren't advocating less salt in the diet, since you're eating salty crackers with it, just less salt in the stew. Any reason why or is it just personal preference? I think one of the benefits of the salty stew is that it would probably have an added preservative effect. Vespine (talk) 22:56, 24 August 2009 (UTC)

I do advocate less salt in the diet. The point of adding salty crackers is that you can make the stew with a low level of sodium, which some members of the household will eat directly. For those who like saltier foods, they can add crackers. Of course, they could also add salt to their individual bowls of stew, but then you'd first have to listen to their complaints that the stew is "bland" (that is, lacks sodium). If they add crackers before even tasting it, they may never make such negative comments at all. StuRat (talk) 15:18, 25 August 2009 (UTC)

Why on Earth would you make this a regular habit? 67.243.4.208 (talk) 16:40, 24 August 2009 (UTC)

Because it's easier to make stew once, and reheat it, than to make stew twice. Thanks for all the answers, guys! Much appreciated. Vimescarrot (talk) 18:12, 24 August 2009 (UTC)

Also note that softening up of the stew contents over days isn't necessarily bad. Some items may be too hard to eat at first, but eventually become soft enough to eat. After several days I can eat a chicken back, discs and all, for example, and get my calcium for the day. StuRat (talk) 17:38, 25 August 2009 (UTC)

Turkey thing

What do you call the floppy thing that hangs down from the beak of a turkey? --✶♏‭ݣ 23:28, 23 August 2009 (UTC)

Wattle (anatomy). --Tagishsimon (talk) 23:29, 23 August 2009 (UTC)

Thanks!! --✶♏‭ݣ 23:32, 23 August 2009 (UTC)

The wattle hangs from under the chin. The snood hangs over from on top of the beak. Here's an impressive one. --Sean 12:55, 24 August 2009 (UTC)

Hmm, now I am curious. Does anybody know what purpose these growths serve? Are they sexual characteristics or something different? Maelin (Talk | Contribs) 03:36, 25 August 2009 (UTC)

I think they serve to attract females. FWiW 98.234.126.251 (talk) 08:21, 25 August 2009 (UTC)

Am pretty sure that the turkey in the photo IS a female. Googlemeister (talk) 14:30, 25 August 2009 (UTC)

Both males and females have wattles, but generally speaking, the male wattles are bigger. (Sort of like breasts in humans, only the other way around.) FWiW 98.234.126.251 (talk) 03:53, 26 August 2009 (UTC)