Wikipedia:Reference desk/Archives/Science/2016 January 19

= January 19 =

Carbs in Stiegl Radler
How many carbs are there in a 0.5 liter serving of this beverage, described on the can as "grapefruit Salzberger Stiegl Radler beer with fruit soda. Malt beverage speciality. 40% Stiegl-Golbbräu and 60% fruit soda. Product code 8-52527-00028-1." On the internet I see statements of 0 carbs to 44 carbs, and both extremes seem very unlikely, but the higher is more plausible. The beverage can provides no guidance. An answer based on reliable sources is urgently desired. Edison (talk) 03:04, 19 January 2016 (UTC)


 * In the United States, the labeling of all malt beverages, regardless of alcohol content ... is regulated by the Alcohol and Tobacco Tax and Trade Bureau (TTB). TTB does not require that the products it regulates bear nutrition labeling. In other words, there are no legal requirements for the producer or retailer to disclose ingredients or calorie information.  Labels for beers are not rule-free: there are mandatory labeling requirements; but these do not include nutrition information like carbohydrate content or calorie content.
 * If you're lucky, you might find some independent food science laboratory who has voluntarily assayed the contents and published the lab results at no cost ... but this isn't very likely.
 * One major American importer lists 118.8 calories per 11.2oz; you could contact them, or the manufacturer, if you wanted more details.
 * WP:OR: By my back-of-the-envelope calculations, this data is sufficient to estimate 30 grams sugar per 500 milliliters of the drink ... by solving simultaneously for the mass of ethanol and sugar, constrained by the alcohol-by-volume, the calories-per-mass, adjusting for serving-size, and so on. This is not an accurate methodology for many reasons, but it's probably in the ballpark.  This is slightly more sugar, and significantly more alcohol, than a typical serving of "cola" or fruit-soda soft drink.
 * Nimur (talk) 05:37, 19 January 2016 (UTC)


 * Thanks for the calculation. 2% alcohol by volume would yield the calories from alcohol, so the total calories less the alcohol calories indicates the carbohydrate calories (since fat and protein are likely nil) and that divided by 4 would yield the grams of carb. I see the article Nutrition facts label which indicates several countries require detailed nutritional labels for "prepackaged food," but do other countries also give alcoholic drinks a pass from such labelling as the US does? It is hard to see why alcoholic drinks should be exempt from any nutritional labelling other than alcohol by volume and ingredients. Edison (talk) 22:01, 19 January 2016 (UTC)


 * I think the logic is similar to cigarettes. That is, they knew they were unhealthy, so regulating them in this way, which supposedly has the purpose of ensuring that they were healthy, seems out of place.  I don't personally agree, though, as there are degrees of healthiness and unhealthiness, and the consumer may well want to know the specifics, so they can make better decisions.  And, for alcoholic beverages, they are only unhealthy if abused, so that's another reason to give them proper labels. StuRat (talk) 22:15, 19 January 2016 (UTC)


 * AU has slightly stricter requirements than USA see here, where it says basically nutritional info is require in some cases. Here should be a table summarizing alcohol labeling laws for different countries, but the IARD site is currently down for maintenance. SemanticMantis (talk) 22:24, 19 January 2016 (UTC)

what field studies maximum world population carrying capacity?
To answer the question what is the maximum world population carrying capacity, it seems as if you would need to know a lot about mathematics and statistics, biology and genetics, medicine, agriculture, economics and possibly several more fields. So what if you went to universities to find the people who know the most about this topic, what department would they be in?--Captain Breakfast (talk) 19:08, 19 January 2016 (UTC)


 * Conceivably demography. Loraof (talk) 19:32, 19 January 2016 (UTC)
 * The figures named in this article seem to be biologists.  Clearly they would draw on work in other disciplines - they would not need to "know" a lot about the work done in those other fields.   Ghmyrtle (talk) 19:40, 19 January 2016 (UTC)


 * Indeed - it doesn't take much to find out the area of land that could potentially be farmed, the maximum yield of that land and the food intake requirements to figure out whether food would be the limiting factor (for example). Repeat that for all of the limiting factors you can think of - pick the lowest number - and you're done.  With access to the right kinds of basic information (much of which is very easy to find) - it seems like anyone with a reasonable scientific background and a command of basic arithmetic could come up with a plausible number.


 * The real difficulty is in identifying all of the things that high population pressure could cause to go wrong. We already know (for example) that global climate change has come about because of the product of the size of our population and our per capita energy use.  We also have reasonable estimates for how far we could push the warming trend without catastrophically (and suicidally) trashing the planet - but we can't easily predict whether technology can step in (eg with effective fusion reactors producing safe/cheap energy) to ameliorate that - or whether that will remain out of reach and with increasing energy demands, we'll burn through even more fossil fuels - thereby hastening the end.


 * But what if some other thing that we haven't thought of is the limiting factor? There have been many things over the years (CFC pollution destroying the ozone layer, for example) that were completely unforseen until we started to investigate them.


 * Being unable to know that kind of thing pushes even the best science into the realms of speculation.


 * IMHO, the true answer is "less people than we have now"...and that highlights another issue. Right now, the earth is carrying 7 billion people - but is that a sustainable total?  If the population doubled overnight, we could probably struggle on for a while before systems started to collapse around us - but there are strong signs of those collapses happening right now.  So if your question is about "sustainable" population size, it's going to be a very different answer than "peak" population size.  What the peak number is would likely be capped by birth rates - what the sustainable number is depends on resource depletion rates, technological advances and so forth.


 * But that adds another layer of complexity to the mix. We're currently running out of some very fundamental resources - copper and helium, for example, are close to exhaustion.  If it turns out that population growth is limited by the amount of copper we have (unlikely - but bear with me!) then starting a super-strict copper recycling system would allow us to have a larger population than if we totally deplete the reserves and mountains of copper stashed in hard-to-recycle landfills.  So the final maximum number of people depends a lot on the route we take to get there...which is one of those political/sociological things that we're disastrously bad at predicting.


 * The problem is more to do with methodology and data capture than specific fields of study/expertise.
 * SteveBaker (talk) 20:09, 19 January 2016 (UTC)
 * There's a lot of assumptions and no references here, as well as some big mistakes. A very important error is your claim that "it doesn't take much to find out...the maximum yield". Hundreds of researchers and thousands of peer-reviewed papers say otherwise. Just search google scholar for /potential yield/, /yield limitation/, and various related terms, throw in agriculture, agronomy, or agroecology in as you see fit. You are right that sustainability makes all this even harder, maximum sustainable yield gets over 4k hits on google scholar just since 2012! So lots of people are building their careers on advancing our understanding of maximum yield. This is clearly a very active area of research, not something that is easy to figure out. SemanticMantis (talk) 22:07, 19 January 2016 (UTC)
 * For a comprehensive demolition of the "running out of helium (etc)" myth, see the in some respects bonkers, but knowledgeable, Tim Worstall. HenryFlower 05:21, 20 January 2016 (UTC)


 * Lots of ecologists estimate carrying capacity of other organisms, but humans are ecosystem engineers, and that complicates things, because then there is no one constant "carrying capacity" like there is for a small closed system, and that number will depend on myriad other factors, some of which will continually change (i.e. changes in technology result in non-stationary distributions for life history statistics and traits).


 * So this is hard stuff, and there aren't really any named subfields that are centered around researching human carrying capacity. There are indeed many people who talk about it, just not all under one roof. Plenty of people are working on related sub-issues, such as how much food we can make on how much land. To further confuse the issue, bio-sciences departments are structured in very different ways at different universities, so the people who work on this will be housed in departments that have a variety of names. Increasingly, a university professor will have a "home" department, as well as memberships in various "centers" or "groups", and if you look into research on carrying capacity, you can find authors with over five different named affiliations!


 * This all complicates the answer to your question, but here are some department names you can look at, some research articles, and some names for general fields of research that include carrying capacity. Members of Agroecology departments sometimes write papers on human carrying capacity of earth. Sometimes you might see this research coming out of an evolution/ecology dept, or "integrative biology", or even just "biology." But names are often political more than scientific. Here is a fairly famous and relevant paper, the authors are housed in an "Energy and resources group", and a "Center for conservation biology". Here  is another highly cited paper, this one written by someone housed in a geography department. That may seem strange, but increasingly Geography is seen as a "big tent," inclusive field, and the departments will include people who do a lot of demography, ecology, and mathematical modeling. U. Arizona has a "School of Sustainability"  that I think touches on human carrying capacity, while QUT has an "institute for future environments" . They have a nice "dashboard" calculator that you can play with to look at results  of modeled carrying capacity as a function of several inputs. So, that's a selection illustrating the high variety of names involved. If you want to learn more about the latest thinking on the human carrying capacity of earth, you're better off searching by term than by department or field. If you want to find people at a specific university, I suggest browsing the keywords in faculty lists, perhaps for many different named units. I'd be happy to help further if you want more along these lines, or want to narrow the question. SemanticMantis (talk) 20:39, 19 January 2016 (UTC)

See urban farming especially vertical farming; hydroponics etc. In theory, you could have orbital solar collectors or deep geothermal energy or fusion reactors powering unlimited food growing space in deeply carved caverns, even as ultra common components of the Earth like silicon and aluminum are used to handle most mechanical/structural needs. Though underground cities seem gloomy, if done well they might provide an opportunity for large parklands to recreate ancestral ecosystems without exotic competitors. I suppose eventually you run out of carbon and nitrogen? The oceans should provide a pretty good supply of most other basics. Wnt (talk) 18:03, 20 January 2016 (UTC)
 * On the question inside the OP's question, I recall Joel E. Cohen's 1995 book How Many People Can the Earth Support? as being a good, level-headed source. He's quoted in the article Ghmyrtle linked to above.John Z (talk) 01:11, 21 January 2016 (UTC)

Why do humans sometimes classify themselves as animals and sometimes not?
Sometimes, they may say, "humans and animals", as if humans are not animals. Sometimes, they are more accurate and say, "humans and other animals" or "humans and nonhuman animals". But a picture book about "baby animals" never seems to include a picture of a human baby, or that an "animal hospital" seems to be really a term for a veterinary hospital. 140.254.77.184 (talk) 20:40, 19 January 2016 (UTC)
 * The English language is not always very precise; formal definitions depend on context. We have an article on definition that covers this topic thoroughly in the general case.  In the specific case of the word "Animal," the word sometimes means something in a formal scientific context; and sometimes it has a more flexible meaning.  Nimur (talk) 20:59, 19 January 2016 (UTC)


 * (WP:EC) See exceptionalism generally, and human exceptionalism more specifically. The general populace just isn't that precise in common speech. Scientists are usually more careful when they publish, for example the phrase "Non-human primate" gets over 60k results on google scholar, and "non-human animal" gets over 27k. Additionally religion can play a role, e.g. most of the world's popular creation myths, and especially the Genesis creation narrative draw a sharp division between humans and other animals.  SemanticMantis (talk) 21:00, 19 January 2016 (UTC)


 * If humans had not been so integrated as they are today, and there may be different populations of hominids, would "humans" be a term for one population of hominids and for other hominids, they will be classified as "non-human hominids"? 140.254.77.184 (talk) 21:23, 19 January 2016 (UTC)
 * I don't know, my WP:CRYSTAL is broken. But personhood is a relevant article for this line of inquiry, including Personhood and Great ape personhood. SemanticMantis (talk) 21:53, 19 January 2016 (UTC)


 * It's really worse than that - it's not at all uncommon to hear people say "Birds, fish and animals" - or "animals and insects". Even when we are trying to be inclusive, we'll often talk about "plants and animals" as a synonym for "all living things" - completely missing bacteria (which are neither) - and more modern definitions of "plant" which doesn't include fungi.
 * As with so many things, language is vague in general use - and only gets tightened up to some degree when speaking formally and/or scientifically.  Even amongst people who should no better, and in the formality of scientific papers, you'll come across: "Our drug has just been through animal testing" - with the implication that no human trials have yet been done.
 * This vagueness is probably acceptable because we know what's intended from the context. But if you get into the arguments about whether a tomato is a fruit or a vegetable - genuine confusion does arise due to sloppy English alone.
 * The problem here is that when we came up with these words, humans were truly NOT considered to be animals. Now we are (well, for most people at least) - trouble is that we now don't have a handy, catchy, well-known word meaning "non-human animal".  Perhaps language will eventually catch up.
 * If you think you're immune to this - quick test: Is a pickup truck an "automobile"?  What about an SUV? SteveBaker (talk) 21:17, 19 January 2016 (UTC)


 * The "is a tomato a fruit or a vegetable" thing is more about different meanings of the words. In a culinary context, a tomato is a vegetable, because it's a savory plant food. In a botanical context, a tomato is a fruit, as it's the ovary and seeds of a flowering plant. There's nothing wrong with words having multiple meanings, though some people seem to get bothered by it. --71.119.131.184 (talk) 21:27, 19 January 2016 (UTC)
 * Hey, thanks. This response prompted me to link polysemy for OP, and then I found a highly relevant article and term of which I was not aware - Essentially_contested_concept. SemanticMantis (talk) 21:53, 19 January 2016 (UTC)


 * That's identical to this case, where humans are animals from a biology POV, but not from a religious or legal POV. StuRat (talk) 21:52, 19 January 2016 (UTC)


 * The term "animal" means any living thing that "breathes", hence the distinction from "plant" (plants also "breathe" but not in a way that humans would have understood 500 years ago). I would think only the most extreme religious fanatic might deny that humans are biologically animals. But that's mere physiology. "Human exceptionalism" figures into it strongly. And it doesn't require being religious to see the enormous intellectual gulf between humans and every other creature known to us. ←Baseball Bugs What's up, Doc? carrots→ 21:22, 19 January 2016 (UTC)


 * Bugs, with due respect, it sounds like you are promoting an etymological fallacy, "that the present-day meaning of a word or phrase should necessarily be similar to its historical meaning." The term "animal" is not wholly defined by its etymology.  Nimur (talk) 21:39, 19 January 2016 (UTC)


 * There's no conflict between the original meaning and the way it's used today. It's been fine-tuned a bit, and humans weren't initially considered animals as such - but the concept of a living thing that breathes still works. ←Baseball Bugs What's up, Doc? carrots→ 21:43, 19 January 2016 (UTC)


 * So you're saying that (for example) a jellyfish (kingdom Animalia) "breathes" but a tree or a bacterium doesn't? Or perhaps you're denying that a jellyfish is an animal?  Jellyfish passively allow oxygen to diffuse through their tissues.  I don't think "breathing" is a suitable criterion for being an animal.  The first paragraph of Animal has a concise definition - from a scientific perspective.  From a common person's perspective, it's a mess.  They'd probably say it's an animal because it moves around by itself...but that's a rather 'iffy' definition too. SteveBaker (talk) 02:55, 20 January 2016 (UTC)


 * Forgive me if I have missed something above, but see Aristotle's "vegetable, animal" and "rational souls". μηδείς (talk) 22:28, 19 January 2016 (UTC)
 * I looked for our relevant article, and surprisingly couldn't find one. Animal-Vegetable-Mineral_Man and Animal, Vegetable, Mineral? are not that relevant, despite both referencing Aristotle's trichotomy. SemanticMantis (talk) 22:35, 19 January 2016 (UTC)
 * Oh, my: Cheese 'n' crackers! Here's the Stanford Encyclopedia: diff. 22:58, 19 January 2016 (UTC)


 * SemanticMantis and the OP, our article Kingdom (biology) describes why those people with a scientific education class the human species Homo sapiens in the kingdom Animalia (Latin for "of the animals") - because humans are not members of the other kingdoms (or domains or empires) into which life has been classified by taxonomists. It also discusses Aristotle's initial classification of the animal kingdom, and Theophrastus's later classification of plant life into its own kingdom, the formation of various kingdoms after the invention of the microscope, and newer proposed taxonomies of life based on conjectures of which forms of life have common ancestors, based on DNA sequences.
 * To the OP: Other posters, above, have been very thorough in pointing to our articles on various reasons why people choose not to call themselves animals. Most of these reasons are listed in our article on Anthropocentrism, one example of which is Genesis 1:26: "And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth."  The meaning of the word "dominion" in this verse is subject to controversy among Biblical scholars, but whether it implies fee simple ownership or stewardship, the implication remains "Animals over there, humans over this way". loupgarous (talk) 06:12, 20 January 2016 (UTC)


 * The issue here is the use of paraphyletic rather than cladistic terms. For example, to this day there are people around here who will swarm out like flies to correct you if you call a chimpanzee a monkey.  "Animal" is used like that in popular speech, to include everything in Animalia except humans.  Are apes monkeys, are humans apes, are humans monkeys, are apes animals, are humans animals...?  Well, that's really a matter of whose semantics you want to use.  My feeling though is that most of the professionals have grown altogether uninterested in policing the application of non-cladistic definitions, though I'm sure somewhere in the world right now there is some lawyer desperately fighting over the definition of a duck or something. Wnt (talk) 13:55, 20 January 2016 (UTC)