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Wikipedia:Reference desk/Archives/Science/2015 June 25

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June 25 edit

What is the most laminar liquid? edit

Question is in topic. Malamockq (talk) 18:24, 25 June 2015 (UTC)[reply]

Pitch Count Iblis (talk) 18:31, 25 June 2015 (UTC)[reply]
Laminar as in flow regime like Reynolds number, or laminar as in some sort of microstructure? shoy (reactions) 18:38, 25 June 2015 (UTC)[reply]
Laminar as in a laminar flow, smooth. Malamockq (talk) 23:45, 25 June 2015 (UTC)[reply]
Fluids are not laminar: flows are laminar. Review the definition of laminar flow (and laminar, in general). Also see intrinsic and extrinsic properties (not to be confused with intensive and extensive properties!). We don't use "laminar" as an intrinsic property of a fluid; it is extrinsic, in the same way that pressure or temperature are extrinsic properties. When you ask "which liquid is most laminar?" ... the question is malformed. It is similar to asking "which liquid is the hottest?" There is no correct answer. These properties depend on the circumstances, both qualitatively and quantitatively. Nimur (talk) 00:38, 26 June 2015 (UTC)[reply]
Agreed, though one would struggle to produce non-laminar flow in anything more viscous than treacle or syrup (at room temperature). Count Iblis and I assumed that Malamockq intended to refer to the intrinsic property of viscosity. Dbfirs 07:40, 26 June 2015 (UTC)[reply]
Ok but some liquids are easier to make a laminar flow from than others correct? Would running a current through a ferrofluid make its flow laminar? Malamockq (talk) 12:41, 26 June 2015 (UTC)[reply]

Stars edit

Moved to 'Cronology of the universe' 'talk' page
  1. When was the population III stars were created? In the ‘recombination epoch’ or in the ‘reionization epoch’? - Article's point to start from
  2. What about population II and I stars? any specific dates?

Space Ghost (talk) 18:28, 25 June 2015 (UTC)[reply]

Population III stars appeared during the ionization epoch. Population II stars followed shortly after them (by a few hundred million years). Population I stars started to appear after Population II stars and continue to form now. Ruslik_Zero 20:55, 25 June 2015 (UTC)[reply]
I can't find any 'ionized epoch' article. I pressed CTRL+F and searched for the 'ionized' word. This two diagram illustrates during/after the reionization epoch [1] [2] also the article I stated. This article states what you stated [3].
Assuming that the population III stars were created after the 'Dark ages' and that it started reionizing, the article I stated, in the 'recombination epoch' 'plasma' was already there, why its is saying that from the 'reionization epoch' 'the universe is composed of plasma'?. Which plasma is it talking about?
If the first stars and quasars were created 400 million years after the Big Bang, then its not stated in the article I stated in the beginning. Can someone fix it after rechecking if I'm correct please? - I believe it should be entered in the 'Structure formation'[4] point. Also 'Star formation'[5] should go up, before 'reionization'[6].
Space Ghost (talk) 09:13, 26 June 2015 (UTC)[reply]
  1. ^ https://en.wikipedia.org/wiki/Chronology_of_the_universe#/media/File:CMB_Timeline300_no_WMAP.jpg
  2. ^ https://en.wikipedia.org/wiki/Reionization#/media/File:Reion_diagram.jpg
  3. ^ https://en.wikipedia.org/wiki/Metallicity#Population_III_stars
  4. ^ https://en.wikipedia.org/wiki/Chronology_of_the_universe#Structure_formation
  5. ^ https://en.wikipedia.org/wiki/Chronology_of_the_universe#Formation_of_stars
  6. ^ https://en.wikipedia.org/wiki/Chronology_of_the_universe#Reionization

literacy in animals edit

Can non‐human animals be taught how to read? Are there chimpanzees that can read? --Romanophile (talk) 18:36, 25 June 2015 (UTC)[reply]

Well you can teach a dog how to read. I know that apes can sign language. But in regards to literacy that is "moderate" (to the extent a non-human animal could read a children's book say) I think you are out of luck. Perhaps one of the smart people on WP/reference desk have further information. Agent of the nine (talk) 18:50, 25 June 2015 (UTC)[reply]

Sort of, yes. See Great_ape_language#Plastic_tokens. Kanzi_(chimpanzee) seems to be the best, though Sarah_(chimpanzee) was the first. This book also looks pretty good, but I can only see a few of the relevant pages about Sarah [1]. Essentially, as I understand it, Kanzi can read and write various things using magnetic symbols. This is not reading and writing English, but it is reading and writing some language in the core sense of those words. David_Premack was one of the key researchers to first seriously look at non-human-ape language acquisition. (It would be really interesting to learn how Kanzi would respond to simple short stories written by humans, something on the level of Goodnight Moon or Dick and Jane. I suspect they've tried something of the sort, but I can't look into it at the moment).
For dolphins, see the work of Denise Herzing (TED talk here [2]). She has a symbol board she uses to create a "shared language" with dolphins, it's not clear to me if any of them do anything like writing though. SemanticMantis (talk) 19:17, 25 June 2015 (UTC)[reply]

Resveratrol content in cranberries edit

Hi. Could someone improve the Resveratrol content table? I was specifically looking for the amount in cranberries. A decreasing table by highest content would be great. Thank you. — Preceding unsigned comment added by 2602:306:CF86:1660:A80A:109C:37C6:1033 (talk) 19:44, 25 June 2015 (UTC)[reply]

The article is at Reservatrol. You can make the tables sortable by looking at how it'd done in other places, e.g. List_of_countries_by_firearm-related_death_rate. This paper [3] says "The concentrations of resveratrol were silmilar in cranberry and grape juice at 1.07 and 1.56 nmol/g, respectively." You can use that ref to add that info to the table too. SemanticMantis (talk) 19:55, 25 June 2015 (UTC)[reply]
I could be wrong, but I think the OP is asking for the average resveratol content in raw cranberries rather than in juice. Nil Einne (talk) 00:58, 26 June 2015 (UTC)[reply]
Oops, yeah, probably. This paper [4] says cranberries have 900 ng/g by dry weight. Perhaps of note, regular Grapes have 6471 ng/g dry. For the heck of it (and since it is paywalled), I'll also post all the the other values from tables 1 and 2.
Unformatted data from Rimando et al (2004), table 2

scientific name (common name) cultivar source resveratrol a (ng/g dry sample) n b V. angustifolium Ait. (lowbush blueberry) not known c Nova Scotia 863 2 V. ashei Reade (rabbiteye blueberry) Tifblue United States 1691 3 V. corymbosum L. (highbush blueberry) not known c Southern United States 1074 3 V. macrocarpon Ait. (cranberry) not known c Nova Scotia 900 2 V. myrtillus L. (bilberry) not known c Nova Scotia 768 2 V. vitis-idaea var. vitis-idaea (lingonberry) not known c Nova Scotia 5884 2 V. vitis-ideae var. minor (partridgeberry) not known c Nova Scotia 924 2 V. vinifera L. (grapes) Table grapes Nova Scotia 6471

Table 1, even messier, slightly better readability in editor view

scientific name (common name) cultivar source resveratrol a (ng/g dry sample) n b V. arboreum Marshall (sparkleberry) not known Leakesville, MS 519 2 Lucedale, MS 125 1 V. ashei Reade (rabbiteye blueberry) Tifblue Lamar Co., MS 106 4 Poplarville, MS 154 3 Stone Co., MS 61 3 Climax Lamar Co., MS 390 4 Poplarville, MS 77 4 Stone Co., MS 583 4 Premier Lamar Co., MS 7 c 4 Poplarville, MS 16 c 4 Stone Co., MS 10 c 3 V. corymbosum L. (highbush blueberry) Bluecrop Corvallis, OR 327 d 2 853 e 2 V. elliotti Chapman (Elliot’s blueberry) not known Poplarville, MS 406 1 Monticello, MS 453 1 V. stamineum L. (deerberry) not known Leakesville, MS 204 2 B-59 Jackson Springs, NC 331 2 B-76 Jackson Springs, NC 503 2 Batesburg White Jackson Springs, NC 47 2 NC 78-8-1 Jackson Springs, NC 322 1 NC 78-8-21 Jackson Springs, NC 104 2 SHF3A-7:13 Jackson Springs, NC 291 2 SHF3A-2:14 Jackson Springs, NC 242 2 SHF3A-2 − 108 Jackson Springs, NC 115 2 V. vinifera L. (grapes) Cabernet Corvallis, OR 2475 2 Pinot Noir Corvallis, OR 5746 2 Merlot Corvallis, OR 6356

It's unformatted but fairly human readable, the value for each Vaccinium spp. comes after the place name (Nova Scotia or United States in table 2). Hopefully someone can add some of the values to the article. SemanticMantis (talk) 16:19, 26 June 2015 (UTC)[reply]


Do it! Be Bold. Here's a link on making Sortable Tables. (I would suggest making an account first, but you don't have to.) Ariel. (talk) 20:17, 25 June 2015 (UTC)[reply]
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