Wikipedia:Reference desk/Science: Difference between revisions
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:[[quantum fluctuation]] might also be relevant, as it refers to changes in energy, and it was quantum fluctuations that were amplified in the inflationary epoch that gave rise to the structure of the universe. Or maybe something completely different. Any ideas for an infinite power source? [[User:PeterPresent|PeterPresent]] ([[User talk:PeterPresent|talk]]) 09:07, 19 March 2017 (UTC) |
:[[quantum fluctuation]] might also be relevant, as it refers to changes in energy, and it was quantum fluctuations that were amplified in the inflationary epoch that gave rise to the structure of the universe. Or maybe something completely different. Any ideas for an infinite power source? [[User:PeterPresent|PeterPresent]] ([[User talk:PeterPresent|talk]]) 09:07, 19 March 2017 (UTC) |
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::Nope -- quantum fluctuation does not actually ''produce'' any energy, and even if you could somehow harvest energy from cosmic inflation, it won't really be an infinite power source (see [[Big Freeze]] and [[Heat death of the universe]] for the reason why). [[Special:Contributions/2601:646:8E01:7E0B:F88D:DE34:7772:8E5B|2601:646:8E01:7E0B:F88D:DE34:7772:8E5B]] ([[User talk:2601:646:8E01:7E0B:F88D:DE34:7772:8E5B|talk]]) 09:11, 19 March 2017 (UTC) |
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March 15
Fire engines on rails?
Are there currently, or were there ever, fire engines which ran on rails (either rail-only, or road-to-rail)? Also, while I'm sure there aren't any such engines now, but were there ever steam locomotives which were outfitted to fight fires using their onboard water supply (similar to Belle in Thomas & Friends)? If there were (or still are) any such fire engines, what is/was their firefighting niche? 2601:646:8E01:7E0B:45D4:4D76:B31B:9250 (talk) 10:37, 15 March 2017 (UTC)
- I know of no such engines, as dedicated fire-fighting vehicles - either locomotives or trucks.
- However railway wagons are a convenient way to move things, and it's easy to put a fire engine or a pump and tank combination, onto a flat wagon and then move that around the railway. These were widely used during the bombing of WWII, for the dockyards that already had good rail access and were bombing targets. The UK produced a few standard designs of trailer-pulled fire pump and as well as being towed on the road, these were used from rail wagons. More recently, preserved steam railways in the '70s and '80s (after the withdrawal of steam in the UK) often had a problem with lineside fires in inaccessible places and so these also made use of them, as the site could be more easily accessible by rail than by road. Andy Dingley (talk) 10:56, 15 March 2017 (UTC)
- A quick google came up with the Burlington Northern Santa Fe (BNSF) Fire Train. http://www.firefighternation.com/articles/2013/11/bnsf-railway-s-unique-firefighting-tank-car.html amongst other webpages and there is a video on youtube. --TrogWoolley (talk) 12:09, 15 March 2017 (UTC)
The answer is yes. I've placed an illustration of one at right. A Google search for "firefighting trains" will find articles about this or a similar one, and plenty of others today: [1][2][3][4]
Their niche is, as you might expect, fighting fires that are close to the railway tracks and not close to roads.
The above examples are modern, but at least one railway, the Southern Pacific, also had firefighting trains in steam days. They did not use the steam locomotive's water supply (which the train needed in order to move), but carried separate water tanks.[5]
--76.71.6.254 (talk) 12:11, 15 March 2017 (UTC)
- The Swiss firefighting trains are presumably useful because of the large number of (rail-only) tunnels there. If there's an accident inside a tunnel and a train catches fire, there's no way to reach it except with another train. --79.237.64.244 (talk) 04:41, 16 March 2017 (UTC)
Wait... what? You mean Thomas the Tank Engine & Friends isn't a documentary about actual trains who live on the Island of Sodor??? (Sniffle). --Guy Macon (talk) 04:55, 17 March 2017 (UTC)
- In Belgium, they have two MAN "road-rail fire-fighting vehicles" for the underground sections of the Diabolo project. See Road-rail fire engines protect Diabolo link. Alansplodge (talk) 20:50, 17 March 2017 (UTC)
- Thanks, all! I see now that firefighting trains do really exist, and do have an important use! 2601:646:8E01:7E0B:1812:83B6:C84E:722 (talk) 02:42, 18 March 2017 (UTC)
Microwave oven effectiveness decline with use
I know that a microwave oven becomes less effective with use but I don't know whether this means it consumes less electrical power or because it becomes less efficient and consumes the same power. Which is it? — Preceding unsigned comment added by 192.41.131.255 (talk) 11:02, 15 March 2017 (UTC)
- The microwave emission from the Cavity magnetron, a kind of Vacuum tube decreases as the cathode coating degrades. As a result, If a new microwave oven boils a cup of water in one minute, after five or 10 years it may take 90 seconds. The oven remains usable but consumes more energy to do the same job slower. See Microwave oven. Blooteuth (talk) 14:25, 15 March 2017 (UTC)
Does insufficient protein intake seemes as causing Erectile dysfunction in a healthy person?
Does insufficient protein intake seemes as causing Erectile dysfunction in a healthy person?
If it is, than what is the mechanism? I didn't find information on this in Erectile dysfunction. 77.179.179.98 (talk) 15:57, 15 March 2017 (UTC)
- Erectile dysfunction is usually a matter of blood flow, or hormone levels. Neither of these is directly related to protein insufficiency per se, although if you get to the point of muscle wasting there might be other complicating factors, such as the fact that lean muscle mass tends to increase testosterone levels. So, basically, "no, but..." and if you have a specific concern, see a medical professional. μηδείς (talk) 18:42, 15 March 2017 (UTC)
- "Low levels of protein are linked to high levels of sex-binding globulin, which locks up testosterone so the body can't use it, according to a study by Dr. Christopher Langcope of the University of Massachusetts Medical School.": [6]. Now low testosterone reduces libido, but that's not quite the same as erectile dysfunction, which is when a male with the desire is still unable to get an erection. The two conditions might be confused, however, especially if the male in question hides the fact that he has no interest in sex with his partner. StuRat (talk) 20:31, 15 March 2017 (UTC)
- Hiding the fact that he has no interest in sex with his partner is matrimonial deceit not erectile dysfunction. The point about erectile dysfuncition is that erection is desired but unobtainable. Richard Avery (talk) 09:28, 16 March 2017 (UTC)
- Agreed. StuRat (talk) 04:49, 17 March 2017 (UTC)
- Dunno, have always had the opinion that libido as purely male is fallatio. [citation needed]? μηδείς (talk) 02:24, 18 March 2017 (UTC)
- Larry Miller used to say that the difference in libido between men and women is like the difference between shooting a bullet and throwing it. ←Baseball Bugs What's up, Doc? carrots→ 02:50, 18 March 2017 (UTC)
- Dunno, have always had the opinion that libido as purely male is fallatio. [citation needed]? μηδείς (talk) 02:24, 18 March 2017 (UTC)
Solubility of sugar in salt solutions
What data are available on the solubility of sucrose in sodium chloride and other salts aqueous solutions compared to solutions without salts? Is there any salt that could increase the solubility of sugar compared to solubility in pure water?--5.15.12.130 (talk) 19:15, 15 March 2017 (UTC)
- I have not found any research paper on the subject of solubility of sucrose in saline solution, per se. But I have found this article, which suggests that NaCl and C12H22O11 both dissolve in water fully. For solubilities of NaCl and C12H22O11, you may check out this picture. Apparently, they dissolve independently of each other. One does not act as a catalyst or inhibitor for the other. 50.4.236.254 (talk) 00:52, 16 March 2017 (UTC)
Reference: Wang, Xiao-Lin; Zhang, Chenghong; Ouyang, Pingkai (2002). "The Possibility of Separating Saccharides from a NaCl Solution by Using Nanofiltration in Diafiltration Mode". Journal of Membrane Science. 204 (1–2): 271–81. {{cite journal}}
: |access-date=
requires |url=
(help)
- See also Salting out. But some otherwise insoluble carbohydrates, like chitin can be dissolved in N,N-dimethylacetamide and lithium chloride. Graeme Bartlett (talk) 01:06, 16 March 2017 (UTC)
- I've tried to test the solubility of sugar in a saturated salt solution. The noticed result has been indeed salting out with the solubility reduced to about half compared to pure water.--5.15.12.130 (talk) 17:40, 16 March 2017 (UTC)
- Dissolving kinetics are an independent situation (some standard test protocols take at least an hour or several). No idea what your exact protocol was to be able to comment further. DMacks (talk) 03:39, 17 March 2017 (UTC)
- I've tried to test the solubility of sugar in a saturated salt solution. The noticed result has been indeed salting out with the solubility reduced to about half compared to pure water.--5.15.12.130 (talk) 17:40, 16 March 2017 (UTC)
- Apparently there is cooperative effect of sucrose and sodium chloride dissolving in water, where presence of either one increases solubility of the other. See:
- Prinsen–Geerligs, H. C. (1908). "Molasses: Its Definition and Formation". The International Sugar Journal. 10: 227–235, 284–292.
- DMacks (talk) 01:47, 16 March 2017 (UTC)
- It seems that salting in for sugar at some concentrations range is given only by urea.--5.15.12.130 (talk) 17:57, 16 March 2017 (UTC)
- I notice that the mentioned journal The International Sugar Journal is not present on Wikipedia!--5.15.12.130 (talk) 18:05, 16 March 2017 (UTC)
Can sugar(s) present both salting out and in by the same salt?(another related question in this context) Thanks!--5.15.12.130 (talk) 18:15, 16 March 2017 (UTC)
What quantitative data regarding the intensity of salting in and out are there as a function of mixing ratio(s) of sugar-water-salt? (I see that these articles salting in and salting out are rather lacking quantitative data! Also I see that there is only fucose (data page).)--5.15.12.130 (talk) 18:38, 16 March 2017 (UTC)
- More refs:
- You, Yumin (2007). Modulation of Molecular Mobility in Sucrose-based Amorphous Solids Detected by Phosphorescence of Erythrosin B. (Ph.D.). Rutgers University.—discusses and cites refs for in-solution interactions between salt and sugar, and that it can be concentration-dependent: at low concentration, repulsive forces dominate and cause salting out; at high concentration, salt–sugar complexes for and cause salting in.
- Honig, Pieter (2013). "2.3 (Sucrose in Impure Solutions: Three Component Sucrose Solutions)". Crystallization. Elsevier. pp. 74–79. ISBN 9781483278001.—has graphs and data for the effect of concentration of various salts on solubility of sucrose and the effect of concentration of sucrose on the solubility of various salts, and data tables for KCl in particular.
- DMacks (talk) 03:39, 17 March 2017 (UTC)
How do double sided cylinder locks work?
(I sort of asked a related question to this several years ago - but I remain puzzled.)
Our front door has a cylinder lock into which the key can be inserted from either side, in both cases with the spine uppermost (so it isn't pivoting levers) and the key is NOT symmetrical along its length. Additionally if a key is inserted on the inside and partly turned, an outside key can also be fully inserted and it freely rotates, achieving nothing. On realizing that you can't lock the door because the key is on the inside, you remove that key and the outside key still does nothing. So you remove the outside key and reinsert it and the door can be locked.
Without doubt, the mechanism is more involved than
. So, how does it work please? -- SGBailey (talk) 19:56, 15 March 2017 (UTC)
- Not having examined your front door, I can only speculate from experience. Most likely the set up is similar to this [7], with two separate but identically keyed lock cylinders and a mechanism to disengage one of there is other is turned. If you live in Europe the setup is most likely like this [8], which is the same thing in a different package. WegianWarrior (talk) 20:19, 15 March 2017 (UTC)
- Your second image looks plausible - they obviously have to have good tolerancing on the split positions in the pegs, but that isn't hard these days. Thanks. -- SGBailey (talk) 23:57, 15 March 2017 (UTC)
- There are two lock cylinders, quite independent. The bolt is worked from the centre, between the two of them, and is operated by a loose dog clutch. Turning either cylinder can activate the bolt. If it's a removable one-piece Euro cylinder (or its variants), this dog clutch is between the cylinders and rotates a single "tooth" around it, which drives the bolt.
- A drawback to some of these, if poorly engineered, is that the bolt can be moved back or forth without needing to defeat the key cylinder, by using some sort of wire pick around the cylinder and working the bolt directly. Andy Dingley (talk) 00:25, 16 March 2017 (UTC)
- Sounds like a not-very-dead dead bolt. DMacks (talk) 01:30, 16 March 2017 (UTC)
- It can be either - a dead bolt, or a sprung sash bolt. Andy Dingley (talk) 11:37, 16 March 2017 (UTC)
- Sounds like a not-very-dead dead bolt. DMacks (talk) 01:30, 16 March 2017 (UTC)
- →[9] --Hans Haase (有问题吗) 19:54, 16 March 2017 (UTC)
March 16
What's the world's rainiest and driest settlement with >19,999 people?
By most average days per year with rain and highest average number of years between rains. Sagittarian Milky Way (talk) 19,999_people?" class="ext-discussiontools-init-timestamplink">15:31, 16 March 2017 (UTC)
- I don't know. I know that Arica, Chile is often regarded as the driest place on earth, but the standard way of measuring this is in annual precipitation. Our article discusses the rather uncommon climate there. See here [10] for a list of other top driest places. As for most rainy days, Guiness [11] says that is Mount_Waialeale. By annual precip, see Mawsynram, and the links therein, leading eventually to the town of López_de_Micay. SemanticMantis (talk) 19:27, 16 March 2017 (UTC)
March 17
The expanding universe
Wikipedia's article states that the universe is expanding at large scales but that galaxies are not because they are gravitationally bound. This implies there will be an astronomical number of roughly spherical boundaries in space, surrounding every galaxy, on one side of which space is expanding and on the other side of which space is not expanding. The presence of such discontinuous boundaries in space seems extremely unlikely. It seems far more likely there is a smooth function relating the expansion of space to the force of gravity. In which case who is to say that galaxies may not expand with the universe albeit with a much reduced rate. A small residual rate of expansion for galaxies would be extremely hard to observe but could have major consequences. Comments please 165.120.168.239 (talk) 00:50, 17 March 2017 (UTC)
- ? Introduction to general relativity is our article on the topic. Nimur (talk) 01:22, 17 March 2017 (UTC)
- Would there really be a hard "boundary" or more of a gradual transition, as with the gravitational influence of different objects? ←Baseball Bugs What's up, Doc? carrots→ 02:03, 17 March 2017 (UTC)
- You're asking for a description, in plain English, about the "smoothness" or "gradualness" of the parameters in a very difficult equation. The trouble is, words like "smoothness" or "gradual" have special meaning in mathematical physics. It's not easy to use plain English to describe these complicated topics in a way that is simultaneously simple, complete, and correct.
- So if you'll accept a little bit of hand-waving, sure - there's a "smoothness" to the universe, for the most part. Discontinuities in the shape of our universe are not common. But, there also seem to exist at least a few real examples of the gravitational singularity, so those are places in our universe where there is an abrupt discontinuity. Most cosmologists believe that we have enough evidence to say that these theoretical constructions of mathematics do manifest as actual real objects in our universe - and that's a much more important statement than most casual readers realize!
- The real take-away lesson, though, is that if you're interested in these complex topics, the best way to understand them is to become extraordinarily adept at using the types of mathematics that physicists and cosmologists use to describe the shape and expansion of our universe. The math isn't just helpful - it's essential to being able to understand it.
- If you're interested in the topic but don't want to deal with the equations, here's a great resource: the Public Lectures series archive from SLAC National Accelerator Laboratory. For example, the most recent presentation was Galaxy Clusters and the Life and Death of the Universe (February 2017), in which scientist Eli Rykoff discusses the state of the art of our knowledge about cosmic structure in a format that is accessible to a non-technical audience.
- Nimur (talk) 23:26, 17 March 2017 (UTC)
- Would there really be a hard "boundary" or more of a gradual transition, as with the gravitational influence of different objects? ←Baseball Bugs What's up, Doc? carrots→ 02:03, 17 March 2017 (UTC)
- One qualitative way to look at this: the universe is expanding uniformly, but gravity locally retards the effects of this expansion. But you really need to do the math. Your vision of "roughly spherical" is a simplification that would be valid only if galaxies were point masses of equal mass. A more accurate(?!) image is a universe with a continuous density variation. For some critical local density, gravity is stronger than expansion. At lower density, expansion wins. -Arch dude (talk) 02:19, 17 March 2017 (UTC)
How accurate is this table?
Could someone verify the accuracy of this time dilation table,since I'm no expert in physics? It's the second table. I'm not sure whether the person who wrote the article has any expertise.Uncle dan is home (talk) 02:44, 17 March 2017 (UTC)
- Which article? ←Baseball Bugs What's up, Doc? carrots→ 02:47, 17 March 2017 (UTC)
This one: [12] — Preceding unsigned comment added by Uncle dan is home (talk • contribs) 03:11, 17 March 2017 (UTC)
- Have you spot-checked any of the calculations in the table vs. the formula? ←Baseball Bugs What's up, Doc? carrots→ 03:19, 17 March 2017 (UTC)
- The numbers are roughly correct, but are shown with more significant digits than are warranted by the accuracy of the calculation—particularly the right-hand column, which was calculated based on a year being exactly 365 days. --76.71.6.254 (talk) 04:57, 17 March 2017 (UTC)
- If you reduce the number of digits too far, the first few entries round to 0, which is not quite accurate. Once the number gets large enough that 365 vs. 365.25 (or whatever) starts to affect the result, rounding to fewer digits would make sense. Also, do you use Tropical year or Sidereal year? ←Baseball Bugs What's up, Doc? carrots→ 05:23, 17 March 2017 (UTC)
- And light years are Julian years. (365.25 exactly) Sagittarian Milky Way (talk) 23:18, 17 March 2017 (UTC)
- In 1582 His Holiness Pope Gregory XIII blessed a popular calendar but that seems not to have persuaded the IAU that every Light-year should be shorter by 194 300 000 km, about -0.2%. Blooteuth (talk) 15:32, 18 March 2017 (UTC)
- (0.002%) Yes, but it's only 18 760 000 km off from the average of the real year (seasons) and real year (stars) and is the real year (calendar) from AD 1900 to 2100. March 0, 1900 is so long ago and March 0, 2100 is almost a century from now so for all practical civil purposes this is the year. You know what's the most awesome calendar?
- 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366,
- 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366,
- 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 365, 366. Repeat forever.
- More accurate than the Gregorian calendar and repeats 12 times sooner. Sagittarian Milky Way (talk) 19:22, 18 March 2017 (UTC)
- (0.002%) Yes, but it's only 18 760 000 km off from the average of the real year (seasons) and real year (stars) and is the real year (calendar) from AD 1900 to 2100. March 0, 1900 is so long ago and March 0, 2100 is almost a century from now so for all practical civil purposes this is the year. You know what's the most awesome calendar?
- In 1582 His Holiness Pope Gregory XIII blessed a popular calendar but that seems not to have persuaded the IAU that every Light-year should be shorter by 194 300 000 km, about -0.2%. Blooteuth (talk) 15:32, 18 March 2017 (UTC)
- And light years are Julian years. (365.25 exactly) Sagittarian Milky Way (talk) 23:18, 17 March 2017 (UTC)
- You are talking about reducing the number of decimal places, not the number of significant digits. --76.71.6.254 (talk) 07:14, 17 March 2017 (UTC)
How do doctors categorize something as a "disease"?
I know that there is variation within a species. Some individuals have a beneficial mutation; other individuals have a harmful mutation. But the ability of all modifications to pass down to future generations is dependent on the environment. Hereditary hemochromatosis is regarded as a "disease", even though those individuals may be just very efficient at absorbing iron from food. Meat is full of iron, so these individuals would fare poorly in a meat-rich (iron-rich) environment. Huntington's disease is caused by a lethal gene that manifests in adulthood. It is only a "disease" when that person lives long enough to manifest it. If the person reproduces at 15 and dies in childbirth at 20, then the gene may be passed onto the offspring, and the manifestation of the gene may not be shown. People on the autism spectrum seem to live happy, fertile lives. And people with Down's syndrome have children. So, my main question is, what are the characteristics of a disease? How is a disease different from a variation that just happens to be maladaptive in a given condition? 50.4.236.254 (talk) 03:13, 17 March 2017 (UTC)
- To answer your second question (from bugs's link) "Disease is often construed as a medical condition associated with specific symptoms and signs". Also "In humans, disease is often used more broadly to refer to any condition that causes pain, dysfunction, distress, social problems, or death to the person afflicted, or similar problems for those in contact with the person". 64.170.21.194 (talk) 03:29, 17 March 2017 (UTC)
- In simple terms the word is an concatenation of dis (without), and ease In other words not-at-ease. As medical science has progressed, it now includes such things as high blood pressure that may not cause symptoms of unease at first.--Aspro (talk) 03:38, 17 March 2017 (UTC)
- In characterizing conditions such as Autism or Down syndrome, it is ethically and politically imperative to distinguish between a Disease - a medical condition associated with specific abnormal symptoms and signs, and a Disability - an impairment of a person's body that restricts their involvement in life situations. See Down syndrome#Ethics for example of debate where these categories are blurred. Blooteuth (talk) 13:06, 17 March 2017 (UTC)
- In simple terms the word is an concatenation of dis (without), and ease In other words not-at-ease. As medical science has progressed, it now includes such things as high blood pressure that may not cause symptoms of unease at first.--Aspro (talk) 03:38, 17 March 2017 (UTC)
- Nosology may be helpful (linked via the disease article). The differences between disease, disorder, syndrome, and injury are laid out, with a few sub-groups. My impression is that in everyday life, people often think of disease as something contagious or "catchy", with other maladies, such as arthritis or most forms of cancer as "something else". This is possibly caused by an over-application of Koch's postulates. Matt Deres (talk) 14:06, 17 March 2017 (UTC)
- The distinction in general can be rather arbitrary - famously, the psychiatric community initially classified homosexuality as a disease, before recognizing it as a natural variation. I think many definitions of mental or even physical conditions now have a term about the disease interfering with a patient's work or being a cause of distress. (But what if the employer, quite legally in some states, discriminates? It seems a rather flimsy kludge...)
- Personally, I think in the genetic context the distinction between gene therapy and eugenics is particularly important, and can be made in a more objective way: it is possible, by examining the distribution of alleles in the population, to determine how long ago they arose. If a condition is caused by individuals for whom the first affected ancestor can be identified in recent genealogies, or even can be inferred to have arisen within the past few thousand years, I think the situation can readily be defined as a disease, if patients want it fixed, and could be wiped out of the germline without much apology to history. However, if the alleles are millions of years old, then they represent an important part of the shared human patrimony and removing them from the population means incrementally pushing the human species closer to extinction by depleting its gene pool. (cf. [13]) A sticky point would be something like sickle cell anemia, which clearly has been preserved and favored by natural selection ([14] and especially [15]). Today it would make sense to wipe the allele out --- provided you are willing to swear that malaria will be eradicated, that for tens of thousands or even millions of years the descendants of the people you alter will be free of that scourge. But if you cannot, then curing one person today may mean that thousands of people in the future struggle under the burden of malaria and are ultimately deleted from the population. Of course, not curing them may mean condemning thousands to a slow death from sickle disease. Messing with the essence and fate of humanity is kind of a big deal either way. Wnt (talk) 16:34, 17 March 2017 (UTC)
Mechanism of action?
See this article here What is the possible mechanism for their strengthened immune systems? (If this is true?) 64.170.21.194 (talk) 03:23, 17 March 2017 (UTC)
- Read Cold shock response for some cautions. ←Baseball Bugs What's up, Doc? carrots→ 03:27, 17 March 2017 (UTC)
- To endorse the claim "children are healthier if they daily run out into the snow in their swimming costumes - and pour a bucket of cold water over their heads" from a source in Russia (average life expectancy: 70.5, USA 79.3, UK 81.2) would amount to giving medical advice that is not the purpose of this Ref. desk. Blooteuth (talk) 12:36, 17 March 2017 (UTC)
- A cynic could argue that by immediately killing the less healthy, those who remain are healthier. StuRat (talk) 20:22, 17 March 2017 (UTC)
- This is most certainly not medical advice "blooteuth".... 64.170.21.194 (talk) 22:21, 17 March 2017 (UTC)
- Medical advice is the provision of a formal professional opinion regarding what a specific individual should or should not do to restore or preserve health. Waterboarding is a form of Water torture of adults that cannot be conveniently dismissed as innocuous when freezing water is dumped on children by guardians In loco parentis. Blooteuth (talk) 15:03, 18 March 2017 (UTC)
- This is most certainly not medical advice "blooteuth".... 64.170.21.194 (talk) 22:21, 17 March 2017 (UTC)
Types of Human genes
I am not a geneticist and don't know much on genetics and I get the feeling that there are two types of genes: Those how go through changes regularly (like genes effecting hair curlyness or color) and genes that seldom go through any change (like genes coding for the very creation of hair or any other body part). Why some genes go through changes so easily and commonly and some others almost never go through changes by means of genetics themselves excluding epigenetic influences? (for example, >99.9% of people with hair that can procreate, could breed children with hair but only <0.1% of these will be totally without hair asuuming there was no epigenetic effect).79.178.144.67 (talk) 08:26, 17 March 2017 (UTC)
- Hair colour and curliness don't arise through changes (mutations) in genes per individual. They come from the fact that different people have different variants of the genes responsible for those traits. Both parents of any given child can have different combinations of those variants, and which specific ones the child gets is essentially random. These variants come from mutations many many generations ago. See Mendelian inheritance and Mendelian traits in humans, where many of these things are discusses, and further links can be found. Fgf10 (talk) 11:29, 17 March 2017 (UTC)
- I think what OP is getting at is that in a given population (say a large city in EU, USA, AU), there will be more variation in the
genesalleles controlling hair color and hair texture, whereas (mostly) all of them have hair, so the bits governing hair production would seem to vary less. The idea that somegenesalleles must be tightly conserved for survival, but others are free to take on many forms without any simple strong effect on viability and fitness. Two relevant articles are Fixed_allele and Fixation_(population_genetics), those talk about how core important functional alleles get "fixed" with little or no variation in a population. Neutral_mutation is what created alleles that have "neither beneficial nor detrimental to the ability of an organism to survive and reproduce". (I'd nitpick that nothing in the real world is truly neutral, but it's still a good model for something like eye color). SemanticMantis (talk) 13:48, 17 March 2017 (UTC)
- I think what OP is getting at is that in a given population (say a large city in EU, USA, AU), there will be more variation in the
- First we should make some distinctions. There is genetic variation which affects how much diversity you see in a population, or even in a family from generation to generation as different alleles randomly turn up in offspring. Genetic variation may result from balancing selection, where certain alleles are more favored under different circumstances so that no one ever loses the genetic contest. Alternatively, there is fixation (population genetics) in which alleles are lost. The success of a new allele arising by mutation depends critically on negative selection or sometimes positive selection -- any disadvantage, however small, can mean that the new allele is lost or becomes universal. So can dumb luck (genetic drift), so population size and population structure matter; for example a founder effect can drastically shape the genetics of an isolated region.
- One reason why minor differences in hair structure are more neutral is that they don't matter as much as losing it entirely. (Being bald on the steppes of Central Asia, where many Europeans and Asians trace back to, would probably not be fun... having your whole scalp being bitten by flies in Africa might be worse?) Another is that changing the hair protein is perhaps (presumably) less likely to have pleiotropic effects. That said there are rare conditions affecting curliness and color like amelogenesis imperfecta and POMC deficiency that do have pleiotropic effects, and I'm not very sure this is really true. I wonder if there might also be some balancing sexual selection (different people like different things) but I have not done any background research on this.
- Another thing to bear in mind is that some genes are simply more prone to mutation, such as CAG repeat expansion. The sequence of the gene itself simply makes it mutate more. (See also transition (genetics) vs. transversion). On average the genes you notice more variation in are presumably somewhat more likely to mutate on this basis, but I doubt it's by any large degree, and I haven't looked up to see if anyone came up with a way to put a number on it. Wnt (talk) 13:48, 17 March 2017 (UTC)
What were the differences in physical appearance between Pleiosaurs and Mososaurs?
Despite the fact that they were not closely related, Mososaurs and Pliosaurs had similar physical characteristics and the same ecological niche as apex marine predators. How do you tell them apart by just looking at them side by side? 70.95.44.93 (talk) 09:54, 17 March 2017 (UTC)
- Tails. Mosasaurs swam with powerful tails (and thus musculature and skeleton), pliosaurs paddled with their legs. The tails of pliosaurs and pleisiosaurs have small or no flukes. Andy Dingley (talk) 11:29, 17 March 2017 (UTC)
- Mosasaurs had a body shape similar to that of modern-day monitor lizards (varanids), but were more elongated and streamlined for swimming. They had double-hinged jaws and flexible skulls (much like those of snakes), which enabled them to gulp down their prey almost whole. Their limb bones were reduced in length and their paddles were formed by webbing between their long finger and toe bones. Their tails were broad, and supplied their locomotive power.::Pliosaurs were distant cousins of modern turtles and distinguished by a short neck, massive toothed jaws and an elongated head. Their bodies were flat and their tails were short. Blooteuth (talk) 12:12, 17 March 2017 (UTC)
- You do realize that Pliosaurs are basal sauropsids, while Mososaurs are rather derived varanid lizards? It's like comparing turtles and armadillos. μηδείς (talk) 02:07, 18 March 2017 (UTC)
- Isn't that rather what the OP's first question stated? They're asking about synecology, not autecology. Andy Dingley (talk) 21:29, 18 March 2017 (UTC)
- Well, then look at Alfred Romer and Euryapsid. μηδείς (talk) 23:13, 18 March 2017 (UTC)
Gravity on a denser planet
Take an object weighing 1 pound (0.45 kg) on Earth and put it on a denser planet, one with the diameter of the Moon and the mass of Earth. It will weigh more, since it's closer to the center of gravity on an object with the same mass, but how much more? I've never understood the maths in this area well at all. Nyttend (talk) 12:39, 17 March 2017 (UTC)
- First of all pounds and kilograms are units of mass, not weight, so
weighing 1 pound (0.45 kg)
should readwith mass 1 pound (0.45 kg)
. (I will assume you are aware of the distinction though.)
- Per Newton's law of universal gravitation, the weight is proportional to the product of the masses divided by the square of the distance. For an object that is much smaller than the Moon, we can assume that the distance is equal to the radius of the celestial body under consideration. The Moon's diameter (hence radius) is about a quarter that of the Earth, so the gravitational force will be about (1/4)^(-2) = 16 times higher (closer to 13.4, using the value from the NASA link). TigraanClick here to contact me 12:46, 17 March 2017 (UTC)
- One wonders what sort of matter this planet could be made up of to have such a high density. How could an object the size of the moon compress matter to the enormous pressure required? Dbfirs 13:09, 17 March 2017 (UTC)
- A pound is certainly a unit of force as well as being a unit of mass. Edison (talk) 15:30, 17 March 2017 (UTC)
- The Earth has a mean Density of 5515 kg/m3. The Moon's diameter is 0.273 of Earth's so the hypothetical planet in the question would have a density of 271055 kg/m3 which is more than any known element, and is only approached at the core of the Sun. This does not affect the math that may be clarified by noting that the distance in Newton's law is measured between the Center of mass (gravity) of each body. Blooteuth (talk) 13:34, 17 March 2017 (UTC)
- Also, if we want to be more precise, we assumed the Earth/Moon to be spheres with homogeneous mass distributions, which allowed to consider them as point particles because of Gauss's law for gravity. I doubt that is the level of detail Nyttend wanted though. TigraanClick here to contact me 14:14, 17 March 2017 (UTC)
- Nitpick- Gauss' law also applies if the sphere consists of concentric shells of constant density, the whole sphere doesn't have to be uniform. Greglocock (talk) 19:55, 17 March 2017 (UTC)
- Also, if we want to be more precise, we assumed the Earth/Moon to be spheres with homogeneous mass distributions, which allowed to consider them as point particles because of Gauss's law for gravity. I doubt that is the level of detail Nyttend wanted though. TigraanClick here to contact me 14:14, 17 March 2017 (UTC)
- The Earth has a mean Density of 5515 kg/m3. The Moon's diameter is 0.273 of Earth's so the hypothetical planet in the question would have a density of 271055 kg/m3 which is more than any known element, and is only approached at the core of the Sun. This does not affect the math that may be clarified by noting that the distance in Newton's law is measured between the Center of mass (gravity) of each body. Blooteuth (talk) 13:34, 17 March 2017 (UTC)
- A pound is certainly a unit of force as well as being a unit of mass. Edison (talk) 15:30, 17 March 2017 (UTC)
- It seems vaguely entertaining to look at this in relation to tidal force. The rule with tidal force is:
- (axial)
- i.e. a unit vector multiplied by twice your distance from the center of the object you're on times the gravitational constant and the (idealized spherical center of gravity) mass of the remote object. If you suppose that has a radius x then the tidal force depends on the density of the object multiplied by its size in the sky. (My attempt to derive that was less than compelling, but [16] agrees) For example, the Moon is the same size as the Sun, so it exerts a bit over twice the tidal force because it is a bit over twice as dense as the Sun.
- That said, the rule for gravitational acceleration is different:
- In other words, the gravitational force is greater for an object of a given density and the same apparent size in the sky in proportion to how far away it is. That's because the object must be bigger (hence heavier) by a factor of R^3 the further away it is, but the gravity goes down as R^2.
- In the case of your example, of course, this is hard to apply because the object fills half the sky. It isn't the angular size that matters and it's not the horizon either - I think it's the apparent diameter of the mid-point of the spherical body, if you could see it, in terms of a straight ruler measurement without reference to angles. Still, it's at least vaguely amusing - if you ever happen to see a rogue planet growing big in your planet's sky you can make a fair guess as to the tide it's raising, but to guess how it's messing with the orbit you need a distance. Wnt (talk) 16:11, 17 March 2017 (UTC)
- An even weirder thing is that orbital period's determined only by density (as long as the orbitee's a sphere way larger and massiver than the orbiter, there are no third party gravitational perturbations and it's the smallest possible orbit).Sagittarian Milky Way (talk) 16:36, 17 March 2017 (UTC)
- So my £1 object would weigh £16 if I intentionally use the wrong symbol for "pounds". Impressive; I had no idea it would be that much of a change. And yes, weight can be measured in pounds, just as it can be measured in newtons; I originally was going to use kg until I remembered that they're only mass, and I didn't want to use newtons because I don't have a good sense of how much 1N weighs. The density was just made up, a convenient figure without regard for realism. Curious: what would be the Moon's mass were it 100% bismuth, the heaviest element without significant radioactivity? And finally, I don't understand the bit about tidal force; how is it relevant? A person weighs the same on a household bathroom scale regardless of the time of day, and I wasn't wanting anything more precise than that. Nyttend (talk) 00:00, 18 March 2017 (UTC)
- An even weirder thing is that orbital period's determined only by density (as long as the orbitee's a sphere way larger and massiver than the orbiter, there are no third party gravitational perturbations and it's the smallest possible orbit).Sagittarian Milky Way (talk) 16:36, 17 March 2017 (UTC)
Time crystals
I wonder if anybody could explain it in plain English? What are time crystals? [17]. There is also an article in Wikipedia but it is a difficult stuff to follow. [18] --AboutFace 22 (talk) 17:33, 17 March 2017 (UTC)
- PBS Space Time on YouTube just put up a video about the topic that I think is fairly accessible. --47.138.163.230 (talk) 17:57, 17 March 2017 (UTC)
- Its just a badly madeup term to put some fake magic into some extreemly boring, jet irritating details of quantum physics. Likely just some silly physicists hoping for more/new funding for their research. --Kharon (talk) 21:10, 17 March 2017 (UTC)
- Space-time crystal might be the most "sufficiently advanced or Star Trek BS?"-sounding invention ever that already exists. Sagittarian Milky Way (talk) 23:33, 17 March 2017 (UTC)
- Maybe someone will pay me to tool around on my room temperature macroscopic time crystal array simulator.--Wikimedes (talk) 20:33, 18 March 2017 (UTC)
- Its just a badly madeup term to put some fake magic into some extreemly boring, jet irritating details of quantum physics. Likely just some silly physicists hoping for more/new funding for their research. --Kharon (talk) 21:10, 17 March 2017 (UTC)
@Kharon, boring? yes. I listened to the youtube lecture and fell asleep. When I woke up the man was still talking. I shut him off. Still I want to understand the issue eventually. --AboutFace 22 (talk) 21:32, 18 March 2017 (UTC)
- User:AboutFace 22, Do you understand the bit about having structures that are periodic in time, as opposed to periodic in space, as conventional crystal lattices are? A checkerboard is periodic in space, but four on the floor is periodic in time. This is making headlines because there is both a) a theoretical basis and conjecture and b) a few labs claim to have made stuff that does this - it oscillates freely in a periodic manner. Importantly, the claim is that the materials exhibit periodic fluctuation in time without any added energy, and without any dissipation due to friction. This is seen by the community (and by popular science promoters) as counterintuitive, interesting, potentially useful, and rather unprecedented. That is my attempt to explain in plain English, as a professional (non-physics) scientist and educator. If you have a more specific questions, please let us know. SemanticMantis (talk) 22:01, 18 March 2017 (UTC)
Yes, I also read the time crystal article in Wikipedia, especially the first paragraphs and it seems I understood it better. It sound like a perpetuum mobile of sorts, a thermodynamic violator or whatnot. I need to go over this a few more times to comprehend. But it is becoming more clear. The fascinating part is that it was first predicted theoretically and then implemented. --AboutFace 22 (talk) 00:06, 19 March 2017 (UTC)
Time dilation and warp drive
If a spaceship were to travel using warp drive,would there still be time dilation?Uncle dan is home (talk) 18:28, 17 March 2017 (UTC)
- Science fiction assumes not (see Warp drive). For a scientific possibility, see Alcubierre drive. Dbfirs 18:43, 17 March 2017 (UTC)
- "If I were driving at the speed of light, and I turned on the headlights, would anything happen?" -- Stephen Wright
- ←Baseball Bugs What's up, Doc? carrots→ 19:32, 17 March 2017 (UTC)
- You need to work within the framework of a theory that violates special relativity, such a theory must be consistent with all experimental data, which imposes some constraints. In this article the details of what is allowed are worked out. E.g. it may happen that lighter particles will decay to heavier particles, so the protons in your spaceship may decay to neutrons. Count Iblis (talk) 20:18, 17 March 2017 (UTC)
- ... but the point of warp drive is that you are not travelling through space, so the restrictions of relativity in space-time do not apply. I agree that this is all fictional, and may never be possible. Dbfirs 20:41, 17 March 2017 (UTC)
- The only point of "warp drive" is to fool the amateur physic knownledge reader with jet another maybe possible way to tell a faszinating story. Faszinating! --Kharon (talk) 21:02, 17 March 2017 (UTC)
- The idea of a wormhole seems fairly well regarded; and if one could exist and, more incredibly, be traversible, the question comes up of how its endpoints are defined, and whether they can move, and if they do move, then consisting of bent spacetime rather than matter, can they move at a rate faster than spacetime. The Alcubierre drive is a weird looking thing, not quite a wormhole, but it also involves highly bent space. There is a whole field of looking at transient distortions of spacetime, starting with gravity waves, gravitomagnetic forces and so on - it clearly is a long way from detecting a distant black hole merger to making a Tipler cylinder, and this would be somewhere in the middle. We don't know it's not doable, and for a decent sci-fi author that is more than enough license. Wnt (talk) 01:54, 18 March 2017 (UTC)
- @Wnt:Gravitational waves is what you probably meant. Gravity wave seems to be a term mainly in Hydrodynamics. These "ripples in spacetime" are a nice example how preposterous many physical concepts in Sci-fi are. Imagine, if these tiny ripples need 2 black holes colliding to "fuel" a tiny, microsecond "ripple", how much force would be needed to "bend" space into making a wormhole. Very likely all the force of the complete universe would not be enough to make a wormhole over a distance of 1 metre. --Kharon (talk) 03:19, 18 March 2017 (UTC)
- @Kharon: You're right about the link. But -- it takes two black holes colliding over a billion light years away to make a ripple we can detect. If you were in the room with the black hole I dare say you would see space bent a bit further. Think Benjamin Franklin flying a kite... there was some work to be done after that before you could use the principle to microwave beans or to execute ceremonial sacrificial rites in state-run chambers... yet it didn't really take that long to get there. Wnt (talk) 22:49, 18 March 2017 (UTC)
- @Wnt:Gravitational waves is what you probably meant. Gravity wave seems to be a term mainly in Hydrodynamics. These "ripples in spacetime" are a nice example how preposterous many physical concepts in Sci-fi are. Imagine, if these tiny ripples need 2 black holes colliding to "fuel" a tiny, microsecond "ripple", how much force would be needed to "bend" space into making a wormhole. Very likely all the force of the complete universe would not be enough to make a wormhole over a distance of 1 metre. --Kharon (talk) 03:19, 18 March 2017 (UTC)
- The idea of a wormhole seems fairly well regarded; and if one could exist and, more incredibly, be traversible, the question comes up of how its endpoints are defined, and whether they can move, and if they do move, then consisting of bent spacetime rather than matter, can they move at a rate faster than spacetime. The Alcubierre drive is a weird looking thing, not quite a wormhole, but it also involves highly bent space. There is a whole field of looking at transient distortions of spacetime, starting with gravity waves, gravitomagnetic forces and so on - it clearly is a long way from detecting a distant black hole merger to making a Tipler cylinder, and this would be somewhere in the middle. We don't know it's not doable, and for a decent sci-fi author that is more than enough license. Wnt (talk) 01:54, 18 March 2017 (UTC)
- The only point of "warp drive" is to fool the amateur physic knownledge reader with jet another maybe possible way to tell a faszinating story. Faszinating! --Kharon (talk) 21:02, 17 March 2017 (UTC)
- ... but the point of warp drive is that you are not travelling through space, so the restrictions of relativity in space-time do not apply. I agree that this is all fictional, and may never be possible. Dbfirs 20:41, 17 March 2017 (UTC)
Brass magnetic?
I know pure gold or silver is not supposed to stick to an average magnet, but I'm wondering if brass does. I have a magnet, but I don't have anything I'm sure is pure brass to test this. White Arabian Filly Neigh 21:18, 17 March 2017 (UTC)
- Brass is not magnetic in the sense you're using (see ferromagnetism). It's composed of copper and zinc, both of which are weakly diamagnetic, so it can be influenced by magnetic fields, but not attracted to them. Matt Deres (talk) 21:27, 17 March 2017 (UTC)
- Magnetism is ordinarily limited by the Stoner criterion, but this can be finessed by adding other materials - like buckyballs - if only in a thin film of copper separated by other materials. See [19]. I'd have to know a lot more to have any sense of how much you could get away with if you had the right structure, but it should be obvious that if you define "brass" in a very standard way, such as to be the exact substance ordinarily found to be non-[ferro]magnetic, it won't be magnetic... and if not... Wnt (talk) 01:43, 18 March 2017 (UTC)
- The Stoner Criterium ususally requires at least an ounce to show its effects, no? μηδείς (talk) 02:01, 18 March 2017 (UTC)
- A criterium seems to be a sort of bike race. I doubt doing it stoned is the best way to win, but who knows. --Trovatore (talk) 18:23, 18 March 2017 (UTC)
- It's the next Robert Ludlum film, set in Seattle, and starring Matt Damon as Rachel McConaughey. 23:06, 18 March 2017 (UTC)
- A criterium seems to be a sort of bike race. I doubt doing it stoned is the best way to win, but who knows. --Trovatore (talk) 18:23, 18 March 2017 (UTC)
- The Stoner Criterium ususally requires at least an ounce to show its effects, no? μηδείς (talk) 02:01, 18 March 2017 (UTC)
March 18
water hardness
This site[20] says the water hardness for Vancouver, WA is 60 to 160 ppm. Looking that up in Hard_water#Hard.2Fsoft_classification show that 60 ppm is soft, while 160 ppm is considered hard.
1. Is it normal for water hardness to vary over such a wide range?
2. What causes such variations? ECS LIVA Z (talk) 02:00, 18 March 2017 (UTC)
- Note these are highest and lowest values recorded which would not necessarily correspond to "normal variation." It's common for hardness levels vary substantially, for example due to seasonal and interannual fluctuations of precipitation, source from which the water is drawn, etc. See e.g. [21]Shock Brigade Harvester Boris (talk) 02:11, 18 March 2017 (UTC)
- This says the readings are from 60-130 - a little closer together, but not much. If you examine the other tests, you see even larger variations than the 100% for hardness. I initially assumed there were multiple sources, but this says they're all from aquifers. Of course, each aquifer may be slightly different and there are apparently 40 separate wells being tapped. As far as whether it's normal or not, the same kind of report on my local water supply is not broken down in quite the same way, but there are values that also more than double in scale. Matt Deres (talk) 02:42, 18 March 2017 (UTC)
- The cause is minerals, usually Chalk in the water and each Water well has its own composition dependent on the surrounding Soil that contains the ground water which is filling it. --Kharon (talk) 03:34, 18 March 2017 (UTC)
- The cause is the presence of soluble minerals, especially calcite in the aquifer rock itself (not really soil). In southern England for example Chalk Group aquifers deliver the typically hard water generally encountered there, although the sandstones of the Lower Greensand Group aquifers [22] deliver softer water. Mikenorton (talk) 12:12, 18 March 2017 (UTC)
Can electrical current change a chemical bond from covalent to ionic?
I swear this is not homework. I am not a chemistry student. I just want to have a little sharper understanding of atoms and not sure I understand this right:
Can a covelant bond between 2 nonmetals suddenly be changed into ionic bond somehow? — Preceding unsigned comment added by 79.178.144.67 (talk) 08:03, 18 March 2017 (UTC)
- See ionization -- the short version is, a high enough electric current can break a covalent bond with the formation of 2 ions, but it wouldn't be an ionic bond because the ions wouldn't remain bonded to each other! 2601:646:8E01:7E0B:1812:83B6:C84E:722 (talk) 12:09, 18 March 2017 (UTC)
- This is a tough one - I don't claim to know a good case. Obviously many ions will tend to react immediately - put H+ and OH- together and they turn into water again. An electric current is applied over a distance, so even if it coaxes the two apart, they will only find new partners in either direction. The best guess that I could think of in five minutes is ammonium hydroxide - in dilute aqueous solution, it is a combination of NH4+ and OH-; yet supposedly there is an "ammonium hydroxide gas" that seems most famously used in pink slime manufacturing, which if true should be an actual covalent molecule of NH4OH since ionic bonds don't tend to work in the gas state. That makes me wonder if you could come up with some nonpolar solvent where NH4OH stays covalent, but you could coax it apart for some duration with strong current. I have absolutely no idea if you can do this, but I've seen weirder chemistry. Wnt (talk) 23:19, 18 March 2017 (UTC)
- A covalent network solid under an applied voltage can behave as a metal (e.g. graphite), as a semiconductor (e.g. diamond or silicon) or as a dielectric (e.g. silicon dioxide) -- depending on the band structure and, to a varying extent, on the presence of impurities (dopants). Applying electric current to a covalent network solid per se doesn't change the bond type. However, if the current is strong enough to cause a phase transition (by increasing the temperature and/or pressure) then all bets are off. Also, as mentioned above, a strong enough current will ionize some of the material, but that's not ionic bonding - just ions (plasma) Dr Dima (talk) 08:58, 19 March 2017 (UTC)
First fotoelement
returning troll/competence-hindered user. Collapsing. See WT:RD for explanation. --Jayron32 02:24, 19 March 2017 (UTC) |
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The following discussion has been closed. Please do not modify it. |
Did a first fotoelement been electrotechnicaly (radiotechnicaly)?--79.139.157.152 (talk) 11:55, 18 March 2017 (UTC)
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Absolutely obvious that are being photosemicoductors as are photodiodes, phototriodes, phototransistors. Did been is absolutely perfect of past teens, it always says us that the action did committed in the past and its consequences cannot be undone or changed.--79.139.157.152 (talk) 03:29, 19 March 2017 (UTC)
Organic chemist needed
I discovered Oxalate degrading enzyme in the speedy-deletion queues (someone had misidentified it as spam) a couple of days ago, since which time it's been significantly reworked — but not in fluent English, and the author clearly isn't familiar with our formatting or layout conventions. I've cleaned up the language and wikified it, but I'm not sure I've done the best. Here's how it looked ten minutes ago:
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Oxalate degrading enzymes Oxalate degrading enzyme, is a catalytic degradation of oxalic acid polymer protein, including oxalic acid oxidase, oxalic acid decarboxylase and formyl-CoA decarboxylase. 1. Brief introduction 2. Classify 3. Calcium oxalate stones and oxalate degrading enzymes Brief introduction Enzymes are macromolecules with biocatalytic activity, and most enzymes are proteins. Almost all of the cellular processes in the body require enzyme involvement to improve efficiency. Oxalate degrading enzyme, is a catalytic degradation of oxalic acid polymer protein, including oxalic acid oxidase, oxalic acid decarboxylase and formyl-CoA decarboxylase.[1] Classify Enzymes that currently degrade oxalic acid in the biology include oxalate oxidase, oxalate decarboxylase and formyl-CoA decarboxylase.[2] Oxalic acid oxidase(EC1.2.3.4)mainly in plants, it can degrade oxalic acid into carbon dioxide and hydrogen peroxide. Oxalate decarboxylase ( Oxalate decarboxylase,OXDC,EC4.1.1.2) is a kind of oxalate degrading enzyme containing Mn2+, mainly in fungi or some bacteria, it can be in the absence of other cofactors under the action of the degradation of oxalic acid directly to form formic acid and CO2.[1] Formyl-CoA decarboxylase(EC4.1.1.8)mainly mediated degradation of bacterial oxalic acid.[2] Calcium oxalate stones and oxalate degrading enzymes Calcium oxalate is the main component of urinary calculi, one of the important reason for leading to calcium oxalate stone disease is for the lack of degradation of oxalic acid metabolic pathway. Therefore, the use of oxalate degrading enzyme for degradation of oxalic acid in the human body has become an important research direction for the prevention and treatment of calcium oxalate stone disease.[2] Studies have shown that with the intake of a large number of foods rich in oxalic acid, the excretion urinary acid in the urine will be significantly increased. Therefore, to reduce the intake of exogenous oxalic acid can reduce urinary oxalate excretion, can significantly reduce the recurrence of stones.[3] Reference materials 1. Properties and Application of Oxalate Decarboxylase Wikipedia [citation date 2016-12-14] 2. Research progress of oxalate - degrading enzyme in the prevention and treatment of calcium oxalate. Wikipedia article [citation date 2016-12-14] 3. The Latest Development of Preventive Treatment of Calcium Oxalate Calculus. Wikipedia article [citation date 2016-12-14] |
And here's what it looks like now:
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An oxalate degrading enzyme is a catalytic degradation of oxalic acid polymer protein, including oxalic acid oxidase, oxalic acid decarboxylase and formyl-CoA decarboxylase. ==Brief introduction== Enzymes are macromolecules with biocatalytic activity, and most enzymes are proteins. Almost all of the cellular processes in the body require enzyme involvement to improve their efficiency. An oxalate degrading enzyme is a catalytic degradation of oxalic acid polymer protein, including oxalic acid oxidase, oxalic acid decarboxylase and formyl-CoA decarboxylase.[1] ==Classification== Enzymes that currently degrade oxalic acid include oxalate oxidase, oxalate decarboxylase, and formyl-CoA decarboxylase.[2] Oxalic acid oxidase(EC1.2.3.4)occurs mainly in plants. It can degrade oxalic acid into carbon dioxide and hydrogen peroxide. Oxalate decarboxylase (Oxalate decarboxylase,OXDC,EC4.1.1.2) is a kind of oxalate degrading enzyme containing Mn2+, mainly in fungi or some bacteria. It can appear in the absence of other cofactors under the action of the degradation of oxalic acid directly to form formic acid and CO2.[1] Formyl-CoA decarboxylase(EC4.1.1.8)mainly mediates degradation of bacterial oxalic acid.[2] ==Calcium oxalate stones and oxalate degrading enzymes== Calcium oxalate is the main component of urinary calculi. One of the important factors leading to calcium oxalate stone disease is the lack of degradation of the oxalic acid metabolic pathway. Therefore, the use of oxalate degrading enzyme to degrade oxalic acid in the human body has become an important research direction for the prevention and treatment of calcium oxalate stone disease.[2] Studies have shown that with the intake of a large number of foods rich in oxalic acid, the excretion of urinary acid in the urine will be significantly increased. Therefore, reducing intake of exogenous oxalic acid can reduce urinary oxalate excretion, thus significantly reducing the recurrence of stones.[3] ==References==
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I've nowiki-ed all the section headers, since I don't want them messing with the WP:RDS table of contents or confusing the archiving bot.
Two questions: were all my changes improvements (or did I damage something unknowingly), and what else can be improved? The final sentence in "Brief introduction" is particularly opaque to me; I'm not sure if it's saying the oxalic acids oxidase and decarboxylase, and formyl-CoA decarboxylase, or if it's saying the compound "oxalic acid oxidase", the compound "oxalic acid decarboxylase", and the compound "formyl-CoA decarboxylase", or something else; oxidase and decarboxylase don't appear to me to be kinds of oxalic acids, but I'm completely out of my league here. Nyttend (talk) 14:15, 18 March 2017 (UTC)
- The place for your question is waiting here. Read WP:BOLD. Blooteuth (talk) 14:31, 18 March 2017 (UTC)
- That's completely useless. (1) With a very new article, and an orphaned one at that, nobody's going to see the talk page. (2) If you'd looked at the article history, you would have seen that I already made these changes; I'm asking for someone knowledgeable to look over the changes. Do not offer answers on topics on which you are not qualified. Nyttend (talk) 16:48, 18 March 2017 (UTC)
- I made a few changes to the article and created the talk page. One change was to remove the erroneous and confusing "polymer proteins", which I hope makes the final sentence of the introduction clearer.--Wikimedes (talk) 05:59, 19 March 2017 (UTC)
- That's completely useless. (1) With a very new article, and an orphaned one at that, nobody's going to see the talk page. (2) If you'd looked at the article history, you would have seen that I already made these changes; I'm asking for someone knowledgeable to look over the changes. Do not offer answers on topics on which you are not qualified. Nyttend (talk) 16:48, 18 March 2017 (UTC)
- Writing articles like this takes time - but some of the scut work like transferring references from other Wikipedia articles cited should be easy, if not glamorous. I sympathize with the original poster just wanting to link the articles rather than screw around grabbing references out of them. There are some things like Oxalate CoA-transferase and Oxalyl-CoA decarboxylase that would bear mentioning, and it seems inevitable to mention bacteria responsible for protection against kidney stones, but also oxalate growth medium (maybe there's a better name?) used to test for certain bacteria. This can be a substantial article... Wnt (talk) 23:56, 18 March 2017 (UTC)
- I couldn't transfer the references because I couldn't find them; none of the articles I checked, none of the articles mentioned in the citations, appeared to have such citations. My question with the links was basically "which of these articles covers the intended meaning in this spot of text" and thus "which ones should be linked here". Nyttend (talk) 00:32, 19 March 2017 (UTC)
March 19
H+
What is the pH of H+?32ieww (talk) 01:49, 19 March 2017 (UTC)
- pH stands for the power of hydrogen. H+ is hydrogen ion in aqueous solution. To calculate pH, you need to take the negative logarithm of the ion concentration. 50.4.236.254 (talk) 02:17, 19 March 2017 (UTC)
- pH explains how it is calculated.
50.4 has given you the wrong answer (well, mostly wrong. There's some negative logarithming going on there, but he doesn't tell you WHAT is being negative logarithm. An ion is not a number, and cannot be logarithmed.) If you want the right answer, read the article on pH.--Jayron32 02:22, 19 March 2017 (UTC)
- pH explains how it is calculated.
- Corrected. I can't believe I removed the word "concentration". 50.4.236.254 (talk) 02:26, 19 March 2017 (UTC)
- Amended my response. --Jayron32 02:29, 19 March 2017 (UTC)
Eating local food
I live at 40 degrees latitude and -83 degrees longitude. There are a lot of grocery stores here. But some things aren't local. Avocados, for example, come from California or Mexico. Oranges may come from Florida. There are countless corn fields here. And there are many coniferous trees and dandelions and cattails, so I may be able to gather pine nuts. I wonder if I may store them in a safe space for the winter. If I want to eat local, then what should my diet be? What should I do about the winter? 50.4.236.254 (talk) 02:53, 19 March 2017 (UTC)
- Wikipedia has an article titled Local food which explains some of the benefits and pitfalls thereof. Please do not solicit opinions from the ref desks as to what you should do. You can come to those conclusions on your own, and don't need us. We can, however, provide you reading material such as the article Local food. This search contains several links to good locally-sourced foods near your locale. --Jayron32 03:04, 19 March 2017 (UTC)
- Not exactly "locally sourced food", per se. But anything in the vicinity, which includes pine nuts. So far, I only know that pine trees, dandelions, and cattails grow here, because I've seen them. I once saw an oak tree too, but I'm not sure if that's common in these parts. I wonder if it's possible to locate specific flora and fauna in the vicinity. 50.4.236.254 (talk) 03:39, 19 March 2017 (UTC)
- Eating acorns right off the tree is not advisable. ←Baseball Bugs What's up, Doc? carrots→ 04:23, 19 March 2017 (UTC)
- Yeah, I know that. I found a website that provides information on how to prepare acorns to make them edible. But I wish to know how various trees - oaks, for example - are dispersed. That may give me some hint to find them. 50.4.236.254 (talk) 04:33, 19 March 2017 (UTC)
- Eating acorns right off the tree is not advisable. ←Baseball Bugs What's up, Doc? carrots→ 04:23, 19 March 2017 (UTC)
- Also, can you point to resources that show how to store food for the winter? 50.4.236.254 (talk) 03:42, 19 March 2017 (UTC)
- Not exactly "locally sourced food", per se. But anything in the vicinity, which includes pine nuts. So far, I only know that pine trees, dandelions, and cattails grow here, because I've seen them. I once saw an oak tree too, but I'm not sure if that's common in these parts. I wonder if it's possible to locate specific flora and fauna in the vicinity. 50.4.236.254 (talk) 03:39, 19 March 2017 (UTC)
- IMHO, a wide variety of food is more important than local sourcing, at least as far as health is concerned. Of course, local sourcing also helps the local economy, at least until everyone else does it and stops buying the food you export. StuRat (talk) 03:46, 19 March 2017 (UTC)
Aqua streaks in ocean
I was at Key West, Florida the other day and the ocean there has aqua-colored streaks in it. (Well, that is the closest color I know - they are actually a little more greenish than aqua.) This photo is a sample. What causes that? Bubba73 You talkin' to me? 04:58, 19 March 2017 (UTC)
- I would guess you are seeing white sand bars close to the surface. There are many other factors which can affect water color, but most are more subtle than this. StuRat (talk) 05:12, 19 March 2017 (UTC)
- I don't think it would be sand bars close to the surface because the ship went through them, and its draft was 8 meters. Bubba73 You talkin' to me? 05:51, 19 March 2017 (UTC)
- Sometimes sunlight getting through the clouds creates patches or streaks of brighter color on the water. Here's how you can tell. If it's the bottom and/or seaweed affecting the water color, the patches don't move much. If it's the clouds and/or wind affecting the water color, the patches move or appear / disappear. In the picture I'd guess it's the sun shining on the water through the breaks in the clouds. Dr Dima (talk) 08:34, 19 March 2017 (UTC)
Overthinking
I don't know how to describe this, but I think it's related to overthinking. I have a habit of overthinking and checking things again and again, and oftentimes, this leads to more inaccuracy. When I rely on my "gut response", I get it right most of the time. I remember the time when I was in 9th grade geometry class and how I initially was a B or C student and then jumped to A student. I finished each test or quiz very quickly and accurately, because I stopped overthinking. I answered all the questions correctly, including the bonus questions, so I always got more than 100%. Later, I've heard that my instructors would caution students about overthinking. So, this phenomenon may not just apply to me. I am wondering if there is a neurological basis for "overthinking". 50.4.236.254 (talk) 05:28, 19 March 2017 (UTC)
- The relevant article would seem to be Analysis paralysis. ←Baseball Bugs What's up, Doc? carrots→ 06:32, 19 March 2017 (UTC)
- It is very useful to be able to think of two different ways to analyse a complex problem and then compare the two solutions. As an example one method might be your gut reaction, and the other a carefully weighted evaluation of the alternatives with score for each attribute. If the two disagree then it can be productive to see why the careful analysis came up with the 'wrong' answer. This can be useful in real life such as choosing where to live, not just engineering and so on.Greglocock (talk) 07:33, 19 March 2017 (UTC)
Earth-Mars common orbiter
Is it feasible to have a space station orbiting both Earth and Mars such that, periodic arrival takes place during shortest distance between both planets?--Almuhammedi (talk) 07:57, 19 March 2017 (UTC)
Can we generate unlimited energy?
Is there anything in physics that theoretically allows an infinite power source? Alan Guth refers to the universe as "the ultimate free lunch", so I'm thinking cosmic inflation or some other phenomenon of GR / cosmology.
I have already searched through the refdesk archives to no avail.
PeterPresent (talk) 08:54, 19 March 2017 (UTC)
- quantum fluctuation might also be relevant, as it refers to changes in energy, and it was quantum fluctuations that were amplified in the inflationary epoch that gave rise to the structure of the universe. Or maybe something completely different. Any ideas for an infinite power source? PeterPresent (talk) 09:07, 19 March 2017 (UTC)
- Nope -- quantum fluctuation does not actually produce any energy, and even if you could somehow harvest energy from cosmic inflation, it won't really be an infinite power source (see Big Freeze and Heat death of the universe for the reason why). 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 09:11, 19 March 2017 (UTC)