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November 7

Construction companies

(Moved to Misc Ref Desk: Wikipedia:Reference_desk/Miscellaneous#Construction_companies. - SinisterLefty (talk) 04:44, 7 November 2019 (UTC) )

This is a conflict of ideology. Followers of capitalism will argue that its the "nature" of the system/humans to compete sometimes or even notorious beyond rules and regulations and that this ("free market") is in the end more helpful for society than Planned economy or more commonly called Socialism.

Strangely something called Third Way, a combination of both, seems to have won the competition historically. Unfortunately this includes benefits and flaws of both systems, including some companies that seem to exploit society and some that lake to much innovation to help society. Btw. there are 100001 books, studies and research papers about this out there. Go reading but you could aswell become a politician and waste your time that way. --Kharon (talk) 04:52, 7 November 2019 (UTC)

Yes (this is a conflict of ideology) and no:

competition is always here, multi-axis, no matter what. Axis being the people you try to make happy so that you get paid and be happy yourself : customers; workers; shareholders; nuisance such like the mob, the press, etc. ; rules and rulers. The political system will dictate how much return you will get from your effort to bend the rules/rulers/nuisance to your side, against your competitors, and also how much is at stake in case of failure (could be goulag or even death...). The idea that planned economy, socialism, state regulation, or whatever erase competition is just false. It just change battle ground. Competition inside socialist states is even fiercer, as bribing (or flattering, or whatever) the ruling party bureaucrat to have competitors goulaged or even executed, is fair game, since this is also what is at stake for yourself. This will not benefit customers, workers, or shareholders ("the people" in case of full fledged socialism).

And yes, Mussolini obviously won, the whole world follows his ideas nowadays. And Orwell's. Gem fr (talk) 22:49, 8 November 2019 (UTC)

November 8

Looking for source on origin of "box" sequence nomenclature

This is a rare question on the ref desk that is explicitly asking for a reference. It is obvious to me from following citations that (at least in terms of literature - I have no idea if this phrase was used prior at a conference or something), the style of naming certain genetic sequences as "____ box" began when Walter Gilbert coined the term Pribnow box in Starting and Stopping Sequences for the RNA Polymerase. Cold Spring Harbor Monograph Archive, North America, 06 Jan. 1976. Available at: http://cshmonographs.org/index.php/monographs/article/view/3898/3115. He presented a number of recently published promoter sequences and discusses specific span of nucleotides that had been called out in earlier work by Pribnow. He draws a literal box around this span of DNA, and thereafter refers to it thereafter as the Pribnow box (first time in quotes as if defining it). The next couple publications to discuss the sequence cite Gilbert and use the name, but never say why it's called a box.

So to the request, as comfortable as I am saying that Gilbert coined the term, and this is why, and the rest are simply following a trend, it feels too close to WP:OR to use Gilbert's paper as the source for that. I'm wondering if anyone is aware of, or can find, a reliable source that explicitly describes the origin of this style of naming things. Thanks. Someguy1221 (talk) 04:17, 8 November 2019 (UTC)

There is some commentary in the lede of TATA box, but it doesn't have a definitive answer for the origin. DMacks (talk) 06:57, 8 November 2019 (UTC)

Yes, I had noticed that, and it seems problematic to me. It refers to the origin being unknown, but this seems to be unknown to the author of the Wikipedia article, as any mystery behind the origin is not mentioned in the cited sources. Actually nothing regarding the source of the name is mentioned in the cited sources. Someguy1221 (talk) 13:57, 8 November 2019 (UTC)

Are all electric blankets lumpy ?

The one I have has these cylinders between the layers, embedded in plates about 1 inch wide and 2.5 inches long. I take it these are thermostats which enable the electric blanket's wattage to be locally controlled, based on the temperature in that zone. That's fine, but when I roll over onto one of those it's as uncomfortable as it sounds. The actual heating wires, on the other hand, don't seem bad at all. So, is the design for mine universal, or are there less obtrusive versions ? SinisterLefty (talk) 05:41, 8 November 2019 (UTC)

Yes, there are many designs without the in-series thermostats. I used to have one like yours, and it was longer-lasting than the modern designs where all the monitoring is in the control box. I wish I could find one like yours, but they don't seem to be avaiable in the UK for safety reasons. Dbfirs 08:30, 8 November 2019 (UTC)

Is mine less safe ? I would think more thermostats, closer to the heat source, would better prevent overheating. SinisterLefty (talk) 15:57, 8 November 2019 (UTC)

Probably. But not as uncomfortable as those very un-ergonomic chairs. Martinevans123 (talk) 17:43, 8 November 2019 (UTC)

In a few minutes, you'd stop complaining, but this chair would give you quite the stiff neck. SinisterLefty (talk) 20:15, 8 November 2019 (UTC)

Oooohh! .... Forget IKEA!! Positively a chair to die for!! Wayne County 123 (talk) 20:30, 8 November 2019 (UTC)

Safety constraints are less demanding for an overblanket than for an underblanket that must remain safe while subjected to varying body weight and possible moisture. The OP's blanket may not meet the highest standards for an underblanket and, by intention or serendipity, be uncomfortable to lie on. DroneB (talk) 23:43, 8 November 2019 (UTC)

Do the lumps get warm? I wonder if they are resistors which have to run at fairly high current because of the low voltage electric blankets now use. In the old days the heating elements were driven directly by wall current through a thyristor dimmer. Talk about a hair-raising experience ;-). There is a trendy gizmo now called a bed jet (bedjet.com) that blows heated air under your regular blanket. The site is heavily sales-y and triggers my skepticism, but my mom has been interested in it and there is a long trial period, so she might give it a try. I've been quite happy with synthetic comforters and don't feel the need for heated blankets, at least here in California. 67.164.113.165 (talk) 07:20, 12 November 2019 (UTC)

No, the lumps don't get hot. That's interesting about the device that blows heated air, but I would also add moisture to it so it can be more humid there than in the rest of the house. (Too much humidity in the house in winter just condenses on the windows and causes mold.) And wow, that company wants $239 for a refurbished, non-returnable basic unit, and $900 for the full system. This is basically a hairdryer with a hose, right ? I would think you could do that for under $50. SinisterLefty (talk) 07:38, 12 November 2019 (UTC)

The $900 bedjet system must include two of the units and their weird blanket. The one my mom wants is about $400 and we are waiting to see if they do a black friday promo. They did another promo earlier in the year where you got about $100 off. I hadn't thought about making one using a hair dryer, but thanks for the idea, I might look into it. And because you reminded me of it, here is an amazing 43 minute video review of a $500 hairdryer: [1] (warning, NSFW language). 67.164.113.165 (talk) 20:46, 12 November 2019 (UTC)

For the hairdryer version you would want a powerful hairdryer, but set on low heat, and high fan, so it won't overheat from the increased resistance caused by the tube. You might also put some holes in the hose right by the hairdryer, so the air has a way out if the hose gets kinked. I'd test it thoroughly somewhere a fire won't spread, like outside, after rain ends. It probably would never be considered safe inside, without all sorts of safety testing, but you could at least see if there's any potential there with the outdoor test. SinisterLefty (talk) 21:54, 12 November 2019 (UTC)

Is there a difference between general electricity to the electricity of the heart?

Is there a difference between general electricity to the electricity of the heart? I'm trying to understand how to defined the similarity and difference between them. It's difficult for me to explain that human body has the electricity in his body. Initially It doesn't make sense to ordinary people who don't have knowledge in biology / physiology. What a short definition should include about it? ThePupil (talk) 21:44, 8 November 2019 (UTC)

Outside the body, electricity has 2 uses:

• Sending power (A/C or D/C).

• Sending information/signals (typically D/C, either analog or digital).

Sometimes it does both, as flipping a light switch on provides power to the bulb and also the signal that it's time to turn on. As for inside the body, electricity sends extremely low power D/C signals only. Most could be considered analog, like pain signals that have a variety of levels. But some could be considered digital, like a heartbeat timing signal, that just says "start beat now". Chemical energy is used by the heart and the rest of the body; electricity is not used for energy (other than the energy needed to send those signals, of course, but that ultimately comes from chemical energy, too). The nerve signals are also sent by a combo of electricity and chemical reactions. Chemicals are also used to send signals, as in hormones that tell an adolescent's body it is time to start puberty, for example. From an evolution POV, electrical signals have an advantage over chemical signals, because they are faster. If I got any of this wrong, somebody will be more than happy to correct me. :-) SinisterLefty (talk) 22:24, 8 November 2019 (UTC)

Could we not say that heart needs internal electrical power to contract repeatedly? ThePupil (talk) 22:35, 8 November 2019 (UTC)

I would change the word "power" to "signals", then it sounds good. SinisterLefty (talk) 22:37, 8 November 2019 (UTC)

Some confusion appeared because Luigi Galvani's experiments showed that the electricity we are now familiar with (he was not) promoted muscles mouvement in dead frog limbs. This would in turn prompt the Frankenstein style "let's use lightning as a power source to bring back life into a corpse", and the idea that muscles had "electricity". This is crude. The signals, for instance action potential, are not really electric, although it involves particles with an electric charge (just check the article);

I would use this analogy:

if the general electricity were a water flow in a canal, D/C would be water flowing in always the same direction, A/C would be water flowing back and forth, and body electricity would be the up and down waves without real flow

Gem fr (talk) 23:13, 8 November 2019 (UTC)

(ec)The first discovery that electricity has functions in the body was in the 18th century by Galvani who found that dead frogs' legs twitched when struck by an electrical spark, the beginning of the study of Bioelectricity. Today doctors use EEG to measure the tiny electrical signals that arise from brain activity to diagnose brain disorders. As SinisterLefty pointed out, the natural electric signals in the body have very low energy. The body will be damaged by Electrocution if accidently exposed to electric current levels that we use in Home appliances. Contact with as little as 20 mA (20 thousandths of an Amp) of current can be fatal, depending on whether the path of the current includes a vital organ such as the heart. Conversely, applying an electric pulse by a defibrillator can sometimes restore heart function. Execution by Electric chair was developed in USA and it applies some thousands of volts to the subject to ensure a fatal current flow. DroneB (talk) 23:31, 8 November 2019 (UTC)

• It's general knowledge that electricity has two forms: static electricity and electricity flowing in a circuit. Physiological electricity, such as in the heart, is neither.

Static electricity is a small amount of charge at a high potential. It's stored on insulators, or on conductors separated by insulators (i.e. capacitors). It's typically at a very high impedance, i.e. ratio of voltage to current. This doesn't flow, or (if it does) it's dissipates and isn't continuous.

Electricity in a circuit relies on conductors, i.e. typically metals, and has a relatively much lower impedance, i.e. greater current and lower voltage. There's a concept of current flow, in a loop.

Biology doesn't work in either of these ways. It's produced by the chemistry, not electrostatics. It's more like (dreadful anaology) being half a battery. A chemical potential at one end of a conductor (a "salty pipe") increases, relative to that at the far end. So there's a flow of electricity, but this is only measurable (in engineering terms) as a flow of charge, rather than a continuous and ongoing flow of current.

So, yes, it's electricity. But it's transient flows, not continuous. It's also very weak. This makes it hard to measure (look at the string electrocardiogram for one of the first diagnostic tools) and it's also quite easily overwhelmed by the application of an external current flow, such as from a defibrilator – which again is usually measured (in this context) in terms of energy (as Joules), rather than a continuous power rating. Andy Dingley (talk) 23:35, 8 November 2019 (UTC)

beware, static electric fields are huge in a cell. The voltage may be low (-0.1 V to +0.04 V), but the distance is so small (cell membrane is just ~10 nm thick), the electric field range in millions of V/m. A cell IS a capacitor, and quantitative models of the action potential looks like regular electric models.

Also, the main difference is that ions, not electrons, are the charge bearers for the (tiny) electric flows

Also, did we mentioned bioelectricity? Gem fr (talk) 08:44, 9 November 2019 (UTC)

November 9

Micellar water?

What's micellar water? Cosmetic cleansers are all about it now. I can't find any article on it.196.52.93.43 (talk) 01:28, 9 November 2019 (UTC)

See [2]. It's a type of emulsion. SinisterLefty (talk) 01:38, 9 November 2019 (UTC)

Soapy water? HiLo48 (talk) 02:02, 9 November 2019 (UTC)

Yes, it’s essentially soap water (or more precisely: surfactants) plus marketing bullshit. We also have an article on micelles, by the way. Cheers ⌘ _hugarheimur —Preceding undated comment added 02:22, 9 November 2019 (UTC)

This is basically dish soap, right? I have a big jug of that from Costco, so can I get the marketing bullshit separately packaged and blend it in at home for a similar end result? Thanks. 67.164.113.165 (talk) 20:41, 12 November 2019 (UTC)

Are humans all one species?

In biology class, I learned that female bull dogs (or some kind of dog breed) require Caesarean sections, because the head is too big. Without human intervention, the puppy is doomed. Online, I learned that interracial marriages are rising in the USA, with the most common type being white male and Asian female. But this type of coupledom may involve more Caesarean sections, as Asian females may have smaller pelvises than European females. So, without human intervention, a woman who cannot deliver the baby will be doomed. A dark-skinned African may migrate to Northern Europe, but may suffer from rickets due to lack of sun exposure. A Northern European may migrate to somewhere near the equator and suffer from malaria because he or she does not have the sickle-cell trait. Humans are separated from each other geographically, and it seems, even biologically; however, with modern medicine, that can greatly reduce the selective pressures acting on humans. Human population A may be adverse to human population B, and this prevents intermarriage. Are they two species? Human population A may be favorable to human population B, and this promotes intermarriage and union of the two ethnicities as one, forming a new lineage. Are they one species? Neanderthals mated with Homo sapiens. Are they one species or two? Where do we draw the line? SSS (talk) 02:31, 9 November 2019 (UTC)

Modern humans are a single species. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:44, 9 November 2019 (UTC)

The usual line, for sexually reproducing organisms, is "Can they mate and produce fertile offspring ?". Not that it must always be successful, just that it sometimes is. I'm not aware of any combination of two races that can never breed to produce fertile offspring. Thus, we are a single species. SinisterLefty (talk) 03:59, 9 November 2019 (UTC)

You might have two distinct species if you have two distinct mating populations that experience hybrid incompatibility when mating with one another, or experience some other form of reproductive isolation. Human races fail this on both parts: A) There are indeed, as far as I can tell, no well documented claims of interracial couples having worse fertility than either race generally; and B) the human races do not constitute isolated populations to begin with, nor are they valid taxonomic subgroups. Someguy1221 (talk) 08:10, 9 November 2019 (UTC)

Well, isolated populations did exist. One of the reason of Spaniards success in America is, Natives had been isolated from Old World for so long, diseases wrought havoc. And much less time was required to create breed of dog or cattle. But human species actually lacks genetic diversity, evolution cannot tap on an already large pool to create distinctive human race, it has to wait for some random selective mutation to appear, and even when critical for survival, such like high-altitude adaptation in humans, this creates rather hard to see variation (that is, you would see the irrelevant blackness of an Ethiopian, not his very relevant specific adaptation). Gem fr (talk) 21:23, 9 November 2019 (UTC)

It's called dystocia. For dogs it seems there may be as many as ten. I've been out with some right dogs in my time, but I always draw the line with the Orientals. One can't be too careful, can one? Martinevans123 (talk) 08:31, 9 November 2019 (UTC)

All dogs are also a single species, Canis Canis aka canis lupus familiaris aka canis familiaris, actually rather one of the 36-38 subspecies of canis lupus, all of them being able to interbreed (even though, a male teckel will have some trouble mounting a doberman female). This to show how large variations can be observed within a single species, in which quite a number of breed are distinguished

Wolf Shar Pei Shiba Inu Chow Chow Akita Inu Basenji Siberian Husky Alaskan Malamute Afghan Hound Saluki other breeds in the study

Cladogram of nine breeds that are genetically divergent from others

See also racialism Gem fr (talk) 09:07, 9 November 2019 (UTC)

See On the Origin of Species (especially the first dozen or so pages) for what is still one of the most profound and insightful pieces discussing the concept of species. Robinh (talk) 19:27, 10 November 2019 (UTC)

• Ah, yes. The species problem. The biggest issue with defining any grouping of organisms a "species" is that for any given definition, there will always exist groups of organisms which don't fit well in the definition. The existence of things like ring species adds some added kinks to definitions. --Jayron32 12:13, 12 November 2019 (UTC)

But here's another problem. Aren't tigers and lions not considered to be the same species? But yet they can reproduce to forms tigons and ligers - 1 is a male tiger female lion, the other female tiger male lion. So clearly there is more of a definition to species. 67.175.224.138 (talk) 12:37, 13 November 2019 (UTC).

Some species that are "close enough" genetically can produce offspring. The mule is an obvious example. They are born male or female, like your typical mammal, but they can't reproduce, with rare exceptions - as with the Liger and the Tigon. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:27, 13 November 2019 (UTC)

November 10

Did The X Files Really Happen?

Did The X Files Really Happen? A lot of Evidence suggests that much of the information and plots of the TV Series were accurate versions of real things that had happened, although Names had been changed.:Scully230 DES (talk)DESiegel Contribs 21:19, 10 November 2019 (UTC) — Preceding unsigned comment added by Scully230 (talk • contribs)

X-files is fiction, but some stories may be based on some kind of reality. There are 202 episodes with different stories, so you would have to consider each episode. Graeme Bartlett (talk) 21:55, 10 November 2019 (UTC)

Check out what preceded this diff[3] and tell us the user is not trolling. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:23, 11 November 2019 (UTC)

The closest real thing to it was Project Blue Book. SinisterLefty (talk) 06:51, 11 November 2019 (UTC)

Just so everybody who is unfamiliar is clear about the basics:

The X-Files was a television franchise and a work of fiction. It is an entertaining, but fictional, dramatization that revolves around a few agents of the FBI who investigate unusual phenomena, including a detailed fictional backstory relating to intelligent extraterrestrial life forms and their effort to interfere with Earth and its major governments.

You can also read about the actual, non-fictional FBI at our Wikipedia article: Federal Bureau of Investigation; and at the official website, FBI: What We Investigate.

The official website of the FBI also maintains a public archive of interesting files relating to unexplained phenomena: FBI Records: The Vault - Unexplained Phenomenon (sic).

If you're truly interested enough to read them, you will find that most of the case files that pertain to the so-called "supernatural" are letters from the American public inquiring whether the FBI has any such files; and archives of the formulaic letter response from the relevant bureau office. Skipping straight into spoiler territory: yes some archives exist; yes, there have been some investigations; yes, if you are truly interested, you can see the files; and no, nothing really neat usually turns up. Every so often, the investigation leads to a successful prosecution for a violation of Federal law, and we can all celebrate our national commitment to justice. After all, the last thing we want is an unchecked conspiracy to defraud the United States by introducing eight-legged aliens into our food supply in violation of clearly-worded Federal fisheries law.

In at least a few instances that relate to space-aliens, the FBI actually expended the effort to investigate a report, if it was credible enough to investigate. In other cases, the responses were coordinated by other Federal agencies.

The astute reader will occasionally even find the letter "X" in these archived FBI files. Woo!

When the FBI actually investigates space aliens - if there is any investigation at all - it typically has more in common with a police-report about a prank-call than it does with a science-fiction television show. The big deal here is that such investigations are like a prank-call to the Federal police, and they operate much differently than your local police-department. For example, if you hassle the local police with a spurious UFO report, they'll probably ignore you and tell you not to abuse the emergency services. On the other hand, most Americans don't usually interact too frequently with the local branch of the Federal government police - the "Feds" tend to, shall we say, speak softly - but if you hassle the Federal Government with such matters sufficiently to draw their ire, you may be committing a Federal crime that can subject you to imprisonment.

Personally, I read a lot of government documents (for fun and for profit); and as many readers here know, I also enjoy the occasional foray into science-fiction literature, television, and cinema. In terms of the efficacy of providing entertainment-value relating to the supernatural, the fictional television program X-Files do a better job than the government dossiers. The real FBI files on that topic are usually pretty dry, and rarely ever even yield criminal prosecution.

But, on more thought-provoking topics, there is a lot of other interesting stuff to find in the FBI Vault: for example, what can we surmise from our national history about the times when the Government is put in the very unusual position of investigating itself for committing crimes of a politically-motivated nature? And if you are a real student of the television-program The X-Files, you already know this stuff. Despite a few vile elements within our Government who may seek to confuse, dilute, and dissuade,... the truth is out there....

Nimur (talk) 13:51, 11 November 2019 (UTC)

November 11

Cleveland rat-squirrel ?

There seems to be a new species of rodent just SE of Cleveland, Ohio. It looks mostly like a squirrel, but is smaller, has a less fluffy tail, and is more aggressive towards humans. Any idea what it is ? SinisterLefty (talk) 06:49, 11 November 2019 (UTC)

Look like this? -- The source is dubious, but they call it a "sqrat". 2606:A000:1126:28D:25BA:5B02:33E7:A409 (talk) 09:04, 11 November 2019 (UTC)

Yea, that looks like it. The 2 useful suggestions there were that it was mange or that the squirrels plucked their tails for nesting material. The mange theory doesn't explain why it's only the tail. Maybe there's a new squirrel-tail mange mite that specializes in just that ? That might also explain the smaller size, if the parasites drain them of nutrients. But when I've seen mangy animals it's typically patchy hair loss, not as uniform as this. As for the plucking for nest material theory, that doesn't explain why there are so many more like that recently. Neither theory explains why they would be more aggressive towards humans. SinisterLefty (talk) 11:28, 11 November 2019 (UTC)

sorry, but this irresistibly draw this to my mind Gem fr (talk) 15:01, 11 November 2019 (UTC)

• Here's an article about them that seems pretty solid. --Jayron32 12:43, 13 November 2019 (UTC)

What size of sink is needed to truely demonstrate Coriolis effect at the equator?

There are these bogus demonstrations where two sinks are a meter apart with the equator between them, and water rotates one way in the north and the other way in the south.

What size of sink will really demonstrate it? — Preceding unsigned comment added by 77.124.56.240 (talk) 21:10, 11 November 2019 (UTC)

Somewhere between the size of the Great Lakes and the size of an ocean ? I say this because the Great Lakes [4] don't show the same rotation as ocean currents. Now the shape of the sea floor and beaches, and inflow and outflow points, do contribute, but still I'd expect to see more rotation than I do, if the Coriolis effect was a major factor in lake currents. SinisterLefty (talk) 22:00, 11 November 2019 (UTC)

See[5] where it says:

Coriolis forces are best observed at a large scale...In your tub, such factors as any small asymmetry of the shape of the drain will determine which direction the circulation occurs. Even in a tub having a perfectly symmetric drain, the circulation direction will be primarily influenced by any residual currents in the bathtub left over from the time when it was filled. It can take more than a day for such residual currents to subside completely. If all extraneous influences (including air currents) can be reduced below a certain level, one apparently can observe that drains do consistently drain in different directions in the two hemispheres.

You can estimate the magnitude effect by applying conservation of angular momentum. For simplicity assume that the basin of water is the same shape as the plug hole (circular) and that the hole is central. For more simplicity let the experiment initially be performed at the north or south pole of the earth (which will maximize the effect).

Before the plug is pulled, the basin and water are rotating with the earth, once in just under 24 hours. When the plug is pulled, the water moves towards the centre and the radius of rotation of each particle of water ultimately decreases in proportion to the radius of the hole to the radius of the basin - say a factor of 1/n. Conservation of angular momentum demands that the angular velocity increases by a factor of n², so the period of rotation decreases by a factor of n². Thus, if the radius of the basin is 100 times that of the hole, the water ends up rotating once in about 24hr/100² ~ 8.6sec - not hugely fast, but possibly discernible.

If the experiment is performed at a lower latitude, the period of rotation is multiplied by (probably) the sine of the latitude (see Foucault pendulum). catslash (talk) 00:24, 12 November 2019 (UTC)

Further to the above, note that the original poster asked about bogus demonstrations with sinks "a meter apart with the equator between them". Now one nautical mile is defined as 1,852 m and corresponds pretty nearly to one minute of latitude. Therefore a position 0.5 m from the equator corresponds to a latitude of 0.5/1,852 of a minute north or south. According to units this angle is equal to about 1/12,700,000 of a radian, and therefore, using the small-angle approximation, its sine is also about 1/12,700,000. So the force is so slight that no such practical demonstration is possible using anything smaller than a sizable lake. (And of course, a sizable lake would have to be farther from the equator to be all one one side of it, requiring a new calculation. But even at say 100 km from the equator, the sine of the latitude is about 1/64,000.) --76.69.116.4 (talk) 09:49, 12 November 2019 (UTC)

In OR, an actual bath tub filled nearly to the top, at above 52°N and drained after standing for a few days showed no obvious rotation. The water appeared to go straight down, right to the dregs. catslash (talk) 00:34, 12 November 2019 (UTC)

Thanks for that. I've never tried leaving the water to stand like that and the bath water has always had a vortex one way or the other for me - except for one time when it disappeared straight down the plughole just like you describe. I was really astonished. It emptied far faster than usual. If somebody could get it to happen again and take a video they'd have a winner. Dmcq (talk) 19:40, 13 November 2019 (UTC)

• Look at Rossby number for a way to quantify this. It's the ratio of the forces for the inertial and Coriolis forces. If Coriolis is greater, then rotation follows the relevant direction for each hemisphere, otherwise it depends on the initial conditions instead. For weather systems, the larger they are, the more likely they are to follow the Coriolis direction. Smaller systems can (and do) go either way. Andy Dingley (talk) 01:12, 12 November 2019 (UTC)

OP here, I am confused. I do not feel ashamed to admit the math and physics in the articles are above me. Is there any straight answer? — Preceding unsigned comment added by 77.124.56.240 (talk) 10:04, 12 November 2019 (UTC)

• We really do need better coverage in the weather articles which shows a comparison list of low-pressure system by their size, so that we can easily see how their behaviour changes according to size. Most large scale weather arises through a similar means, warm air cooling down and its pressure dropping, but what that then turns into depends so much on how big a mass of air is acting as one.

You need to get to the point of having an idea what Rossby number means (even without the maths). It's the ratio between the non-Coriolis forces and the Coriolis forces. The Coriolis forces are weak, but increase with size of the system. So small systems ignore Coriolis, large ones (hurricane and upwards) are affected by it. Middle-size ones might be. Your bathroom sink is so much smaller than any of this that Coriolis is just insignificant.

Smaller than a hurricane (and that includes tornadoes) and they rotate either way, depending on the starting conditions. Try a circular bathroom sink in the UK. Sometimes you can demonstrate this as "Hot water rotates one way, cold water rotates the other". The trick is that in the UK we still mostly have two separate taps, not single mixers, and that water enters the basin with pre-existing spin, depending on which side the tap was mounted. This rotation continues for enough time for you to then pull the plug and demonstrate rotation during emptying, with either direction of rotation, and predictably.

There's also the ice skater effect. The rotational energy stays mostly constant (it's lost, but only slowly) and so if a rotating system shrinks in diameter, then it has to speed up. So in your "big funnel by the side of the equatorial road" sideshow example, it might start off with no discernible rotation in the water, but as it approaches the plughole it speeds up so obviously - we've all seen this in the bathroom. Now what you're seeing there is conservation of angular momentum, not Coriolis, but it's great sideshow patter to present it that way. Andy Dingley (talk) 11:21, 12 November 2019 (UTC)

As Andy Dingley explains, it won't work with a draining sink. The forces are just too small, especially near the equator. These forces are strongest at the poles and zero on the equator. At higher latitudes the effect can be seen from a Foucault pendulum (if you have patience, at my location it is takes over a day). Rmvandijk (talk) 12:55, 12 November 2019 (UTC)

What with, say, 500Km sink (well, reservoir). The question came form an argument I had with guys who saw this YouTube vid. So for the sake of the argument i wanted to say what terribly large "sink" will be required.

I think I got the general idea of this Mossby number: Larger than 1 - Coriolis not effective. lower than one - effective. But to get proper answer I need to do calculation like the angles sinus from above, and even than I will surely mess things up. If you guys can lend a hand that will be great. Just think of enlighting the uneducated... — Preceding unsigned comment added by אילן שמעוני (talk • contribs) 13:35, 12 November 2019 (UTC)

Did some moss grow on the Rossby number ? :-) SinisterLefty (talk) 13:46, 12 November 2019 (UTC)

• It depends on the relative density of air and water too. But for air you need something the size of a hurricane, so even though denser water allows you to do the same at a smaller scale, that's still bigger for "the sink" than any building to put it in.

Also, as noted, the Equator itself (nearby to it on either side) is just the wrong place to do this, as it's where the forces are smallest.

I've built Foucault's pendulums myself. They're not trivial either, but you can do it for a school science project, if you have a way to hang a weight from the top of a gym roof. One of mine is still running in a science museum - that's about 50 lbs of concrete in an oil drum, dressed up on the outside. Andy Dingley (talk) 15:23, 12 November 2019 (UTC)

I'm trying to get to the point where I can say confidently "Sure mate, you only need like 500Km (approx. 300 miles) wide sink and it will work out just fine...". With air it wouldn't have that impact. — Preceding unsigned comment added by אילן שמעוני (talk • contribs) 17:36, 12 November 2019 (UTC)

It's not going to have a sharp cut-off, due to all the factors listed, but 500 km would be a fine approximation. SinisterLefty (talk) 17:39, 12 November 2019 (UTC)

November 13

Fungus eggs?

Clathrus ruber "eggs"? No they are not pretty, sorry. No really... These ones are called "Stinkhorn baskets" (baskets are the cute ones)

Hallo, various species of fungus produce what are called "eggs" or sometimes "fruiting body". What is the proper term for that? Sporocarp (fungus) and spore don't specifically cover it. ~ R.T.G 00:28, 13 November 2019 (UTC)

Fruiting body or "sporocarp" is the correct name. They don't all resemble eggs. Many resemble flowers. And then there are mushrooms. I don't see anything obvious missing from the the article. SinisterLefty (talk) 01:10, 13 November 2019 (UTC)

In my unqualified opinion, they seem to be unique enough to require a further categorisation and seem to be called "eggs" so often I checked to see if I couldn't start an article, but I just wanted to find something focused specifically on the "eggs". It feels like they are mentioned endlessly but without any deep focus. Might still be possible, but so much easier if I found a book or two called "This is what a fungus egg is!" xP ~ R.T.G 01:29, 13 November 2019 (UTC)

Functionally they are the same, whether egg-shaped, flower-shaped, or mushroom-shaped. So, the shape isn't all that important to mycology. SinisterLefty (talk) 01:39, 13 November 2019 (UTC)

See puffball. 85.76.45.42 (talk) 09:59, 13 November 2019 (UTC)

Now wait. This thing is not like a sporocarp or a puffball. This thing doesn't spray. It seeds. Birds eat this stuff and spread it. ~ R.T.G 19:38, 13 November 2019 (UTC)

Are you sure about that ? I'm not aware of a fungus with spores able to survive digestion. SinisterLefty (talk) 04:19, 14 November 2019 (UTC)

Effects of sensory deprivation tank (floating) without tank or drugs

Good Day

I am wondering if it is possible to have similar effects like in a sensory deprivation tank (“floating”) without the use of a tank or drugs.

Thank you very much for your answers!

With kind regards--2A02:120B:C3E7:E650:18C8:AAB0:523A:9250 (talk) 01:09, 13 November 2019 (UTC)

To some extent. A soundproof, lightproof room will help. Still, there will be odors, and slight wind currents, and you will feel pressure points where you are sitting or lying down. When stimuli are few, those that do exist seem to grab your attention. SinisterLefty (talk) 01:20, 13 November 2019 (UTC)

Spending an evening with an insurance salesman could do the trick. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:35, 13 November 2019 (UTC)

I suppose the ultimate in sensory deprivation would be to sever the nerves going to the brain, being careful to leave those coming from the brain intact. That would be foolhardy, now, as there would be no way to reconnect them all correctly. But, with future technology, this might be possible, and even desirable, say for burn patients with pain throughout their body. SinisterLefty (talk) 03:40, 13 November 2019 (UTC)

Meditation will do this, though for most people those states require competent teaching and a lot of practice.--Shantavira|^{feed me} 08:59, 13 November 2019 (UTC)

Toward the end of Surely You're Joking, Mr. Feynman!, the chapter Altered States memorializes the experiences of one famous physicist on exactly this topic, including his experiences with sensory deprivation tanks and the altered state of mind he experienced. For the most part, Mr. Feynman did not participate in heavy drug use, because he respected the physiology of his own brain, and did not "want to screw up the machine."

I would not endorse everything that Mr. Feynman tried: he initially documents his sensory deprivation efforts while completely sober, but he also participated in sensory-deprivation tanks under the influence of prescription drugs including ketamine. Although that might be an ill-advised life-choice for the recreational physicist - consult your personal physician! - we can at least learn from Feynman: "I got this strange kind of feeling which I've never been able to figure out when I tried to characterize what the effect was." The chapter then proceeds to describe his experiences and non-experiences with the sensory deprivation tanks, including what he calls "hallucination" and out-of-body experiences.

When I want to get high and float - "without the use of a tank or drugs" - I prefer to separate myself from the surface of the Earth. With enough discipline, this can be safely conducted in compliance with good medical self-care and all local, state, and federal laws; and it's a lot safer than playing with psychoactive chemicals. On the other hand, it's probably more expensive than a sensory-deprivation tank.

It is said that astronauts experience the overview effect - a "cognitive shift." If I may wax a bit poetic, at the expense of a little bit of accuracy: that grandeur described by the astronauts is simply the most severe form of the psychological disorders related to hypoxia; and with enough effort, we can all experience it in small doses ... and with the right type of vessel, we can even make ourselves float.

And so far as sensory deprivation: there is probably no more effective way to isolate a human from their sensory perception than night IMC. If you can imagine nothing - you are nearly there; and it is absolutely an altered state of mind that fuses the most intense cognitive focus with the most intense absence of meaningful sensory stimuli. As described by Shantavira, this type of scenario absolutely requires "competent teaching and a lot of practice," especially if you plan to ever get out of it. To directly quote one of our books of great wisdom and knowledge: "disregard your sensory perceptions." (17-10.8).

Nimur (talk) 15:05, 13 November 2019 (UTC)

• List of bodies of water by salinity. ~ R.T.G 01:26, 14 November 2019 (UTC)

Insularia Canaria

From one of our foreign language Wikipedias, Did you know that the Canary Islands are not named after birds but rather after dogs as the Latin Insularia Canaria translates to Islands of Dogs. While interesting this reminded me that when I was there I took a boat trip around one of the islands and noted that there were no birds. No birds anywhere on the island. Also there was no sign of birds such as guano on the rocks. I asked the tour guide who was able to confirm that he had never seen a bird there but that he had not really noticed until I pointed this out and that he was not able to explain the absence of birds. One would expect that like most oceanic islands, it would have a healthy population of birds, yet they are conspicuously absent. Why? Thank Anton 81.131.40.58 (talk) 15:16, 13 November 2019 (UTC)

Maybe the dogs ate them all? No, actually there are plenty of birds. See Category:Birds of the Canary Islands. I suspect your tour guide was just pulling your drumstick. ←Baseball Bugs ^{What's up, Doc?} carrots→ 15:37, 13 November 2019 (UTC)

Introduced species, like house cats, can decimate bird species on an island. I don't know if this happened there, though. Eventually, either the native species of birds would adapt to survive, or new bird species, which are able to survive with predators around, would move in. One important adaptation would be nesting in trees instead of on the ground (cats can generally only climb the trunk, not out on branches). SinisterLefty (talk) 16:57, 13 November 2019 (UTC)

The article Atlantic canary indicates it was named for the islands, and by implication it is quite common there - except for a couple of the islands in the chain where it is much less common. Maybe one of them is the island you were touring? ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:07, 13 November 2019 (UTC)

Having just come back from Tenerife, I can confirm that we saw both seabirds (gulls, I think) and songbirds (unidentified species ;-), though maybe less than you would expect. --Stephan Schulz (talk) 00:16, 14 November 2019 (UTC)

November 14

Enthalpy of fusion

A solid crystal (such as ice) is a more ordered state than water, so one would expect that when transitioning from water to ice extra energy is expended to order the atoms in the ice crystal lattice. When ice melts back into water, I would expect that that energy that had been bound into the system gets released, so melting would be an exothermic reaction. Yet it seems that melting a solid actually binds energy. The example in the article clearly states that it takes 333.55 kJ/kg extra energy just to move from 0C solid to 0C liquid water. Why is that so? Where is the fault in my conceptual model? 93.136.57.235 (talk) 00:09, 14 November 2019 (UTC)

In a simple form, the answer is right there in the article: ``The liquid phase has a higher internal energy than the solid phase. This means energy must be supplied to a solid in order to melt it and energy is released from a liquid when it freezes, because the molecules in the liquid experience weaker intermolecular forces and so have a higher potential energy (a kind of bond-dissociation energy for intermolecular forces). `` This is true for all solid-liquid transitions (unless quantum-mechanical effects become dominant and stabilize the liquid phase even at T = 0K, but that's irrelevant for this discussion). The volume may increase (normal transition) or decrease (anomalous transition, as water has at about 1 atm of pressure) but the key is that the internal energy of a liquid is always higher than that of a solid. Hope this helps. Dr Dima (talk) 00:55, 14 November 2019 (UTC) . To add, I don't really like the "weaker intermolecular forces" formulation in the article because, first, the enthalpy of fusion is positive for all materials undergoing first-order solid-liquid transition: metals, molecular solids, etc.; and second, because the forces are not necessarily weaker per se, but rather because the melting causes the atoms / ions / molecules to move against those forces, that is, to perform work (for which the energy must be supplied from outside), hence the positive enthalpy of fusion. Dr Dima (talk) 01:04, 14 November 2019 (UTC)

Yes I see that it has a higher internal energy, but why? It's a more disordered state. I see an analogy with a tower of bricks arranged one atop of another, which obviously has more "energy" (in this case gravitational potentional energy) than a pile of collapsed bricks, which is obviously the opposite of what is the case with states of matter. What analogy works here instead? 93.136.57.235 (talk) 01:16, 14 November 2019 (UTC)

Hmm I thought about this some more, thank you for reminding me that in a crystal atoms have to first overcome the forces holding them in stable symmetry to create the disorder that is a liquid. But when you look at it from the opposite side, the freezing, then energy is obtained from the system by binding it in this highly organized and improbable state? Why isn't that a violation of the law that entropy always increases? 93.136.57.235 (talk) 01:27, 14 November 2019 (UTC)

Its called Phase transition and water is a special case. See Liquid-liquid critical point.--Kharon (talk) 04:41, 14 November 2019 (UTC)

Relativistic jets and black holes

Reading the article on relativistic jets, I get the impression that they can be produced by black holes. But black holes absorb all matter with nothing escaping. What's the relationship between relativistic jets and black holes? How are relativistic jets produced? 5225C (talk) 00:58, 14 November 2019 (UTC)

They are created by the accretion disk, which is outside the event horizon of the black hole (the point of no return). SinisterLefty (talk) 03:23, 14 November 2019 (UTC)

My layman's impression is that it's a situation similar to the gravity assist. Matter is attracted from somewhere else to the vicinity of the black hole, does a pirouette outside the event horizon and gets accelerated and focused in a narrow beam by some mechanism. You'll have to ask someone else what that particular mechanism is. I suspect it's extracting work from the rotation in case of a rotating black hole, but no idea for when the hole isn't rotating. 93.136.57.235 (talk) 03:53, 14 November 2019 (UTC)

Obviously some black holes dont absorb everything. Quasars have already been found in the 1960s to typically develope these jets. So science knows for 60 years now that black holes dont absorb everything. --Kharon (talk) 05:14, 14 November 2019 (UTC)