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June 8

The highest point in Buffalo, New York

Where can I find a source that states the highest point in a city—specifically, Buffalo, New York? I already know where that particular point is, but I need to find a published source. Thank you. Buffaboy (talk) 07:23, 8 June 2021 (UTC)[reply]

https://www.google.com/search?q=highest+point+in+buffalo+new+york 67.165.185.178 (talk) 07:27, 8 June 2021 (UTC).[reply]

Some meagre results. Reportedly, the tower of the D. S. Morgan building was the highest point in 1896. (Paul's Dictionary of Buffalo Niagara Falls Tonawanda & Vicinity). In 1948, WBEN-TV was transmitting from "the highest point in Buffalo", but the source does not identify its location (Broadcasting, May 17, 1948). It may help to focus the search for a source if you reveal what you know to be the highest point. --Lambiam 08:45, 8 June 2021 (UTC)[reply]

In 1917, Hotel Lenox, North St. at Delaware Ave., claimed to be the highest point.^[1] --Lambiam 09:15, 8 June 2021 (UTC)[reply]

List of tallest buildings in Buffalo notes Seneca One Tower as the tallest building in the city. I have no idea what the tallest natural point would be, or if there is a taller structure, such as a radio tower. The building itself has several radio antennas on it. --Jayron 32 11:14, 8 June 2021 (UTC)[reply]

I'll bet it is the 688 ft on the University of Buffalo south campus. Abductive (reasoning) 16:50, 8 June 2021 (UTC)[reply]

The answers above mostly assume that Buffaboy was asking about the highest point on a (hu)man-made structure. This may be the case, but my most natural reading of his wording would refer to a ground elevation. Perhaps he could confirm which was meant? {The poster formerly known as 87.81.230.195} 2.121.163.176 (talk) 19:12, 8 June 2021 (UTC)[reply]

The OP claims to already know the answer, but wants confirmation. It would be nice if he actually posted what he thinks the answer is. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:19, 8 June 2021 (UTC)[reply]

@Baseball Bugs: @Lambiam: @Abductive: I posted this as I was going to bed, it's my understanding that the highest point in the city is in the vicinity of High Street and Ellicott Street, hence the name "Hospital Hill". At the same time, Abductive may also be correct (from personal knowledge), but how do we verify this? I'm trying to figure out why this is the case though, for the Buffalo article's Topography section. Buffaboy (talk) 19:27, 8 June 2021 (UTC)[reply]

So you're talking about the geographical high point, not to do with buildings? King of like with Hilltop Park in Manhattan? ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:32, 8 June 2021 (UTC)[reply]

That's right. There's this USGS mapping website, I guess I can approximate? Buffaboy (talk) 19:34, 8 June 2021 (UTC)[reply]

I see 688 ft at 42.95312 N 78.81900 W on the World Topo map available by clicking on the coords on the Wikipedia page and selecting Acme. The high point of Hospital Hill is 682 ft. Abductive (reasoning) 19:51, 8 June 2021 (UTC)[reply]

@Abductive: Hmm. I think I'll try and use that as a reference. Thanks. Buffaboy (talk) 21:33, 8 June 2021 (UTC)[reply]

Hot Bodies

The average human body temperature is around 98.6°F; yet at that ambient temperature it is uncomfortable. Why would a person sweat at that temperature in order to cool off, while the thermoregulatory system works to maintain that internal temperature? And, why does it need to be that high? Warm-blooded animals need to maintain above-freezing temperature, of course; but wouldn't 40~50°F be sufficient and less energy taxing? —2603:6081:1C00:1187:EC40:B2AE:BE0E:8875 (talk) 19:00, 8 June 2021 (UTC)[reply]

Read Hypothermia. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:07, 8 June 2021 (UTC)[reply]

More generally, the body is always producing "waste heat", and needs to shed it into the environment. If the environment is too warm to do this via convection, it needs to do it via evaporation. If the wet-bulb temperature is to high for that to work, humans overheat and eventually die. As for lower temperatures: The human body is, to a rough approximation, a mass of chemical reactions in a bag of rather dirty water. As a rule of thumb, many "normal" chemical reactions double in speed when the temperature increases by 10℃. Or, in other words, it halves if the temperature decreases by 10℃. This would throw the whole system out of whack. That's why the body is so good at thermoregulation... --Stephan Schulz (talk) 20:36, 8 June 2021 (UTC)[reply]

We have an article on Human body temperature which may help your understanding. BTW, 98.6°F is a textbook example of false precision - see here for the details. Matt Deres (talk) 14:42, 10 June 2021 (UTC)[reply]

A lot of animals will be killed by freezing, including a lot of "cold-blooded" animals. Maintaining a higher body temperature gives benefits like faster movement. The tradeoff, as you note, is this requires more energy to maintain the temperature. You will want to read thermoregulation. It's quite a detailed subject. --47.155.96.47 (talk) 16:12, 14 June 2021 (UTC)[reply]

June 9

Epoxy blob COB on DIP breakout board

What, if anything, is the proper term for COBs put on a breakout board then used in a standard DIP socket? 108.29.92.115 (talk) 08:14, 9 June 2021 (UTC)[reply]

I think you'll find the answer within the article List of integrated circuit packaging types, which has so many acronyms it is making my head spin (see above on this page at WP:Reference desk/Science#Evolution and the wheel?). Mike Turnbull (talk) 10:30, 9 June 2021 (UTC)[reply]

Some more links: COB = chip on board, "breakout board" means a printed circuit board used for prototyping, and DIP = dual in-line package. --Lambiam 10:58, 9 June 2021 (UTC)[reply]

The OP mentions "epoxy blob" in the header; this makes me thing they are asking about Potting (electronics). --Jayron32 13:51, 9 June 2021 (UTC)[reply]
- @Jayron32:. Yes, I wondered that too. However, the article I linked to also uses the term epoxy blob in referring to COBs, with "this reference"., so maybe that's all they needed. Mike Turnbull (talk) 14:28, 9 June 2021 (UTC)[reply]
  If it ain't got that black blob, it ain't a COB. See the pix in our article Chip on board and in the referenced write-up. I do not truly understand the question. To fit in a DIP socket, a component needs matching pins. Are these attached to the PCB on which the chip has been glued? So are the dimensions of the PCB those of a typical DIP package? --Lambiam 09:01, 10 June 2021 (UTC)[reply]

Okay trying to restate the question. In some older electronics (usually cheap toys or knockoff handheld videogames from the '90s or early '00s), I semi-frequently run across your standard black epoxy blob COB, but instead of being directly on the device's board it's on a small separate board similar to a surface mount adapter. The adapter is in the form factor of one of the large old 20 or 24-pin DIPs, and usually slotted into a socket. I'm having trouble finding anything about that particular technique (and why it was used since these are cheap devices and it looks to me like it would just increase costs) anywhere on the internet, and was wondering if there's some kind of specific name for it that I'd need to google to find out more. 108.29.92.115 (talk) 08:43, 13 June 2021 (UTC)[reply]

Periodic table

If you see a periodic table, this for example (I take this from wikipedia, so no there are any problems of copyright in theory), you see the position of Lantanio and Attinio (I dont know the english name, La and Ac). I am a question about La and Ac, I don't understand if they are members of the group IIIb. Seems yes but I have got indecision. Can you answer me? In what group they appartainment? Thank you --79.30.183.69 (talk) 17:44, 9 June 2021 (UTC)[reply]

This has been one of the biggest disputes among chemists. The rational thing to do would be to adopt the 32-column periodic table and think of them as group 3 elements while the elements scandium, yttrium, lutetium, and lawrencium are group 17 elements (numbering the groups from 1 to 32.) Georgia guy (talk) 17:51, 9 June 2021 (UTC)[reply]

We have Group 3 element#Dispute on composition, with lots of technical analysis of the situation. DMacks (talk) 18:27, 9 June 2021 (UTC)[reply]

(edit conflict) The answer is "whatever is more useful to you". Group 3 element notes that most modern chemists include lutetium and lawrencium as the period 6 and 7 elements in Group III, while older sources may have favored lanthanum and actinium, and some systems include NO period 6 and 7 elements in the group, OR including all of the f-block elements in the group. The entire point of groups of the periodic table is to keep elements with similar properties together. In terms of properties, essentially all of the f-block elements share a lot of common properties (part of what made the Lanthanides so hard to isolate is that they are basically chemically and physically indistinguishable from each other). At some point, someone decided that the electron configuration was the most important thing to consider (and there's really a strong argument to be made that it isn't, but whatever), and spectrographic analysis determined the ground state configuration of lutetium and lawrencium better matched that of scandium and yttrium, but in all honesty, there's not a lot of agreement on the matter. Ultimately, there periodic table is a tool that helps chemists do their job better, and there's not a lot of lutetium chemistry out there to do; making the matter the wonkiest of chemistry debates; ultimately no one ever really came to an agreement on it because its not that big of a deal. --Jayron 32 18:29, 9 June 2021 (UTC)[reply]

Bunch of interesting sandwich compounds of lutetium, such as Lutetium phthalocyanine, and some tuck-over complexes. "A little niche" might be a nice way to describe it. Lutetium#Chemical properties and compounds needs some attention. DMacks (talk) 18:48, 9 June 2021 (UTC)[reply]

There are long discussions in archival Talk pages, for example Talk:Periodic_table/Archive_12 where the few Wikipedia editors for whom the Group 3 question is a big deal have debated the issue. The OP may feel that this is WP:TLDR — and I would agree. Mike Turnbull (talk) 10:35, 10 June 2021 (UTC)[reply]

See bikeshed effect. --Jayron 32 16:04, 10 June 2021 (UTC)[reply]

June 11

Aquatic Locomotion of Apes

Looking at Aquatic Locomotion (after watching Disney's Tarzan), are there any apes which are even close to Humans in their ability to swim? (Let's say > 100 meters) Naraht (talk) 00:46, 11 June 2021 (UTC)[reply]

This study details two apes who learned to swim in captivity. The max distance reported was about 12 meters (less than half a swimming pool), so not very good compared to even the average person. Even so, these apes are very unique in their ability to swim, as wild apes avoid deep bodies of water, and few reports of them swimming have been made. Zoos typically use water moats as an effective way to keep apes in their habitats, for example to prevent them climbing up the walls. The article concludes that the lack of swimming ability in apes is due to behavioral differences as a result of the terrestial life of apes and not any innate physical barriers. It also notes humans do not swim instinctively either, meaning swimming is not a natural ability of ours but rather an ability we invented. Pinguinn 🐧 01:31, 11 June 2021 (UTC)[reply]

I call the last assertion into doubt. I have read on several occasions that young babies spontaneously exhibit natural swimming ability when introduced (under close supervision, of course) into sufficiently deep water, and I myself personally witnessed a young baby of barely walking age accidentally fall into a model boating lake (in Gorleston-on-sea) and swim using doggy paddle quite effectively and with apparent enjoyment (audibly laughing) for several seconds until an adult rescued it.

I would not dispute that this ability is seemingly lost once children become older, and has to be re-learned later, but I hypothesize that this may be due to cultural practices which do not permit early instinctive swimming to be continuously practiced.

My dim childhood memories of the Tanka (or boat) people of Hong Kong (where I lived on the Stanley Peninsula for two years), is that their children of all ages down to babyhood routinely swam, but given the span of time (approaching 60 years) and my lack of observational rigour at age 6–7, I may be mistaken in this. {The poster formerly known as 87.81.230.195} 2.122.0.58 (talk) 04:46, 11 June 2021 (UTC)[reply]

"Re-learned" is not the appropriate term, since the "swimming" of newborn infants is part of a set of neonatal reflexes on submersion and not learned behaviour. These reflexes disappear spontaneously and are typically gone when they are about one year old, when the infant becomes a toddler and starts loosing the baby fat that helps to keep them afloat. Early supervised "swimming" may make the child feel comfortable in deeper water, but swimming lessons before that time will not be very effective in terms of later swimming ability. --Lambiam 07:13, 11 June 2021 (UTC)[reply]

We have an Infant swimming article, that includes mention and links to the relevant reflexes. DMacks (talk) 14:11, 11 June 2021 (UTC)[reply]

Here is a video of a mandrill swimming for about 40 seconds (or at least managing not to drown) between jumping into the middle of a moat and succeeding in getting out. --Lambiam 07:23, 11 June 2021 (UTC)[reply]

Not apes, but primates at least, Japanese macaques are known to swim in hot springs - see JAPANESE MACAQUE SWIMMING. Alansplodge (talk) 12:54, 11 June 2021 (UTC)[reply]

"This video may be inappropriate for some users. Age-restricted video (based on Community Guidelines)". Of all the inappropriate crap on Youtube, this is what they flag? DMacks (talk) 14:09, 11 June 2021 (UTC)[reply]

Extracting energy from hydrocarbons without producing CO or CO2

Does any chain of reactions exist which is exothermic, takes hydrocarbons and abundant gases (such as oxygen or nitrogen) as reagents, and does not produce carbon monoxide or carbon dioxide as an end product? Neon Merlin 04:25, 11 June 2021 (UTC)[reply]

This is the first result I found using your header in Google. --Jayron 32 14:03, 11 June 2021 (UTC)[reply]

Jayron32's link includes a Youtube video >1h, but the slides are available separately here. Be warned that it is a fairly chemistry-heavy presentation. Tigraan^{Click here to contact me} 14:59, 11 June 2021 (UTC)[reply]

If your definition of "hydrocarbon" includes dihydrogen, then H2 + 0.5 O2 -> H2O fits the bill. Hence the current hopes about hydrogen. Now, onto the question of how to produce it... Tigraan^{Click here to contact me} 14:59, 11 June 2021 (UTC)[reply]
You can get hydrogen from hydrocarbons, with no CO2 production, via pyrolysis. --Jayron 32 16:28, 11 June 2021 (UTC)[reply]

In regards to Rep Gomert's question.

In regard to: https://thehill.com/homenews/house/557558-gohmert-asks-if-federal-agencies-can-change-earth-or-moons-orbits-to-fight

Would a unified Humanity (Beijing, Moscow & DC's biggest dispute is in the sport of Curling) within 15 years be able to noticibly (either 1% decrease or 1% increase) alter the expected change in the Moon's Orbit year over year? (Significantly changing the appearance of the surface of the moon from the explosion is just fine)

The closest that I've seen to calculating this actually a larger question in regards to Space:1999 indicating that all of the energy produced by humans wouldn't be enough to accelerate the moon even out to Mars Orbit, must less interstellar...Naraht (talk) 16:07, 11 June 2021 (UTC)[reply]

It is more likely that this was an example of a politician who used a leading question, in a form of grandstanding, in an effort to disclaim any agency or responsibility for addressing the real problem: in other words, you're trying to parse an argument based on logical fallacy in a quest for some kernel of scientific accuracy.

If you're actually interested in the science, here is a nice open-access review article from American Geophysical Union: Reflecting on 50 years of geoengineering research (2016). "...Leading experts in the field of geoengineering research ... contribute brief reflections on the development of the discussion over the past decade and to consider where it may be going in the next 10 years..."

The point is, real scientists have scientifically considered whether humans have the capacity to use our technology to intentionally substantially alter Earth's climate. Changing the orbit of Earth, its moon, or any other astronomical body, is not the most prominent plausible path in the near-term.

When a politician asks a question to which the answer is an already-known negative, the politician is probably not seeking new information - they are probably trying to perpetrate one or more logical fallacies - in this case, I would say an association fallacy - by planting the seed-idea in the listener's mind: if we can't change the orbit, why should we do anything?

Phrased another way: politicians are not stupid - and they're not even necessarily scientifically illiterate - they just act that way when it serves their interest. Arguments - especially in the United States Congress - are frequently won through intentional application of logical fallacy, inaccurate fact, and emotional manipulation: when facts are not on your side, why bother using them?

Nimur (talk) 16:27, 11 June 2021 (UTC)[reply]

Louie Gohmert is more full of shit than a manure truck. I would pay him less than no mind on any utterance from his mouth. He is on record saying that masks cause COVID-19 and is also on record as saying that the Alaska pipeline would lead to increased fecundity of caribou. His nonstop and incessant bullshit isn't even worth fact checking. You can ignore anything he says, and doing so will likely make you all the smarter for it. --Jayron 32 16:33, 11 June 2021 (UTC)[reply]

Some politicians say crazy stuff just to get the media riled. Like when Trump talked about ingesting Lysol to treat COVID. ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:14, 11 June 2021 (UTC)[reply]

He was musing aloud whether injecting disinfectants, presumably in patients' veins, might treat COVID-19, after considering internal UV irradiation (by mini UV lamps circulating in the bloodstream?). I believe this was meant to be a serious suggestion, which he hoped experts would consider. --Lambiam 21:21, 11 June 2021 (UTC) ([Watch on YouTube].)[reply]

Trump has a sadistic "sense of humor", so it's hard to know for sure what he was on about. ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:50, 11 June 2021 (UTC)[reply]

Trump likes reading Facebook and has the kind of conspiracy theorist mentality that's open to any ideas that are strongly opposed by 'mainstream media' (ie, the entire scientific community and anyone with a modicum of education), and I suspect that he was genuinely musing about the possibility of using so-called "Miracle Mineral Supplement" to treat COVID, which was being touted on Facebook at around that time.

The Guardian reported that while the source for Donald Trump having suggested coronavirus could be treated with disinfectants remained unknown, Mark Grenon had written a letter to Trump only days earlier recommending MMS as a treatment, as well as posting on social media and sending a bottle of MMS to the White House.^[1]

nagualdesign 22:58, 11 June 2021 (UTC)[reply]

References

^ Pilkington, Ed (24 April 2020). "Revealed: leader of group peddling bleach as coronavirus 'cure' wrote to Trump this week". The Guardian. Retrieved 2 February 2021.

(ec)No, mankind (at the current technological level) is not be able to change the orbit of the moon by one percent either way, much less within 15 years. The moon weights 7.342E22 kg. The gravitational force between Earth and moon is about 2E20 N. For a 1% distance, we can assume gravitational attraction to be nearly constant, so you would need to move the moon 3844000 m (1% of the average distance) against a force of 2E20 N, so an energy of 7.688E26 Joule. Or of 24378488077 Gigawatt-Years. Unless I dropped a zero somewhere, that is 1.2 Million years worth of the current total primary energy production of humanity. --Stephan Schulz (talk) 16:43, 11 June 2021 (UTC)[reply]

I rather doubt Stephan Schulz's reasoning here, even though the result is probably in the correct ballpark. I think they make the assumption that moving the moon requires to apply a force equal (or similar to) the gravitational pull of Earth on the Moon (and then calculate the work for a given distance). That assumption is not correct: if we fired a laser pointer at the Moon, the radiation pressure would be very low and the change of orbit over a year negligible, but it would slightly affect the trajectory, and with enough patience the desired deviation could be achieved.

However, because gravitational forces are conservative, we can make a reasoning of potential energy. Displacing the Moon requires to change its (gravitational potential + kinetic) energy/ies. Now, the derivative of gravitational potential energy with distance is equal to the gravitational force, but the change in kinetic energy is not zero. Younger me knew how to do the calculations, but older me will just say that Kepler's third law will probably tell us that the change in kinetic energy is of the same order of magnitude as the change in potential energy at least when moving on different circular orbits. Hence taking the change in potential energy alone gives more or less the good result (again, that reasoning only works because gravitation is conservative). Tigraan^{Click here to contact me} 17:18, 11 June 2021 (UTC)[reply]

You think wrongly. I do not assume that any particular force has to the applied, just the old Energy=Force times Distance. But yes, I did not take kinetic energy into account. --Stephan Schulz (talk) 17:27, 11 June 2021 (UTC)[reply]

According to the virial theorem, the kinetic energy is exactly -1/2 times the potential energy. PiusImpavidus (talk) 09:33, 12 June 2021 (UTC)[reply]

Thanks! There was something nagging about 1/2 in my hindbrain. So 600000 years worth of current world energy production. That's about twice the time span of Homo Sapiens on Earth. If, given the question, we keep using that name ;-). --Stephan Schulz (talk) 11:27, 12 June 2021 (UTC)[reply]

Scott Manley's just posted a video about this: How to Move The Planet Earth To Save It From The Sun nagualdesign 18:32, 11 June 2021 (UTC)[reply]

If I carefully read the question (I didn't read the link though), it's not about a 1% change in the Moon's orbit, but a 1% change in the expected change of the Moon's orbit. The Moon's orbit changes at about 38mm per year (in semimajor axis), which makes the question: Can we change the speed of the tidal evolution of Moon's orbit by ±0.38mm per year within 15 years? That might be closer to feasible. Suppose we build dams connecting France to England and Scotland to Norway. This has been seriously proposed to protect the North Sea and Baltic coasts from sea level rise. That would eliminate tides from the North Sea, affecting the transfer of angular momentum by tidal forces between Earth and Moon. I doubt it would be a 1% change, but it won't be off by many orders of magnitude and may be measurable. Now, we can't build those dams in 15 years, but we can build them before the end of this century. PiusImpavidus (talk) 09:33, 12 June 2021 (UTC)[reply]

We can reuse Stephan Schulz's calculation which he made for another distance of 3.8e6m. We want here the result for 3.8e-4m, so it is easy to compute by multiplying the result by 1e-10. They found that the energy for their one-time pull was 1.2Mhyp (where hy=human year of production), so a one-time pull of 0.38mm requires 0.12 mhyp, or 0.01% of yearly primary energy production. While there would surely be massive engineering challenges in how to transfer that energy to push the Moon away or pull it in, and probably large conversion losses, it does look like it could be achieved. Tigraan^{Click here for my talk page ("private" contact)} 10:36, 14 June 2021 (UTC)[reply]

Pumping massive amounts of CO2 in our atmosphere causing a large sea-level rise is pretty much the only thing we can do that can have a measurable impact on the lunar orbit, see here. Count Iblis (talk) 12:19, 12 June 2021 (UTC)[reply]

June 12

Chemistry questions.

1. Combination reactions can be exothermic or endothermic, but are more often exothermic. Decompositions reacts are therefore mostly endothermic. What is the pattern for combination reactions that are exothermic, and endothermic?

2. When magnesium sulfate is placed in water, temperature of water rises, and when ammonium nitrate is put in water, temperature of water gets cold. Is there a pattern for this? And these I believe are not considered to be decomposition reactions, they are simply "placing in water" reactions because the opposite would be "taking them out of water" reactions which is not combination reactions. But I believe the answers have something to do with hydrogen bonds and hydration. I heard it is more easily to predict by looking at the cation-end. And if you criss-cross these 2, meaning magnesium nitrate and ammonium sulfate, then putting them in water is more of a neutral change in temperature yes. Thanks. 67.165.185.178 (talk) 07:51, 12 June 2021 (UTC).[reply]

Your second paragraph shows some confusion, so I will take a few steps back to the basics.

Atoms "want" to have around them a number of electrons that fits properly the outer atomic orbital (in many cases, this means the same number of electrons as the closest noble gas). This can be achieved by taking or giving away electrons from other atoms, but the resulting ion has an electric charge, and will therefore "stay close" to other ions so that the resulting ionic compound is net neutral. The introduction of our article ionic bonding is well-written and worth a read. Another way is to share two electrons more or less equally between two atoms (a covalent bond).

Breaking a bond (covalent or ionic) costs energy, while making one yields some. (The article is bond energy but it is rather poor.) Hence, in a chemical reaction, the "combining" is exothermic and the "breaking" is endothermic. (This is why many reactions require an initial "push" to start, to overcome the activation energy.) However, breaking a covalent bond usually creates highly unstable stuff which will immediately recombine, so (most?) macroscopic reactions involve some breaking and some combining. There is no real way to tell whether they are exo- or endothermic, apart from taking the bond energies from a handbook and computing the balance. (Also, I make it sound like dissociation energies can be computed as the sum of bond energies, but in reality there are non-local effects - for instance, the dissocation energies of E-Z isomers is not always the same.)

"Placing in water" ionic compounds (such as magnesium sulfate or ammonium nitrate) causes a dissolution reaction. Depending on the size of the chunk of solid you toss in, you might think nothing is dissolved, but some of it is (up to the solubility limit and subject to how quick the reaction occurs). The equation of such a reaction (for instance MgSO
₄→Mg²⁺
+SO²⁻
₄) makes it look like there is only breaking going on, no bond forming, and hence it should be endothermic. However, the trick is that the starting compound is in solid phase, while the resulting ions are in aqueous phase, which means solvation should be taken into account. In the case of water, this usually means hydrogen bonds, indeed.

How many hydrogen bonds form for a given ion and the energy of those is not a trivial thing to assess. This Quora answer claims that dissolving an anhydrous salt is usuall more exothermic than dissolving a hydrate, and I find the reasoning fairly persuasive, but I have no reference to back it up. Tigraan^{Click here for my talk page ("private" contact)} 10:01, 14 June 2021 (UTC)[reply]

Oh yes, solvation. I'm looking at the solubility rules, and both nitrate and sulfate are both soluble. Nitrates are generally soluble, and, for sulfates, most sulfate salts are soluble, important exceptions to this rule include CaSO4, BaSO4, PbSO4, Ag2SO4 and SrSO4. Given that both were soluble, I find it odd 1 is still exo and 1 endo. 67.165.185.178 (talk) 14:25, 14 June 2021 (UTC).[reply]

~~The above user admits to evading a ref desk ban.[2]~~ ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:43, 14 June 2021 (UTC)[reply]

No, they don't. 1 year from May 2020 is May 2021, and it is currently June 2021. They are not evading an active ban. You've already been told this, so please drop the false ban-evasion accusation. --OuroborosCobra (talk) 16:46, 14 June 2021 (UTC)[reply]

You're right. He posted on June 10th and spoke about it in the present tense. Fooled me. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:45, 14 June 2021 (UTC)[reply]

stem cell from living humen

How do biologists extract stem cells from human hair? For example, to grow fresh skin?--178.10.6.170 (talk) 10:51, 12 June 2021 (UTC)[reply]

I'm pretty sure they are not collected from hair. I also don't think we've gotten to regrowing skin yet, that would be major news. Typically adult stem cells needed for a particular use to be gathered from the same or similar organ or tissue type. Bone marrow, or other tissue samples are taken with a Jamshidi needle or other biopsy tool, and then, it seems, plated on a dish and encouraged to divide with hormones. Those cells that show lots of divisions and look undifferentiated are then gently collected and put in a cell culture flask which is kept moving on an agitator. Abductive (reasoning) 11:40, 12 June 2021 (UTC)[reply]

You are both right and wrong. Stem cells per se aren't collected from hair. However cells from hair follicles are routinely collected to make iPSCs, which are arguably a form of stem cells (this terminology is a pet peeve of mine, I won't bore anyone with details), and these can indeed form skin or indeed pretty much anything else. They have in fact been grown from my own hair follicles. This seems to be what the OP is talking about. Fgf10 (talk) 08:05, 13 June 2021 (UTC)[reply]

We have an article at Stem-cell therapy that explains the sources and procedures in its section on sources_for_stem_cells. Matt Deres (talk) 12:41, 12 June 2021 (UTC)[reply]

June 13

Does person feel orgasm if he/she have Congenital insensitivity to pain medical condition?

Our article Congenital insensitivity to pain doesn't discuss about Orgasm anywhere. Rizosome (talk) 03:14, 13 June 2021 (UTC)[reply]

Why wouldn't they? Orgasm is not normally painful.--Shantavira|^{feed me} 08:07, 13 June 2021 (UTC)[reply]

Orgasm uses some of the same pathways as pain. There is overlap in the scientific literature on this, nothing conclusive. It may depend on which gene is not functioning. Patients with congenital insensitivity to pain are extremely rare. One patient, when given naloxone to treat his insensitivity, reported that he was feeling an all-over-his-body orgasm, which suggests that 1) there is a connection, and 2) he already had been having orgasms. Abductive (reasoning) 10:41, 13 June 2021 (UTC)[reply]

June 14

Tidal forces from a black hole

If a white dwarf or a neutron star were orbiting a black hole, could they be ripped apart by the tidal forces from the black hole’s gravity? I’m wondering how much the white dwarfs’s(and neutron star’s) own strong gravity would protect it. Rich (talk) 18:21, 14 June 2021 (UTC)[reply]

See tidal disruption event for the more general phenomenon (where the disrupted star is usually not a white dwarf or a neutron star). There's a review volume [3] with articles on various aspects of this topic, where one of the articles [4] covers disruptions of a white dwarf. You can also find a preprint of this article on arxiv: [5]. As you say, the white dwarf's own gravity is quite important. Eq. 2 in the chapter gives a simple formula for the tidal radius, that is, how close the white dwarf must get to the black hole before tidal disruption begins. Although this type of event should be possible, it does not seem that they have been observed so far. There are also some articles on tidal disruption of neutron stars, where the idea seems to be that the tidal disruption can change the gravitational wave signature of the NS-BH merger: [6], [7]. --Amble (talk) 20:04, 14 June 2021 (UTC)[reply]

So far, there are no definite detections of a NS-BH merger at List of gravitational wave observations. But there has been an observation of what might be a gravitational wave event that might be associated with something that might be a gamma-ray burst that all might have come from a NS-BH merger that might have involved tidal disruption of the neutron star: [8]. --Amble (talk) 20:21, 14 June 2021 (UTC)[reply]

It has also been suggested that a neutron star's own gravity might participate in the merger by eating it from the inside rather than protecting it: [9] --Amble (talk) 20:23, 14 June 2021 (UTC)[reply]

(I was fascinated to learn about the candidate event and the precursory collapse idea, so thanks for leading me to those!) --Amble (talk) 20:27, 14 June 2021 (UTC)[reply]

What happens if you drink liquid methane?

This is a question my child asked me. I know it's ridiculous, but I told him I'd ask! So, what would happen if you drank liquid methane?173.54.208.122 (talk) 19:01, 14 June 2021 (UTC)[reply]

How old is this child and what context led them to this question? As methane has a boiling point of -182 °C, your mouth, esophagus, and stomach tissue would very quickly freeze, and I imagine things go downhill from there. 0 out of 10, would not recommend. --OuroborosCobra (talk) 19:33, 14 June 2021 (UTC)[reply]

From [10]: "Skin contact with liquefied Methane can cause frostbite"

Also read: Methane#Safety--Bumptump (talk) 19:37, 14 June 2021 (UTC)[reply]

I think the blood in the arteries may start to freeze as the liquid goes down the esophagus. The ascending aorta and the common carotids run close.^[11] Although they are separated by the trachea, −182 °C (−296 °F) is really really cold. Ice crystals in the blood may cause an embolism cutting off the blood supply to the brain. Another risk, which I think is real, is that the methane will boil fervidly, causing the stomach to explode. I recommend not to try this at home or elsewhere. --Lambiam 21:57, 14 June 2021 (UTC)[reply]

Liquid nitrogen has a very similar boiling point. I suggest you check our article on liquid nitrogen cocktail. I quote:
On 4 October, an 18-year-old woman (...) was admitted to hospital with severe abdominal pain and shortness of breath after drinking a cocktail prepared with liquid nitrogen while celebrating her birthday at a bar in Lancaster city centre.[6] A medical team diagnosed her condition as perforated stomach, and performed a gastrectomy to save her life.[6].
. Your effect will be similar enough, provided the evaporating methane doesn't ignite before you get to that point. Fgf10 (talk) 22:56, 14 June 2021 (UTC)[reply]

June 15

Why do hot bodies emit smokes sometimes but won't emit smoke ?

I went to industry, where they produced hot rebar coils. I only see mirage effect above coils but not smoke. Why do hot bodies emit smokes sometimes but won't emit smoke ?Rizosome (talk) 04:05, 15 June 2021 (UTC)[reply]

Smoke is just soot, and usually carbon specifically. A substance has to oxidize to produce soot. If there was nothing in the rebar that would oxidize (burn) at the temps experienced, there wont be any smoke. --50.234.188.27 (talk) 04:57, 15 June 2021 (UTC)[reply]

[1] Pilkington, Ed (24 April 2020). "Revealed: leader of group peddling bleach as coronavirus 'cure' wrote to Trump this week". The Guardian. Retrieved 2 February 2021.

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