April 17

Hi. The medical field has been using Modified-release dosage tablets/pills/capsules for decades.

Today, I heard about Nicotine pouch on the news. I have never came across this delivery method before, so it got me curious. Nicotine pouch slowly release Nicotine over time, in an analogous way as modified-release dosage tablets/pills/capsules slowly release medication over time.

1. Are there any medication that is delivered via the pouch method?

2. There are Nicotine pouch, Nicotine patch, Nicotine gum, and Nicotine Lozenges[1] that is kept in the mouth but must not be swallowed. There are probably many other nicotine delivery methods that I am not aware of. Are there any Modified-release dosage nicotine tablets/pills/capsules that you swallow?

3. To the best of my knowledge, it seems like almost every nicotine delivery method that goes in the mouth is kept in the mouth, and must not be swallowed. Is there a reason for this?

OptoFidelty (talk) 05:28, 17 April 2024 (UTC)[reply]

• It seems that nicotine causes nausea and vomiting when it hits the stomach. Also, the stomach acids destroy it, according to Quora. This article says that a time release pill for treating ulcerative colitis with nicotine gets a lot of nicotine where it's needed in the colon, but not so much in the bloodstream. The nicotine in the pouches and other delivery methods needs to travel across the mucous membranes, skin, or lungs to get people feeling good. Abductive (reasoning) 10:37, 17 April 2024 (UTC)[reply]

Thank you! OptoFidelty (talk) 18:53, 17 April 2024 (UTC)[reply]

Some medications (and foods) besides nicotine are being packaged in edible film pouches or capsules. [2] It's been studied for new methods of drug delivery [3] but I haven't personally seen anything other than self-medications taken with these kinds of pouches. Reconrabbit 01:42, 19 April 2024 (UTC)[reply]

April 20

One of my favorite webcomics, Saturday Morning Breakfast Cereal, once made a joke about Xia's five-body configuration (comic here). I went looking for what it was talking about and found our article on the Painlevé conjecture, to which I added a redirect-with-possibilities. As an aside, the article could use some TLC; the most glaring problem is that it introduces variables without saying what they represent.

Anyway I was trying to figure out where this infinite energy was supposed to be coming from. My best guess so far is that the five bodies are idealized as point masses, which means that the gravitational energy released as you let two of them approach one another grows without bound. This of course would make them black holes in our actual universe, so that energy wouldn't be available, but in the universe of the comic, I guess this wouldn't be a problem (I've never thought very deeply about what happens to general relativity as c approaches ∞, so I'm not sure about that). But in any case there's no new energy appearing that wasn't there before, so the comic's claim that "the universe collapses" seems wrong.

No, really, I actually do have a sense of humor. I just want to know if I've understood this correctly. Does anyone have a different understanding? --Trovatore (talk) 19:50, 20 April 2024 (UTC)[reply]

O/T That article rather overeggs the pudding. The various proofs are for the 2d case ie planar. Perhaps it is obvious that if it works in 2d it'll work in 3d. Greglocock (talk) 21:22, 22 April 2024 (UTC)[reply]

I'm not too sure what it means to "overegg the pudding" but I was not interpreting the configuration as planar; if that's correct then I've misunderstood the drawing. Can you point me to why you say that? --Trovatore (talk) 21:43, 22 April 2024 (UTC)[reply]

It means exaggerating the utility of . The repeated use of the word planar is what I was getting at.Greglocock (talk) 05:45, 23 April 2024 (UTC)[reply]

The last section of the AMS article by Saari and Xia has this: "While we now know that noncollision singularities exist, several mysteries remain. Any partial listing has to include whether n = 5 is the cut-off for this surprising behavior, or whether the four-body problem can propel particles to infinity in a finite time. Can, for instance, Anosov’s suggestion be carried out? Are there planar examples with small n values?" This implies IMO that Xia's construction is non-planar. I think the sketch of the construction also implies this: the orbits of the pair of point masses m₁ and m₂ are said to be parallel to the x-y plane and highly elliptical, while m₃ moves along the z-axis. The orbits of the pair m₄ and m₅ are also orthogonal to the z-axis, with their major axes shown at an angle to those of m₁ and m₂ in the accompanying figure.  --Lambiam 12:52, 23 April 2024 (UTC)[reply]

Energy borrowed from the potential energy shed by point masses approaching each other closely but not, in the finite time, "arbitrarily closely", can only be finite. To reach infinity their distance has to become less than any positive number, which means it is zero. Doesn't that qualify as a collision? What is worse, in Jinxin Xue's 4-body solution all four bodies are said to escape to infinity in a finite time. Do they scoot off in four different directions?  --Lambiam 13:18, 23 April 2024 (UTC)[reply]

I believe the idea is this: as you approach the time of the singularity, the separation between some pairs of masses approaches zero, but the positions of those masses diverge to infinity. If you consider a collision to be when two masses have identical, finite coordinates, then that never happens in this scenario. --Amble (talk) 22:59, 23 April 2024 (UTC)[reply]

How hard would it be to construct it from satelitees? Zarnivop (talk) 22:41, 25 April 2024 (UTC)[reply]

You could put satellites in the right pattern at some starting time, but they wouldn’t actually behave as predicted by Xia’s model. That’s because the model requires perfect point masses in a Newtonian universe affected only by one another’s gravitational pull. Real satellites have other forces acting on them, have negligible influence from each other’s gravity, and are not point masses. And of course, real satellites aren’t in a Newtonian universe. —Amble (talk) 02:25, 26 April 2024 (UTC)[reply]

April 23

While adding a brief historical context section to that lemma I noticed some former changes of another IP which I doubt to be correct. Please could somebody countercheck, since I have no access to the referenced Elsevier source documents from which the data has been obviously originally taken. Here the difflinks in question:

• Special:Diff/1218613828 Section or not a section?
• Special:Diff/1218613911 Greater or less than 100.000 Volts? Grounding or grounding substrate?
• Special:Diff/1218614055 Second half of a sentence was removed. Does that make sense?
• Special:Diff/1218614423 Negative or positive? Discharge or charge?
• Special:Diff/1218614559 100 million volts or only 100 volts?

I would tend to revert these unverified changes, they look illogicaly to me, but wanted to ask here first.

Many thanks! --92.117.130.94 (talk) 05:06, 23 April 2024 (UTC)[reply]

P.S.: Maybe there is a need to improve my wording or grammar in the historical section I have added, since I'm not an English language native speaker, sorry if I've used unusual or strange wording. --92.117.130.94 (talk) 05:12, 23 April 2024 (UTC)[reply]

Thanks for noticing. I've reverted these edits because they look like vandalism to me. HansVonStuttgart (talk) 08:13, 23 April 2024 (UTC)[reply]

April 26

Are there analytical expressions that describe how the radii of white dwarfs change with mean molecular weight? JoJo Eumerus mobile (main talk) 19:06, 26 April 2024 (UTC)[reply]

See White dwarf#Mass–radius relationship. The radius goes down fairly quickly as the mass increases. NadVolum (talk) 20:13, 26 April 2024 (UTC)[reply]

The radius depends on the mean molecular weight through the number of electrons per unit mass N. Ruslik_Zero 20:27, 26 April 2024 (UTC)[reply]

Thx. Is there a similar approximation for nondegenerate matter like brown dwarfs? JoJo Eumerus mobile (main talk) 13:56, 27 April 2024 (UTC)[reply]

Brown dwarfs don't really change in radius as their mass changes. Radius stays nearly constant as mass increases from the onset of significant self-compression (about Saturn's mass) to the onset of hydrogen burning (turning into a red dwarf at about 75 Jupiter masses). So they'd all more or less be one Jupiter in radius – you already see the low end of this in the Solar System, with Jupiter not being much larger in radius than Saturn. Double sharp (talk) 18:10, 27 April 2024 (UTC)[reply]

@Double sharp: Does the radius change with mean molecular mass, though? JoJo Eumerus mobile (main talk) 13:07, 28 April 2024 (UTC)[reply]

In terms of their major components, wouldn't brown dwarfs all resemble Jupiter in composition? Particularly so since many would have depleted their deuterium through fusion by the time we observed them. So I kind of doubt mean molecular mass would vary that much between them to produce noticeable changes. But admittedly I'm guessing here. Double sharp (talk) 05:46, 1 May 2024 (UTC)[reply]

April 29

I have discovered by an accurate empirical method that a constant needed in a predictive mathematical formula is 0.986093(7). In the SI metric system, the constants generally turn out to have simple origins, e.g., 2, pi, 4/3 times pi and the like, or fundamental constants such as the speed of light c, which I believe is not relevant here. Can anybody spot the components of 0.9860937 ? I have not been able to deduce it. ```` Dionne Court (talk) 14:35, 29 April 2024 (UTC)[reply]

, or, if you like, . —Amble (talk) 16:37, 29 April 2024 (UTC)[reply]

OK, I'll bite. How did you get that? Greglocock (talk) 00:36, 30 April 2024 (UTC)[reply]

Nothing too clever — I just guessed there should be good matches with for some integer n and p. I tested n by brute force, and for each n, used , rounded to the nearest whole number. There are many possible answers, with n=4 as the first one. Although I took the (7) at the end to be an uncertainty level, and looking again, that may not be what OP intended. —Amble (talk) 03:51, 30 April 2024 (UTC)[reply]

I included brackets around the 7 to indicate that due to random experimental error, the value is centred around 7 but could be anything. Thus you could infer that the 3 before it is accurate (if I made no error in procedure).

The n^-p form doesn't help much because I cannot imagine any reason why it should be so. Its a bit like how we were taught in school to use 22/7 as pi - there is no reason for it, it is just a coincidence that 22/7 evaluates to equal pi to 3 places. It gives no insight into WHY pi equals 3.1416..... ```` Dionne Court (talk) 11:30, 30 April 2024 (UTC)[reply]

Right. The n^-p form is a silly example. The point is that you can produce a matching value in an infinity of ways. Without more information about the underlying process, there's no possible way to know which (if any) may be relevant. The notation I'm familiar with uses parentheses to indicate the standard uncertainty in the final digit (or digits), as shown in the NIST page here: [4]. --Amble (talk) 17:18, 30 April 2024 (UTC)[reply]

You may be interested in this inverse symbolic calculator, though it doesn't seem to recognize your constant. Staecker (talk) 23:31, 29 April 2024 (UTC)[reply]

I love that calculator. I wish I had known about it before. Thanks. ```` Dionne Court (talk) 00:56, 30 April 2024 (UTC)[reply]

I used to work with a lot of predictive formulas and nearly all of them had constants. They were calculated by using large populations and working out a best fit regression formula. The resulting constants were not based on pi or the speed of light or anything recognizable. They were based on average biological processes of humans, such as how many creatinine is cleared by the bladder on average. 12.116.29.106 (talk) 12:40, 30 April 2024 (UTC)[reply]

The problem I have been working on is not a biological process, as you may realise from the six-digit precision of the constant. It is within the realm of physics. In physics one seeks to discover why the constants are what they are and thus understand the process.

In complex biological process, the constants could be any weird thing, as dozens or hundreds of sub-processes are involved. In physics, the constants are usually very simple combinations of integers, pi, squared or rooted, trig identities, whatever. ```` Dionne Court (talk) 02:29, 1 May 2024 (UTC)[reply]

That formula above uses less symbols when printed than the given constant, I think that's pretty impressive. Too many of these approximations are worse 22/7 = 3.1428 with four symbols is only just about shorter if one says the 28 is close to 16. NadVolum (talk) 17:15, 30 April 2024 (UTC)[reply]

355/113 gets pi to six figures past the decimal point, which is eight symbols if you count the 3 and the period. The fraction is only seven characters if you write it without spaces. --Trovatore (talk) 23:23, 30 April 2024 (UTC)[reply]

Of course π itself is just one symbol.... --Trovatore (talk) 23:29, 30 April 2024 (UTC) [reply]

I think they told us in high school to use 22/7 so that we could more easily spot where algebraic cancellation could be used by dumping unnecessary precision. If it was about saving digits, they could have just told us to memorise 3.142. ```` Dionne Court (talk) 02:36, 1 May 2024 (UTC)[reply]

Yeah, I remember problems were often rigged to have a factor of 7 that you could cancel upon approximating pi as 22/7. With 3.14 that would be much harder. Double sharp (talk) 05:48, 1 May 2024 (UTC)[reply]

April 30

Hi all! I was looking through a machine translation of this press release PDF, which seems to indicate that the smart glass used for the walls of one of the toilet designs for the Tokyo Toilet project is locked into the opaque state during months where there's a drop in temperature. This document includes the word "Defects" in the URL, which I assume refers to this design only being operational during certain times of the year as a solution to some unspecified problem, but I'm struggling to find out why/how exactly the temperature affects this toilet's smart glass functionality. It's specifically tricky because trying to perform a cursory search on how temperature affects smart glass seems to mainly pull up info about passive thermochromic smart glass, but other articles and footage of the switch toggle have led me to believe that this is an active and electrically switchable smart glass setup, so unless I'm mistaken, that thermochromic info wouldn't be relevant here. Basically, I'm just looking for any leads as to what's going on here lol thanks! ~Helicopter Llama~ 16:14, 30 April 2024 (UTC)[reply]

Sounds like it's a cholesteric liquid crystal panel or something similar. These were briefly fashionable for electrically switchable opaque/transparent wall panels back in the 1990's. The company I worked for had it on one floor of their high rise head office. They were notorious for not working at low temperatures (< 10 C) and failing completely at high temperatures (> 35 C)

Another possibility is the method used in auto-switching variable darkening welding helmets - I don't know how they work, other than knowing they are battery powered and are controlled by a light sensor. ```` Dionne Court (talk) 02:12, 1 May 2024 (UTC)[reply]

May 1

If a copy of Jupiter (with a copy of all the moons) was a rogue planet freely floating in space, how close would it have to be to the Solar System for us to be able to detect it? And how close would it have to be for us to be able to detect the Galilean moons? Double sharp (talk) 05:58, 1 May 2024 (UTC)[reply]