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July 9

true taxa

true bug, true dog, true eel, true fly, true fox, true nut, true owl, true rat, true ray, true rib, true yam, true aloe, true arch, true crab, true crow, true deer, true fish, true frog, true goby, true mass, true mole, true seal, true sole, true toad, true tuna, true wren, true adder, true berry, True Brown, true conch, true conga, true eagle, true finch, true grass, true lemur, true loach, true melon, true morel, true mouse, true mulga, true myall, true oxlip, true sedge, true shrew, true snail, true squid, true value, true viper, true widow, true bantam, true cereal, true cherry, true cicada, true clover, true corals, true daikon, true ginger, true indigo, true limpet, true mosses, true mussel, true myrtle, true oriole, true oyster, true parrot, true pigtoe, true shrimp, true spider, true thrush, true weevil, true buffalo, true cricket, true gharial, true herring, true katydid, true lemming, true lobster, true sparrow, true unicorn, true violets, true warbler, true armyworm, true babystar, true believer, true cardamom, true cinnamon, true forester, true lavender, true mangrove, true opopanax, true plantain, true redstart, true sergeant, true ungulate, true wild dog, true crocodile, true fig shell, true fox sedge, true jellyfish, true lac scale, true millipede, true plantains, true predation, true quillwort, true scorpions, true silk moth, true stinkwood, true tree frog, true water bug, true chinch bug, true eques cory, true fire skink, true horn snake, true salamander, true sandalwood, true slime mold, true woodpecker, true cattleheart, true dung beetle, true glass snails, true insectivores, true service tree, true armyworm moth, true forget-me-not, true yellow mombin, true water moccasin, true castor oil plant, true funnel-web spider, true mountain-mahogany, true lover's knot (moth)

What determines which clade of a polyphyletic group gets to be "true"? —Antonissimo (talk) 10:36, 9 July 2026 (UTC)

Starting with "true bug", it looks like specialists in the field have come up with those designations. ←Baseball Bugs ^{What's up, Doc?} carrots→ 12:21, 9 July 2026 (UTC)

There's not going to be a single answer for all that stuff, but the broad answer is that it developed as biologists, especially taxonomists, tried to separate out the popular names for organisms into more logical groups. The bug example there is still very active: "bug" gets used for all kinds of living things, ranging from true bugs to beetles to all insects to all arthropods to anything small that isn't furry to... etc. To help solidify that, the members of Hemiptera started being called "true bugs". The issue is that taxonomy turned to be way more complicated that anyone could have conceived, especially with the introduction of genetically-informed cladistics. So, taxonomists started creating more and more "true" categorizations, largely to combat polyphyly and paraphyly. Which side retains the virtuous and glorious "true" designation versus getting slapped with the "false" (or other) moniker? Its going to come down to what seems to work best for the people involved, including how hard it will be to switch things. In the case of true spiders, the choice would really come down to saying, "Okay, tarantulas are distinctly different from all other spiders. We could make up a new name for spiders + tarantulas (spatulas?) - but since people popularly consider tarantulas to be a kind of spider, the taxonomists (apparently J. Coddington, but it's not 100% clear to me) went the bug route and instead narrowed the definition into "true spiders". Matt Deres (talk) 17:41, 9 July 2026 (UTC)

Which genus were the true believers assigned to again?  ​‑‑Lambiam 05:36, 10 July 2026 (UTC)

Maybe the subspecies Homo sapiens semi. ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:39, 10 July 2026 (UTC)

Well, for crocodiles, there were species that were called "crocodiles" as common names before scientific classification was a thing. These animals were united with alligators and gharials in a larger group known as "crocodylians" which are also called "crocodiles" for short. The "true crocodiles" are those species that were called crocodiles before science got hold of them. This group may also be taken to include extinct species more closely related to modern crocodiles than to modern alligators. Oddly enough, crocodilians (including true crocodiles) trace their ancestry back to a group known as "pseudosuchians", which means "false crocodiles". A group called "true ____" is most often going to be the largest, most coherent group of organisms called ____ that exists. -- User:Khajidha (talk) (contributions) 19:53, 13 July 2026 (UTC)

Extinction rate or intensity

I just heard a lecture in which the lecturer said that extinction currently is higher than in the last 10 million years. That caused the question „What happened 10 million years ago? Was there a mass extinction event in the middle of the Tortonian?“ The lecturer replied, with typical scientist restraint, that the “10 million years” was just to express that we don't have secure enough data for earlier times.

Extension intensity without the present one

This led me to consider the diagram shown here. I see two problems with it:

1. For no communicated reason it omits the most interesting increase of extension intensity - the current one.
2. The label for the ordinate is not correct, as a simple dimensional analysis shows: Extinction intensity is not, as implied by measuring it in %, a dimensionless quantity, but ${\mathsf {T}}^{-1}$. The error in this diagram is worse than a mere choice of words, since the reader is given no clue what time period is used. Without that information, the information has no numeric value. (The summary of the file itself is a bit more helpful, at least mentioning “in each interval of time”, but it also fails to indicate which intervals were used for the diagram.) Since “extinction intensity” is a redlink, unsourced and not as clear, I would call such a quantity “extinction rate”. (That's currently a redirect with no explanation at the target.).

With that, back to the question: Is there any diagram that would show all extinction rates? (Ideally with error bars, to honor the scientist's concern.) ◅ Sebastian Helm 🗨 14:25, 9 July 2026 (UTC)

So why did you ignore this definition in the summary for the file "This figure shows the genus extinction intensity, i.e. the fraction of genera that are present in each interval of time but do not exist in the following interval. "? A simple dimensional analsysis indicates that the y axis is a ratio and is hence dimensionless.Greglocock (talk) 05:30, 11 July 2026 (UTC)

I didn't ignore it: I even cited it! Please reread what I wrote. ◅ Sebastian Helm 🗨 13:18, 11 July 2026 (UTC)

Um so the lede to para 2 is nonsense. Why would I read more nonsense? I normally stop reading at the first error. Greglocock (talk) 22:18, 11 July 2026 (UTC)

Don't have children then, and don't work with other people, or pets. Rich (talk) 01:58, 22 July 2026 (UTC)

The diagram seems to show exactly what it claims to show and that's something I wouldn't call extinction rate. For the background extinctions, the given percentage depends on the duration of the time intervals and drops with shorter intervals. The length of the intervals isn't given in the description. Judging from the width of the columns in the diagram, between 150 and 200 Mya the time interval seems about 2 My, but looking at the interval 250 to 300 Mya, it seems more like 5 My. If the time interval indeed changes, the diagram is useless for the background extinctions. For single extinction events, much faster than the chosen time interval, the height of the peak is independent of the interval, but a shorter interval would make the peak thinner.

For something called extinction rate, I agree that this ratio must be divided by the duration of the interval, giving a dimension of inverse time. This makes the background extinction rate independent of the chosen time interval (and it can be varied with available data), while making the peaks of single events taller and thinner with shorter intervals, keeping the integral constant. For a single, unresolved extinction event, the height of the peak would be useless.

So the current high extinction rate isn't shown in the diagram because the diagram doesn't show extinction rate. Further, it shows the extinctions of genera, not (sub-)species. The disappearance of one or two subspecies of tigers wouldn't be shown until all the big cats were gone. And the diagram focuses on marine genera that fossilise easily, because they provide the best palaeontological data, but for the current extinction event, data on marine genera are relatively poor, with most of the focus being on terrestrial vertebrates. And there may be a systematic difference in the taxonomy of extant genera vs. fossil genera, as classification methods are very different. PiusImpavidus (talk) 09:51, 11 July 2026 (UTC)

Your statement “exactly what it claims to show” presupposes you have an exact definition in mind. Before we dive into details, can you please point me to an article that contains that definition? (Or, if it's in no article yet, we could add it, given appropriate sources.) Maybe that will clarify some misunderstanding I have. Likewise, it would be nice if you pointed me to some article or RS explaining the difference of classification methods you're bringing up. ◅ Sebastian Helm 🗨 13:18, 11 July 2026 (UTC) @Boivie:

A supposition of the diagram seems to be that extinction events are virtually instantaneous on a geological time scale. So the plot is not the graph of a continuous function, but a sequence of smaller and larger spikes, many of which are so close together in the plot that they touch each other. Whether this is realistic and useful or not, I cannot say, but it explains why the y-scale is dimensionless.  ​‑‑Lambiam 21:06, 12 July 2026 (UTC)

Interesting idea; that would be a nice explanation. But what reason do you see for this supposition? To me, it seems contradicted by "This figure shows the genus extinction intensity, i.e. the fraction of genera that are present in each interval of time but do not exist in the following interval." ◅ Sebastian Helm 🗨 17:58, 16 July 2026 (UTC)

July 11

Unique photographic film

My girlfriend has provided me with a curious object: A band of thin plastic film in the colours cyan, magenta, yellow and colourless, quite probably from a longer piece, on which photographic prints can be seen - different on each colour. There are no signs or wording on the film. It is approx. 10-12 cm wide, each colour section 20 cm long. I have uploaded images to Filebin here. Neither she nor the person who gave this to her knows anything else. I am putting this under science because this is probably the effect of scientific research, it may be miscellaneous but I dare say I am not wrong in this. If anyone has any ideas, thank You! --Ouro (blah blah) 10:54, 11 July 2026 (UTC)

Those are CMYK plates used for commercial colour printing. My guess is that the person pictured is an author and these are the plates for use on the back cover of a book. Matt Deres (talk) 12:39, 11 July 2026 (UTC)

Climate reanalysis plot

The climatereanalyzer.org website is now undergoing maintenance, and the custom temperature map plot has been disabled. For other similar sites showing custom temperature anomalymaps, KNMI Climate Explorer is quite similar but its plots do not show political boundaries and it only allows to use standard normal periods (like 1991-2020 or 1981-2010), and not any custom periods of comparison. Is there any other application that allows, on a global or regional map, to compare mean temperatures of a single month to an other single month, from any year to more than 50 years in the past, such as January 1950 to January 1951, or August 1966 to August 1969, on the web and not in e.g. a GRIB file? --40bus (talk) 18:07, 11 July 2026 (UTC)

A minute's search allowed me to find the site . How does it fare as regarding you needs? --Ouro (blah blah) 18:14, 11 July 2026 (UTC)

Itonly allows to create graphs for specific places, not maps. --40bus (talk) 18:35, 11 July 2026 (UTC)

July 13

3-Octanone

From 3-Octanone#Occurrence:

It is produced by oyster mushrooms as an insecticide to kill roundworms.

Shouldn't that be 'vermicide' instead of 'insecticide'? But after looking at the article Vermicide, it seems to be only used for man-made drugs. So what is the correct term for that? Bayahiu (talk) 13:31, 13 July 2026 (UTC)

Roundworm is another name for a nematode, so the correct term is "nematicide". My guess is that 3-octanone is a rather ineffective compound for that purpose but the article's content should be based on the cited source. Mike Turnbull (talk) 13:40, 13 July 2026 (UTC)

I think that's the correct term. Thanks! Bayahiu (talk) 13:44, 13 July 2026 (UTC)

July 14

Purification of cadaver fat

After reading GLP-1s are shrinking bodies. Cadaver fat is plugging the gap, I wonder how the fat from a foreign body is accepted by the patient's immune system. Fat grafting says:

fat processing (processing the extracted fat) and fat injection (reinjecting the purified fat into the area needing improvement).

To ensure survivability, the fat graft should not be manipulated too much and it must be quickly reinjected.

I think that, with a different body, the problem should be harder. -- Error (talk) 14:45, 14 July 2026 (UTC)

While there is no FDA regulation of its procedure, cadaver fat bottling company Tiger Asthetics reassures that the donor's DNA is removed in the purified fat. ~2026-39925-22 (talk) 17:20, 15 July 2026 (UTC)

As far as I know, it is not foreign DNA that causes transplant rejection. That article says:

These antigens are located on the endothelial lining of blood vessels within the transplanted organ

I guess there are few blood vessels in fat tissue, but since autotransplants may fail, I guess there is a fallible cleaning process involved.

--Error (talk) 18:20, 15 July 2026 (UTC)

July 16

Recent JWST study on exomoons?

In a recent Quanta Magazine podcast interview with David Kipping, Kipping mentions a recent study by the James Webb Space Telescope that failed to identify large exomoons around a close analog of Jupiter. Which planet was this, and where can I find this study? –LaundryPizza03 (dc̄) 02:15, 16 July 2026 (UTC)

There was earlier news about some excitement over a possible exomoon of WASP-39b, so further study may have led to a negative, less likely to be reported in pop-science news.  ​‑‑Lambiam 04:39, 16 July 2026 (UTC)

If it's astronomy, physics or mathematics, you can find a preprint on arxiv.org in most cases. In this case, it might be: https://arxiv.org/pdf/2511.15317

Icek~enwiki (talk) 17:50, 17 July 2026 (UTC)

Pricing of Personal Watercraft

I’m hoping to gain a clearer understanding of why small recreational watercraft remain so expensive. For example, RIBs frequently cost around £50,000 despite being built from relatively lightweight plastics and inflatable materials; jet skis are priced similarly to family cars despite being far smaller and mechanically simpler; and outboard engines command premium prices even though they are lighter and less complex than car engines of comparable power. Could you explain the main factors that keep these products at such high price points, and whether emerging technologies, particularly electric propulsion, or changes in manufacturing scale might help bring costs down in the future? I apologise if this is not the right place to ask this, I would appreciate it very much if I could be pointed in the right direction if this is the case. Pablothepenguin (talk) 21:15, 16 July 2026 (UTC)

Consider it from an economics perspective — personal watercraft are a luxury for most buyers, unlike cars, many of which are owned by people who would have a hard time in their daily lives if they couldn't drive. There's much more competition in the automobile manufacturing business than in the personal watercraft business, whilst those buying personal watercraft often have surplus money (otherwise they wouldn't spend so much money on something recreational) and may care less about the specific price. For some luxury goods, higher prices can even increase sales, since the higher price indicates that the good is a status symbol. Nyttend (talk) 00:51, 17 July 2026 (UTC)

If an outboard engine is lighter than a car engine of comparable power, that would explain very well why it's more expensive. Both big ships with huge diesels and small utility boats with outboard engines (similar to moped engines) can be satisfied with a low power-to-mass ratio, but the kind of high-speed boats you're looking into need more power compared to their mass. They're designed to exceed their hull speed, which comes at a big price.

Don't expect too much from electrification. Utility boats, slow recreational boats, even 2000 tonne freighters for river use can be made battery-electric today (or 30 years ago), but those fast boats would drain their batteries too rapidly.

I think this kind of fuel-guzzling recreation is something we cannot afford in these days of climate change.

(Didn't you ask a similar question before?)

PiusImpavidus (talk) 09:06, 17 July 2026 (UTC)

Wikipedia:Reference desk/Archives/Miscellaneous/2024 October 17 § Some vehicle-related questions.  ​‑‑Lambiam 09:25, 17 July 2026 (UTC)

For the record, I do remember that post. I thought about it and realised that there wasn’t enough detail about why the prices are so high. Some insights about engine power and mass production were given, but I feel we are still not addressing the great mismatch between the cost of the components and materials and the price of the thing. RIBs for example are made of rubber and plastic and won’t have as much metal in them as solid hulls. Pablothepenguin (talk) 11:27, 17 July 2026 (UTC)

We have been using metals for thousands of years, have great experience with them, and for simple purposes they can be simple alloys, easily made and fashioned. Rubbers (particularly artificial ones) and plastics are much newer, and materially may be more difficult to design and make and fashion for a particular function.

Cars, (decreasingly) made of metals, are very numerous and we are used to their expected failure rates. Even if a particular individual car fails mechanically or materially and causes one or more deaths, the sales of cars in general and that make and model of car are unlikely to be much affected. I suspect we have less tolerance for boat failures because drowning is an additional hazard, not usually present when driving cars, so the failure of a particular recreational boat may significantly depress the sale of recreational boats in general and that model of boat in particular, perhaps leading to its manufacturer's bankruptcy. For this reason, manufacturers of recreational boats likely expend more care and expense in designing and manufactuuring their boats, making them more expensive.

You persist in thinking that the ruling factor in an item's cost is the cost of the components and materials. This is often not so. The materials can be cheap but the manufacturing procedures expensive, whether or not true mass production is involved (yes for cars, no for boats) is crucial, and goods are retailed at a price designed to balance with sales numbers to produce the maximum profit, not to "fairly" reflect those goods' materials costs.

Finally, buyers' tolerance for prices depends on how the perception of goods' "worth" has been manipulated: some goods, let us take diamonds as an example, can be sold for vastly more that their extraction, processing and rarity warrants, because buyers' perceptions of diamond have been carefully manipulated by the diamond producers and vendors. This process operates to a greater or lesser extent for every non-essential good.

TLDR: the prices of recreational boats are high because people are prepared pay those prices. {The poster formerly known as 87.81.230.195} ~2026-36805-68 (talk) 13:07, 17 July 2026 (UTC)

One factor could be what's known as "snob appeal". ←Baseball Bugs ^{What's up, Doc?} carrots→ 13:45, 17 July 2026 (UTC)

I was hoping for a detailed explanation of why manufacturing is so expensive. In particular I want to why the techniques used to make cars cheaper aren’t used for boats. Also how does a rubber boat cost five figures? That’s the answer I need. Pablothepenguin (talk) 15:35, 17 July 2026 (UTC)

The primary way to make cars cheaper is to make millions of them. The scale of boats is much much much smaller, so they don't get the same economy of scale. ~2026-35239-54 (talk) 16:17, 17 July 2026 (UTC)

What the OP could do is to make a list of the various types of watercraft and find estimates of how many of each kind are sold each year. That could be a strong indicator. I'd venture a guess that there are lot more small motorboats or rowboats sold annually than there are yachts. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:35, 17 July 2026 (UTC)

Sea-Doo (over 70% of the jet ski market) produces at most 100,000 jet skis (all models) every year. Toyota, as one example, makes over 300,000 Camrys each year. That is just one model. For all models, Toyota makes over 11 million vehicles each year. The scale difference is over 100 times the scale. Therefore, I do not believe it is necessary to hunt down production numbers. What if Sea-Doo does twice as many jet skis? That's 200,000. What if Toyota had a bad year and made a million less cars? That's 10 million. The scale difference is still so wide it doesn't matter what the actual numbers are. ~2026-35239-54 (talk) 17:00, 17 July 2026 (UTC)

How much could you push cost per product down through economies of scale when increasing production by a factor of, say, 100? 5%? 50%? 95%? That requires detailed analysis. Some products actually get more expensive when production increases, but I don't think that would be the case here. PiusImpavidus (talk) 19:21, 17 July 2026 (UTC)

There are three main classes of products that do not follow economies of scale. Unique items that have value in uniqueness must be artificially inflated in cost when production increases or the product itself loses value. Then, limited use items, such as the heat shields on a rocket ship, will have any possible savings offset by a temporary and expensive increase in infrastructure to produce at scale. It is was not a temporary use item, the increase in infrastructure could pay itself off as an investment. Finally, products based on rare materials don't scale unless there is a chance to scale up the rare source material first. Average boats don't fall into any of those categories. ~2026-35239-54 (talk) 19:44, 17 July 2026 (UTC)

I think that in my country (Netherlands) more people drown as a result of car accidents (driving their car into a canal) than as a result of sinking boats. PiusImpavidus (talk) 18:19, 17 July 2026 (UTC)

I'm not in the boating business and don't have a detailed breakdown of costs, but I just checked a random webshop selling boats and outboard engines. A small rigid inflatable boat without an engine is sold for €995, a matching 6 horsepower outboard engine without a boat (yes, this webshop uses horsepowers. They're practically obsolete in Europe, the only other people still using horsepowers are car enthusiasts) is sold for €1655. That's a pretty small engine. So it looks like the engine is responsible for most of the cost. PiusImpavidus (talk) 18:55, 17 July 2026 (UTC)

That makes perfect sense. An engine in, say, a motorcycle doesn't need to be able to handle being in water (possibly saltwater) all day. You can use materials that will be ruined if the engine gets submerged. A boat engine requires every single component to be able to handle constant wet environments. Also, I've never seen a boat (or equivalent) with gears. On the road, we use gears to keep from redlining the engine for long periods. In boats, it is normal to hear a boat engine scream by for long periods of time. That puts a lot of stress and temperature strain on the engine. Yet another reason the boat engines need to be built better. ~2026-35239-54 (talk) 19:12, 17 July 2026 (UTC)

Actually, many ships (and also many aircraft) have something equivalent to gears: variable pitch propellers. They boost efficiency somewhat. Boats can do without (it's just less efficient), as the speed of the propeller isn't rigidly linked to the speed of the boat. On land vehicles, the speed of the wheels is rigidly linked to the speed of the vehicle, so to keep the engine at acceptable speed, you need gears (or some other form of variable transmission). But indeed, the engines of boats (and aircraft) tend to run near full power much of the time; those of road vehicles don't. You can get the engine of a car pretty hot by driving up to a mountain pass; many cars aren't really designed for that. PiusImpavidus (talk) 19:52, 17 July 2026 (UTC)

The main confusing thing for me is the fact that many boats cost more than family cars despite family cars being larger, heavier, and in possession of more complex electronics and mechanics. Note that cars these days often have on board computers that manage everything from engine/battery temperature to fuel level/ battery charge, to even your Spotify playlist. Pablothepenguin (talk) 09:51, 18 July 2026 (UTC)

There's a phenomenon called Price discrimination. Ask yourself this: What's the practical difference between a top-of-the-line Rolls-Royce and a bargain-priced Kia? ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:32, 18 July 2026 (UTC)

Above I found a 3 person rigid inflatable boat with a 4.4 kW engine for €2650, cheaper than a car and only 5% of the price you quoted above. That was the first boat seller I found on Google. You can get an even cheaper boat, but it will have a smaller engine. But as you mentioned that you compared the price to that of a car with a similarly powerful engine, it seems you're more interested in the fast market segment. There it gets more expensive. A Lamborghini is more expensive than a Citroën, isn't it? You need a big engine, that can handle being run at full power most of the time, in a wet environment. Internal combustion engines are complex mechanical devices, responsible for a large fraction of the cost of all vehicles that have them. You need a strong hull. A planing hull bumping into waves at high speed has to take a lot of abuse. And, as other hinted at, you'll get some features that aren't really useful but give status to the owner and add profit margin for the builder. Like a shiny logo of some expensive brand.

Actually, the top speed is mostly for bragging rights too. Just as a sports car can only be legally used to its full potential on quite days on the German Autobahn, a fast boat can easily exceed the legal speed limit on most waterways (typically 20 km/h in the Netherlands, 6 km/h in the UK). PiusImpavidus (talk) 09:59, 19 July 2026 (UTC)

July 17

Five-year survival rate for cancer

In general, when five-year survival rates for diseases are calculated, do the statisticians pay attention to unrelated deaths? Let's say I get diagnosed with a rare type of cancer (so one person's death can mathematically affect the small sample size), and as I'm leaving the doctor's office, I get run over by a reckless driver. Do I drag down the five-year survival rate for my type of cancer? Nyttend (talk) 00:47, 17 July 2026 (UTC)

it depends. If observed survival rate is being calculated, the cause of death doesn't matter, only survival. So you would be included as you suspected. If relative survival rate is being measured, you arr included but in comparison to the general population, who are also being killed on random events. Your unexpected death is balanced out by someone else's unexpected death. If specific cause rate is being measured, you are excluded because you did not die of that specific cause. You mention this in relation to cancer, but it shows up more in vaccines where people confuse rates to push narratives for social media clicks. ~2026-39968-68 (talk) 02:20, 17 July 2026 (UTC)

Overwhelmingly, cancer studies report a relative survival rate. So, while people in the cancer cohort will have car accidents, that is compared to the general population which also has car accidents. That is why the rates are percentages. They are a percent of the general population. Something like 70% means the survival rate for the cancer cohort is 70% of the general population. The benefit with doing it this way is that the analysts don't skew the results by trying apply rules about which deaths are included and which are not. Then, they have to work out when a person would die if they didn't die from some other cause. ~2026-35239-54 (talk) 11:07, 17 July 2026 (UTC)

Comparing relative to the general population also accounts for deaths that are only indirectly caused by cancer. Suppose brain cancer causes problems with balance and vision. That reasonably leads to poorer identification of emergent situational threats and ability to move to safety. So we have a a pedestrian getting killed by a bad driver because they didn't realize the car was coming towards them and then stumbled back into the street trying to get back on the curb at the last minute being an increasingly likely scenario due to cancer. I would think this should be counted as a reduced overall survival due to cancer, but cannot be direclty traced to the cancer itself in any specific indiviual's death.

Take it a step further: common side effecs of chemotherapy include all sorts of neurological damage, including with to vision and balance, and do have a greater statistical likelihood of falls and similar accidents. Given old folks are both more likely to have cancer and more likely to have worse outcomes from falls themselves, if grandpa has cancer, he is less likely to survive even if the cancer is not the direct cause of death itself. DMacks (talk) 15:39, 18 July 2026 (UTC)

Then let's imagine that there's a convention for people with a rare kind of cancer, and the attendees represent something like 50% of those with this cancer in a country. A gas line ruptures and causes the whole building to explode, and everyone inside (patients, dining staff, support workers, maintenance staff, etc) is immediately incinerated. Aside from the topic of the event that they're all attending, these people's deaths have nothing to do with their illness. Nyttend (talk) 12:06, 20 July 2026 (UTC)

From Nyttend's morbid Thought experiment we draw the wisdom that Correlation does not imply causation. No participants were injured in this experiment. ~2026-39925-22 (talk) 15:39, 20 July 2026 (UTC)

Obvious xkcd, for those who haven't seen it. DMacks (talk) 21:46, 21 July 2026 (UTC)

Well, people without cancer also sometimes get run over … —Antonissimo (talk) 00:59, 18 July 2026 (UTC)

A single additional random accidental death could distort the survival rate numbers in a small enough sample size. At population levels or in samples of multiple thousands, it doesn't make a difference. -- Avocado (talk) 20:58, 18 July 2026 (UTC)

I think it is also important to recognize that people undergoing treatment for cancer have a higher rate of accidental falls, and of suicide. Also, these five year survival rate studies have an issue with patient retention. Best practice is to only make comparisons to groups of patients getting the other treatment(s). Abductive (reasoning) 17:45, 19 July 2026 (UTC)

Of the 987 patients in the group receiving the novel treatment, 212 were alive at the end of the five-year study, while of the control group of 1024 patients receiving the traditional treatment, 210 were alive. What formula should the study use to report the five-year survival rate with the novel treatment? Or should survival rates not be reported at all?  ​‑‑Lambiam 07:58, 20 July 2026 (UTC)

A recovery rate with documented change in symptoms is a meaningful verification of a novel treatment but a survival rate alone, possibly in spite of ineffective treatments, is not a reliable measure. ~2026-39925-22 (talk) 15:48, 20 July 2026 (UTC)

July 19

Altimeters

Do aircraft commonly (also) have metric altimeters in countries which measure altitude in feet? And how common is to measure altitude in meters in such countries? --40bus (talk) 17:08, 19 July 2026 (UTC)

Didn't you ask this same question a year or two ago? ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:48, 19 July 2026 (UTC)

I don’t remember asking such a question.

Well it was 2024, see here. Heights are in feet except above China.Shantavira|^{feed me} 07:53, 20 July 2026 (UTC)

Similar things were asked on more occasions. I remember commenting that in Europe, gliders often have metric altimeters (and also vertical speed in metres per second, airspeed in kilometres per hour). This also applies to historical aircraft, as before 1945, European aviation (except in the UK and Ireland) was metric. After all, Europe (except the UK and Ireland, except some ballooning) metricated before the start of aviation. And modern glass cockpits can be converted between metric and imperial with the push of a button. PiusImpavidus (talk) 09:21, 20 July 2026 (UTC)

It’s a bit more nuanced. Altitudes and flight levels are reported in feet worldwide, including Europe. Russia and China have historically used meters for some altitudes and flight levels, but most commercial operations use feet. The altimeter itself doesn’t use feet or meters internally. It uses barometric pressure. ATC assigns altitudes in feet, but also gives a pressure setting. In the U.S. and Canada, the pressure is given in inches of mercury (inHg). In Europe and most of the world, it’s given in hectopascals (hPa). Pilots set the altimeter to the assigned pressure (e.g., 29.92 inHg or 1013 hPa). Once everyone is using the same pressure reference, their indicated altitudes will be consistent relative to each other, which is what matters for separation. ~2026-35239-54 (talk) 16:24, 20 July 2026 (UTC)

Still, ATC will tell a flight to maintain 3000 feet, not to maintain 90 kPa.  ​‑‑Lambiam 19:40, 21 July 2026 (UTC)

On initial approach, ATC will usually (I don't know of an exception) give out the air pressure such as "QNH 1017" or "Altimeter 29.92" and then the instruction "Descend and maintain 3000 feet." The first is to calibrate the altimeter. The second is the actual altitude. But, it still remains that with very rare exception, feet is used as the altitude unit. I've seen China and Russia used as examples where feet is not used, but that appears to be changing. Their major airports have switched to feet to standardize with the rest of the world. ~2026-35239-54 (talk) 19:56, 21 July 2026 (UTC)

July 20

Obscure catalog entry name that closely resembles the Wolf–Rayet catalog

While co-writing someone else's draft about a W Ursae Majoris variable (Draft:V523 Cassiopeiae), I discovered a reference to a designation of the star as "Wr16" (not to be confused with the Wolf–Rayet star catalog entry WR 16):

Jeong, Jang-Hae; Kim, Chun-Hwey; Lee, Yong-Sam (2010-06-15). "Photometric Observations of the Contact Binary System V523 Cassiopeiae". Journal of Astronomy and Space Sciences. 27 (2): 81–88. doi:10.5140/JASS.2010.27.2.081. ISSN 2093-5587.

SIMBAD's entry on this star lists this name as well (under the catalog "SV*"), but has no information about the catalog. What is SV*? Would the "Wr16" designation require a hatnote from WR 16 to V523 Cas once the draft is published? –LaundryPizza03 (dc̄) 06:29, 20 July 2026 (UTC)

"Wr" probably refers to Weber (1958), . Would have to precess the coordinates to J2000 to be sure. --Wrongfilter (talk) 06:41, 20 July 2026 (UTC)

July 22

Do people become passive aggressive from being bullied, or from being unloved or what?

Do people become passive aggressive from being bullied or being unloved, or what? Or is it behavior pattern opurtunistically picked up on by an unhappy person, or conceivably, by a happy, untroubled person?Rich (talk) 01:53, 22 July 2026 (UTC)

There are some clues in Passive-aggressive behavior. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:59, 22 July 2026 (UTC)