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April 15

Cats with the same or similar fur pattern

How probable is it that there are two or more cats (of either sex) anywhere with the identical or very similar fur color pattern (not only twins)? 212.180.235.46 (talk) 18:21, 15 April 2022 (UTC)[reply]

Black cats all look pretty similar to me! However, I guess their mothers can tell them apart.... Mike Turnbull (talk) 19:27, 15 April 2022 (UTC)[reply]

Seal point Siamese cats, while not monochrome, have very similar coats. The European shorthair has a distinctive stripe pattern, but it is not hard to find a pair that is difficult to tell apart. For calico cats it is hard to find a really similar pair; assigning a probability (which would have to be done experimentally) requires a workable operationalized definition that draws a line between "very similar" and "not very similar". See how many similar-looking couples you can spot here – but be aware that some photos show the same cat in different poses. If n is large enough and you find s very similar pairs, the probability is roughly 2s/n². --Lambiam 22:31, 15 April 2022 (UTC)[reply]

All white Persian breeds have the same (lack of) pattern. Van cats are especially similar down to skull shape and eye color. 97.82.165.112 (talk) 00:29, 16 April 2022 (UTC)[reply]

While the validity of Lambiam's caveat (regarding a firmer metric of what constitutes 'similar') cannot be questioned, I can nevertheless tell you with some certainty that the probabilities are actually extremely high, if we are talking about Felis catus. I've done a lot of domestic, feral, and wild cat rescue over the course of my life and have had an opportunity to observe how Mendelian inheritance plays out in coat pattern expression/phenotypes of various breeds, and I can tell you that I have many times seen nearly identical cats be spit out by the same breeding group, sometimes as siblings, and sometimes generations apart. Indeed, in a given breeding pool, even when you do not get near-identical pairs, you will often see numerous cats sharing a large number of idiosyncrasies in the expression of patterns in their fur. On the converse side, however, remember also that expression of the genes controlling appearance can be heavily influenced by epigenetic factors, both in utero and during juvenile development: even genetic twins will sometimes end up looking quite differently after variant environmental factors and diet. I realize this isn't the most empirical or precise of data to answer your inquiry with, but rather an impressionistic answer to your question, but let me put it to you this way: if you were to raise 30-40 cats from one maternal line across 3-4 generations, I would bet you would end up with at least two or three pairs that you would probably be able to tell apart easily enough, but who would confuse the hell out of anyone not super familiar with them. SnowRise ^{let's rap} 15:26, 16 April 2022 (UTC)[reply]

The definition of "twin" in a species that produces litters can be problematic. Most cats are fraternal twins inasmuch as they come with other kittens from a single pregnancy, but the kittens may only be half-sibs. A queen on heat will mate with multiple toms, given the opportunity, and so some of the fraternal twins are only half-twins! Martin of Sheffield (talk) 16:46, 16 April 2022 (UTC)[reply]

Well, arguably I used nomenclature that was too imprecise, in an effort to keep the info accessible to the OP, but I was specifically talking about monozygotic twins: even these can end up having markedly different coats as they develop, which is a surprise to many people, as it feels unintuitive to their experience/understanding of the largely identical nature of most human monozygotic twins. Of course the truth is is much more complex than that with humans as well, but that's the common perception. SnowRise ^{let's rap} 20:28, 17 April 2022 (UTC)[reply]

April 17

Wood in motor cars

Which was the last production motor car that used wood in the main structure or frame of the vehicle, i.e. not just as a decorative interior feature? Thanks. 86.181.187.25 (talk) 19:29, 17 April 2022 (UTC)[reply]

The Morgan Motor Company still does this. Bazza (talk) 19:34, 17 April 2022 (UTC)[reply]

Surely, it's less safe than metal? 86.181.187.25 (talk) 19:37, 17 April 2022 (UTC)[reply]

Morgan claim it's safer. DuncanHill (talk) 19:57, 17 April 2022 (UTC)[reply]

I wonder what's worse: To be impaled by a piece of wood or a piece of metal? --←Baseball Bugs ^{What's up, Doc?} carrots→ 06:07, 18 April 2022 (UTC)[reply]

Are you a vampire? Then wood is worse unless the metal is silver, particularly when coated in garlic. --Lambiam 07:06, 18 April 2022 (UTC)[reply]

So it's the upper body structure, covered in aluminium sheeting, rather than the chassis. "Morgan’s research shows that the wooden frame makes its cars safer than conventional steel frames on impact tests." Doesn't the UK Government have to do independent tests? Thanks. 86.181.187.25 (talk) 07:40, 18 April 2022 (UTC)[reply]

Neither the USA or the UK governments routinely do crash tests. Instead the manufacturer gets their cars tested at a crash test facility. I think in theory you can get a car into production using your own test lab. Greglocock (talk) 09:47, 18 April 2022 (UTC)[reply]

You do have to watch where the wood is fitted. Martinevans123 (talk) 09:30, 18 April 2022 (UTC)[reply]

Certification in the UK is by the Vehicle Certification Agency. Actual testing was by the Road Research Laboratory (RRL), which was privatised in 1996 as the Transport Research Laboratory (now TRL Limited). TRL was instumental in setting up Euro NCAP in the EU. Testing by these bodies seems to be voluntary, but not having a rating by them isn't a good selling point. Alansplodge (talk) 15:47, 18 April 2022 (UTC)[reply]

Morgan isn't listed on the Euro NCAP site. Perhaps people who buy Morgans aren't that fussed about modern standards? -- Verbarson ^talk_edits 20:57, 18 April 2022 (UTC)[reply]

"Of course, there is only so much safety tech that the Plus 4 offers -- there are no air bags, for instance -- and crumple zones are just bodywork that will crumple in a crash. In this case it was fortunately enough to prevent a far worse outcome".

Morgan Plus 4 driver miraculously survives this high-speed rear-end crash. Alansplodge (talk) 13:13, 19 April 2022 (UTC)[reply]

(EC) Our article suggest at least in 2005, they had limited or no airbags, so I would expect they do fairly poorly in a number of modern tests whatever the alleged benefits of the wooden frame. Nil Einne (talk) 13:18, 19 April 2022 (UTC)[reply]

Marcos made cars with wooden chassis but they appear to have swapped to steel in 1969.[[1]] --Ykraps (talk) 09:18, 20 April 2022 (UTC)[reply]

April 19

Short cutoffs

When driving a steam train at high speed, how can you tell if you've set the cutoff too short? I do know that the effect of this, in physical terms, is a "checking action" where the steam cannot fully exhaust to the blastpipe and creates a pressure cushion in the cylinders -- but my question is, how does this manifest itself in terms of sound and/or feel (sharper exhaust blasts, increased shaking, etc.)? And is the sound/feel in this case different with Stephenson valve gear than with Walschaerts? 2601:646:8A81:6070:8D25:F11A:29AC:2783 (talk) 00:05, 19 April 2022 (UTC)[reply]

Surely a longer cutoff would supply too much steam to the cylinders; a short cutoff would supply less? See Cutoff (steam engine). (Would that I had the experience to actually answer the question!) -- Verbarson ^talk_edits 10:04, 19 April 2022 (UTC)[reply]

Not my field, but I found Explaining 'Cut Off' on a rail enthusiasts' blog, which may help. Alansplodge (talk) 13:02, 19 April 2022 (UTC)[reply]

Just read it, but it only explains what a cutoff is (which I already know), and the (rather obvious) effects of having it set too long while cruising at speed -- wasted steam and coal (and reduced performance due to lack of steam available), fire-throwing with consequent emissions of excessive smoke (harmful to the environment, could be dangerous in tunnels) and possibly sparks (fire hazard), and with a lever reverse also possible injury to the engineer if he tries to adjust it and it flies open uncontrollably under steam pressure -- but what it does not cover is what happens if the cutoff is set too short while cruising under power. 2601:646:8A81:6070:2152:CE20:4F73:F64E (talk) 09:14, 20 April 2022 (UTC)[reply]

@User:Verbarson: True, but a short cutoff also gives the steam less time to exit the cylinder to the blastpipe during the exhaust phase -- this is why setting it too short can lead to a checking action which reduces speed. 2601:646:8A81:6070:2152:CE20:4F73:F64E (talk) 09:17, 20 April 2022 (UTC)[reply]

April 20

What's the proper umbrella term for ultimate carbon bats, swords, elevator cables, vehicle bodies, illegal golf clubs, armor vests, I-beams and similar?

I could say ultimatium or unobtainium but what's meant isn't obvious. If I said i.e. carbon tool, carbon tennis racket or carbon bike that sounds like carbon fiber composite which is not nearly weightless like a real nearly unimprovable human-powered bike would be. What about calling them carbon nanotech objects, could that be unclear as to whether it includes non-structural nanotech such as transistors or something? Sagittarian Milky Way (talk) 00:59, 20 April 2022 (UTC)[reply]

We have Category:Nanomaterials. Perhaps "carbon nanomaterial objects"? Card Zero (talk) 07:46, 20 April 2022 (UTC)[reply]

Would carbon-fiber-reinforced polymers cover what you have in mind, Sagittarian Milky Way? Mike Turnbull (talk) 09:42, 21 April 2022 (UTC)[reply]

No, those already exist and are far heavier or weaker than anything near the ultimate macroscopic strength limits of atomic bonds. What's the correct term I can use for atomically perfect 3D printed (macroscopic) X's if I don't know if the best X's are nanotube X's or graphene X's or buckyball-nanotube-graphene fractal foam composite magic X's? Will the best baseball bats be nanotube or graphene foam or a single giant multi-wall nanotube or a spiral of one sheet of graphene or what? I have no idea but I shouldn't have to know to the general category right? I don't know if it'll ever be feasible to 3D print so many atoms into an atomic-level flawless lattice but that might be the way (to make the strongest or thinnest possible stick or sheet or string or whatever). Sagittarian Milky Way (talk) 01:29, 22 April 2022 (UTC)[reply]

Very likely there is no "correct term" for such a class of hypothetical things because nobody has yet had any need for it. Feel free to invent one – it might even catch on. {The poster formerly known as 87.81.230.195} 90.197.101.71 (talk) 04:01, 22 April 2022 (UTC)[reply]

Railway construction

Generally in a new railway construction project like the UK’s High speed 2, are the stations the most complex part in the early civil engineering stages of construction? Compared to say bridges, tunnels, earthworks, retaining walls, boxes etc? Clover345 (talk) 22:12, 20 April 2022 (UTC)[reply]

Train station design is largely the province of architecture. In terms of civil engineering, there is nothing much special or demanding about station design, but remodelling existing stations to meet the demands of modern railways can be a challenge – the easiest may be to build a new station. It is difficult to say something in general about the complexity of new railway construction projects, since so much depends on the local circumstances. The civil engineering complexity of HS2 is incomparable to that of HS1. Also, where do the early civil engineering stages of construction start (do they involve the detailed selection of the route?) and end? --Lambiam 07:29, 21 April 2022 (UTC)[reply]

I would think building bridges and tunnels is much more difficult than building stations. There are many known delays with those types of projects due to unforeseen problems with the terrain, even after exhaustive planning and environmental studies. The risks are also greater. A bridge or tunnel fiasco could derail an entire project, especially if there are no alternatives to bypass that location. They also tend to happen in more remote places, which makes the logistics more difficult compared with stations, which are usually placed in more populated areas with existing infrastructure. GeorgiaDC (talk) 19:04, 21 April 2022 (UTC)[reply]

It also should be noted that there's a distinction between the station and the platform, the former is really superfluous to the operation of the railway. A station is really just a place to wait to board the train; a "station" could be a simple as a bench: see for example Appalachian Trail station. I used to take Amtrak from Newark station in the 1990s, at the time there was no indoor station, just a place to wait to get on the train with a few benches, and a large commuter parking lot (the original station building was there, but it was boarded up IIRC) You couldn't even buy tickets there, you had to purchase them from the conductor once you got on the train. It looks like it has since been upgraded, FWIW. Yes, really complex modern train stations resemble airports, but they aren't any different from, say, a shopping mall with a place to access the platforms. --Jayron 32 19:34, 21 April 2022 (UTC)[reply]

In terms of the engineering of the permanent way Lambiam, GeorgiaDC and Jayron have pretty well covered it. Where a station (as a against a simple platform) does increase the complexity is in the pointwork, crossings and signalling to direct trains to the appropriate platforms. Then add in the main buildings with its associated supplies (water, electricity, in the past gas), drainage (rainwater, foul water), vehicular access and parking. There's bridges (either over or under the line) with associated lifts, escalators lighting etc. All supplies crossing under the tracks need to be insulated against ground movement due to trains passing over. HS2 has overhead electrification so each separate road or siding needs cateneries. None of this is as unpredictable as tunneling or as complex as significant viaducts but it's still not trivial. Martin of Sheffield (talk) 20:19, 21 April 2022 (UTC)[reply]

For HS2, the stations seem just as complicated if not more complicated than the tunnelling and other civils. Most of the station contracts are worth over £1 billion which is the same value as most of the civils contracts covering a much larger area. — Preceding unsigned comment added by Clover345 (talk • contribs) 00:50, 22 April 2022 (UTC)[reply]

But is this complexity due to civil engineering requirements, as specified in the question, or does it stem from architectural requirements)? --Lambiam 14:26, 22 April 2022 (UTC)[reply]

Would you happen to have any reference or related information on these contracts for more details and comparison? GeorgiaDC (talk) 18:50, 22 April 2022 (UTC)[reply]

April 21

Do all flowers need sunlight to blossom?

Having located the linked article my wife and I have had a heated debate concerning flowers. We would like the following question answered.

Do all flowers require sunlight in order to bloom? Clearly not all flowers need sunlight to develop, and not all plants need sunlight in order to survive. Our question relates specifically to the opening and blooming of flowers.

https://news.mongabay.com/2019/08/new-orchid-species-from-japan-lives-on-dark-forest-floor-never-blooms/amp/

Thank you — Preceding unsigned comment added by 2A00:23C6:6888:C600:28F4:D64D:6F71:62B8 (talk) 20:57, 21 April 2022 (UTC)[reply]

There are a lot of plants that bloom at night (see Category:Night-blooming plants) I don't know what triggers them to bloom ("when it's dark" vs "when it becomes no-longer-light"). So I'm not sure if that does or doesn't qualify for your interest. DMacks (talk) 21:50, 21 April 2022 (UTC)[reply]

BTW, all plants need some sunlight, even if not directly - see photosynthesis. Alansplodge (talk) 22:43, 21 April 2022 (UTC)[reply]

Tell it to Gastrodia kuroshimensis. (That one doesn't bloom, which is the key to the question.) --jpgordon^{𝄢𝄆𝄐𝄇} 23:04, 21 April 2022 (UTC)[reply]

This being the Science Desk and all, I think some precision is required here. Is the question asking about direct sunshine on the flowers being required for them to bloom, or just daylight? If it's the former, the answer is obviously no. Many flowering plants in deep mountain valleys never experience direct sunlight. HiLo48 (talk) 00:07, 22 April 2022 (UTC)[reply]

OP here, different computer. Without being in a cave it would be well nigh impossible to have no sunlight. The question relates to the plant receiving direct sunlight in order for the flower to bloom. Deep valleys may have flowers but they are not dark to the point of near 0 sunlight such as experienced in deep jungle floors where the flower in question grows. Thanks — Preceding unsigned comment added by 62.252.54.42 (talk) 11:04, 22 April 2022 (UTC)[reply]

Flowering room plants often do not need (and do not receive) direct sunlight. For a few examples, see here. --Lambiam 14:21, 22 April 2022 (UTC)[reply]

OP again. Thank you, and if the flowers do not receive any sunlight such as those that exist in caves...those never bloom because they never receive sunlight? Is that accurate without deviation and exception? Thanks — Preceding unsigned comment added by 62.252.54.42 (talk) 15:24, 22 April 2022 (UTC)[reply]

April 22