Wikipedia:Reference desk/Archives/Science/2022 April 20
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April 20
editWhat's the proper umbrella term for ultimate carbon bats, swords, elevator cables, vehicle bodies, illegal golf clubs, armor vests, I-beams and similar?
editI 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)
- We have Category:Nanomaterials. Perhaps "carbon nanomaterial objects"? Card Zero (talk) 07:46, 20 April 2022 (UTC)
- Would carbon-fiber-reinforced polymers cover what you have in mind, Sagittarian Milky Way? Mike Turnbull (talk) 09:42, 21 April 2022 (UTC)
- 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)
- 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)
- 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)
- Would carbon-fiber-reinforced polymers cover what you have in mind, Sagittarian Milky Way? Mike Turnbull (talk) 09:42, 21 April 2022 (UTC)
Railway construction
editGenerally 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)
- 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)
- 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)
- 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. --Jayron32 19:34, 21 April 2022 (UTC)
- 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)
- 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. --Jayron32 19:34, 21 April 2022 (UTC)
- 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)
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)
- 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)
- 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)
- If you want to see this in action a new entrance, ticket office and footbridge are nearing completion at Hackney Central railway station. If the station becomes part of the Chelsea to Hackney Line the engineering will be very different. 2A00:23A8:4306:5D01:B995:7B23:A571:2AA9 (talk) 11:20, 23 April 2022 (UTC)