Zompist Bboard Again

I'm posting this here instead of in Ephemera because for now, I find the question mainly relevant for Future Earth conworlding and general futuristic society conworlding.

Back in 2007, Alex Harrowell posted this blog post about maglev technology: https://www.harrowell.org.uk/blog/2007/ ... v-is-dead/

I think he made some good points in that post, and for a long time, my attitude towards the technology was based on it. But re-reading the post today, I think that Robert in the comments makes some fair points, too. So I'm not sure what's likely to happen now.

(In case you're wondering what this whole thing is in the first place, here's the Wikipedia article on maglev: https://en.wikipedia.org/wiki/Maglev)

I've got both maglev and vac trains in my sci-fi setting. In the Tarkentian empire it lets you travel north south down the Khardan continent - about 12000 miles - in 3-4 hours

I feel as if maglev trains are like hovercraft in one point - an expensive solution to a transportation problem that has cheaper solutions already.

WeepingElf wrote: ↑Sat Nov 02, 2024 3:45 pm I feel as if maglev trains are like hovercraft in one point - an expensive solution to a transportation problem that has cheaper solutions already.

Then again, hovercraft at least have the advantage that they require less of a specialized infrastructure.

Raphael wrote: ↑Sat Nov 02, 2024 3:51 pm

WeepingElf wrote: ↑Sat Nov 02, 2024 3:45 pm I feel as if maglev trains are like hovercraft in one point - an expensive solution to a transportation problem that has cheaper solutions already.

Then again, hovercraft at least have the advantage that they require less of a specialized infrastructure.

And yet, they turned out to be too expensive. The hovercraft ferries across the Channel had to be subsidized to the end, and when the railway tunnel was opened which offered an even faster and cheaper connection, they were discontinued. If you want something that can run on both land and water, just build a boat with wheels.

You may be asking because of a comment of mine, so I should hastily clarify: it's just common in near-future sf, largely because it's faster than bullet trains. Maglevs are things that exist today, though so far as I can see all the existing tracks are quite short.

If you want even more futuristic oomph, maybe try a vactrain. Most of a maglev's power consumption is due to air friction, so the idea is to run it in a vacuum tube. (And hope your thousand-mile tube doesn't develop a leak, I guess.)

If it's not a key plot element, you can also use that most useful of sf elements, handwavium. That is, invent a techy-sounding name— or name it after its inventor. After all, people just use transportation, they don't explain it to each other as they board.

zompist wrote: ↑Sat Nov 02, 2024 6:23 pm If it's not a key plot element, you can also use that most useful of sf elements, handwavium.

Note to non-chemists: if you're looking for this on your Periodic Table, it's element number -1, and its symbol is Hw.

zompist wrote: ↑Sat Nov 02, 2024 6:23 pm You may be asking because of a comment of mine, so I should hastily clarify: it's just common in near-future sf, largely because it's faster than bullet trains. Maglevs are things that exist today, though so far as I can see all the existing tracks are quite short.

If you want even more futuristic oomph, maybe try a vactrain. Most of a maglev's power consumption is due to air friction, so the idea is to run it in a vacuum tube. (And hope your thousand-mile tube doesn't develop a leak, I guess.)

If it's not a key plot element, you can also use that most useful of sf elements, handwavium. That is, invent a techy-sounding name— or name it after its inventor. After all, people just use transportation, they don't explain it to each other as they board.

Thank you. The thing is, for relatively short distances, as in, within a mid-sized city, I'm not really sure how public transportation could improve on the buses and subways of our time, except for turning the buses electric.

Why bother? The Chuo Shinkansen makes sense because Japan doesn't have oil; if you do have oil (or airplane-sized batteries), airplanes are faster. The Chuo Shinkansen is planned to have a cruise speed around 300mph; typical airplane cruise speeds are upwards of 500mph. Giant tubes would be a maintenance nightmare. The Hyperloop never made sense.

Raphael wrote: ↑Sun Nov 03, 2024 1:16 pm The thing is, for relatively short distances, as in, within a mid-sized city, I'm not really sure how public transportation could improve on the buses and subways of our time, except for turning the buses electric.

In the US, most cities are two-dimensional, which is cheap to build but inefficient in terms of space, but urbanization in the US is recent and politically unpopular. Societies a few more centuries out from the urban transition will probably have much more three-dimensional cities, like Chongqing. Once cities are three-dimensional, with multiple stories even outside, things like aerial tramways could start to make sense - there's already one in Portland to get up a big hill.

Raphael wrote: ↑Sun Nov 03, 2024 1:16 pmThe thing is, for relatively short distances, as in, within a mid-sized city, I'm not really sure how public transportation could improve on the buses and subways of our time, except for turning the buses electric.

That's a good point, but it may be worth thinking more abstractly about what transit does to a city. What precisely should we make easy? What perhaps unexpected effects will our decisions have? How seriously do people take it?

My user model of the Paris metro, based on about three weeks' using it in the 1980s, is that it was a really good system. Trains came quickly, everything was relatively clean and felt safe, there was almost always a station within 0.5 km of where you needed to go. The only major bit of friction was having to change train lines. So a blue-sky futuristic system might be one where any node can connect to any other. (For the end user, maybe that means smaller cars.)

So to have at least that level of service, you need lots of trains, lots of stations, and people caring enough about the system to make it user-friendly. The Chicago el is like 75% as good in all these areas.

Someone's noted that cities through history seem to accommodate themselves to transit times of an hour. If it's walking, the city is an hour's walk in diameter. If it's trains, it's an hour's train ride. Making trains faster may simply enable the city to grow till it's an hour big at the faster speed.

Station distance is another parameter you can adjust, since it's a source of friction. Healthy young people can handle that 0.5 km walk, but what about old folks or children?

Larry Niven posited a system based on teleportation, but organized by the street grid. If I recall, there were portals at each intersection that would jump a city block, and then longer-range portals if you were going farther. It'd be an ideal system for Americans, probably: fast and flexible, but obviously designed by people who place no value on the travel itself.

(Also, maybe typical of Niven: he didn't think about second-order effects. Think of going through the teleportation grid with a toddler. You lose track of them for 10 seconds, and they're suddenly in Shanghai.)

zompist wrote: ↑Sun Nov 03, 2024 8:06 pm Larry Niven posited a system based on teleportation, but organized by the street grid. If I recall, there were portals at each intersection that would jump a city block, and then longer-range portals if you were going farther. It'd be an ideal system for Americans, probably: fast and flexible, but obviously designed by people who place no value on the travel itself.

(Also, maybe typical of Niven: he didn't think about second-order effects. Think of going through the teleportation grid with a toddler. You lose track of them for 10 seconds, and they're suddenly in Shanghai.)

Apart from the fact that such a system relies on unknown physics, of course.

WeepingElf wrote: ↑Mon Nov 04, 2024 5:10 am

zompist wrote: ↑Sun Nov 03, 2024 8:06 pm Larry Niven posited a system based on teleportation, but organized by the street grid. If I recall, there were portals at each intersection that would jump a city block, and then longer-range portals if you were going farther. It'd be an ideal system for Americans, probably: fast and flexible, but obviously designed by people who place no value on the travel itself.

(Also, maybe typical of Niven: he didn't think about second-order effects. Think of going through the teleportation grid with a toddler. You lose track of them for 10 seconds, and they're suddenly in Shanghai.)

Apart from the fact that such a system relies on unknown physics, of course.

Well, this is the conlanging and conworlding forum...

Raphael wrote: ↑Mon Nov 04, 2024 5:15 am

WeepingElf wrote: ↑Mon Nov 04, 2024 5:10 am

zompist wrote: ↑Sun Nov 03, 2024 8:06 pm Larry Niven posited a system based on teleportation, but organized by the street grid. If I recall, there were portals at each intersection that would jump a city block, and then longer-range portals if you were going farther. It'd be an ideal system for Americans, probably: fast and flexible, but obviously designed by people who place no value on the travel itself.

(Also, maybe typical of Niven: he didn't think about second-order effects. Think of going through the teleportation grid with a toddler. You lose track of them for 10 seconds, and they're suddenly in Shanghai.)

Apart from the fact that such a system relies on unknown physics, of course.

Well, this is the conlanging and conworlding forum...

Yes, but I understand this thread to be a discussion of what is likely in the foreseeable future, and there, teleport network are utterly out of the question. You can't say "There won't be maglev trains because they are too expensive and offer too little improvement over existing technologies, but teleports may be the next big thing in transportation" without making a complete fool of yourself.

WeepingElf wrote: ↑Mon Nov 04, 2024 7:40 am Yes, but I understand this thread to be a discussion of what is likely in the foreseeable future, and there, teleport network are utterly out of the question. You can't say "There won't be maglev trains because they are too expensive and offer too little improvement over existing technologies, but teleports may be the next big thing in transportation" without making a complete fool of yourself.

Ironically, Niven is generally known, and probably thinks of himself, as a hard-science guy. Sf stories include impossibilities all the time. You can certainly keep them out of your own stories, but few writers avoid them entirely.

But I didn't mention teleportation as something Raphael should use in his story, but as part of discussing how transportation affects cities and societies. It's an end case in the project of increasing speed, and also highlights what we could call the philosophy of transportation: Niven's ideal state is to eliminate travel*, not (say) to make it a pleasant or restful.

*Almost. Niven's scheme involved walking between portals, and didn't put portals everywhere. Again, interesting design decisions, not descriptions of real physics.