Viability of options for super tall tower

6

I've been reading through other posts about such megastructures and they're getting me part of the way to my destination. Wanted to see about a few specific options my imagination has latched onto.

The original concept is a tower, an arcology with a 1 km base level (willing to taper it as it gets higher if necessary), reaching to at least 8 km altitude.

Assume that available power is not an issue.

One idea is: Blocks, rectangular or triangular prisms, containing powerful electromagnets that are the 'mortar'. I liked this option because the society is ancient, and a blocky look fits the aesthetic better, masking the futurism. I realize it is power inefficient. Would such a thing work on this scale?

Thanks!

EDIT to reflect excellent comments:

Trying to avoid elegant solutions such as Space Fountain, Space Elevator, etc. We want to solve the issue of structural stability with brute force as much as possible. Would a system like this hold up versus gravity, bending and torque at high altitudes?

TJA

Posted 2018-04-13T14:20:22.023

Reputation: 89

1Hello and welcome. Please see [tour] and [help]. This site is for specific questions with specific answers, answers that can be judged valid or invalid. It is hard to tell what's your specific question here. Phrases like "Insight?" belong to a discussion forum, not Stack's Q&A model. – Mołot – 2018-04-13T14:26:01.570

Thanks! Made a few edits to clarify each section of the question. Lmk if not good enough. – TJA – 2018-04-13T14:35:06.093

Now this looks like 4 question in one post. This is not OK. You can have 4 questions asked at one time, but it is not allowed to ask more than one question per, well, question. – Mołot – 2018-04-13T14:43:03.910

Read about space elevators on [Space.se]. They have some useful remarks about maximum tower heights

– None – 2018-04-13T14:43:50.280

What's a CNT? Please [edit] – None – 2018-04-13T14:44:56.337

@JanDoggen I just assumed Carbon NanoTubes, but you are right, this calls for explanation. – Mołot – 2018-04-13T14:46:23.157

Appreciate your patience as I learn to interact in your environment :) – TJA – 2018-04-13T14:53:04.603

"powerful electromagnets" need... to be powered. Continuously. And wired up to the power source. Thus, while it sounds cool, seems really impractical. – RonJohn – 2018-04-13T14:56:25.563

1This starts to look good :) To whoever downvoted: please reconsider now. Maybe it's good enough? As we can see OP is doing his best to make it a really good question. Let's do our best to help him, and to find an answer. – Mołot – 2018-04-13T14:57:14.240

2What is exactly the purpose of those electromagnets that are the 'mortar'? I would expect that the sheer weight of the structure would hold the blocks in place; the Great Pyramid does not use mortar. Mortar is for bricks; bricks don't have enough strength in compression to hold an 8 km tower. – AlexP – 2018-04-13T14:58:26.870

@RonJohn OP states "Assume that available power is not an issue." - so in his world it is practical. Or he is planning to do something spectacular with power down. Either way, he seems to know about that issue and explicitly make it not a part of the question. – Mołot – 2018-04-13T14:58:32.137

@Mołot good point there; though I usually tend to check back on questions I downvoted once a few days after doing so to see if it was improved :) – dot_Sp0T – 2018-04-13T14:59:18.853

Right, part of the concept is the society has abundance of materials and tends to brute force problem solving. Solutions are high-tech, but inelegant. I guess my question was more along the lines of, 'does this setup have enough resilience vs. gravity, bending, torque etc.' Thanks for all replies as well, I need critique from all avenues. – TJA – 2018-04-13T15:00:23.737

@Mołot if power is not an issue, then OP can do almost anything he wants, since just about anything is possible with the application of enough energy. – RonJohn – 2018-04-13T15:10:23.983

Can you give is more information on what the blocks are made of? – bendl – 2018-04-13T15:11:32.687

2https://en.m.wikipedia.org/wiki/Space_fountain this might be useful. Active support is hella cool – Ummdustry – 2018-04-13T15:15:09.800

1Check into “space elevator” construction ideas. – SRM – 2018-04-13T15:21:17.310

@bendl I figured the blocks could be as simple as steel, or maybe something like titanium carbide or even carbon nanotubes just for fun. But again the idea is to stay inelegant, and if it's carbon nanotubes, one might just say 'why not make the whole tower out of them'. Iirc, CNTs should be able to achieve my target height. – TJA – 2018-04-13T15:28:04.693

@Ummdustry and SRM I looked into these a bit, and I love the space fountain idea, but it gets to be a little too elegant for my goal. With a space elevator, I was considering another question concerning how and if structure could be affixed to the central tether. Wouldn't you want it to be free of restrictions and clutter? – TJA – 2018-04-13T15:31:21.943

Suggest closing this as a duplicate: https://worldbuilding.stackexchange.com/questions/63047/100-mile-high-mega-tall-building-physically-possible

– Thucydides – 2018-04-13T20:39:34.793

Answers

3

I am enamored of the combination of unlimited power and primitive blocky architecture!

My suggestions:

  1. Spin. The entire tower spins on its axis. This provides

1a: Gyroscopic stabilization. The tower will be disinclined to tip while spinning, for the same reason a spinning bicycle wheel stabilizes the bike.

1b: Levitation. There are propellers mounted along the tower which use the tower as an axis. The spin generates lift, reducing the weight of the tower by pushing down against the air.

  1. Static electricity. The tower is predisposed to hold a charge, because it is made of obsidian glass. Just as a static charge streaming up a hair will lift the hair from the head or a straw from a table, a static charge generated by the unlimited power source and streaming up the tower reduces the weight of the tower. The tip of the tower is sharply pointed and is surrounded by a bright corona discharge which will turn into upwards lightning bolts if any clouds come near.

I would like the static electricity to come from some sort of earth current or earth-sky conductive circuit. I would like the static electricity to somehow also be responsible for the spinning motion. That way the thing can stay working, unattended after the original builders are gone. Explorers can find it in some later age, still spinning, still sparking.

Willk

Posted 2018-04-13T14:20:22.023

Reputation: 162 210

That is a really cool idea. So basically we're still looking at this notion of lifting the structure as in a space fountain, just through other means. I hadn't thought of lifting it another way! – TJA – 2018-04-14T12:22:52.107

3

The tallest building in the world is the Burj Kalifa in Dubai - it required much ingenuity but mainly the issues it faced were:

  • The foundations - getting solid enough grounding to support the building
  • The width - the taller your building, the wider the base to support it. The wider then the less light penetration. The Burj was split into 3 to deal with this problem.
  • The height - even at only 828m in height, the building would sway significantly in the wind and could cause distress to occupants
  • The elevators - most elevators can only do a limited height at a time. Most skyscrapers then use 'sky lobbies' as a way to solve this problem, but it is only a matter of time (or height) where this becomes a nuisance too much for people.
  • The money - Tall buildings are very expensive, not only to build but to maintain, service and occupy. Also, there comes a point where the cost to benefit ratio is no longer there - even the Burj was on the verge of unfeasibility when it was built.

I read another article that it is conceivable to build an 8km tall skyscaper, the height of Everest, but the base would likely be the width of Everest too. At this size it would be difficult to have satisfactory solutions to the above issues.

flox

Posted 2018-04-13T14:20:22.023

Reputation: 12 245

1Not to minimize the problems, but one seems to have a solution: Elevators. There is currently exiting (but not deployed) technology to use linear induction motors to lift elevator cars. This mean no need for cables, the ability to have multiple cars in one shaft, and the ability move cars sideways (e.g., between shafts). This makes the elevator system much more like automobiles and eliminates most of the bottlenecks. – Mark Olson – 2018-04-13T16:55:19.390

@MarkOlson awesome comment. Elevators were my next stop – TJA – 2018-04-13T17:22:33.917

The question is a duplicate: https://worldbuilding.stackexchange.com/questions/63047/100-mile-high-mega-tall-building-physically-possible

– Thucydides – 2018-04-13T20:39:58.857

@Thucydides I did read that thread, but my question wasn't about getting an insane amount of height and pushing the upper limits, it was about using a less efficient method to achieve a much lower (but still impressive) height. – TJA – 2018-04-14T12:17:44.430

@flox - The width. As far as I care the wider the better. I see no need for natural light. A very wide building can have many more elevators than a narrow building of the same height. And if people have all the amenities on the same floor they won't need to go up or down often. – M. A. Golding – 2018-04-14T19:23:54.777

1@M.A.Golding Natural light is actually a requirement in most building codes throughout the world - also studies have shown exposure to natural light conditions increases productivity by up to 20%. It is a major limitation to the design of a building and the main reason size and shape of all buildings is limited to certain configurations in plan. Most buildings that appear wide from the outside actually have courtyards, light wells, or even translucent roofing to transmit this natural light into the interior. – flox – 2018-04-16T14:10:18.763