[carapace]

Make it big, get it up out of the water.

The larger your ship is the more efficient it can be, and the less of it in the water the less energy is needed to push it.

So make big big ships with really really big sails. You want the ships to fly with just the keel in the water to steer against the wind.

You might think I'm joking or talking nonsense, but look up Alexander Bell's cellular geodesic kites, and Bucky Fuller's "Cloud Nine" floating city.

[nradov]

I think you're joking and talking nonsense. There are practical limits to the size of a planing or foiling vessel. This is just basic physics. Adding more sail area isn't helpful; at some point it's counterproductive and actually slows the vessel down.

[_carbyau_]

Well ok. But my limited understanding of material science says no. For now at least.

Material strength doesn't scale well to go "properly big big" in the sci-fi sense.

OTOH, I am constantly amazed by what material science keeps managing to do, so I have hopes that maybe one day your dream will be true.

[carapace]

Cheers!

Are you familiar with Bucky Fuller's concept of "tensegrity"?

https://en.wikipedia.org/wiki/Tensegrity

https://mymodernmet.com/tensegrity-architecture/

He pointed out that the struts could recursively be made out of tensegrity structures. Or you can make them out of balloons:

https://en.wikipedia.org/wiki/Tensairity

I was being a little coy in my previous comment. The structures I'm thinking of are more like kites than sailing ships. They would "dip a toe" in the water to tack, perhaps, but they would be aerial not marine in nature.

A. Bell lifted a man with his cellular geodesic kites. https://en.wikipedia.org/wiki/AEA_Cygnet

In any event, I hope my dream does come true one day. :) Cheers!

[_carbyau_]

While not aware of the phrase tensegrity I have rarely seen various forms of "floating tables".

Initial thoughts:

- seems like a manner of construction to swap tensile strength in certain spots, thus allowing for an awesome "against intuition" visual effect.

- could be nice from a packaging point of view. Collapsible objects, the wiki link mentions the nasa ball robot.

- maybe it could shift Bill-of-Materials costs through smaller amounts of expensive extremely high compression/tensile capable materials to be offset by savings on larger amounts of cheaper other capable sections.

- I am not convinced it would allow the superstructures much sci-fi requires as the basics of tensile strength, compression strength are still in play.

- As mentioned in the tensairity article, if humanity could make a pressure withstanding, airtight object, say a sphere, around a vacuum with less mass than the air it displaces, we could have architectural "anti-gravity".

Including an airship with a toe in the water. :-)

Finally, I simply don't know enough.(Do we ever?) It looks cool and is worth investigating further. I am going to lose lots of time thinking about, checking out and printing out occasional bits from thingiverse now!

[carapace]

Cheers!

> - seems like a manner of construction to swap tensile strength in certain spots, thus allowing for an awesome "against intuition" visual effect.- seems like a manner of construction to swap tensile strength in certain spots, thus allowing for an awesome "against intuition" visual effect.

I recommend building physical models. It's hard to convey how strong and light these structures can be. Very "against intuition". :)

> - could be nice from a packaging point of view. Collapsible objects, the wiki link mentions the nasa ball robot.

https://en.wikipedia.org/wiki/Hoberman_sphere

https://www.nasa.gov/jpl/news/origami-style-solar-power-2014...

Yes. :)

> - maybe it could shift Bill-of-Materials costs through smaller amounts of expensive extremely high compression/tensile capable materials to be offset by savings on larger amounts of cheaper other capable sections.

https://en.wikipedia.org/wiki/Ephemeralization

Bucky again.

(Kevlar tendons and carbon fiber struts...)

> - I am not convinced it would allow the superstructures much sci-fi requires as the basics of tensile strength, compression strength are still in play.

I'm not an engineer, but we can already build some impressive structure w/o advanced materials. Cf. "bamboo scaffolding" (DDG image search: https://duckduckgo.com/?t=ffcm&q=%22bamboo+scaffolding%22&at... )

I'm imagining swarm cellular kite robots that can self-organize to create whatever size lifting body is needed. I'm thinking about things like how to move millions of people at a time (which we might want to do due to climate change, etc.)

Have you read Vinge's "Rainbows End" (sic)? ( https://en.wikipedia.org/wiki/Rainbows_End ) There are buildings in the story that are too flimsy to stand up without active control and feedback, something like that could work with these kite-bots.

> - As mentioned in the tensairity article, if humanity could make a pressure withstanding, airtight object, say a sphere, around a vacuum with less mass than the air it displaces, we could have architectural "anti-gravity".

We don't have to go that far (although it would be neat if we could, diamond vacuum bubbles?) Did you read about "Cloud Nine? https://en.wikipedia.org/wiki/Cloud_Nine_(tensegrity_sphere)

I've thought about this a lot but not yet gotten my act together enough to do it. I wrote up some of it here: https://lists.sr.ht/~sforman/heliotrope.pajamas/%3C202012290... ("heliotrope.pajamas" is my mailing list if you want to reach me in re: this stuff)

Well met!

[nickserv]

Take the idea just a notch further and you've got yourself an ekranoplan.

https://en.m.wikipedia.org/wiki/Lun-class_ekranoplan