# Megastructures



## SkepJ (Aug 23, 2005)

Megastructures in sci-fi are pretty cool aren't they? Ringworld was the first book I read with one in it. It's a neat idea, shame there's no such thing as scrith to build one though. All hope for full scale ringworlds isn't lost because of this though. I read an interesting idea on how to build one recently. Imagine a ringworld of the same physical dimensions as in Larry Niven's book. The ringworld rotates at the speed needed to create one gee on the surface(or less if desired). What keeps the ring from flying apart from the outward force is there is another massive ring on the non-star facing side of the inner ringworld. This outer ring doesn't orbit the star below at all; so the outer ring is in compression from the star's gravity acting on it. This inward force balances out against the inner ringworld's outward force. Pretty neat hmmmm? 

This is kind of what the view on the surface of a ringworld would look like: http://www.orionworks.com/shop/SVJShop/planetary/RingWld/Approaching_Dawn_600.jpg

I like the idea of a ringworld having no night, an endless growing season for plants! The entire ring's surface, what's not ocean, could be rainforest, rolling grassy fields, snowy mountains, whatever. 

I also very much like the ideas of supramundane and suprastellar shells. If you want to read about how they'd work look here: http://www.paulbirch.net/
And scroll down to the science papers section. Billions of time's Earth's area around one star(if you build multiple shells); how neat is that?! Imagine a city that covers the surface of one of the shells. That'd make Coruscant from Star Wars look like a small town out in the boondocks. Or an entire shell of ocean an tropical forest, or anything.


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## cyborg_cinema (Aug 23, 2005)

SkepJ said:
			
		

> Megastructures in sci-fi are pretty cool aren't they?


...Niven rocks. Here's part of the reason why... Science Fiction Inventions by Larry Niven


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## kyektulu (Aug 23, 2005)

*Could you explain in a bit more detail what a ring-world is SkepJ? I havnt heard of one before and am all curious now. 
 I am a bit of a sci fi virgin you see! 
*


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## cyborg_cinema (Aug 23, 2005)

I found some verbage to share with you all...



> ...Ringworld is a huge ribbon circling a star; the inside of the ribbon is habitable. An example of the scale of the Ringworld is this: on Ringworld, there is an ocean large enough that a full scale map of earth is a tiny archipelago separated from other such island groups by an ocean voyage of up to a half million miles, or twice the distance from the earth to the moon.
> 
> ...the surface area is about 3 million times the Earth's. Shadow squares...provide a day-night cycle of 30 hours, but when the sun is not shadowed, it's always directly overhead - it never rises or sets. ...you can see the stars, but the biggest feature of the sky is the Arch, the other side of the Ring from where you are. Somehow, the Ringworld became inhabited by primates half a million years ago or so and now there are dozens of species of human-like but non-human creatures filling the Ring, some intelligent, some not.—Physics in Science Fiction


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## SkepJ (Aug 24, 2005)

cyborg_cinema said:
			
		

> I found some verbage to share with you all...




That's a good description of it. It left off the part about the 1,000 mile high walls on each side of the ribbon, which keep the atmosphere from flying of into space. The two walls are made to look craggy, like a mountain far higher than is possible on Earth.  


Possible spolier below:
















In addition to the millions of miles of 1,000 mile high mountains, the ringworld also has a mountain called Fist of God. It was formed when something, something big impacted the back side of the ringworld. This formed a giant dent with a tear in the top. The tear is far above the ringworld's atmosphere so the air can't leak out through the hole. This plot device wouldn't work on a real ringworld made of plausible strength materials like I'm talking about. Scrith, as described by Niven, is almost unbreakable. It'd have to be as strong as the force that holds atom's protons and neutrons together. This force is called the Strong Force, for a very good reason!


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## cyborg_cinema (Aug 24, 2005)

SkepJ said:
			
		

> This formed a giant dent with a tear in the top. The tear is far above the ringworld's atmosphere so the air can't leak out through the hole.


...what a trip.


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## Brian G Turner (Aug 24, 2005)

This is in the same vein as a Dyson Sphere, yes? Was once featured in a Next Gen episode with Scotty as the guest star.

Always thought a Dyson's Sphere seemed like a remarkable waste of invested energy - great in terms of theoretical constructs, but I simply cannot see the short term costs being justified excepting on extremely far-fetched timescales. 

2c.


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## Jayaprakash Satyamurthy (Aug 24, 2005)

Somehow, as a story Ringworld and its sequels never grabbed me. I prefer several other Big Dumb Object stories in the SF canon, such as Clarke's Rama or Pohl's Gateway. The Ringworld concept is of course pretty cool, but Niven's storytelling didn't really do it for me.


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## dreamwalker (Aug 24, 2005)

I, Brian, you have any more imformation on the Dyson Sphere, any physics or information relating there of to idea's similar to it?
Also, check out...
http://www.merzo.net/
And look at the "BIG" section


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## dreamwalker (Aug 24, 2005)

I answered my own question ^^
http://www.nada.kth.se/~asa/dysonFAQ.html


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## Foxbat (Aug 24, 2005)

> Always thought a Dyson's Sphere seemed like a remarkable waste of invested energy - great in terms of theoretical constructs, but I simply cannot see the short term costs being justified excepting on extremely far-fetched timescales.



It's a great concept if you're an Isolationist


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## cyborg_cinema (Aug 25, 2005)

Foxbat said:
			
		

> It's a great concept if you're an Isolationist


...and the ring is full of primates—who wants to be the monkey in the middle?


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## Taltos (Aug 25, 2005)

David Brin had some structures that were even bigger than dyson spheres in his books - fractal worlds. Don't have the exact description at hand currently, but the concept was something like this: The sunlight doesn't have to land on surface at 90 degrees, so the construct doesn't have to be sphere ... etc. If someone is interested i can look the concept up, in the evening.


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## SkepJ (Aug 25, 2005)

Taltos said:
			
		

> David Brin had some structures that were even bigger than dyson spheres in his books - fractal worlds. Don't have the exact description at hand currently, but the concept was something like this: The sunlight doesn't have to land on surface at 90 degrees, so the construct doesn't have to be sphere ... etc. If someone is interested i can look the concept up, in the evening.


 

Sure, I'd like to read about that.


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## Taltos (Aug 29, 2005)

Sorry, searching from a paperback takes a little bit more time than searching from file - as I just found out  

The description in the book was - Fractal world is a "criswell" structure, where spikiness creates a fractal shape, of dimension approximately two point four. The interior has a bitmore folding, where the purpose is to maximize total surface area getting some exposure to sunlight, even if it comes at a glancing angle.

Simply put it is a sphere with knife like protrusions sticking out and in from all sides or a curled up hedgehog


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## Stalker (Aug 29, 2005)

Dan Simmons in his _Rise of Endimion_ also makes reference to Dyson's sphere constructed by the Ousters.
I also would like to recall some misterious artifacts left by yet more misterious Alien constructors gone long ago and humankind in its space expanion stumbles upon them here and there - this trick is used widely for sci-fi series.
Peter Hamilton in his _Night's Dawn_ trilogy uses such an "Ultimate" structure as _Deus ex machina_ to finalise his series in ancient style or simply because of lack of imagination. 
Soviet-Russian sci-fi writer _Serguei Snegov_ in his _Men Like Gods_ trilogy acts even on a greater scale. His _HI Persei_ nebula is completely an artifact created by cybercivilisation of Destroyers. But even more stiking his reconstruction of the Core of our Galaxy as artificially maintained by a legendary elder civilisation of Ramirs. 
Brin also makes reference to the Elders, doesn't he?


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## Taltos (Aug 29, 2005)

Stalker said:
			
		

> Dan Simmons in his _Rise of Endimion_ also makes reference to Dyson's sphere constructed by the Ousters.


Have read Endymion some time ago ... but honestly don't remember


			
				Stalker said:
			
		

> Peter Hamilton in his _Night's Dawn_ trilogy uses such an "Ultimate" structure as _Deus ex machina_ to finalise his series in ancient style or simply because of lack of imagination.


Haven't gotten that far with Hamilton serie ... thanks for the spoilers


			
				Stalker said:
			
		

> Soviet-Russian sci-fi writer _Serguei Snegov_ in his _Men Like Gods_ trilogy acts even on a greater scale. His _HI Persei_ nebula is completely an artifact created by cybercivilisation of Destroyers. But even more stiking his reconstruction of the Core of our Galaxy as artificially maintained by a legendary elder civilisation of Ramirs.


Snegov was unknown author to me - but looking at the time when he wrote his books 60-s and 70-s - no wonder 


			
				Stalker said:
			
		

> Brin also makes reference to the Elders, doesn't he?


Which of the SF authors doesn't, they are a very good source of mysterious artifacts.

Back to the original question, I think it was Charles Sheffield who had 2 planets connected to eachother by a artificial cord and other iteresting precursor engineering feats.


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## Stalker (Aug 29, 2005)

Taltos said:
			
		

> Back to the original question, I think it was Charles Sheffield who had 2 planets connected to eachother by a artificial cord and other iteresting precursor engineering feats.


Yes, I've already started this series. The plot itself is a little bit dull but mechanics of that double world is peculiar and intriguig. Think, before too long, I'll read it to the end.
BTW, the last novel of Snegov's trilogy The Ring of Reversed Time (Kol'tso obratnogo vremeni) was written in 80s. In any case, if you missed that trilogy, I advise that you read it.
I also am the member of the "YESLY"-sci-fi-magazine forum. http://www.esli.ru/forums/
Join that community if you feel like.


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