h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Larry Niven's Ringworld - a Vast Construction in Space - A43307426
Author: Gnomon - U151503

Everyone who is interested in Science Fiction should know about the Ringworld.

Great entry, Gnomon. Quite comprehensive. The only thing that appears to be missing is the phrase 'Big Dumb Object', which the Ringworld most definitely is:

http://www.sf-encyclopedia.com/entry/big_dumb_objects


Geggs

I have not read the Ringworld books. An interesting Entry and very well written.

The first one is worth reading.

It's at least 20 years since I read these books, so I might be mistaken, but I vaguely remember that there were long rows of large rings along the outer edge of the retaining walls, working like a maglev railway, which were used to accelerate incoming spaceships up to ring spin speed....

If you've got a copy of the books handy and can verify whether or not I'm imagining things it might be worth inserting into the 'Space Travel' section.

Not sure how those would work, as the ship would have to travel in a curve to use them.

Not really, as you passed through a ring it would pull you back 'down' towards its centre, and as long as the next ring in the series is not too far away, you'd pass through that at a point slightly above centre, and get pulled back down again... The only problem would be that, relative to the ring, the nose of your spaceship would appear to be rising, until, if it took a 90° arc to accelerate your ship, you'd be pointing directly away from the ring.... a problem which could be resolved using the ship's own directional thrusters.

Pretty sure this was in either the second or third book... But as I said, it's been quite a few years since I read them.

I remember the rings too, I think they worked as a sort of magnetic accelerator / decelerator to help ships match speed with the spinning ring.

I also think that the idea of a ring world was used recently in a film... Elysium I think, but I'm not sure how different that is from a ring world and an orbital.

I've added the following two short paragraphs to the Space Travel section, to cover the issue of the mag-lev accelerator:

"The spaceport designers provided a magnetic linear accelerator consisting of a sequence of mag-lev hoops. The approaching spaceship would have to line up exactly with the first hoop. It would then pass through each hoop in turn and as it did so would be magnetically accelerated to the rotational speed of the ringworld, before docking.

"This is not as easy as it sounds - from the point of view of the spaceship, the first hoop would be approaching at 2.7 million mph - not much room for error there!"

Elysium was more of a big space station than a ringworld, so it's not really relevant here.

Just wondering whether the sf encyclopedia entry on Larry Niven would be useful:

http://www.sf-encyclopedia.com/entry/niven_larry


Geggs

Thanks for that, Geggs. It tells me that Ringworld won the Hugo and Nebula awards, which is worth mentioning. I'll put a link to that encyclopaedia somewhere in the entry.

Brlliant stuff Gnomon. Right up my street, being a Sci-fi fan.

I think this is virtually ready to go? That it's fairly light on internal links would be my only observation right now.

I'll add some links.

OK, there are now links to 14 other h2g2 entries, including the obligatory link to the Sex entry.

As far as I'm concerned, this is ready to go.

Just two minor queries from me.

You mention that it would be easier to build the World around the star than to move the star, but what about moving the World to the star?

In the Erosion section, I had just learned that the mountains are not eroded, so I wondered where the silt came from.

You could conceivably build a ringworld in deep space and then tow it to the star, but the most likely source of construction material is a planet, and these are easier to find orbiting around stars than in deep space.

I'll add a footnote saying that.

The Ringworld is made of metal, but this overlaid on the living surface with a layer of rock and soil to make it seem like a real terrain. It is this which is eroded.

Another footnote needed.

OK. I've made a couple of changes.

- in the section on building the ring around the star, I've mentioned that you could build it elsewhere and tow it to the star, but that the best source of building materials is already in orbit around the star.

- in the section on Erosion, I've mentioned that the construction is rock and soil on top of metal, and it is the rock and soil that get eroded.

- in the section on Details the Engineers forgot, I've added a paragraph explaining that we're not told how the soil and rock eroded from mountains are replaced to prevent the mountains becoming bare metal.

Excellent

Great entry: I don't read sci fi due to being a pretentious , but now I want to read this. Seems like a fascinating concept.