It's actually more obvious than you might think. You can actually see the curvature of the Earth if you are by the ocean. Ships on the horizon will only have their masts visible.

It's also the whole principle of the light house. If the Earth were flat, you wouldn't need to bother making them tall, since there would be nothing obstructing the light. But they are tall because they need to be seen over the horizon

Quote from: JeremyR;1025369It's actually more obvious than you might think. You can actually see the curvature of the Earth if you are by the ocean. Ships on the horizon will only have their masts visible.

It's also the whole principle of the light house. If the Earth were flat, you wouldn't need to bother making them tall, since there would be nothing obstructing the light. But they are tall because they need to be seen over the horizon

Yeah, and for ease of gaming I would keep that. However, there would still be NPCs who claim the world to be flat. They would have some theories about this curvature effect, or would just arrogantly discard it as "being irrelevant". A possible theory, deriving from my precedednt post about the flat world rotating on itself: some sages would speculate that since the world rotates, then, what you can't see behind the horizon, is a part that is already "more rotated that the part you are standing in." The explanation doesn't need to make sense. In fact, science in the middle-ages rarely made sense. I have read an anecdote: Once, several centuries ago, in France, some bits of a meteorite fell in a peasant's farming field. He took a few of them and brought them to savants in some university. These "scientists" dismissed him as if he were a simpleton, telling him that "everyone knows that rocks are too heavy to fly in the sky". Period.

My idea with flat vs. spherical is that it might be a plot device where some NPCs direly argue over the notion. Thus, an incentive to hire the PCs to go after clues and thus into adventures. And then, even if the players believe that their PCs found evidence that the world can only be spherical, the PCs are unable to convince those who think otherwise. You understand: I don't care myself if the campaign world is flat or spherical. I just wondered if that could make an interesting idea to drive the PCs into adventures. So far, reading most of the answering posts, it doesn't seem an interesting plot device though.

Quote from: Turanil;1025306Well, it isn't that clear, but my idea is not to determine if the world on which Albion is, is actually flat or spherical. It's a fun plot device to send PCs adventuring.

Eratosthenes calculated the diameter of the Earth without leaving Alexandria over 2000 years ago. It was already known to be round.

Quote from: Gronan of Simmerya;1025327It's a flat spherical planet world.

Heresy! It's a hollow cylinder, so that one can use the about-to-be-published map set and still have 'realism' with all the ships at sea. You sail north or south - or 'up' and 'down', if you like - to reach the polar access to the inner face of the map. This allows for inclusion of the next game setting, and increases sales of products.

Quote from: chirine ba kal;1025538Heresy! It's a hollow cylinder, so that one can use the about-to-be-published map set and still have 'realism' with all the ships at sea. You sail north or south - or 'up' and 'down', if you like - to reach the polar access to the inner face of the map. This allows for inclusion of the next game setting, and increases sales of products.

Only lack of ambition holds me back...

Quote from: chirine ba kal;1025538Heresy! It's a hollow cylinder

Observably not. Curvature at sea occurs in whichever compass direction you sail. What you want is not a hollow cylinder but a hollow sphere (or oblate spheroid) with openings at the poles.

You can run this as a campaign premise.  Just be ready for the PCs to be in awe of your sages ablity to disapear up his own butt.

Quote from: Headless;1025656You can run this as a campaign premise.  Just be ready for the PCs to be in awe of your sages ablity to disapear up his own butt.

Okay, that actually made me laugh out loud.

Quote from: Bren;1025652Observably not. Curvature at sea occurs in whichever compass direction you sail. What you want is not a hollow cylinder but a hollow sphere (or oblate spheroid) with openings at the poles.

Chirine once ran a campaign where the world was a hollow cylinder and people could sail inside.  Merely mentioning it for your amusement.

Quote from: Gronan of Simmerya;1025668Chirine once ran a campaign where the world was a hollow cylinder and people could sail inside.  Merely mentioning it for your amusement.

That's an O'Neill Cylinder.

Quote from: Gronan of Simmerya;1025668Chirine once ran a campaign where the world was a hollow cylinder and people could sail inside.  Merely mentioning it for your amusement.

With the compass directions 'Left', 'Right', 'Up', and 'Down'; the three moons orbited clockwise, counter-clockwise, and in and out of the cylinder. And it was a fun campaign, too, with a couple of guys I knew from the theater as guest players: Jessie Borrego and Don Cheadle. We did have fun...

I have kicked around the concept of a Mobius strip world.  Instead of spheres or planes it is something of this sort, as the characters make discoveries beyond the knowledge of sages.

The old hollow world set-up at first thought seems pretty (overly) simple, but if some thought is put into it, it can be very strange.

Quote from: Gronan of Simmerya;1025668Chirine once ran a campaign where the world was a hollow cylinder and people could sail inside.  Merely mentioning it for your amusement.

Was it rotating to create pseudo gravity on the interior of the cylinder? Cause that would work.

Quote from: Bren;1025732Was it rotating to create pseudo gravity on the interior of the cylinder? Cause that would work.

No; the only reason I had the cylinder rotate was to give the third moon different ground paths on each orbit, so sailors could use it to navigate by. (I like reading and compiling ephemerides, which is why I did my articles on Tekumel's astrology.) Lunar conjunctions were great fun, as tidal effects always seem to catch players by surprise. The sun orbited the cylinder, along with the rest of the planets in the system, because I had a lot of fun building the orrery. Gravity was because I said so.

Quote from: chirine ba kal;1025671and Don Cheadle.

THE Don Cheadle?