Infiniterrains

[AtlasSniperman]

Infiniterrains

In many worlds the idea of a demiplane is one reserved for high powered magic. A demiplane being seperate from everything, a pocket away from the known universe. Demiplanes also exist on outer planes, often called "realms" and are the homes of deities.

But what about Demiplanes on the material plane? Areas that seem to occur naturally, yet contain an infinite amount of space. These Infiniterrains have no obvious boundries, and can even be measured from outside relative to places around them. An infiniterrain may be 5 miles wide when measured from outside, making it easy to see one side from the other, but have an infinite radius as measured from inside. A gentle rolling field with a signpost at the far end. But entering the infiniterrain produces an odd effect; everything gets further away rather than closer the more you walk. It's as if the world is stretching away. Eventually the signpost will disappear into the distance, and perhaps a village will spring up in its place, closing the distance as yet more fields appear beyond.

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If this makes sense to you, I would like to ask a question; how would a world work with these? how would it look walking around an infiniterrain(would the area inside twist and distort to be an average of the terrain over the distance)? Would there be a possible non-magic test to find the edge of one?

Opinions, questions, ideas, feedback. Help me integrate this into a world as logically as plausible.

[Amechra]

Infiniterrains are basically bounded infinite planes. As such, there aren't any mundane tests you could run to find the edges, iirc.

As for what it would look like inside... it really depends on how the magic that manages it works.

(I'm reminded of the Endless Desert in Exalted; while it is, in fact, infinite, it takes exactly five days to cross. Yes, that includes walking right in and then trying to walk back out again.)

[The Mentalist]

I think that it would lead to a decrease in sea travel due to the fear of storms blowing you into a place you might not get out of, increased fear of liches who could wander deep enough inside a danger zone to be inaccessible by mortals just because of lifespan, entire cultures could spring up just inside them, perhaps having worked out ways to get back out to trade, someone who can control literally infinite arable land can become very powerful and infinite population capacity can make an army sneaking out of one a real threat. I think discovered ones would be highly policed and guarded.

[AtlasSniperman]

I think that it would lead to a decrease in sea travel due to the fear of storms blowing you into a place you might not get out of, increased fear of liches who could wander deep enough inside a danger zone to be inaccessible by mortals just because of lifespan, entire cultures could spring up just inside them, perhaps having worked out ways to get back out to trade, someone who can control literally infinite arable land can become very powerful and infinite population capacity can make an army sneaking out of one a real threat. I think discovered ones would be highly policed and guarded.

All very good points. It makes sense that Liches would retreat into them(I usually just play my liches as anti-social nerds just interested in learning, so that works fine). And the idea of whole cultures existing inside one is completely reasonable and quite terrifying, an infinite landmass has infinite resources after all.

[The Mentalist]

Non-magic but labour intensive way to detect the edges would be grid pacing with expendables. Have the non-lost or those who lose track of others report back with the sections they were in.

[AtlasSniperman]

Non-magic but labour intensive way to detect the edges would be grid pacing with expendables. Have the non-lost or those who lose track of others report back with the sections they were in.

I actually thought it might work to use two people roped together at a set distance(say 50ft rope, walk 35ft apart) and when the rope goes taught, the person at the front has entered. Though that may be a bit too physics driven for D&D XD

[Amechra]

You're assuming that you can actually reach the edge once you're inside. Something that, say, rotates you through a dimension or two might not actually have an edge you can intersect on the inside. To give an example: here (https://www.youtube.com/watch?v=-kVsxVBz1Mg).

Also, you're assuming that cultures inside the infinite landmass would actually be able to hold more of it than a comparable culture could outside without splintering.

[AtlasSniperman]

You're assuming that you can actually reach the edge once you're inside. Something that, say, rotates you through a dimension or two might not actually have an edge you can intersect on the inside. To give an example: here (https://www.youtube.com/watch?v=-kVsxVBz1Mg).

Also, you're assuming that cultures inside the infinite landmass would actually be able to hold more of it than a comparable culture could outside without splintering.

Correct. If a traveller is being moved inside the area outside their own power, then exiting is likely impossible. However if a traveller is not being moved by the terrain, then while the radius is infinite; the distance anyone has travelled can only ever be finite.

To address the Black hole point however;
The difference between a Black Hole and an infiniterrain is gravity. While both are(correctly so) infinite in radius but finite in observable width from outside, the Black hole accomplishes this by increasing gravity in the center. An infiniterrain can be different from this by functioning in a completely different manner; namely that the distances as you near the center are being compressed by virtue of a ratio, rather than gravity. In the case of an Event Horizon, time stops once you cross it, but there is no point where you "cross" within an infiniterrain, there is no point where time stops. While a Black Hole is a useful tool for attempting to understanding the concept of a contained inifnity, it does not work for estimating the way travel works within.
TL;DC: Black holes(while infinite) have a finite inner boundry(edge of the Event Horizon), an Infiniterrain does not.