D&D General Does Earth (or at least a fantasy version of it) have a crystal sphere and exist in the D&D Cosmology?

[James Gasik]

However, since magic apparently functions on Earth (if you accept The Wizards Three as canonical), nothing stops Elminster from casting the spell to make a Spelljammer Helm on Earth to find out!

 

[James Gasik]

In a number of Appendix N sources characters either come from or visit earth- even if they don't know it. I can't recall which, but in one of the L. Sprague de Camp novels (it's a burly wizard apprentice iirc? a series of books) a Rope Trick leads him into a place that the magician I think calls purgatory, but it's basically the middle of a nighttime modern highway with cars going this way and that- I think it was well described, so that you didn't know what it was at first but quickly figured out after a paragraph or two of this guy dodging cards on a highway in the dark.

Not a direct answer to D&D cosmology- but I think that the Elminster-visiting-Ed Greenwood-type answers are the best you'll get.

Oh and Murlynd apparently visited the Boot Hill 'verse to get six shooters.

 

[Reynard]

However, since magic apparently functions on Earth (if you accept The Wizards Three as canonical), nothing stops Elminster from casting the spell to make a Spelljammer Helm on Earth to find out!

Except Earth's universe demonstrably does not have a crystal sphere or aether.

 

[Seramus]

However, since magic apparently functions on Earth (if you accept The Wizards Three as canonical), nothing stops Elminster from casting the spell to make a Spelljammer Helm on Earth to find out!

Interestingly, people have apparently attempted to bring Earth tech to the Forgotten Realms and had it woefully malfunction, sometimes explosively, thanks to Gond keeping the realms mostly tech stagnant (Lantan aside). I even remember a Candlekeep post where Ed joked about Larloch wanting and being unable to import cell phones.

 

[EldritchHistory]

The original Spelljammer box set has Earth Space listed in tables for distances between the planets, potentially just as a reference point but I think its fun to theorize what that could be like.

I like the idea of adding other flawed scientific ideas like Nemesis or Planet X. Or digging into old SciFi and Fantasy books where other planets have dinosaurs or ghosts or are actually giant spaceships.

 

[Tonguez]

Except Earth's universe demonstrably does not have a crystal sphere or aether..

aether did exist for Earths theorists between 16th and 19th Century before being dusmissed by Einstein.

However English physicist Paul Dirac once suggested that Quantum vacuum descriptions of SpaceTime being non-empty at extremely small scales may be the equivalent in ‘modern’ physics of a particulate aether. More recently debates about dark matter have also looked back to aether theories.

So for Earths purposes where the normal laws of the multiverse are superseded by ‘Physics’ aether might still exist but be theorised differently. For instance our Solar system is contained inside the sheath of Heliosphere (the cavity formed by the Sun in the surrounding interstellar medium). physics views this as plasma interactions between solar winds and interstellar medium, but maybe in normal arcane space the plasma crystalizes

 

[James Gasik]

Except Earth's universe demonstrably does not have a crystal sphere or aether.

Our Earth, yes. Given that I'm talking about fictional characters visiting Earth, unless you're positing that Elminster is real, then I think it's safe to say that a fictional Earth could follow different rules.

 

[dead]

I'm pretty sure it's another "dimension." In the BECMI version of the rules, other dimensions could have different laws and properties, and I'm pretty sure that non-magical Earth qualifies.

Yep, that’d be the way to explain it. A different dimension. I don’t know if current D&D uses the term dimension, though. Going by the 3E Manual of the Planes, I think we’d have to say Earth, as we know it, would be explained as being in a different cosmology - one outside the D&D Cosmology (Great Wheel) which consists of one Prime Material Plane with lots of crystal spheres/worlds in it.

I might add a fantasy Earth to my D&D Cosmology, though, to explain where all the real-world pantheons come from. My fantasy Earth will be in a crystal sphere like all the other D&D worlds/settings.

 

[dead]

The most notable instance of a fantasy Earth was the "Gothic Earth" setting from AD&D 2E's Masque of the Red Death setting. We know that it was part of the AD&D cosmology, if for no other reason than it not only had planar AD&D monsters in it, but a piece of it was actually torn off to become the domain of Odiare in Ravenloft, as per Domains of Dread.

Oh, yep. I forgot about Gothic Earth. In terms of flavor, you wouldn’t expect it to be in a crystal sphere, though. Maybe the tendrils of the Domain of Dread can reach into different cosmologies/dimensions. Maybe the planar monsters just happen to be identical in the Gothic Earth cosmology/dimension as they are in the D&D cosmology/dimension. Quite possible if there’s infinite dimensions/cosmologies.

 

[dead]

Besides, if I remember correctly, there is a Becmi Immortal adventure in which you can visit New York.

Oh, I forgot about that adventure, too - IM1 The Immortal Storm. Yes, the PCs travel to New York.