Personal dome
The personal dome, dome of vision, or azimuthal grid of vision[1][note 1] is a nonsensical and ad hoc concept used by flerfs to "explain" observations of the celestial sphere that are incompatible with flat Earth.
The concept is approximately as follows: encompassing each observer is an equidistant dome, onto which all celestial phenomena are "projected" in exact accordance with what the globe predicts from their location. Flerfs generally agree that the personal dome is only a conceptual model to illustrate apparent celestial positions, rather than a physical object that follows each individual around.
To at least some degree, it is an extension of the concept of flerfspective, but adherents usually believe that light-bending is involved too.
The personal dome is essentially a desperate rescuing device, because flerfs realise how radically incompatible observations of the sky are with their models.
Types of personal dome concepts
The personal dome concept can be separated into two main subconcepts depending on what is mechanistically causing it. Not all flerfs will agree on the same mechanism(s), but most will agree the mechanism(s) result in the following:
- the personal dome displays half of the celestial sphere;
- the altitude of the nearest celestial pole exactly matches the observer's latitude.
Perspective only
This view holds that the two criteria above are created solely as a result of linear perspective. Anyone who can work with basic trigonometry (or even common sense) will realise obvious flaws with this hypothesis.
Regarding the first criterion, there is no reason half of the celestial sphere should be seen in a given location, because the altitude angle to something (like a star) will never reach zero if it is physically higher than the observer. All stars would remain above the horizon from an observers perspective, and the proportion of the celestial sphere visible would entirely depend on visibility conditions (i.e., fog, clouds etc.). Some flerfs however do lie about the proportions we see.
Regarding the second criterion, the altitude of the celestial pole would not match the observer's latitude, given the fact that latitude lines are equidistant (even the AE map agrees this is the case). The angle would decrease asymptotically, not linearly as is observed.
There is also the issue that the perspective hypothesis cannot account for the existence of the south celestial pole.
If flerfs still hold onto the perspective hypothesis after having these flaws explained to them, they are practicing flerfspective.
Perspective + light bending
When pressed on the perspective only view, many flerfs will concede that the personal dome can only account for the two criteria above and a south celestial pole if light bending is involved.
This then leads to questioning the mechanism behind the light-bending.
Problems
Its more difficult to identity what is not problematic with the concept.
Unfalsifiable
The personal dome is, by its own nature, unfalsifiable (and therefore pseudoscience). There is presently no observation which could disprove the idea, because the required light-bending lacks any coherent mechanism that can be tested.
The concept technically cannot be falsified until every conceivable mechanism is falsified, of which there are virtually infinite. Even if countless mechanisms are disproven, flerfs will still resort to an explanation that is not or cannot be disproven, such as asserting that "the personal dome is created by unicorn farts".
The unfalsifiablility also means the personal dome is not exclusive to flat Earth models; it could be used in exactly the same way to rescue the theory of a banana-shaped Earth.
Cannot be modelled without the globe
See also
Notes
- ↑ A term coined by Austin Witsit