If you want to play around with it too, the way these pictures were made was with a free program called Gaia Sky available here: https://t.co/2n75LeINmw And in order to get the asteroid orbits I have included, you need to download these extra datasets to it from the obvious

A visualization of how the inner solar system looks like when you include the orbits of most of the currently known asteroids:

Google books copy of "half Hours in Air and Sky" https://t.co/TMJWRfxQnH And also if interested Alexander Wilson's sunspot observations: https://t.co/FlmghKuCIV

The reason for this belief for the sun at that point seems to stem from the previous observations of Scottish astronomer Alexander Wilson's who focused in recording examining sunspots. Which he was fairly convinced were depressions on the Sun's surface (somewhat accurate and

Despite being for "young readers", the books even dedicates chapters explaining electricity, mirages, and spectrography (also a thing by then!) So its not actually meant to be a sensationalist or crackpot science but actually very serious reading. (The cross like thing in

The book is actually fairly accurate for the most part. By then people had discovered all 8 planets and were aware of their accurate orbits, sizes and distances. And its even past the time when people thought of Saturn's rings as a rigid solid (so even explain those fairly

Diagram of a multilayered hollow (and potentially habitable) Sun. From a victorian 1877 popular science book called half Hours in Air and Sky.

(Bonus picture of the Earth, Moon, current "Asteroid Belt Planet" and Ceres all together)

Keep in mind that despite the mass of the total material in the asteroid belt being so tiny, this is not necesserily the size the original protoplanet (or protoplanets) that may have once broken up to form it had. Since many fragments of it, likely either got ejectected from the

And it is worth noting that even so, Ceres accounts for about 39% of the mass of it. If one were to exclude it, then you'd only get an 1102 km diameter object instead. Which drawn together would only look slightly larger than Ceres. (it would be heavier, but volume increases

Despite the asteroid belt looking fairly scary when you see visualization that plot every single object. All of these are fairly tiny objects spread around a trully vast space. And together mass to only about 2.39 x 10^21 kg, or a mere 3%-ish of the mass of our Moon.

The size the asteroid belt would have if you were to concetrate it again into a single object: The resulting "asteroid dwarf planet" in this case has a diameter of 1,299 km. And I assumed it to be a mostly rocky/icy object with the density of Ceres (2.08 g/cm³)

In the end the point of all of this is not to dunk on Halley. It is to ponder what an archievement it is to get anything right in the first place, when you exist in a world where everyone is stumbling in the dark and pretty much this was the level of science all around you. And

Back to Halley. He is of cource very much aware of other limitations, such as light. Albait at this point the argument not being anything more beyond "well, there may be other ways to produce light" and essentially later on "well, it would be a waste if the Creator didn't make

Another fun section. When he comes to the point of discussing the habitability of the inner globes, he uses the sentence: "But since it is now taken for granted that the Earth is one of the Planets they are all within reason supposed Habitable" Again, this is par the course

Most of it is a complicated theory trying to explain Earth's magnetic field behaviour, however, here's some sections I find cute from that Royal Society letter. First, he is very much aware that one argument someone would immediatelly think of, is that such a structure in

Edmond Halley. Famous and forever immortalized astronomer for accurately mathematically predicting Halley's comet return. Probably a bit less famous and accurate about: His multi-shell hollow earth theory. https://t.co/GaTMELitDv

And here's a couple of actual targetting pods: In this one, the polygonal cover would be stationary, and the camera would move inside around it. And even in those where it seems the dome has some turning capability of its own, the actual camera will still be some distance

Yes, that's extremely obviously bird poop/bug smear or similar a far as I am concerned. However I have noticed some interesting comments by people saying "oh yeah, then why does it sometimes move back and forth compared compared to the rest of the hud?" or "oh year, and how

Water also tries to make itself into a sphere when it freefalls, but due to air resistance it deforms to a shape like this. (Presumably so does lead somewhat but holds its shape better resists air better due to its higher density. And was good enough for that time's use case)