There have been many theories as to how the earth and moon were formed. Here are a few possibilities from a few points in time.
- 1863 “Reasons Why: Physical Geography”
The first and oldest book does not mention the moon but offers two explanations of the earth’s core. It is either molten or solid (and full of tunnels). If molten they believe that the heat is left over from the formation of the earth. If the solid theory is true it would be chemical means melting the rock in tunnels. They do not explain what chemical means. A geologist apparently does not care about this information.
2. 1921 “The Book of Knowledge” (Canada)
In 1921 the solar system starts with a nebula. This nebula became hot and shrunk to become the sun. The earth is merely a small piece of the sun that cooled from a gas to a liquid and finally a solid. When it was liquid pieces spun off the surface to become the moon. The books shows that the core of the earth is a hot gas.
In this book they repeatedly mention that poets often refer to a nebula as “the great fire mist”. I have been unable to find any example of this in a poem so I wrote one. “Sat upon a summer lawn, I gazed into the great beyond, beyond the dark and falling dusk, was the fire mist of the universe”
3. 1926 “The Book of Knowledge” (America)
In 1926 the theory from 1921 remains with minor changes. The nebula no longer shrinks from heat but the forces of gravity. This book spends most of the chapter repeating what was written in the previous edition. At the end of the chapter is a paragraph which introduces the possibility of the Planetesimal theory. As explained by the book this theory is that the sun was originally the center of a nebula and the planets were the arms. The planets and moons grew by crashing into each other and space material. The earth did not start with a hot core but developed it over time through radioactive elements.
This book also mentions the poems about “fire mist” I still cannot find any.
4. 1931 “The wonder Book of Science”
This final book does not go into detail about the wonders of science. It shows the formation of the moon as pictured above and states that the earth was formed from the sun in the same manner.
The book shows that the earth has a solid core made up of stone, metal, and heavy elements. It takes a stance against humans making it to the moon, while describing exactly how we did it.
I find it interesting to see how information in these books goes back and forth. It is easy to imagine that all of our current knowledge was gathered one piece at a time and added to a growing pile of organised facts. That if someone suspected the world had a molten layer under the crust in 1863 that fact would continue through to today because we know it is true now.
But instead it is like a billion piece puzzle where the pieces keep going missing and some are from other puzzles and everyone is disagreeing on what the final picture is. Just because someone had a center piece while they were making the edge doesn’t mean it got placed until the puzzle filled out more.