Space.com has an interesting read on how space was viewed in the Middle Ages.
The idea that our universe may be just one among many out there has intrigued modern cosmologists for some time. But it looks like this “multiverse” concept might actually have appeared, albeit unintentionally, back in the Middle Ages.
When scientists analyzed a 13th-century Latin text and applied modern mathematics to it, they found hints that the English philosopher who wrote it in 1225 was already toying with concepts similar to the multiverse…
In De Luce, Grosseteste assumed that the universe was born from an explosion that pushed everything, matter and light, out from a single point — an idea that is strikingly similar to the modern Big Bang theory.
At first, wrote the philosopher, matter and light were linked together. But the rapid expansion eventually led to a “perfect state,” with light-matter crystallizing and forming the outermost sphere — the so-called “firmament” — of the medieval cosmos.
The crystalized matter, Grosseteste assumed, also radiated a special kind of light, which he called lumen. It radiated inward, gathering up the “imperfect” matter it encountered and piling it up in front, similar to the way shock waves propagate in a supernova explosion.
This left behind “perfect” matter that crystallized into another sphere, embedded within the first and also radiating lumen. Eventually, in the center, the remaining imperfect matter formed the core of all the spheres — the Earth…
And although De Luce never mentions the term “multiverse,” Bower said that Grosseteste “seems to realize that the model does not predict a unique solution, and that there are many possible outcomes. He needs to pick out one universe from all the possibilities.”
“Robert Grosseteste works in a very similar way to a modern cosmologist, suggesting physical laws based on observations of the world around him, and he then uses these laws to understand how the universe formed,” Bower said.