Yui proved with the help of Gracia her theory that ponies subconsciously use their spirit sides to arrange magical molecules into ordered structures. She did it just before her return to Earth.
She also became a sort of celebrity, as she would tell any of her fellow tengu who would listen about her discovery of the new world. She wasn’t the first to make such a discovery, but it didn’t happen very often. Many of her kin decided to meet with her to learn more about this alien land. Yui hadn't given out many specifics, but a few details here and there were enough to spark curiosity.
Of course, she had to write a detailed report to the Coalition, but that was a necessary precaution to prevent information leaks and possible misuse. She got a verbose response, mainly about what she could tell others and what she should keep secret. And her kin were very good at keeping secrets.
Her parents gave her the magical journal Medley had sent them, and with it she wrote letters to them. Of course, the Coalition staff had their own device, and they exchanged some useful information for the mutual benefit. Yui only wrote about personal stuff to the ponies she knew well, especially Rainbow and Gloaming. Yui hoped that, after comparing Earth languages and the pony language, the Coalition linguists could arrange a more exact translation of ponies' names someday.
Rainbow soon wrote that she finally spoke to Shimmering about her issues. Shimmering said she had suspected something like this, watching Rainbow’s behaviour. Rainbow also progressed to the next level of force magic while she was in the spirit world. Now she could fly anywhere, even in a vacuum.
Curiosity asked about things like clothing, furniture, and designs of buildings, so Yui sent her several books aimed for children, which had a lot of pictures and not many words. Curiosity could understand most of it without translation, and then could use a handheld device to translate the difficult parts.
A week ago, Gracia told Yui that Medley had made great progress in her studies. Soon, Medley would come to Earth to meet her first friend from another world. Yui also wanted to meet the pink pony in person once more. Maybe she could even bring other ponies, for example Rainbow or Curiosity.
Bright Eyes perfected her ability to grab random things from other worlds, though she still had difficulties using Invisible Magic to travel. Possibly her talents were in other areas.
Gloaming was very enthusiastic about meeting the first delegation from the Coalition. So enthusiastic that the humans soon learned to avoid her. Fortunately not everyone, though, so Gloaming still got her share of information about Earth. Yui hoped that Gloaming would be the first pony to get a computer with encyclopedias and other books, once the linguists finished the translator.
The humans were very interested in pony magic, and experimented with transferring magical organelles into Earth life forms with some success. Ponies had already done this with some animals and plants, so the Coalition scientists aimed to transfer the organelles to humans. Most plants, and even some animals, could not use magic, so the humans were more promising subjects for experimentation. The nature of organelles and magical atoms were still debated, though most human and pony scientists agreed that the atoms were simple automata, or maybe even a form of life, and that the magic effects appeared due to the design of the atoms, either intrinsically or due to emergent properties.
Also, several humans began participating in educational programs to get a first hand impression of how the pony education system worked.