For Frieren, this was also a two-way learning process.
After all, her world was vastly different from the modern world, to the point that there were many things Frieren had never seen before. Rias and Mary still had to teach her slowly, but as a Great Archmage, Frieren had an excellent mind. She quickly figured out how to use many things without much effort.
For example, a television was a tool that could show events happening far away, while a cellphone was a tool that allowed people to contact others anytime and anywhere, and so on...
But for Frieren, this clearly wasn't enough, so she soon had another question.
"If the humans of this world have no magic, how did they create all this?"
"This..."
Faced with Frieren's perfectly natural question, Rias, Naruse Mio, and Mary were all dumbfounded. They only knew how to use these things; as for the principles behind them... they didn't understand them either!
So Frieren went to find Duanmu Huai. Naturally, Duanmu Huai didn't understand them either.
But that didn't matter. He went straight to a bookstore, bought a copy of 100,000 Whys, and tossed it to Frieren. Take your time flipping through it.
Frieren then began flipping through 100,000 Whys. First, she wanted to find out why cellphones could make calls and how signals could be transmitted without magic.
Oh, she found it. Cellphones transmitted information by receiving signals.
Then what were cellphone signals?
She flipped further. Cellphone signals were a type of electromagnetic wave. All right, then what are electromagnetic waves?
When Duanmu Huai returned a few days later, the 100,000 Whys in Frieren's hands had already been replaced by Classic Physics Fundamentals...
"Are you planning to take the graduate school entrance exam?"
Seeing Frieren sitting by the window with the massive book