"Current... what exactly does that mean? How can you know the future?"
Mo Ling voiced the question that had been nagging him.
This was something even Lin Nian, with all her intelligence, couldn't comprehend.
"I'll explain it using concepts you can understand. It might sound a bit hazy, but the basic principle is correct."
The robot turned its head, holding its hands out in front, side by side.
"An electrical current is generated by voltage."
It raised its left hand. "This is the positive terminal."
Then it raised its right hand. "This is the negative terminal."
"There's a potential difference between them—one is high, the other is low. Electrons are like objects sliding down a hill, from here to here, and that's what creates a current."
The robot lifted one hand higher.
"The act of me raising my hand creates this difference in height. This is the 'cause'."
It then looked at the unmoving hand.
"This one, which remains unchanged, is the 'effect'."
