William was teaching his little brother how the magical formation for the cooler worked. Some might have said that he was too young to learn something so complicated, and William thought there was no better time to start. Besides, he could break down something complicated into simpler parts to start learning from. “See here Stefan? This is the key thing that connects the formation with the other parts.” William held up a triangle made out of bronze. “I have four of them here. See if you can figure out how they are supposed to face.” William put down three more triangles. “Now, you can’t use just any kind of triangles. The shape is important. These triangles have a corner like a square here, and the two sides coming off of them are the same length. They don’t all have to be this size, being bigger and smaller will have different strengths, but for a specific formation they all have to be the same size as each other.” William wasn’t sure how much information Stefan was absorbing, as he was currently fiddling with the triangles. Perhaps William would have to repeat the information many times, but then he might have a chance to find out the proper terminology for isosceles right triangles in gevai.

“Umm… hmm…” Stefan stuck out his tongue as he worked, moving the triangles around. “I think they go… like this.”

William looked down. Stefan had formed a diamond by putting the corners together. “Okay, and why do you think it should go like that?”

“Umm… it’s a nice shape?”

“It is a nice shape. Do you know what this would do?” Stefan shook his head. “Well, by itself, this wouldn’t do anything. This isn’t what I was looking for, but this kind of formation could be used to gather power to the center of a square formation.” William sketched in the dirt with a stick. “The power could flow here, from the corners, to the center of each side, to these in the middle.” William drew some arrows showing the direction of the energy flow. “However, we want energy to flow from the middle out. This would work for that too, but we don’t need an exact center, so these would be extra.”

“Umm… Josef, don’t we want to make it cold in the middle? Doesn’t the cold go in?”

“That’s a good question. Cold doesn’t actually go anywhere. Can you tell me what cold is?”

“Umm… cold is… when you’re cold. Like winter, or water, except when water is in stew.”

William stroked his chin. There was a lot of information he was going to have to convey. “Actually, heat is the proper measurement of everything there. Even cold things have heat, just less of it. You can think of it like…” William’s lecture continued, trying to make Stefan understand without making him feel stupid for not knowing yet.

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“Umm, big brother… ‘bacteria’ are tiny little insects right?”

“Something like that, yeah.”

Stefan squinted his eyes. “I can’t see them.”

“No, they’re so small that you can’t see them.”

“How do I get rid of something I can’t see?”

William shrugged. “You can’t see the air, but you can move that.”

“But… I can see air.” Stefan chanted briefly, and a small breeze blew through the grass, causing it to bend and swirl. “See? I can’t see bacteria though.”

William wasn’t sure what the problem was. That barely counted as seeing air anyway, and Stefan could just imagine the bacteria… couldn’t he? Maybe he couldn’t. He didn’t really have any idea of the scale that they were on, and calling them insects wasn’t really correct. That could probably affect his ability to do magic involving them. That wouldn’t matter for the construction of the formation, but it still was important. “Hmm. How about I think of a way you could see them.” A powerful microscope would do, but it wasn’t like those existed. Lenses were limited to telescopes and sometimes eyewear that could be called rudimentary glasses… and magnifying glasses. Those weren’t good enough though.

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William had some trouble using magic to achieve the effect of a microscope. Bending light the wrong way just ended up with a blurry image that William wasn’t even sure was showing smaller things. It took a lot of work, and finally the help of an actual magnifying glass he borrowed from someone in the city. William had to look at it to refamiliarize himself with how it looked. He would have liked to have one of his own but lenses were quite expensive. He considered making one of his own, but that would take a lot of time, and he was currently finishing the first larger cooler, and needed to do so before harvest. Still, he had a bit of time to use for fiddling with light.

Finally, William came up with a way to do what he wanted, as long as it was daylight with sufficient natural light. Otherwise, there was not enough to focus into a larger image. Even so, William had to set up a miniature stand for where he would put his face, because the focal lengths were pretty precise. He couldn’t concentrate on adjusting the image as well as keeping the spell going… and actually looking at the same time. The first thing William noticed was that he’d only had a very vague idea of what cells and bacteria looked like, with the exception of things like red blood cells. He supposed almost a hundred years had made his memory pretty fuzzy… or he’d never really known things as well as he thought. He supposed the bacteria could be different as well. It had actually been hard to find bacteria, even when he’d gotten to the right focal length. They seemed more scarce than he thought they should be… but on the other hand they also varied widely in size.

William showed Stefan what he’d done, and Stefan was suitably impressed by seeing cells and bacteria for the first time. William’s parents were as well, and fortunately they didn’t ask where he learned about such things.

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William stared at the yogurt in his hand. It was bad. Not that it was poorly made, or even that it had spoiled. It had been in the cooler, after all. Instead, there was something else wrong. It had just stopped being yogurt, which made it bad. Everything else had lasted just fine, fruits and vegetables and meat, but yogurt didn’t. Something about that made William frown.