"I am glad to hear you enjoyed yourself then, Mr Potter. And I hear exciting things are being planned for next term, too..." He interrupted himself as the second badged Gryffindor entered the classroom.
"Miss Laksh! Welcome. Have a seat, please," Risu said, but she'd already wandered off to join the Head Boy near the window. Good choice of seat, Risu thought to himself. Part of the price one had to pay to live in the highest point of the castle was the more noticeable weather. It was colder in winter and hotter in summer than in the rest of the school. Risu gladly put up with it, though. Stoves and short-sleeved shirts had been invented for a reason, after all.
"I'm good, thank you," Risu replied. "And how are you? Have a seat, please, we will begin momentarily."
"Hello, Miss Beaumont. Glad you could join us. Have a seat." Risu paused again, waiting for everyone to get settled before standing in front of the class.
"Welcome to this final Astronomy lesson, students," he said, spreading out his arms. "I assume most of you are looking forward to your summer holidays already, and with exams and the, er, exciting announcement made at the Alumni Ball, I am sure most of you have little patience and time to spare for my humble subject. We will not learn a lot of new things today, I think."
Risu began wandering up and down in front of his desk. "Barring any... accidents, I will return next term to teach again. And if I do, it will finally be time to really delve into the work of an astrophysicist. Most of this term's topics covered the basics, and as such might not have been very interesting, but they are an important foundation upon which further understanding of the Universe can be built."
He pulled out his wand. "And in this last lesson, I want to talk to you about the nature of understanding. Over the centuries, but, predictably, in particular in recent times, a startling amount of scientific progress has been made. Our picture of the cosmos began very simple," and now Risu flicked his wand, and the projector, with a mechanic stutter, flashed an image against the wall.
"The so-called Flammarion woodcut, a work of 19th-century art and science. It has been replaced, at least in the latter, by
this."
With a second flick, the image changed.
"Anyone care to venture a guess as to what this is? Wild guess?"