"Stick stick Stick" She mumbled. "All i knew is that, since most modern astronomical research deals with subjects related to physics, modern astronomy could actually be called astrophysics" Jessica whispered.

Camille nodded in response and diligently continuing her notes as the discussion was going on. thienth, she thought, laughing a little inside. too thienth.

For the most part, Santi agreed with what the professor had said, thoroughly enjoying most of the discussion. However, on a few points he would've very much liked to argue what was said. This isn't the time, he told himself. Best not to aggravate the professor on the first day by pointing out mistakes in certain places. Instead he had sat quietly listening, he wasn't one to take many notes.

Cedric definitely knew Astronomy and some of its branches. Well, it's mostly because they had to study it. He listened carefully to the professor's very informative inputs about Astronomy. But his mind had been rather muddled up as the Professor Risu mentioned something about a 'stick'

He didn't know what the professor meant by that or if ever, Professor Risu was implying something, it was way too incomprehensible for students to decode. And he started rummaging his mind, trying to remember if he had heard about a 'stick' in Astronomy before.

Ced hadn't come up with something interesting and precise yet. Epic faiiiiilure.

Keeley was still rather confused at trying to keep up with all this astronomy talk, but she got the basic gist of it. Sort of. Anywho... her notes were still going, so that must've been acounted for. Yet her cherry red hair turned into brown, and she felt the sensation of slight boredom tugging at her. Ugh.

Aileen had been listening professor's every word, because she was quite interested in stars and the other stuff related to it. She was writing down all things that had been said. Then she paused and raised her hand.
"Um...professor, if I may have a question...do you believe that there is life outside our planet? I mean...I've heard lot of Muggles talking about it and I'm just curious what you think about it." she said shyly.

Noir listened carefully to her Professor and she write a note in her parchment..she always loved Astronomy..she loved stars so much it makes her clam.."I'm going to enjoy this class" she whispered to herself..

Risu was just about to continue when the door creaked open and a student hurried in. He watched with raised eyebrows as she slid into a seat and unpacked. "You are... late. Extremely so." She was basically approaching punctuality from the other side. "Please make sure to be on time from now on," he told the girl sternly.

OOC: *

More interruptions? Risu turned. "Um... we can discuss this after class if you want, but," he tapped his wrist where his watch would have been if he owned one, "we have to continue with the lesson."

He paused. Then he remembered where he had left off. He smiled brightly. "Yes, a stick. Unlike the pyramids and Stonehenge, this stick of ours was used for actual scientific work, and nothing but. I shall explain in a moment. But first... We return to a time now before there was anything so stringent and important as the scientific method. The third century BC."

Risu began wandering up and down again. He realised that this made it easier to speak. "At that time, the centre of learning of the entire world could be found in Egypt." He nodded at the girl. "I am talking about the Library of Alexandria. Also known as the Great or Royal Library. The brightest minds, usually of Greek origin, were assembled there. It was almost completely destroyed a few centuries later, historians aren't quite sure when, and most of its knowledge was, tragically, lost to us.

"Among the chief librarians of this library was a man named Eratosthenes, and he used a stick - or, to be more precise, a gnomon - to calculate the circumference of the Earth. We will see how in a minute, but first - can someone provide a few biographical details on this scholar, Eratosthenes?"

Gold raised a hand. "He had a funny name, and was born in Cyrene, Greece, sir. Mathematician, astronomer, and athlete. He's the founder of 'modern' Geography, so to speak - not to mention, the first person to use that word. AND he's the founder of Scientific Chronology, so that's pretty cool, too." She paused, for a second.

"--- He was a librarian, at some point. Of the Alexandrian library, I think." She had other stuff she could tell, but she fell quiet, in order to give everyone else a chance to share something unique.

Cue prettyyyy smile.

"He was a greek scholar born in modern-day Libya, who discovered longitude and latitude, he was also the first to use the term 'Geography'," Selena said. She remembered reading about him. "He also discovered the tilt of the earth's axis and was the first to measure the circumference of the earth accurately." Selena added. Selena was satisfied with her answer, it was pretty good, at least she hoped i was good enough.

Alex hesistantly raised her hand and answered, "Eratosthesnes was nicknamed Beta because of his being second best in his fields. He served as librarian at the great library in Alexandria, and wrote works of mathematics, geography, philosophy, and astronomy. At the age of 80 being blinded and weary he died of voluntary starvation. If I remember correctly sir." Alexandrie read a lot of books and had come across someone named Erathosthesnes once she just hoped it was him.

Santi sat there silently. Eratosthenes? Who the heck was that? He knew a great deal about science, but history? Bah! What a waste of time. It didn't matter how something came about, just that it did. Knowing what was is much more important than how it came about.

He stared down at his notes, which he thought were quite good at least compared to his other classes, tapping his pencil on the desk. This class he didn't feel much like pretending to be interested when he wasn't for he did love astronomy and therefore was genuinely attentive most of the time. But history? Really?

Simon put up his hand. "he was was a Greek mathematician, elegiac poet, athlete, geographer, astronomer, and music theorist. He was the first person to use the word geography and invented the discipline of geography as we understand it." Simon then continued. "He also made Several discoveries didn't he?" Simon wasn't sure about that.

Maddie raised her hand. She liked this class, and Proffessor Antares was definitely nice
'Proffessor, Eratosthenes was born in Cyrene which is now in Libya in North Africa. His teachers included the scholar Lysanias of Cyrene and the philosopher Ariston of Chios who had studied under Zeno, the founder of the Stoic school of philosophy. Eratosthenes also studied under the poet and scholar Callimachus who had also been born in Cyrene. He spent some years studying in Athens. He was a mathematician, and athlete, and he was also the first to use the term 'Geography.' she hoped that would be ok

"All true, all true, very good," Risu said with a nod. "Eratosthenes, as many thinkers during his time, was interested in many different philosophical and scientific fields, and he is indeed credited with coining the term 'geography'. And, as Miss Zabini-Riddle has rightly said, he is the first person we have credible evidence for to calculate the Earth's circumference."

Risu pulled out his wand and waved it in the direction of the projector. It flickered, and a new image appeared behind Risu's head.


"This is a map showing the two cities of Alexandria and Syene. Eratosthenes was nothing if not a keen observer of nature, and he noticed that if one rammed a stick - a gnomon - into the ground in Syene in midsummer, it would not cast a shadow. The sun, therefore, was shining from directly overhead. This is what we call the zenith. But in Alexandria, several hundred kilometres to the north, this was not the case. What, then, was the reason for this?" He looked at the class. "Anyone know?"

Maddie raised her hand
'Sir, the zenith distance is the angle from the zenith to the point where the Sun was at noon; it is also 90 degrees minus the altitude. At Syene, the zenith distance was 0 degrees; at Alexandria it was about 7 degrees.'

Trixie raised her hand again. She loved this lesson. "Please sir. As many have already said before me, he was a greek mathmatician, poet, athlete, geographer, music theoristr and as should be common knowledge, astronomer. Most well known for his work in geography, using the geographical knowledge of the era he was able to create the first map of the world. He also made systems such as longitude and latitude, and was able to calculate the circumfrence of the world" she smiled. "But seeing as this is a Astronomy lesson, I'm guessing you want his work in that field yes?" she asked glad that she might be able to answer.

She raised an eyebrow as she heard the younger students answer to his question. "As this young girl has just said, it is all due to the alignment of the sun" she smiled. How would she know that? "Did you know Alexandria was his hometown and so he was able to use these discoveries to work out the circumfrence of the Earth?" she smiled not adding any more about this Alexandria business seeing as other people had already commented on it.

Selena's face flushed red. She knew it. She didn't even need to look in a mirror. The fact that she was right made her smile. Selena then looked up at the board. "Since the geography was different, the way the sun shone on the stick cast different shadows." Selena tried. She wasn't exactly sure how to word it, but she hoped the teacher understood. "The sun was at a different spot to Alexandria compared to Syene," Selena added. Maybe that would clarify some things? Probably not though...

OHMYGOSH!! so many confusing words... Zenith? What the heck was that! And Eratosthenes, who were these people!? When are we going to start looking at stars and planets and horoscopes and stuff? That was the stuff she was into. They were pretty.

She knew that? Seriously? Okay, Santi had been able to guess that it was 0 degrees at Egypt due to the tilt of the Earth. But to know that it was 7 degrees at Alexandria was much more than even he could've guessed. Perhaps she knew how many degrees for each kilometer, or she read a lot, but where would one read that? But still, it was impressive... if it was correct.

"Very good, Miss Force." Risu nodded in her direction. "You and your classmate are correct. The sunbeams hit Syene at a right angle to the ground, essentially making the shadows disappear. But in Alexandria, due to the curvature of the Earth, a 90-degree angle pointed in a different direction in the sky, away from the sun. As you've correctly pointed out, that difference was about seven degrees. Eratosthenes himself calculated that figure through a second set of observations."

Risu pointed his wand at the projector once more. "You can see the difference between the sunbeams in Syene and those in Alexandria here."


"Seven degrees are about one fiftieth of a full circle. Basic maths." He smiled faintly. "Eratosthenes then employed one the king's official step counters," his smile turned into a grin, "who I am not making up for this, to travel from Alexandria to Syene to figure out the distance between the two cities. We well get to the exact numbers in a minute, but please tell me, why was this important to know?"

Maddie grinned, and raised her hand again. This was excellent!
'Sir, he knew how far it was from Alexandria to Syene, so he used geometry and the difference in zenith angle to estimate the size of the Earth.' she seriously could not wipe the smile off her face. Unless, of course, she was wrong...

GAAAH!! maths. mathematics. math. Astronomy wasn't very fun so far... Everyone else was like, whip smart... and Kenna, she was like, half dead in the class. Math was a foreign language. "Isn't this a magic school? Why are we doing stupid math!" She grumbled.

Sapphyre bit her lip as she tried to wrap her head around all of this. Now, it seemed, she knew that it was easier with visual aides. Much easier. Raising her hand unsurely, she hoped her answer wouldn't be wrong. "It's important to know the distance between the two cities, Professor, as to understand the effect the Earth's curve had on the different views. Therefore, knowing the distance, one could calculate the light's change despite their placement." She hoped it hadn't come out as a question... Merlin, this was hard...

Finally, something Santi may be able to answer. He was bored of sitting quietly and he was quite good at math. Raising his hand, he answered, "If you know the distance between the cities and the angle being one fiftieth of a circle you could correctly calculate the full circle by knowing this distance which is one fiftieth of it. Basically multiply by fifty and get the full circumference." Santi smiled politely, having answered his first question, he wanted to give a good impression when the professor looked at him... hopefully he hadn't noticed his previous agitation turned boredom.