Eino entered the classroom with an uncommon enthusiasm. Although the class was unusually early, he was prepared and looking forward to it. He never took an interest to Astronomy, but he was eager to learn it, since he liked Divination he assumed Astronomy was also related to the art and practice of foretelling the future, but he also expected to be more than just that. "Good Morning, Professor." He greeted with a smile as he took a seat in the front and center. He impatiently took out parchment, quill, and a bottle of ink and placed them on the table, along with his Astronomy book.

Pretty much skipping breakfast since she woke up too late, the Slytherin started up towards the seventh floor, a giant scowl on her face the entire way. No, she was still not fully awake yet, and no, she was not in a good mood.

Obviously.

Rolling her eyes as she FINALLY made it up to the seventh floor, Evelyn yawned, stretching her back before walking into the classroom, mustering up a small smile to the professor. If he was even there. Her eyes were half closed so she didn't know, nor did she care.

Desk...sit...bag on floor...head on table...arms covering her head...

ZZZzzzzzzz....

Freya was walking towards the seventh floor where the Astronomy Tower was after having a quick breakfast in the Great Hall. She pushed the door to the Astronomy Tower open. She blinked her eyes couple of time. She only saw two other students there. Where were everybody? She looked around and she couldn't see Professor Antares in his desk or around the class. She was in the right classroom, right? She decided to take a seat maybe the other were still in the Great Hall.

Kurumi had been left with a giant headache after the first class...and she was beginning to wonder why she was putting herself through the torture that was astronomy again. Call it her being stubborn as she just could not accept that there was a class she could not grasps the concepts...but it was probably more her fear of failure that brought her here today. Besides, she had OWLs she had to start thinking about...in a few years.

Entering the classroom and noticing the professor wasn't in yet, Kurumi took a seat toward the front and lay her textbook, parchment, and quills out. Time to put on the serious study face!

See, Vashti liked Astronomy. It might not be as simple as just learning the planets and the stages of a star's lifetime like in elementary school - some of it was really quite difficult to understand, but that was okay really, because how was anyone supposed to learn if they didn't challenge themselves?

However, she definitely did not like how early this class was starting. Not one bit. She hadn't even gotten to eat breakfast, for Merlin's sake! Sure, that meant she didn't have to walk as far as some students, since her dorm and common room were on the same level, but still! She didn't want to starve!

Upon entering the classroom and seeing that the professor wasn't there, Vashti briefly considered running down to the Great Hall real quick to at least get a piece of toast but knew she didn't want to risk it. She probably wouldn't be fast enough to go up and down seven floors before class started. Being late and losing points was far worse than not eating for an hour or two. So instead she took a seat by the only person she recognized - the Gryffindor girl she'd met in that ancient!Quidditch flying lesson - and tried to ignore her empty and unhappy stomach.

Rene enjoyed the last class and was excited about having this class but wasnt so excited about the double period or how early she had to get up in order to make it there on time.

It was early and she stopped by the Great Hall to get some grub. She stashed some in her bag for the class because it was so long.

She walked into the class and took a seat, grabbed her books, parchment and pens. After placing everything on the desk she reached for a piece of bacon and quickly ate it before anyone saw.

Trixie arrived at Astronomy with a huge smile on her face. She'd always loved this lesson, it interested her greatly. All the planets and knowing about not only about the goings on in the Solar System but everything really. Astronomy covered more than many expected and the Blonde absolutely adored the subject in its whole.

So that is why she sent the hugest grin over at the Professor as she walked straight in. "Hello Professor" she almost chimed. It was also good that this was only her second lesson after her return, it meant she was truly looking forward to the rest of term, though she was praying it would go as slowly as possible, not only for herself, but for her besties sake as well. She didn't want him to go, not one bit. Which is why she had returned to make the most of the time he had left here.

The sixteen year old Slytherin took a seat next to Vashti, the only person whom she knew well in the room and let out a happy sigh.

Teehee...

Astronomy this early in the morning? And Sarah had thought Professor Antares was a nice guy. Now she wasn't so sure. Not while she was half asleep and having to trudge up seven flights of stairs. O____o

Bleary eyed she entered the classroom and scanned the room for faces. There was Trixie - or at least she thought it was. Could have been the back of anyone's blonde head. Sighing, she figured it wouldn't hurt to sit next to them anyway, and made her way over to an empty seat.

Yawn.

Plopping herself down next to the girl in the Slytherin robes, Sarah yawned. "Heyyyy." Mumble. Her head hit the desk and her eyes tried to close. Must stay awake. Must stay awake.

Risu strode in. "Morning, everyone. Hello. Morning," he said to everyone he passed, wandering towards the front of the room quickly. His hair was on end, and a certain amount of pinkness on his nose suggested he had just come out of the cold (not that it was that cold now). Or, perhaps, had some invigorating exercise (not that he did).

"I do apologise for the delay, there was a little, er, emergency with the telescope in the Observatory," he explained, trying to flatten his hair absent-mindedly and putting his wand down on top of a stack of books on one edge of the desk. "Had to do a little... climbing." He paused. "I don't recommend it."

Then he smiled brightly at his students. Ordinarily, he would have looked as sleepy as some of them did, but trying not to fall down the Astronomy Tower was a very good way of becoming alert in the morning. "We shall begin momentarily. A minute or two to give our latecomers, if there are any, a chance to arrive."

Luna sighed heavily in disappointment. She hated Astronomy, but she wasn't going to tell the Professor that! But surprisingly, Star was her last name, so maybe she would grow to like it? And why oh why was it in the morning?!? "Good Morning Professor," she said. She liked the Professor even though he teached one of Luna's least favourite subject. Nevertheless, points were points right? Luna wanted to earn as many points as she could for her house, no matter how bad the consequences were. "So what are we learning about today?" she asked.

Keefer walked in just as Professor Antares began to talk. Oh good, I'm not late! he thought. He had run all the way from the Great Hall, so now he needed a few seconds to catch his breath. He stood, doubled over, huffing and puffing in front of the doorway. Recovered, he looked for a seat. He didn't immediately spot anyone he knew, so he just made his way to a seat in the second row. "Top o' the mornin', Professor!" he said brightly as he walked past. Then he took his seat, rummaged for quill and parchment, then mentally prepared for a really long lesson.

"Morning Professor" she called out

Risu gave up on tidying up his desk. He turned around. "You will find out... well, now, because I think we should begin," he said, waving a hand lazily at the classroom door. It swung shut behind the last students hurrying in.

"Now, then. Welcome, everyone. Before we begin, I am conscious of the fact that we are having the pleasure of a double period today, and I will try my best not to make it seem like it's even longer. The topics we are covering today are very complex, but a brief introduction at least should be possible."

He discovered to his slight annoyance that his desk was that cramped that he couldn't even lean against it. He had to make do with standing upright without support then, it seemed, always a difficult proposition for the weary scientist. "My course aim for this term is, as I explained, to give everyone an overview of the physical laws that govern the cosmos. Last time, we talked at length about the idea - and evidence - of the expanding Universe and its initial state of extreme density and heat, the Big Bang.

"Today our focus lies on two very important theories that explain in great detail the development and current state of the Universe. They're both comparatively young theories, having been developed at more or less the same time over the first half of the 20th century, but they're at the heart of a great deal of modern physics, astronomy included." He grinned. "I won't keep you in the dark; our focus will be on the theory of relativity, and, later on, quantum theory.

"These theories are very complex, as I said, and contain many subtleties, but I am sure we will be able to discover we can understand some of what they're telling us about the world around us." Risu clapped his hands together. "So! Without further ado... We will begin with relativity. Its founder is perhaps the iconic figure of all of science." He picked up his wand and flicked it at the wall. A picture appeared.



"Everyone should know this photograph. And the person pictured. Dare I ask... who is it?"

Trixie grinned over as she saw Sarah enter, her face lighting up more as the Head Girl sat down next to her. "Hey" she answered back at the Hufflepuff her lips curling up into a huge grin but then returning back into a frown as she put her head on the desk. "Err...Sarah?" she whispered.

*Poke*

"The lessons started" she continued whispering, so she wouldn't get into trouble. She was only waking the Head Girl up, that wasn't bad though yes? Anyway back to learning.

"It's Albert Einstein Professor" the Slytherin smiled after raising her hand straight up into the air. It was though right? That picture had kinda always scared her though, what with the creepy poking out the tongue business.

"Snnugdnutnuughhghhh.....what?"

Sarah grunted awake as she felt a poke in her ribs, and she looked accusingly over at Trixie. Then the professor caught her eye. "Ohhh, right. Yes." Giving her friend a thankful nod, she turned her attention to the front. Pffttt, she had NOT been asleep.

A picture....offff....Albert Einstein!

"Albert Einstein, yeah."

But of course Sarah was not quick enough to answer, with her brain just focussing on the lesson. Trixie got in there first, so she just nodded sagely and pulled some parchment out of her bag, scribbling the answer down. She always needed notes for this subject - it was so complicated.

Oh class was starting already? Marie really wasn't ready for class, but at least she was more ready than Evelyn was. Reaching over to her friend she gave her a poke in the arm. "Hey, wake up, class started." They didn't need to have any snoring interrupting the lesson. Not that Evelyn was snoring, but you know, just in case she did.

Looking at the picture on the wall she tried remembering where she had seen it before. Oh right, in her text book when she had been bored and was flipping through pages. She grabbed her book, flipped through the pages again and stopped when she found the picture. "That's Albert Einstein sir," she said as she raised her hand. " He was a theoretical physicist, philosopher and author who is widely regarded as one of the most influential and best known scientists and intellectuals of all time." Or so the book says.

"Yes, it is! Well recognised. I see we're up to par with our popular culture references," Risu pronounced cheerfully, looking up at the black-and-white picture. "When Albert Einstein made his monumental discoveries, however, he was much younger. He looked more like... this." Risu waved his wand again.



"This picture," Risu continued, "was taken in the early 1900s. At that time, Albert Einstein was an inconspicuous patent clerk in the Swiss patent office. In 1905 he published a paper called 'On the electrodynamics of moving bodies', and even though it's a rather clichéd thing to say, it changed the world."

He paused briefly, for effect. "It forced us to get rid of concepts such as absolute time and space, and as such, relativity seems very counter-intuitive. Perhaps that's why it took us so long to figure it out. And we will talk about this in a little while, but first we need to figure out what the prevailing view of the Universe up to that time was. I already mentioned the ideas of absolute time and space. Can anyone guess what those are? Let's take space first. What do you think 'absolute space' could mean?"

When Jacqueline saw the picture she quickly said ''It's Albert Einstein professor!''



''Absolute space is hypothetical concept closely tied to the thought of Isaac Newton. The existence of absolute space contradicts the internal logic of classical mechanics since, according to Galilean principle of relativity, none of the inertial frames can be singled out.Absolute space does not explain inertial forces since they are related to acceleration with respect to any one of the inertial frames.It acts on physical objects by inducing their resistance to acceleration but it cannot be acted upon.'' She knew something about it. Her dad likes physics so does she. This class is going to be very interesting.

"Absolute space is a concepts that are closely related to Iassic Newton. Absolute space is when physical space is independent of what is occupying it. This however is a contridiction. According to the Galilean princpleof relativity none of the inertail frames can be singled out." she said and cont'd "It acts on acceleration or energy and is focused on physical objects."

Meh?

Sitting up straight rather quickly and taking a deep breathe, the Slytherin blinked several times before looking over at Marie. Class started?

Eh. Nodding her head, she took out her notebook and quill before focusing on what the Professor was saying. Something about this person named Albert right?

Taking Astronomy class so early in the morning, was not a good idea. She was beginning to think that having skipped the last one was a rather good idea. Why did she come to this one again?

Hearing the other answers, she definitely could not process that in her mind. Gah, Astronomy was a hard class. "So...Absolute space isn't just space itself?" she asked, trying to make things clear in her mind. It was definitely harder to do then what she expected.

Gotta wake up! Wait, so what does absolute mean? Meh? Glancing over to some other girl who spoke up, the Slytherin sighed and closed her mouth. Well, that was one way of putting it she supposed.

"Good answers, both of you," Risu said, smiling faintly. "Textbook even, you might say. I was really looking for your own ideas of what absolute space might be, but this works, too."

The picture of the young Albert Einstein disappeared from the wall as Risu continued, "As you rightly said, Isaac Newton is a person often mentioned with the notions of absolute space and time. In his view of the Universe - and, I might add, almost everyone else - space was more or less a... shall we say, backdrop. Or a stage, perhaps, on which the stars and planets moved in their orbits."

He nodded in the direction of the Slytherin who'd asked a question. "These descriptions might answer your question, Miss Flores-Shepherd. Even if you're not sure what 'absolute space' means, it's still a very obvious, easy to understand picture, isn't it? We don't think of space as something that can be stretched or moved. Space is space. It's a big," he shrugged, "something or other that everything else happens in." He paused again.

"But no, not quite. It seems superfluous to ask, with your books ready and everything, so I shall dispense with the question and comment briefly on absolute time. It's an even more intuitive concept than absolute space, wouldn't you say? You might be able to think of non-absolute space; maybe a Muggle submarine being compressed as it enters deeper waters with more pressure, but what would 'different' times look like? How can time run slower? Or faster? How is it not, er..." he glanced at a clock perched rather precariously on top of a stack of books on the desk, "9.42am everywhere in the Universe? Newton clearly thought it was, and many, many other people do too. Sometimes that includes me."

He looked at the class. "We shall attempt to answer these questions. Now that we have an idea of what absolute time and space are, let's focus briefly on the opposite. We speak of relativity. The saying that 'everything is relative' is almost a joke nowadays, but what is relative? And I'm not even talking about physics here, just in general. What do we mean when we say that something is 'relative'?"

Writing notes between listening to answers of his fellow classmates, Simon was paying full attention but staying quiet at first. At the last question, he thought about it for a moment, something clicking in his mind from something he had read so he raised his hand deciding to answer.

"Don't we mean that what we're talking about is only important when seen from a certain perspective. Like its all how one sees it?" he replied suppling his thoughts while asking if it was correct.

Aaaaaaand Kurumi was lost already. Although, at least she had known the picture was Albert Einstein. But...now the professor may as well have been speaking in French or maybe Latin as the gears in her head began turning and going into overdrive. Everything is relative....but wait....hadn't she read somewhere that Mr. Einstein thought his Theory of Relativity should have been called Theory of Invariance?

Timidly, and unsure if this was the proper time to be asking this question, Kurumi raised her hand. "Professor, didn't Einstein himself think his Theory of Relativity should have been called Theory of Invariance because the theory shows that physical laws do not vary across reference frames?"

There was something about Galileo's theory of relativity...and a boat moving a X speed and the captain moving at Y speed...then something about the captain moving at X+Y speed but that being too fashion and not taking into consideration some laws that Einstein did...but Kurumi wasn't really sure or the details, nor was she sure that she was going to make any sense trying to verbalize that.

Risu was impressed. "Very true, Miss Hollingberry. Einstein at first proposed the name, er... Invarianztheorie," he pronounced it slowly, with an apologetic grimace to the German language, "meaning, as you said, invariance theory because the speed of light remains constant - invariant, that is - no matter what each relative frame of reference. It was his colleague Max Planck who came up with the name relativity." He waved a hand quickly so as not to scare even more students off. "But we will talk about all of that in a moment. Don't worry if you didn't understand. Any other answers? Yes!" He pointed to the next student.

"Very good," Risu said with a smile. "It's a matter of perspective. Touching on what your classmate just said, it's easy to see why Einstein himself wasn't very happy with the name. He thought it made abusing his theory in non-scientific contexts too easy." Risu shrugged. "That's exactly what happened, in fact, but there wasn't much Einstein could do, relativity beat out invariance.

"But perhaps we shouldn't be surprised. While there are certain unchanging things about Einstein's universe, most things that we think of as unchanging - space, time, ... - are definitely less, well, solid than we might wish."

He began walking up and down the length of his desk. "In everyday language, the meaning of relative is," he smiled faintly, "relatively clear. In science, however, as some of you might remember from last term, words have specific meanings sometimes. Think 'theory'. In physics, then, the concept of relativity is something very precise. Joking about how 'everything is relative' is an irritating distraction at best. We will, as you probably guessed, focus on the scientific side.

"The idea of relativity wasn't completely unheard of in Newton's times. We already heard the name Galileo. His experiments led him to declare that there was no such thing as absolute motion or absolute rest. You could only be moving or standing still relative to something else. Indeed, there is no way you can decide, not even in principle, what's moving and what's standing still." Risu paused to let this sink in.

"It seems very strange and paradoxical, but that's because it's very difficult for us to think in relativistic terms. Perhaps what first sparked Galileo's interest will clear things up: He came to this profound insight because of the Earth. We know the Earth is circling the Sun, circling it rather fast, in fact. But to us, wandering about on its solid surface, it is pretty stationary, doesn't it? How then, wondered Galileo, can something be moving and standing still at the same time? That's what made him give up the idea of absolute motion and absolute rest." Risu paused again. "Everyone following so far?"