They were searching for alien life? He thought they were just talking about how to, but actually doing it. Maybe that was coming up soon. It would be like hunting for pogrebins, only they were hunting for aliens instead. Suddenly, this class got interesting. Maybe he could learn a few tips on how to hunt for aliens and apply to his own pogrebins hunts. Well, everything was unclear but he doubted the Professor could clarify everything so he shook his head and waited for class to proceed.

‘Alien life, such as bacteria, has been theorized by scientists to exist in the Solar System and quite possibly throughout the Universe.’, Gwendolyn started saying. Without caring about what she said before, she continued: ‘The ability to form organic acids and amine bases gives rise to the possibility of neutralization dehydrating reactions to build long polymer peptides and catalytic proteins from monomer amino acids, and with phosphates to build not only DNA, but also ATP. ‘
After having finished with that, she made a short break, just to try thinking if what she said made sense.
‘Due to their relative abundance and usefulness in sustaining life, many have hypothesized that life forms elsewhere in the universe would also utilize these basic materials. Is that true? But if not, what does the DNA of an alien look like? I mean, I know no one knows exactley, but is it the same with one of a human’s, similar to one of a human’s ore…totally different?’, the girl asked.

Risu shrugged. "Most likely yes. The factors in the equation are supposed to be as accurate as possible, of course, but some of them are averaged and others can't ever be much better than an educated guess. Without investigating every single star and every planet in our galaxy for a definite yes or no, that's how it works. All we can hope to do, if we work with this equation, is to close in on the true values of those factors as much as possible. Now, as I said, I don't think most of them can be known to any degree of accuracy, but if you somehow figured out that the average developed civilisation lasted, say, 550 years before inevitably dying out, then that would be a good value for L."

Risu tapped at the letter on the blackboard. "Since this is an average this will mean that some civilisations will not be included in this factor. A particularly violent civilisation might blow up its planet within 100 years, for instance, and a peaceful alien race might exist for a thousand years, but this would mean that a bog-standard civilisation could be expected to transmit signals for 550 years." He paused and grinned. "I do hope I calculated that correctly. Of course, with just two examples, 550 years for L would still be nothing more than a guess - perhaps the majority of alien life is peaceful, which would mean the true value of L is closer to 1000 than 550, but if we knew about, say, 20 civilisations, then we could get a better average."

He shrugged again. "But the most important criticism still stands, in my opinion. It seems very, very improbable to me that we will figure out more than, perhaps, one or two of these factors. Not in my lifetime, at least," he added with another grin.

Risu pointed at the next student and listened to her question. He smiled and gave another little shrug. "That is the question. If you ask me, I'll say yes, I do think so, but no one can give a definite answer until we actually do find other forms of life."

He nodded. "I do agree. You might be aware, perhaps, of the rather famous story surrounding the discovery of pulsars."

Risu looked around at the students for any sign of recognition. As far as he could see, there was none. "Perhaps not as famous as it is in astronomer circles." He smiled. "Really quickly, then: A pulsar is a certain type of star that's spinning very, very fast, sending off a beam of radiation with every rotation. These beams come at very regular intervals, one every few seconds." He paused, and then an analogy occurred to him. "Think of a lighthouse. Now, because these pulses of energy were so regular and smooth, when they were first discovered they became known as LGM-1, LGM standing for little green men. At that time, it was unheard of that a natural object such as a pulsar could be as regular as clockwork.

"My point then is, and yours too, I presume, is that even if we discover a certain type of signal, we can't automatically assume that it is coming from," he smiled, "little green men. Perhaps a natural source is more likely."

"You, er, must have a very big interest in biology, I guess," Risu said. "Well. A lot of the search for alien life assumes that this life will be similar to life on Earth in some respects. It'll need water and an atmosphere, and so on. If that were the case, then yes, it would probably employ similar chemical components. Maybe not DNA, but another molecule. Of course, carbon might not be the only stable basis for life. Silicon, for example, has similar chemical properties. Perhaps we will one day find silicon lifeforms - they would not necessarily require the same things that we require, and therefore we'd need to be searching for them in different ways."

OOC: Please don't forget to cite the source if you're quoting from somewhere. :>

"Any other questions?" he asked.

Fee listened to the professer intensly as he turned his attention to her.Ohh that was nice.He really answered all the questions.Nodding her head to signalize that she was listening the blonde let all the information flood to her.Okayy, sooo she hadnt been that wrong,That was good."Thank you professor",the girl smiled,"that really helped a lot."

Okay.... so now that was the equal.To Fee it didnt look so obvious.It kinda looked like these realyl complicated subjext they tought at muggle schools.Math or something,the blonde wasnt quite sure.But non the less the girl decided to still listen.Maybe it would get easier later.So trying to get everything the professor said into her head it became seriously confusing but with every explanatiokn the Slytherin understood a little more. Not fully but with a little pactise it would be okay.


To be honest Fee was overstrained with everything the professor said.She was only 14 how did he expect her to discuss such topics?The other students didnt seem to have toommuch problems with it but still,the blonde didnt feel to well with it.Placing her head into her hands the girl sighed a little.What could she say about this?!"Well i think the universe is something you cant just count mathematically,she said"its wayy to huge and no one n´knows how huge and how many things may be out there.Even though we know how many planets are there but we dont know anything about them."Hopfully that made even the tiniest bit of sense.

Zara smiled and looked over at Ryden, her eyebrows raised as if saying, "I told you so."

"That would be all, professor. Thank you."

Aurora stared, once more at her parchment, it looked like it should make perfect sense but she just couldn't get her head around it. She let out a small groan and rested her head on the desk in front of her. All this was so confusing it was giving her a headache. She looked up at the professor, questions? She couldn't think of anything to ask that would make it easy to understand, she'd just take all the notes she could and look at them over and over until she understood.

Ryden doodled on her parchment as she waited for the lesson to continue. She found the bit about the pulsars quite interesting, but it had been too fleeting for her to really take it all in. Perhaps she could ask the professor more about it later, after class. In any case, the fourth year sank into her chair, decidedly bored now that people were back to asking bizarre questions. . . Like that girl who sounded like she was regurgitating a textbook.

Eep. How did DNA get stuck into the discussion? This was getting more and more complicated.

She began to revise her notes as she waited for some kind of more discussion.

"No, I have never heard of pulsars professor but they do seem rather interesting. I am also glad we are on the same page and I have no further questions for now", Chloe said to the professor and then quickly coppied down some notes on pulsars and added it to her parchment.

Then a kid started taking about bacteria life on other planets. Chloe totally believed in that but she had no idea how complicated all the factors to allow it were, very interesting.

"Alright then," Risu said with a smile. "Let's put the Drake equation aside and focus on a second concept. This one is, let's say, a bit bleaker in its outlook on the question of life in the Universe. I am speaking of the so-called Fermi paradox."

He picked up his wand and waved it at the blackboard, where the writing rearranged itself to move to one side of the surface. On the other half the words "Fermi paradox" appeared. "Fermi's paradox is a challenge posed to those who think extraterrestrial life exists." Risu explained, replacing his wand on the desk once more. "It originated with the Italian physicist Enrico Fermi, who first came up with it in 1950. The idea was later fleshed out by a fellow scientist by the name of Hart, whose paper on the subject appeared in the quarter journal of the Royal Astronomical Society.

"The paradox, very simply put, is this: Billions of stars exist in our galaxy. If, as a lot of evidence seems to suggest, our Sun is a fairly ordinary star, and if - again, as quite a bit of evidence suggests - the Earth is a fairly ordinary planet, then it seems highly probable that a lot of other life should exist in our galaxy and the Universe at large." He raised a finger. "However, says Fermi, if that's the case, how come we haven't made contact with anything yet? The sheer size and age of the Universe suggest that a lot of highly developed extraterrestrial civilisations should exist. But there is no evidence to support this."

He paused. "Any first thoughts on this?"

Fermi paradox. "I think this is the part where we lack evidence or proof of the existence of these alien civilizations. It's just another contradiction to the Drake equation since before we actually know the number of the alien civilizations that communicate with us, we have to know if these so-called alien civilizations do exist." Thinking about it for a while, this led her to those news she watched on TV. "But what about those UFO's? Are they considered as alien civilization that so happened to actually be in our planet?"

Aha, moving forward. Drawing a line on her parchment, Ryden quickly jotted down "Fermi's Paradox" then scribbled swiftly as the words tumbled out of the professor's lips. The more he spoke, the more Ryden's frown deepened until she was positively scowling at her page.

Hmpf. Quite the little know it alls, these guys were. Ryden took her time to think before slowly raising her hand. "Professor... Um, it's true that with probability it would seem like we should have encountered alien life by now but. . . Well, probability isn't always right. And perhaps, as we said earlier, the life we're looking for doesn't actually exist but some OTHER type of life that we haven't defined yet? Perhaps it's right under our very noses, or just a few light years away from where we've reached?" she said, a little uncertainly this time.

It was a paradox, after all. Hmm. And then there WAS something else. "Also, we know for a fact that the universe is beyond enormous. If you take that into account, how large is the area we've probed, all in all? It can't be that big, can it? And how many planets have we actually studied? Not that many, if you take the size of the universe and the vast amount of galaxies. And each galaxy has a vast amount of stars - and those stars have planets... And aren't there loads of galaxy CLUSTERS floating around?" the brunette said, lowering her hand after she was done.

Well, it was any consolation, it made sense in her head.

Hmmm. This Fermi was... interesting. At least his paradox.

Helena raised her hand quickly, when professor Antares stopped speaking. "If the Earth is an ordinary planet, then why wouldn't there be life on other planets? And I suppose we haven't made contact with anything because... maybe if there is life on other planets, the creatures, or whatever they are, are more..." more... what? "Intelligent? And maybe they don't want to be discovered." Yup. That had to be the reason.

And that was Helena's paradox.

Aurora raised her hand. "I guess we haven't made a considerable effort to communicate on a large scale so if Earth is similar to other planets then maybe they just haven't reached us yet." She said.

"This paradox is definitely a strong criticism of the Drake equation," Risu said, nodding. "As for your question... UFOs are, by their very nature, a grey area. That's what the abbreviation means - unidentified. If you ask me personally, none of the proposed alien sightings have been convincing at all, so I think the question of whether alien life exists or not is still very much undecided. UFOs of any kind aren't very helpful."

"That's the paradoxical part of the whole problem," he said. "There undoubtedly are a gigantic number of galaxies, and even more stars and planets. Even if life in the Universe was incredibly improbable with a chance of, say, one in a billion, that would still mean we'd have life on billions of planets due to the sheer number of stars and planets. Ditto for any other galaxy. With that being the case, why aren't we in constant contact with other lifeforms? That's the paradox."

Risu nodded. "That is, in fact, one of the possible 'solutions', if you wish, of the Fermi paradox. Alien civilisations consciously hide themselves from view. Of course, if that's the case, doesn't that suggest they're already so far above our own level of technology that they wouldn't be in any danger if they made their presence known to us?" He threw up his hands. "Now we're speculating about possible motives of possible alien civilisations. This is probably not going anywhere productive." He chuckled. "But you've made a very good point. Anyone else?" he asked, looking around the classroom.

He nodded again. "That is true, we haven't. But what about those other lifeforms? The galaxy and the Universe are, of course, very, very large, but if our assumptions about the development of life are correct, then there should be so much alien life that even if we didn't make the effort to communicate, we would still pick up signals from elsewhere. What do you think?"

Maddox raised her hand, "How do we know they haven;t made contact? I mean we might be looking for them to pop up and hand us a butterbeer and we shoot the breeze. But they could have sent us a present like velcro or something as some form of communication." she said simply. "And muggles would rather to believe sunshine could bounce out of their bums before they believed that aliens existed let alone made contact." she added.

Okaaaay. Helena didn't expect this.

She really didn't expect the Helena paradox her idea to be actually good. "It does," the girl said, nodding. "But if they are in no danger in case we find out about them... why are they hiding themselves?" Oooh she had an answer for her question. "Maybe they would find us annoying? I mean the ones who'd attempt to find out more about them?" Them... the aliens?

Riley raised his hand at this comment about the other life in the universe making contact first. "Well Professor, perhaps they have. Throughout history there have been many carvings and monuments that seem impossible for the time. Pictures of people coming from the sky and shapes on the ground of animals that can only be seen from the sky have been found all over the planet. Now what use would shapes on the ground that can only be seen from space have if they didn't have air travel at the time?" Riley asked the question at the end to try to make a point.

He believed they had been here, no doubt.

"Perhaps, like someone said here, they don't want to be found?" Ryden replied, deep in thought. "Or they're so completely foreign that we don't even recognizable their life form? Or perhaps they don't live on the surface of the planet? Maybe they're so small, or so big for that matter, that we don't even look at them as life, but as things that we can disregard?" she asked, sounding quite a little foolish even to her own ears.

But, honestly, there were probably thousands of explanations to this... If one just sat down and thought them through, perhaps they'd reach the most likely answer. "Maybe they're already destroyed, or just a little bit away from being formed? What if they live VERY long lives, or insanely short ones?" What if, maybe, perhaps. She was starting to lose the meaning of the words, she'd said them so often.

"Maybe they've already been here." Now THERE'S a thought. Hmm.

Zara nodded. "I guess these aliens probably exist. They just don't reveal themselves or want to communicate with us. I think they're even in our planet right now, though not revealing to us their true identity. Probably for safety purposes. They're unknown to us like we're unknown to them, so I guess it's better not to make contact anymore to cause any chaos or confusion between the two parties." Well, that was what she thought. Of course, people have their own opinions, suggestions, and arguments when it comes to these. Although, there is no concrete evidence of their existence.

Kimalia raised her hand, "Perhaps because a lot of research and money is going on to discover the other planets in our solar system that we aren't willing to adventure past our own yet?" she decided to add in another theory. "There have been rare sightings of U.F.O's throughout the 1950s and 60's, but nothing confirmed.. Maybe deep down people are afraid of finding out the unknown since all those reported details were concluded as mysteries." Personally the last tidbit made the world sound ignorant, but it definitely is true how some people refuse to believe in the unknown when evidence leads to it.

"Could be, could very well be," Risu conceded, nodding, "but I'm not sure your reasons would convince a proponent of the Fermi paradox. As I said, if an extraterrestrial civilisation were that advanced that it fly across the galaxy to our little planet, why would they hide from us? It seems fairly obvious to me that there wouldn't be anything we could do to stop them.

"Further," he said, wandering up and down in front of the blackboard, "a few of you have pointed out, quite correctly, that we cannot assume alien life to be remotely similar to us, so that, to us, it would look like... rocks, perhaps. Or like nothing we would recognise as 'alive'. But then... if they are so different from us, how can you speculate that they don't want to be found? Hiding because of fear or in order not to startle or scare someone is a very human motive, and as you correctly said, we cannot assume they are even remotely like us. The differences between cultures are already enormous here on Earth, amongst our own species. An alien civilisation might not even have a concept of 'hiding'. Or 'fear'. You are assuming human thought patterns and reactions where none exist."

Alex tapped his chin a few times before raising his hand. He still wasn't sure about all this alien stuff, but it DID make him think about the possibility of there being other life forms out there that they just...hadn't found yet.

"Well, professor, I think maybe because, as you said, our universe is SO big that we simply haven't stumbled upon them yet. I mean, we have eight other planets...erm, wait, seven," he paused and corrected himself. That Pluto thing didn't count, technically, right? "Anyways, we DO have other planets around us that we KNOW for a fact don't have the resources to sustain life, which makes us the minority in our personal solar system," he explained. "So maybe, just by looking at our own little line of planets we can infer that it ISN'T common to find planets that can sustain life so really, it's like looking for a needle in a haystack," he said.

He thought he made sense. Maybe. It made sense to him.

Who was assuming human emotions? Ryden certainly wasn't. Eying the rest of the classroom, she shrugged. SHE hadn't meant that the aliens were hiding. Maybe they had the whole Earth under a spyglass and didn't like what they see at all so they're not showing themselves because, well... We're not really nice, are we?

But is that human too? What WASN'T human? "But professor," she raised her hand again, a thought popping into existence inside her head, "can we, as humans, even be able to THINK of non human things? I mean, I know we only use 10% of our brains right now and whatnot, but even when we've somehow managed to use all of it - do you think it's even possible to really think so far outside the box? Quite literally?" Ryden remarked, smirking slightly at the small pun. BOX. Hehe.

Oh, how much more clever she was than Bridget. The idea of that gave Ryden some peace of mind and she leaned back, chewing the end of her quill as she continued to listen to the professor.

Right well now Nika is very confused. "I though astronomy was about stars and planets not aliens." She muttered silently so no one could hear her. So are there aliens or not? If there isn't a definite answer then why are they trying to learn about them!? AHH!!! This is all just too much for her little brain to handle. "I think Aliens might exist. Maybe not in our galaxy, but maybe in others. We've already said that they don't have to look like us at all." She said then she came up with a weird sort of question. "Professor, isn't the Earth pretty new compared to other places? What if there is this really old planet out there in another galaxy far away right... And our technology has been advancing at a really fast pace. So what if there technology is even more advanced because they're older than our planet. Then could that mean they're watching us right now?" Her thoughts were starting to get all jumbled up now.