| Bugbear
Join Date: Jul 2006 Location: In Haven
Posts: 32,320
|  The REAL Sorting Hat: "Ravenclaw!" This monkey is bananas.
Ariana stepped up to the front, a large display in her hand. This display was different; instead of colorful drawings of compact disks, and historical information it had pictures of flowers and children laughing. Placing the display onto the ground, she unfolds a front flap and the words "Compact Disk" appears in changing colors. She smiles, glad that her friend had taught her that charm and turns to look at the crowd.
"Hey, the item I had picked was, and probably is one of the coolest Muggle inventions ever. It's called a Compact Disk, a round circular object capable of holding music, games, programs such as Microsoft Word, if you know what computers are you probably know what Microsoft is." She chuckled and gave a wink before speaking again.
She dropped her first photo of a compact disk and stopped to pick it up. "Sorry, I have butterfingers today." she joked grinning at them as she put it on the diorama. Looking back among the crowd, she held up her compact disk in it's case. The smiling face of a purple dinosaur waving happily winked back at them all with the words "Barney's Sing-a-long." "Yes, this is my brothers." she said laughing at their expressions.
"What I have here is a history of this wonderful device. Please feel free to look this disk over at the end if you wish, I just need it back after class is over." She showed them a compact disk with a picture of a purple dinosaur. Waiting for silence, she turned towards her display and gave it a tap with her wand. The words "Compact Disk: A History" appeared in dazzling blue writing at the top, and a diagram of a compact disk being put together could be seen. 
"A Compact Disk, or as some of you who use them, CD's have an interesting history. They can be traced back to the Muggle development of something called Muggle electronic technology and particularly digital electronic technology in the 1960s. These Muggles were very bright back then, not worrying about what things looked like or how they sounded to other Muggles.
"However the at first they didn't make the first CD's to record finding increasing use in audio components as the technology evolved. Though during the same period, many companies started experimenting with something called 'optical information storage and laser technology'. I don't quite understand how it works howevre.Among these companies, Muggle electronic giants Sony and Philips made notable progress in this area."
Ariana took a breath, feeling her tiredness come back. Stifling a shuddering yawn, which by now she had become a pro at, she smiled happily at the crowd and continued, "By the 1970s, digital and optical technologies had reached a level where they could be combined to develop a single audio system. These technologies provided solutions to the three main challenges faced by the developers of digital audio.
"The first challenge was to find a suitable method for recording audio signals in digital format, a process known as audio encoding. A practical method of audio encoding was developed from the theories published by C. Shannon in 1948. This method, known as pulse code modulation (PCM), is a technique that samples a sound during a short time interval and converts the sample to a numerical value that is then modulated or stored for later retrieval."
She waited while the students finished writing, or chatting and continued, "I'm almost finished, no need to fall asleep yet!" she joked, winking at them all ."The storing of audio signals in digital form requires a large amount of data. For instance, to store one second of music requires one million bits of data. The next challenge, therefore, was to find a suitable storage medium to accommodate any significant amount of sound. The solution to this problem came in the form of optical discs. An optical disc can store large amounts of data tightly compressed together. For example, one million bits of data on a CD can occupy an area smaller than a pinhead. This information is read by means of a laser beam that is capable of focusing on a very narrow area as small as 1/2500th of an inch.
 To make compact discs, you first have to make an original glass master disc from which all other discs are molded of liquid polycarbonate and covered with a thin coat of aluminum. Find out how over 100,000 compact discs are turned out daily at this facility." Ariana stopped and laughed at herself. "Well, I don't want to bore you all into the next century so I'll stop and show you some pictures of music CD and computer program CD, such as Microsoft." She paused and turned, looking through her stuff.
Finally she had found what she was looking for. Standing up she held out a device which looked very odd, even to her standards. It was slightly round with a square edge on the back of it. She also pulled out long, wirily looking ears? No, these were earphones. She looked up and grinned at some of the people's expressions. "I can tell what you're wondering. I wish I could actually let you listen to what this devise does, but Muggle stuff doesn't work here unfortunately. 
"What I have here is a CD player. It enables the listener to place a CD in the CD compartment." She pushed a button and a flat surface popped open." Make sure you don't touch the laser in the middle that could be deadly to the device." She warned as she carefully took a Barney CD and held it by the edges with her fingers. "You should always hold a CD by the edges, this way you won't get any scratches or stains on it from your fingers." Ariana explained with a smile as she closed the device up. She held the device up and showed the class the end of the earphones.
"These are called 'earphones. They allow you to listen to the music without your mother or father hearing. Very useful for when you're supposed to be in bed and can't sleep. You can dance on your bed and listen to your music without them ever knowing." She winked and showed them how to put the earphones in. "Most earphones have color codes on them, usually a circular color around the top of the metal thingy, you place the end of the metal part into the hollowed out part in the back of the device." She showed them, making sure it was secure.
"Now, onto the last and final part. Turning it on is easy. All you have to do is look for a button with a triangle facing right, and push it." She demonstrated. Of course nothing came out since the magic was too strong. "Of course we can't hear anything, but if we were in London or another Muggle place, you would be hearing the Barney theme song right now." She laughed and added, "It's my baby brothers' favorite song right now."
She flicked her wand and two last images appeared on her diorama. The first was round and bubbly, with a handle. Pointing to it she smiled and said, "This is a CD player, something like a CD player I just showed you, yet bigger. It's for home use, or work use.  "And this is for the automobile; it's called a Car CD player." She said grinning as she held up a picture of a car radio.
She could tell they were getting restless and knew it was over. Placing the devices back in her bag, she stood and grinned again. "That concludes the lesson about CD or compact Disks. If you want, you can view these, but please be careful; my mother would seriously ground me if anything happened to the Barney CD." She didn't laugh, knowing the truth. Closing the large display, she picked it up and moved aside.
__________________ Forget the future signature;
HAPPY BIRTHDAY, MAH ARI!!!
Last edited by Golden Monkey; 08-26-2007 at 02:24 PM.
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