Ashante Rachard
Science Fair Project
1/7/2013
90: Good work. Use the comments below to help remodel.
Which has more data tracking, a CD or a DVD?
Ashante Rachard
Research Topic and Procedure
1/7/2013
Question Being Asked:
DVDs can hold from 7 to 25 times the same amount of data on a CD, depending on the DVD format. Do you think the DVD data track spacing will be greater, lesser, or the same as the CD data track spacing? If greater or lesser, how much?
Hypothesis:
I think it will be greater than the CD data track spacing, approximately 2x greater. (How much bigger?)
Description of Process:
First, I will try to make the workspace suggested for this project. The workspace is kind of complicated to explain. But once I am finished with making the workspace I will then make some different measurements presented in the diagram shown in the picture on www.sciencebuddies.org to calculate the data tracking space. To do that I have to put cardboard to the right and behind the CD then placing an index card in front of that taping a protractor to it (a very non specific description of the workspace I have to build). And that is how I will not only find my data but complete my project.
I am not following this procedure. Please take some time to be specific in this area.
Ashante Rachard
Background information
1/7/2013
Hypothesis:
I think the DVD tracking will have greater data tracking space than the CD.
Background:
CDs and DVDs are seen everywhere now a days. DVDs and CDs are multilayered disks mostly made of plastic. A CD has a single spiral track of data, circling from the inside of the disc to the outside. The layer that contains the data is made of tiny spaces or pits. The data layer is coated in a thin layer of aluminum or silver, making it reflective. The pits that hold the data are very small. In diameter, they are about 500 nanometers, which is in fact, very tiny. For example, a millimeter which you can see with the naked eye is a thousandth of a meter. Just think how small those tiny pits are. On the CD, the bits have some black spaces that are also known as “land”. These can be on either side of the disk. This means that the data tracks of the spiral are normally spaced. The normal spacing on the disk is the shimmering colors you see when you tilt a CD back and forth.
A CD and a DVD are the same and different in various ways. But the biggest difference is that DVDs hold more data. The amount of data a DVD can hold is more than 4x the amount a DVD can hold. So basically a DVD holds more data and a CD doesn’t. DVD-audio has the potential to replace CDs because of the higher quality of the sound. Other than the amount of data CDs and DVDs can hold they are VERY similar to each other.
How does the information you found on CD’s compare to DVD’S? Research this and add it the essay in another paragraph.
Ashante Rachard
Bibliography
1/7/2013
Alleman, Gayle A.. "HowStuffWorks "How DVDs Work"." HowStuffWorks "Electronics". N.p., n.d. Web. 20 Nov. 2012. <http://electronics.howstuffworks.com/dvd3.
"Carolina Jacob - Project Description." Stony Brook Laser Teaching Center. N.p., n.d. Web. 20 Nov. 2012. <http://laser.physics.sunysb.edu/~carolina
"Using a Laser Pointer to Measure the Data Track Spacing on CDs and DVDs." Science Fair Project Ideas, Answers, & Tools. N.p., n.d. Web. 20 Nov. 2012. <http://www.sciencebuddies.org/science-fair-projects/project_ideas/Phys_p011.shtml#background
Ashanté Rachard
Observation Data
01/07/13
Ashanté Rachard
Conclusion Statement
01/07/13