## data track spacing

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### data track spacing

I am doing the data track spacing experiment on the science buddy web site. I can't get the laser to refract more than 3 angles. Am I doing something incorrectly?? Also I was able to compute my CD track spacing data and how do I interpret a negative result?? Should I be getting a negative results.
Thanks
Chris
I cannot get the laser to refract more than 3 angles on dvd's. Am I doing something wrong?
Should I have negative results for my CD data and how do I interpret that?? Thanks
Chris123

Posts: 2
Joined: Tue Jan 23, 2007 5:38 pm

### Re: data track spacing

Chris123 wrote:I am doing the data track spacing experiment on the science buddy web site. I can't get the laser to refract more than 3 angles. Am I doing something incorrectly?? Also I was able to compute my CD track spacing data and how do I interpret a negative result?? Should I be getting a negative results.
Thanks
Chris

Hello, Chris123!

I think your question about refraction should be posted in the Physical Science forum. Some of the experts there will probably be able to help you.

To help you by answering yoru question about how to interpret negative results requires more context, and maybe the folks in the Physical Science forum can help with this question, too, but we certainly need more context. If you could describe how you are calculating CD track spacing the folks in this forum might be able to help.
Brian Castelli (OneBriiguy)
Engineering Specialist
OneBriiguy
Former Expert

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### Re: data track spacing

Hi Chris,

I assume you're looking at the project at:

http://www.sciencebuddies.org/mentoring ... p011.shtml

Correct?

If you go down in the text to the phrase "So, how can you use diffraction to measure the data track spacing on a CD or DVD?," you get:

both:

the formula for calculating d, the data track spacing
the use of multiple angles

I'm sorry, I thought I had posted this message on Wednesday. There must must have been fat-fingering on my part. Please excuse if you've already figured this out.
Cheers!

Dave
davidkallman
Former Expert

Posts: 675
Joined: Thu Feb 03, 2005 3:38 pm

Thanks I will try that!
I cannot get the laser to refract more than 3 angles on dvd's. Am I doing something wrong?
Should I have negative results for my CD data and how do I interpret that?? Thanks
Chris123

Posts: 2
Joined: Tue Jan 23, 2007 5:38 pm