Project Context

---

Home for All Projects

This Project Home

Prior Knowledge

Project Context

Resources

Can a group of teachers do a particle physics experiment in Snowmass Village, Colorado?

We cannot always get use of an accelerator to look at high-energy, relativistic particles. Nor can we find a train, airplane, automobile, or spacehip that would move close to the speed of light. Not even a Yugo GT goes that fast. However, nature provides us--literally bombards us--with relativistic particles everyday: cosmic ray muons.

It is possible to at least plan how you can investigate relativistic lifetimes by measuring cosmic ray counts at different altitudes. To do this, it helps to answer some key questions:

1. Do you want to show the time dilation effect on muon lifetimes quantitatively or qualitatively?
   
   
2. What materials will you need? What materials do you have?
   
   
3. How will you get to different altitudes? Consider your current location. Can you get somewhere high enough to make a difference?
   
   
4. Using the equipment you have--or can make--how will you obtain a fairly accurate muon count?
   
   
5. How will you display your data? How will you analyze it?
   
   
6. What will you do to minimize and deal with error?
   
   
7. How will you communicate your results?
   

Data Analysis

1. If you made a graph of your data (muon count as a function of altitude), what sort of curve did you get? Could you find an equation for this curve?
   
   
2. From the equation of the curve, you ought to be able to find the lifetime of the muon. What do you get?
   
   
3. Are muon lifetimes the same for lab and for atmospheric muons? (For the lifetime of a muon in the lab, consult your Particle Data Book or the Particle Data Group Website.
   
   
4. Calculate the lifetime of atmospheric muons in their rest frame. How does this compare to to the lifetime for lab muons?
   
   
5. What does all of this tell you about the Special Theory of Relativiy?