What are the key applications of Relativistic corrections in modern physics?

[taoke]

Relativistic Correction
I had a few questions about Relativistic correction:

A. Where in physics are Relativistic corrections made? and why?

B. What are some examples of technologies that must apply Relativistic corrections? and why?

 

[HallsofIvy]

Here are several links to sites discussing the use of relativity in GPS systems:
http://relativity.livingreviews.org/Articles/lrr-2003-1/
http://www.phys.lsu.edu/mog/mog9/node9.html
http://metaresearch.org/cosmology/gps-relativity.asp