The present world record for man made particle collisions is 6.5 TeV per beam @ LHC. (See Wikipedia LHC page)
This is a very small amount of energy compared to the energy of some cosmic rays hitting Earth; by a factor of 10+ million.
For a sample of ultra-energy cosmic rays see...
Let me try to get the discussion back to the question that Objecta99 had asked. I want to make a few points regarding my previous post.
Let me first thanks to PeterDonis for his explanation. I was trying to indicate that observers in different inertial frames of reference will measure...
An example of asymmetric SR time dilation
Let me jump here and give an example of asymmetric time dilation. This is not done by two observers looking at each other's clocks, but by comparing their clocks to a common event. A little background.
Muons are created when cosmic rays strike...