Practical Benefits of Particle Physics #3

Cosmic Rays

Cosmic Rays consist of a variety of particles, mostly protons, travelling through space at extremely high speeds. When they collide with nuclei in Earth's atmosphere, they produce showers of other subatomic particles, which are called "secondary cosmic rays." Though the atmosphere absorbs most of these secondary rays, the remainder arrive at Earth's surface so frequently that roughly "an area of the size of a hand is still hit by about one particle per second."

Cosmic Rays were discovered in 1912 by Victor Hess, who won the Noble Prize in Physics in 1936. Many sources, including our sun, other objects in the Milky Way, and extragalactic objects, produce Cosmic Rays. Some sources remain unknown. These particles are affect our lives in several ways.

• Secondary rays are a small part of natural background radiation that causes cancer and other mutations in life on Earth.
• These rays are a potential danger to astronauts and electronic instruments in space that must be understood and managed.
  
• They are being used to examine the structure of an ancient Mexican pyramid and could be used to scan the interiors of cargo containers and semi trailers.
  
• They may affect cloud formation and thus climate change; the CLOUD Experiment at CERN, which is currently under construction, will study these possible effects in more detail.
• They may also trigger bolts of lightning during thunderstorms.