Cosmic Rays

لا تنسى ذكرالله

High energy electrons, protons, and complex nuclei can be produced in a number of astronomical environments. Such particles travel throughout the universe and are called cosmic rays. Some of these particles reach our Earth. As these objects hit our atmosphere, other particles called pions and muons are produced. These particles then slow down or crash into other atoms in the atmosphere. Since the atmosphere slows down these particles, the higher we travel, the more cosmic radiation we see. When you visit the mountains or take an airplane ride, you will encounter more cosmic radiation than if you stayed at sea level.
Most cosmic radiation is very energetic. It can easily pass through an inch of lead. Since cosmic radiation can cause genetic changes, some scientists believe that this radiation has been important in driving the evolution of life on our planet. While cosmic radiation can cause some damage to individuals, it also has played an important role in creating humans. Our atmosphere is naturally shielding us from harmful effects. However, if we were to leave the earth and travel to some planet, we could be subjected to very high levels of radiation. Future space travelers will have to find some way to minimize exposure to cosmic rays.

To find out more information, please take a look at experiments (10-14).
Cosmic Ray Exercise

Turn on the Geiger counter. Use the most sensitive scale. Make sure that no radioactive material is nearby. What do you hear? Every few seconds, you will hear some beeps from the counter. Some of these counts are caused by cosmic rays. Surround the counter by some concrete or iron. Do the counts go away? Take the Geiger counter to a mountain such as Mount Diablo or Mount Tamalpias. Can you measure an increase in rate? It might be necessary to make measurements for five to ten minutes or more to achieve sufficient statistical accuracy.