Cosmic rays are energetic particles originating from space that impinge on Earth's atmosphere. Almost 90 percent of all the incoming cosmic ray particles are protons, about 9 percent are helium nuclei (alpha particles), and about 1 percent are electrons. The term "ray," however, is a misnomer, as the particles arrive individually, not in the form of a ray or beam of particles.
These rays originate from a wide variety of sources—ranging from energetic processes on the Sun all the way to the farthest reaches of the visible universe. Most cosmic rays possess kinetic energies between 107 electron volts (eV) and 1010 eV. Some cosmic rays have energies that exceed 1020 eV, far higher than the 1012 to 1013 eV that man-made particle accelerators can produce.
Cosmic rays form a fraction of the annual radiation that people on Earth are exposed to. For astronauts, however, the risks of exposure are much higher, and it is therefore important to assess these risks. Cosmic rays are thought to trigger electrical breakdown in lightning. Their role in climate change, however, is under dispute.
From a Unification perspective, we can make several points:
- The study of cosmic rays helps people understand the nature of the Sun and distant objects in the universe. What is learned about cosmic rays may have little practical significance for daily life (although it takes on significance for astronauts). Yet people pursue such investigations because of an inner drive to know the truth about the universe, transcending practical concerns. From a Unification perspective, this inner drive is connected to a God-given spiritual dimension, which motivates people to seek the values of truth, beauty, goodness, and true love. This inner motivation and outward expression of it set humanity apart from all other species on earth.
- The more scientists have attempted to discover about distant objects in the universe, the more they have found—it never seems to end. Also, with every set of answers retrieved, new questions arise. If people think they have solved the mysteries of the universe, they have to think again. Just as human curiosity doesn't end, there is always more to discover. One lesson here is that people need to learn humility. Compared to God's wisdom and creative powers, human concepts and abilities are very limited.
- The knowledge people have gained about cosmic rays needs to be shared with others. Even though the benefit does not come in materialistic terms, it brings humanity internal satisfaction to expand its knowledge of the universe. In addition, it expands the appreciation of God's insights and creativity.