Astroparticle physics, the same as particle astrophysics, is a
branch of particle physics that studies elementary particles of
astronomical origin and their relation to astrophysics and
cosmology. It is a relatively new field of research emerging at
the intersection of particle physics, astronomy, astrophysics,
detector physics, relativity, solid state physics, and
cosmology. Partly motivated by the historic discovery of
neutrino oscillations, the field has undergone remarkable
development, both theoretically and experimentally, over the
last decade. The field of astroparticle physics is evolved out
of optical astronomy. With the growth of detector technology
came the more mature astrophysics, which involved multiple
physics subtopics, like mechanics, electrodynamics,
thermodynamics, plasma physics, nuclear physics, relativity, and
particle physics. Particle physicist found astrophysics
necessary due to difficulty in performing comparable experiments
to those found in nature. For example the energy scale in t