Once food has reached the sea floor, currents carry this food and organisms filter it without having to use their own energy to go and get food. Another way organisms use energy is by coming out at night and rising to feed on upper-level organisms.
Physical Science redirects here. It is not to be confused with Physics. Physical science is a branch of natural science that studies non-living systems, in contrast to life science. It in turn has many branches, each referred to as a physical science, together called the physical sciences.
Graduate school for a physicist proposes additional challenges as budding scientists ponder which branches of physics they wish to pursue for their scientific career. Physics is a sub branch of science which fundamentally applies to all forms of physical science studies. Physics acts as a root to myriad studies in the scientific community as it is provides the knowledge of how matter and energy work which are essential to the fundamental principles of biology and chemistry.