Final answer:
Symmetry involves elements being arranged in a balanced and proportional manner around a central line or axis. In both natural and engineered structures, from the biological symmetry of organisms to the symmetrical design of optical devices and artwork, symmetry provides functional and aesthetic advantages.
Step-by-step explanation:
The concept of symmetry pertains to the balanced and proportional arrangement where parts are organized around a central line known as the line of symmetry or axis of symmetry. In optical devices like mirrors and lenses, this axis, also referred to as the principal or optical axis, denotes a path through key points that implies a symmetrical design. In biology, bilateral symmetry is notable in the human body plan and involves a single plane that creates two mirrored halves; the human senses extend this symmetry as each sensory organ also has a symmetrical layout.
Symmetry does not only apply to optical devices and living organisms; it is also observed in physics. Notably, contemporary research utilizes concepts of symmetry in the pursuit of understanding the fundamental particles of the universe, with facilities like the Large Hadron Collider at CERN investigating these phenomena. The same principles of symmetry are also found in artwork, such as in the radial design of a sunflower or sacred images which suggests unity and balance in the piece.