Strings (tennis)
In tennis, the strings are the part of a tennis racquet which make contact with the ball. The strings form a woven network inside the head (or "hoop") of the racquet. Strings have been made with a variety of materials and possess varying properties that have been measured, such as dynamic stiffness, tension retention, thickness (gauge), string texture (shape of the string), and rebound efficiency.
Cosmic string
Much has changed since these early days, primarily due to the second superstring revolution. It is now known that string theory in addition to the fundamental strings which define the theory perturbatively also contains other one-dimensional objects, such as D-strings, and higher-dimensional objects such as D-branes, NS-branes and M-branes partially wrapped on compact internal spacetime dimensions, while being spatially extended in one non-compact dimension. The possibility of large compact dimensions and large warp factors allows strings with tension much lower than the Planck scale. Furthermore, various dualities that have been discovered point to the conclusion that actually all these apparently different types of string are just the same object as it appears in different regions of parameter space. These new developments have largely revived interest in cosmic strings, starting in the early 2000s.