# String (physics)

hypothetical physical entity in string theory

In string theory and theoretical physics, strings are hypothetical objects that are believed to be the elementary particles of the universe. If they exist, they would not be point-like particles, but rather 1-dimensional "strings" of energy that vibrate in various dimensions. The image to the right illustrates the various possible dimensions that a string could vibrate in. (Currently, physicists accept the fact that there are at least 11 dimensions in our universe: 1 time dimension and 10 spatial dimensions.) The length of the strings would be determined by Planck length:

${\displaystyle e_{p}={\sqrt {\frac {\hbar G}{c^{3}}}}}$

It is still not known whether these strings actually exist. They are pretty much the main topic of string theory.