But whereas the electron, proton and photon are vibrations of open-ended strings, like violin strings, the graviton is the vibration of a closed loop, like a rubber band.

• 其中的差异只在于，电子、质子和光子是类似于小提琴弦般的开端弦，而重力子则是类似橡皮筋那样的封闭弦振动。