iJMorgannn
2021-07-11T20:43:35+00:00
有的说:电子有质量,光子无质量。无质量的粒子必须以光速运动。
[img]https://img.nga.178.com/attachments/mon_202107/15/-7Q2o-3j3mZnT3cSgo-p0.jpg.medium.jpg[/img]
[img]https://img.nga.178.com/attachments/mon_202107/15/-7Q2o-3j3mZnT3cSgo-p0.jpg.medium.jpg[/img]