?? ?????????????:7????????
![](https://image.chezhanri.com/2019/0813/20190813170749227.jpg)
????:1???????:??????????
2?????????????
3??????????????
4??????????
5?????
??8??7???(??? ??)???????,7?,???????????????????,7??????????????2??,?20000?????????????????????????????????(????????4??),?2.2??????????(???????????????1.58?????????????)?
??????8???????????7??“Geological evidence reveals a staircase pattern in Earth’s rotational deceleration evolution(??????)”?????«??»(PNAS)????????????
?????????,??????,???????????????????
???,????????????????????????,???????????
?????????????????????????????,??Jacques Laskar???????????????2?????????????,???????????????????????????????????????7???2??????????????,?????????????,??????????
??,?????7??2???????????????????,????????????????????????
?????????????????,???????????????????????????????????????,???????????????????,?????????????
??????????????????????????,??????????????(???????????) ???????????:?????????????????????