????:1??????:??????

2?800?????????

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?????????????????????????????????????????????,???????

???????????,???????????????????????,????????????????????????????????????????????,???

??????????????????,????????????????????(?????????) ?????????????:?????????????