Aboutl.3billionyearsago,twomassiveblackholeshiteachothe...
問題詳情：Aboutl.3billionyearsago,twomassiveblackholeshiteachotherandformedanewone.Theenergysetfreebythecollision(撞擊)createdaripple(波紋)inthespace-timestructureandspreadoutwardingravitationalwaves(引...