TheexplanationmaybeinEarth's mantle, the layer ofrockunderlyingthetectonicplates and extendingdownover 1,800 milesto the outeredgeof Earth's iron core.
Hamilton, who recovered from 9-5 down to edge Michael Holt 10-9 in the final qualifying round of the world championship last week, compiled breaks of 92, 47, 68, 87 and 77.
The blades are vibrated from side to side, as well as up and down(edge fatigue and flap fatigue) for millions of cycles, simulating twenty years of activity in the real world.