You may be offered hip replacement surgery if: 1  you have severe pain, swelling and stiffness in your hip joint and your mobility is reduced. 2  your hip pain is so severe that it interferes with your quality of life and sleep. 3  everyday tasks, such as shopping or getting out of the bath, are difficult or impossible.
The Earth is made up of four distinct layers: 1  The inner core is in the centre and is the hottest part of the Earth. 2  The outer core is the layer surrounding the inner core. 3  The mantle is the widest section of the Earth. 4  The crust is the outer layer of the earth.
Let's review. The Earth's mantle is the thickest layer of the planet and accounts for about 84% of the Earth's volume and 67% of its mass. It lies between the crust and the core. The Earth's mantle is never very far away from us; much closer than the Moon, for instance. But, it's truly an alien environment down there, a realm of extreme temperatures and pressures where rock undergoes convection like boiling water in a kettle.