The coreis the hottest, densest part of the Earth. Although the inner core is mostly NiFe, the iron catastrophe also drove heavy siderophile elements to the center of the Earth. What is the difference between a
Adding the 70-plus “private” standard and narrow gauge railways, many of which are also partly or fully in public ownership, takes that network to around 5,300 kilometers, the densest rail network in the world. A heavily co-ordinated network integrates SBB’s trains with numerous other ope...