New theory explains how Earth's inner core remains solid despite extreme heat

摘要

Even though it is hotter than the surface of the Sun, the crystallised iron core of Earth remains solid. A new study from KTH Royal Institute of Technology, Sweden, may finally settle a longstanding debate over how that's possible, as well as why seismic waves traveL at higher speeds between the planet's poles than through the equator. Spinning within Earth's molten core is a crystal ball -actually a mass formation of almost pure crystallised iron -nearly the size of the moon. Understanding this strange, unobservable feature of our planet depends on knowing the atomic structure of these crystals - something scientists have been trying to do for years.