A sad fact about physics is that we are still not really sure about what happens inside the earths crust and mantle and absolutely uncertain about what occurs in the core. We actually know for certain more about the structure of the sun then we do about that of our own planet. This is because we have many ways of analysing the sun from spectroscopy to observation and nuclear modelling. For the earth we have to use mediocre mining depth (the equivalent of putting a scratch on a bowling ball) and the analysis of seismic waves travelling through the planet. A relatively recent discovery in this field was that of low frequency waves that result in “slow earthquakes,” which we still know next to nothing about. A few days ago these waves were observed and we have started to put together a theoretical model of how these earthquakes form. It uses the idea of the borderline between static and kinetic friction in the rock that can cause an elastic movement in the material over a long period so long frequency. More evidence still needs to be collected before the details of this theory can be formed and added to the larger model of the earth and its internal movement.