What is a constructive force by the convection currents in the earths mantle?
The best idea might be that these massive forces drive plate tectonics. We suffer vulcanism and massive earthquakes with accompanying tsunami phenomenon as a result, and this is devastating. But when the earth suffers a massive hit by a rock from space, the planet can heal by virtue of weathering and tectonic action. The damage is “smoothed over” and only a scar remains. Over geologic time, it can disappear completely. And tectonic action, driven by those convection currents, is a “large scale” force (albeit a slow one) with planet-wide effects. Life forms aside, the planet itself is alive.
