Orogeny

shove india into asia with your thumb.

push the plate, raise the Himalaya, ease off and watch them erode

India has been driving into Asia for about fifty million years, and it has not stopped -- the plate is still moving north at a few centimetres a year, and the Himalaya are still rising to meet it, on the order of millimetres a year at the fastest points. What keeps that from being simple addition is that erosion never clocks out: rain, rivers and gravity are wearing the range down at the same time it is being pushed up, every single year, not just when the pushing stops. The skyline you see is not the mountains winning. It is the running total of both forces at once, read off at this exact moment.

Concepts: geology, erosion.

An interactive you play with one thumb, on Wundr.