The Indian subcontinent isn't really part of Asia. It's a separate tectonic plate that, around 120 million years ago, broke away from the ancient supercontinent of Gondwana and started drifting north at an unusually fast pace — about 15 centimeters per year. It was, geologically speaking, sprinting.

About 50 million years ago, India slammed into Asia. It has been pushing into the Asian plate ever since, currently at around 5 centimeters per year. There is nowhere for all that crust to go but up. The collision crumpled the northern edge of India and the southern edge of Asia into the largest mountain range on Earth — the Himalayas — along with the Tibetan Plateau, which sits higher than most of Europe's mountain peaks.

The collision is still happening. GPS measurements from dozens of stations around the Himalayas confirm that Everest rises roughly 4 millimeters per year. That's 4 centimeters per decade, 40 centimeters per century. The mountain you can see photos of from 1953, when Hillary and Tenzing summited, is demonstrably shorter than the one today.

Erosion is doing its best to keep up. Himalayan glaciers and monsoon rains carry massive amounts of sediment down into the Ganges and Indus river systems — the annual sediment output of the Himalayas reshapes deltas thousands of kilometers away. On long timescales, the mountains are roughly in balance: uplift versus erosion.

But India hasn't stopped pushing. In roughly 10 million years, if current rates continue, Everest will be another 40 kilometers taller — assuming the rock and the planet cooperate, which they usually don't.