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Foundations · branch

Physics

The world has conservation laws. Energy, momentum, charge. A simulation, if it exists, still has to render this.

This hangs on First principles.

See on the tree

If you want a trunk that does not care about your story, start here. Isolated systems conserve energy. Momentum is conserved. Charge is conserved. Mass is measured. These are not metaphors. They are the loudest physics we have, and they are why rockets are hard.

At Code Conference in 2016 he taught the well in public: there is no such thing as an escape altitude. There is only an escape velocity. Height is not the unlock. Speed is. The Sun’s escape speed at Earth’s orbital distance is 42.1 km/s. Wikipedia’s table, and the formula sqrt(2GM/r) at 1 AU, agree. That is measurement.

A game engine can fake a sky. It has a much harder time faking Noether’s theorem for free. Any serious simulation claim has to say whether the substrate obeys these laws, approximates them, or only shows them to observers.

This branch is here so later leaves (computation, multiplanetary life, even “are we in a game?”) have mass to hang on. The letter-sum VELOCITY prints 111 / 42. That is play, found after. The 42.1 does not need it.

There’s no such thing as an escape altitude. There’s only an escape velocity.
Elon Musk2016Code Conference

There’s no such thing as an escape altitude. There’s only an escape velocity. You need a certain speed to leave the well. Gravity is a funnel. Height is not the unlock. Speed is.

Hangs on Physics

Hangs on

What hangs from here

Sister worlds

Sources