The web isn't just confined to visualisations, it's also capable of the realistic simulation of many things from solar systems to atomic structures. Here are a couple of examples:

This demo was built for schools to help visualise the solar system - to get a sense of how far away everything is and how big the planets are, especially in relation to the Earth.

Interact with the simulation -> Solar System

The web can also simulate real-world physics with the aid of libraries such as the Rapier Physics engine used here. Dunk the laughing robot by throwing balls at the targets!

Play the game -> Physics game