Intriguingly, Hamilton developed his mechanics using an analogy between the path of a light ray and that of a material particle. His analogy with light paths worked regardless of light's true nature, but at the time, there was good evidence that light was a wave. Subsequent experiments would prove him right, but it was already clear that quantum particles, such as electrons and protons, played by very different rules from everyday objects. A new kind of mechanics was needed: a "quantum mechanics". Hamilton had hoped the mechanics he developed by analogy with light rays would prove widely applicable.