[VadeRetro]

The "Ideal Gas Law" only works with Ideal gases.

A law can be wrong. Physicist likes to cite Ampere's law as another example. He could have used Newton's Second as easily, as F = ma goes seriously wrong at observed velocities near that of light.

A law is not a theory, nor does a theory become a law, nor do lawyers make very good scientists.

[AndrewC]

He could have used Newton's Second as easily, as F = ma goes seriously wrong at observed velocities near that of light.

I'm intrigued. Could you derive that?