Recently, I was reading about Hawking Radiation in A Brief History of Time. It says that at no point can all the fields be zero and so there's nothing like empty space(quantum fluctuation etc.). Now, the reason mentioned was that virtual(force-carrier) particles cannot have both a precise rate of change and a precise position(Uncertainty Principle). So, my question is : This video (https://www.youtube.com/watch?v=bKldI-XGHIw) says that virtual particles don't follow normal physical laws. So, how can we say that they obey the uncertainty principle?