An Interactive Play Button on Van-de-Graaf Experiments

[JMetalian]

Describe the feature you'd like In both of the Van-de-Graaf Experiments, the system is initiated by pressing "Play" button. However, the button is unresponsive, so that it decreases the interactiveness. An interactive play button would add a better experience.

Is your feature request related to a problem? Please describe. It confuses me whether the system is initially working or not.