You can use multiple physics Scenes to manage or work around complex physics contexts. In particular, you can create and set up independent Scenes with physics properties that are different from those of the main scene.
You can use Multi-Scene editing to create multiple Scenes in general (although you can also instantiate them by script). However, you have to use the Unity scripting API to use independent physics Scenes in runtime.
More precisely, to get the expected physics results, you must write a script that takes care at least of the following tasks for each separate physics Scene: