I sense you are asking me to explain the physics of the other realms … I have not the faintest, but I can use my theory hat to give you an explanation …
Now according to Isa (AS) imagine that he is taken from his time Ascended and then for him immediately put into our time … although for him only a few seconds, or minutes or not even that pass, but for the rest of the world centuries pass. My point in saying this is the Shari’ah is limited to this world … prayer can almsgiving can be done in another form in that domain as well I have no idea about it .. but it does not mean that it does not exist and it does not mean that he Isa (AS) is not there.