> What happens after we propagate to other planets? Relativity will become a pain and we'll have significant lag on communications to the tune of several minut

> What happens after we propagate to other planets? Relativity will become a pain and we'll have significant lag on communications to the tune of several minutes within the Sol star system and years for anywhere else, so you'd end up using asynchronous communication like email, workdays would be based on local conditions (and likely not map to a local day on some planets), etc.