This presumes humanity is a space fairing or interplanetary civilization.
How would something like the fediverse, internet, cryptocurrency, etc function with major latency? As an example, a signal takes between 5 and 20 minutes to travel from earth to mars. A roundtrip response would take at best 10 minutes and at worst 40 minutes. Now lets say you live on mars and your home lemmy instance is mars.social. You want to see what news people are chatting about on earth and heard that !news@beehaw.org is a good community. If you put that into your instance search box on mars.social the absolute best you can hope for is a response in 10 minutes. I assume the request would totally fail anyway due to rtt being set to low and the packets expiring before they ever reached the destination. The internet we all know and love is totally intolerant of high latency. Just ask people who use satellite internet or tor.
Edit: i think, but am not certain, that ipv6 replaced rtt with hop count. If so this may not be an issue as the time it takes would not matter as long as the hop limit was not reached.
Protocols can be swapped out. That has to be one of the easiest parts of expanding to a new planet. Lemmy already has a problem with displaying the delay accessing a new community to users, but I imagine it will be fixed soon, and then we’ll just have to get used to it. Differences that can’t be engineered away:
Fediverse/internet: Real-time chats won’t exist between planets, and between stars asynchronous communities like this one will be impossible. Instead, years-old content will role in, and if you want to send something specific it will have to be in a self-contained package that can be consumed without much context, almost like a time capsule.
Cryptocurrency: Whatever you’re buying will take at least as long as the data to reach you, and for anything physical probably many, many times more, so it will work about the same.
PS. I habitually use Tor. It’s pretty fine actually, the bigger problem is stuff understandably blocking me.