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.
The only issue might be when Mars and Earth are on opposite sides of Sol. Then the cache get’s held for however many weeks it takes for a clear signal to go through.
https://en.wikipedia.org/wiki/Interplanetary_Internet
there has been some thought about this. imagine a series of interplanetary satellites that act as nodes. so you don’t need a clear signal from mars -> earth. you just need a clear signal to the next node, which would presumably be easier
obviously this is all sci-fi talk at this stage, but setting up internet on a mars colony is probably not gonna be the hardest part of colonization