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.
Presumably there would be a cache on Mars of !news@beehaw.org so that anybody who wants to view it would not have to wait 10 minutes… they would get the cached update - so they would immediately see the community as it was 10 minutes ago.
This cache would be continuously updating so to the user on Mars, there actually isn’t that much disruption. Every time they check, there would be updates.
10 minutes or even 40 minutes is not that long in the grand scheme of things. We start talking about lightyears is when I think it starts to break down.
But how would the cached copy be started to begin with? Take a server to earth and plug it in to the net? Rsync (if it will establish the connection to begin with)?
We’d need a networked connection between Earth and Mars. As far as what does the caching software-wise, it’d be done using Mars-based Lemmy instances
TCP/IP stacks are going to need pretty large buffers if a packet needs resending and takes 20 minutes round trip to get it.
Link layer protocols are going to need to implement some kind of redundancy and parity scheme that accounts for the enormous latency (I’m sure NASA already has something like this)
here’s hoping we invent the ansible (and that whatever physics voodoo required to run it isn’t so expensive that it remains inaccessible to the general public)
it would be cosmically funny if we end up with FTL physical transport before FTL information transport, and thus a gigantic interstellar sneakernet industry.
*slaps roof of warp-capable starliner* this bad boy can fit so many fuckin exobyte flash drives in it
GALACTIC SNEAKERPUNK
Even with normal comms. I wouldnt be shocked if there are times where things, like the sun, would interfere with radio communications and thus we may need some type of relay arrays.
My guess is latency of 15-20 minutes would be acceptable and there would be a big infrastructure to cache and handle distribution.
Heck even lemmy synchronization can get behind by more than 15 minutes……
But the real answer is in Star Trek “open. Subspace channel”
Usenet over UUCP used to function with effective latency of 24-48 hours: 0-24 hours to wait for the nightly dialup call to exchange new messages, and 24 more hours to get the responses. There are a lot of protocols that don’t work well, but federated message exchange is one that actually is more or less perfectly suited to a high-latency environment.
