I'm a big fan of Zombie movies and comics. I suspect I am not alone in this, Zombies have never been more popular than they are right now. One of my favourite parts about these movies is how they typically end: a small group of survivors in a post-apocalyptic wasteland, scrappily starting to build a new civilization amongst the rubble of the old.
Being a nerd, it's a fun thought experiment to wonder how a world in this state would use the technology all around them and communicate, re-build the internet, re-connect with each other. What would the web look like?
This low-power future implies a lot about the devices we'd be using. Low power mobile devices might be the only thing we could run - all these data centers running Twitter & Facebook would go dark after a few weeks. Imagine this scene: a small encampment of survivors generating power using improvised hydroelectric from a small river, charging deep cycle marine batteries and using power inverters to power a minimum number of AC devices.
The good news is that as a survivor you wouldn't be short on entertainment. Just raid a nearby Walmart / Bestbuy and you've have all the movies you'd want. Power any laptop or tablet from your dodgy bicycle-powered generators or batteries, and you've got movie night to keep you sane in a world gone mad!
Communications would be much harder. All the equipment required to run our modern mobile data networks is completely dependant on high-power infrastructure. Like with power we would need to improvise, fall back on sneakernet meetups, shortwave radio for voice communications, eventually longer range wireless tech like WiMAX. We'd need software that's just as home being offline as it is syncing local changes to remote data.
Interestingly enough, this idea of 'offline first' apps and eventually consistent data is exacly what we need for mobile web apps right now. The toolset you would need to provide service with relatively unreliable infrastructure is basically what's described by the 'offline first' project:
Frequently not having any data connection in even the wealthiest and most developed cities of the world has led us to conclude that no, the mobile connectivity/bandwidth issue isn’t just going to solve itself on a global level anywhere in the near future.
It strikes me that the conditions we imagine for ourselves in a post-apocalyptic world aren't that different than thouse that exist right now in 3rd and 2nd world countries, after a natural disaster or even on certain networks in the heart of Silicon Valley ( I'm looking at you AT&T ). The tools we deliver to these environments would be no different, and having our apps and data handle bad networks just makes sense given how bad networks can be even when there isn't a disaster happening.