Modernity is an unprecedented period for many reasons. One that is often cited is telecommunication: for the first time in history, all humankind is connected and able to communicate almost instantaneously across the globe.
I would argue that this fact is so exceptional that ours might be not only the first, but also the last time in history when this is possible.
The reason is simple and has nothing to do with nuclear war and post-apocalyptic scenarios. Rather, it has to do with two facts that we discovered in the 20th century.
A great power with a cosmic limitation
The first fact is that nothing can travel faster than light (aka electromagnetic waves). It is one of the principles underpinning Einstein’s theory of relativity since 1905: just when telegraphs and radios were revolutionising our world we learned that it was physically impossible to get faster than that technology.
It isn’t a big deal from a practical point of view most of the time, given that the speed of light is a mind-blowing 300,000 km per second. A beam of light can go around the Earth 7 times per second. When it comes to videocalling your friends it doesn’t matter how far they are, the communication is practically instantaneous.
Space is big
But here comes the second fact that we discovered in the 20th century: space travel is possible. We haven’t taken advantage of it as much as sci-fi writers were imagining in the 60s, but the technology is continuously improving and getting cheaper. It is only a matter of time before we colonise other planets in our Solar System. When? It is hard to predict but it seems unlikely that it will take much more than a few centuries.
And here is the thing about space: the light is not that fast compared to the distances between planets, let alone stars. Just sending a message to Mars, one of the closest and most likely planets to be colonised, takes an average of 13 minutes. Forget any Whatsapp call with your friends on Mars. And these delays become ridiculous when we look at other stars: it takes 4 years to send a message to the exoplanet closest to us. Around 50,000 years to send a voicemail to the other side of the galaxy.
Back to the past
What will happen when humanity start colonising other planets then? There are so many things we cannot even imagine about people living so far in the future, but one thing we can say for sure: they won’t be able to keep in touch. For all their technology and scientific knowledge, when it comes to telecommunication it will be like going back in time. Back to a past when internet, telephones and even telegraphs weren’t available. When “talking” with someone far away meant sending a letter and waiting months or years for a reply.
Exactly like our ancestors, these future people will be able to have a real-time conversation with only a restricted network of people. This network will include everyone quickly reachable with light signals (i.e. everyone in a ~300,000 km radius), which is a big upgrade from the villages of our ancestors, but it is still insignificant compared to the interstellar distances that humanity will cover and colonise.
Maybe old social dynamics and practices will play out again, just in different forms. Writing letters (or their futuristic equivalent) could become again a common and natural way to keep in touch. Societies will differentiate greatly, reverting centuries of cultural globalisation, simply because far away communities cannot catch up in real time.
Our pre-modern past – a history of fragmentation and bubbles – will come back and there will be no way to escape it. These few centuries of “global village” we are currently living in will be remembered in history as a curious interlude, the temporary gap between the invention of radio and the launch of space colonisation that allowed all humanity to be connected for the first and last time.