The Architecture Machine Group at MIT, which evolved in 1985 into the MIT Media Lab, was very concerned with issues of “virtual presence”. How can we use technology to help us feel that we are in the same place, even when we are not?
Soon, with the help of future reality technologies, we will be able to do the opposite. You will be able to walk through a crowded physical space, and if you like, perceive only those people who are nearest to you (the ones that you would physically bump into if you weren’t able to see each other).
In such an experience, people will by default seem to materialize only when they are nearby. Yet if there is one particular person in the large crowd that you are trying to find, that person can be made visible to you even when they are far away.
It can go the other way as well. People can choose to “go stealth”, and become invisible to anyone other than their nearest physical neighbors. Many permutations are possible.
In time, we might come to regard “virtual absence” as something so normal, that we will forget it was ever any other way.