Film is based on an illusion of mobility. ‘Persistence of Vision’ is the way a number of still frames, when moving very quickly through a machine and separated by a black bar, creates the impression of movement. Cinematic movement is an illusion that is so successful that we hardly question its authenticity.
It’s for this reason, that I find an interesting correspondence between the primary illusion of cinema and the primary illusion of social media. But instead of the persistence of vision, we can talk about the persistence of presence. Consider an application like Twitter – a micro blogging system that encourages users to answer the question "what are you doing?" (I just wrote a twitter that said I was writing a blog entry about twitter.) People can then follow other people’s twitters as they periodically declare their activities. But what’s important about twitter is not the activity, but the declaration of presence. Regardless of what you’re doing, you’re stating that you’re doing something. You are present. Through these periodical instances, trackers construct an illusion of of presence of the person tracked. While I don’t have constant access to those twitter-ers I track, a comment every few minutes, hours, or even days, assures me of that person’s existence.