These glowing images look like a kind of luminescent jellyfish at the bottom of the ocean, but they're actually the trails left by an LED attached to a RFID tag. These tags create invisible patterns as they move through cities.
The images above, illustrating the limits of the field where the Radio Frequency ID tag is able to interact with the reader, when the tag is held parallel and perpendicular to the reader. A group of researchers at Berg, including io9 contributor Matt Jones, decided to study the patterns an RFID reader makes, as a means of seeing RFID tags the way they "see" themselves.
There are four billion RFID tags in the world, and they'll soon outnumber people — they include your bus pass, the inventory tags embedded in your clothes, your work ID, and many other forms of unique identification that a reader can ping. As people move through cities, carrying these tags around, they create data trails, which linger like ghosts. As Berg's Jack Schultze puts it, referring to the Oyster public transit pass:
Having produced these visualisations, I now find myself mapping imaginary shapes to the radio enabled objects around me. I see the yellow Oyster readers with plumes of LED fluoro-green fungal blossoms hanging over them – and my Oyster card jumping between them, like a digital bee cross-pollenating with data as I travel the city.