Realometer: A=A ? Magnetism
There are those objects (sign chains) which are in a text. And then there are those who are outside the text. These objects are attracted or repelled by the text. Attraction and repulsion are words for magnetic phenomena, which we cannot experience directly. We need needles, we need texts and images do get any clue about magnetic phenomena. The computer you are sitting at contains micromagnets. Storing and deleting in your computer is done via magnetic fields, so reading and writing are related to magnetic fields outside of the text.