I have to make a confession: I have not been completely honest with you. In previous chapters, I boasted about the perfect inner workings of the HoloLens. It knows where you are all the time, so it can place the holograms at the right position all the time. The truth is: this is not what is happening. Yes, the device knows where you are, but it does not know this to the millimeter. It needs to make educated guesses and sometimes, it gets this wrong. In fact, this does not only happen sometimes; it happens frequently. If you pay close attention, you will notice that the holograms move about a bit the whole time. We usually do not notice this. There is a good reason for this. Again, our brains come to the rescue. If we look at something in the real world, such as a coffee mug, we expect it to be standing still on the table. It would be weird if it started to move all of a sudden. So, when our eyes detect slight movement in an object that is not supposed to move, our...