 So then the next question is, how do you do it? How do you do a calculation on an atom? You can't even see an atom. You can't touch an atom. So how can you do a computation on an atom? Well, let's take an atom and notice that it is spinning and put it in a magnetic field. It can spin up. It can spin down. So there are two modes that an atom can spin, up or down, in a strong magnetic field.