3.1.11. Part 1: Inducing Coherence With a Magnetic Field

1. *Summary: The text describes an experiment using ferrofluid, a mixture of oil and iron nanoparticles, to demonstrate how an external magnetic field can induce coherence in a previously random system. The experiment shows that when a magnet is brought near the ferrofluid, the iron particles align, creating an ordered pattern. This illustrates the principle that molecular coherence can be induced by an external magnetic field in materials sensitive to it.*

Okay. Next step. What if -- what will happen if we put some very, very small iron particles in olive oil? So in this case, what you can do is you can take powder from the laser printer, the toner. It has black ink and embedded in the ink that is a nano particles of iron. So you mix this with olive oil or any kind of oil, makes it really well. And this is called ferrofluid, meaning it's oil with suspended metal particles, iron particles. So if you have this ferrofluid in a -- like in a glass dish, as you can see here, and without external magnetic field, obviously, all the individual particles are looking in all different directions. So it's completely random. There is no order. But if you put a magnet under this dish and you kind of put it close, put it next to it, you will see suddenly this ferromagnetic fluid start to take shape. Now it becomes growing this with the shapes like needles. So what we're doing here is a very important process. We are inducing coherence in this case in the fluid with external magnetic field. So the basic observation here again very simple. Molecular coherence can be induced by external magnetic field. Important point here, when material is sensitive to magnetic field. Okay. So if this material originally is not coherent and all the particles looking in all kinds of directions, there's no order. We apply magnetic field, if you remember, which is inherently coherent force. So when we apply this external field to this randomness, what you will get is that the material will change its property. It will start orient itself until there is again coherence. So, okay, keep this in mind. So, we can say order as in orderly orientation in space. So, each particle is orienting itself north-south in the same direction.