There are lots of ways to get low flux density:  Low absolute field from one source.  Low net field from multiple sources (such as by cancellation), large reluctance gap, low permeability material (including due to saturation)

Certainly.  Yet, history is littered with so many failures down that road, as low flux densities produce no energy, while consuming energy to change their condition.  The energy required to change flux path direction while maintaining HIGH flux density has proven to be worthwhile in a number of impressive devices over the years.


Howard Johnson


Qin Gang


Stephen Kundel


To name just a few.

BUZZ!!!


WOW, STRANGE ARTEFACT !!! This could be my lucky day! Tho, yet to be verfied:


I took a paper and on that paper I had some graphite powder, maybe a tablespoon of it. I was shaking the paper gently, so the powder would spread somewhat.
Then I took a magnet pretty strong one from a huge 20 Mb Harddrive (when it comes to magnets from harddrives: the older the bigger the better, anyway).


I moved the magnet under the paper to see the diamagnetism when I made this amazing observation:


When I moved the magnet forward (away from me) and back, some graphite went always away from me!!! That means, when I was getting closer to that certain crumble from the distance, it was attracted, but ad soon as the magnet passed by, it was repelled, when I moved it the other way, its behaviour was reversed !!!!!!!! I even angled the paper, so the crumble had to travel upward, and it did!
Orientation in Space may play a role.
I don't have to explain you, that this would allow for a perpetual Spin! And some Nanotubes made of carbon may have extreme diamagnetism values.
I had to hold the magnet in a certain angle to the paper, maybe 45 degree, otherwise it wouldn't work.


Gotta verify this... So can you!

Update: Asymmetriy on certain field angles persists, Graphite has then a tendency to travel in a certain direction, regardless of magnet position.


Also, diamagnetic reaction of powder is very jumpy, nonlinear and in a strange way time-delayed. This may have something to do with the phenomen described before. It may even be the cause.


Forces involved are tiny, so probably not such a big deal.

The pencil graphit may contain iron impurities. But, I have to say, I also experienced the same: a bit of graphit powder, on the surface of some water, was attracted to the a magnet clearly! Weird: it was attracted when the pm was closer than a certain distance , like about 1/2 inch, but was slightly repelled when furter away.


I am working with graphite from a stirring rod for precious metal melting pods, from ebay, that I thought was pretty pure graphite, tho I ain't got any % Numbers.


I made s few more experiments. I failed to get that powder on water rotating using the said magnet angle, even with soap to neutralize bonding tension of the water surface to the beaker.


I also tried a pendulum made of a graphite cylinder, diameter about 1/2", height maybe 2/3". It shows interesting features, when exposed to the magnet and finds its equilibrium rest much later that without the magnet, at least it seems so. But no rotation. I may try a surface that has an angular asymmetry in diamagnetic "response", like in a vertical wind wheel, although that doesn't work with ferromagnetism. But Diamagnetism does really have some special features.


I do however have to say, forces are tiny, and the anomaly that made me "BUZZ!!!" before was performed with my hands, which is no good test condition, and when working with powder, the diamagnetism might be interferred by static electricity fx significantly.


So for now, I leave this graphit phenomen as yet to be fully investigated, but very tiny in energy density.