The airbubble in the magnetic fluid - what if?

[Low-Q]

OK. I had some ferrofluid in a box, and put a magnet on one side, so most of the fluid was "falling" sideways towards the magnet. I used a straw and stucked it in the middle of the fluid and blew bubbles. It was harder to blow the bubbles with the magnet present, because the magnetic force (I use a strong neodym magnet) made the "gravity" in the fluid very strong. So it took some force to push away the fluid with air.

Anyway, the bubble came out sideways away from the magnetic field. The ferrofluid wanted to occupy the airspace in the bubble in the direction of the magnetic force. I thought: "Ofcourse stupid, I should foreseen that!"

After my findings about the bubble direction, that it was hard to blow bubbles because the ferrofluid is very "heavy" in the precense of a strong magnetic field (Like blowing bubbles in mercury), I have a few questions left:

What happens if I fill a box partially with water, and then place a magnet on the side, then fill some ferrofluid (It is oil) in it. Then I put a buoyancy wheel in it. Will the weight of the ferro fluid be greater in the direction of the magnetic force, and normal in the direction of gravity? Will the density of the ferrofluid stay the same, but still different from the water - so a buoyancy wheel would feel different gravity on each respective sides? Would a gravity wheel with weights be lighter inside the ferrofluid than in air?

Those questions, or at least a one of them will be answered when I start to experiment further - with a gravity wheel partially covered by ferro fluid on one of the sides.

Stay put, but do not hold your breath

Vidar

[Low-Q]

Hi,

Finally I got a drawing to show you. No pictures of experiments yet though

Here is what I want to test:

The olive colored wheel is made of a non magnetic material. Some of the spokes are inside the ferrofluid. The spokes will displace some volume of ferro fluid. The displaced volume of ferrofluid represent a given weight. This weight is making a difference in weight on the left and right side of the wheel. In this case, the wheel will rotate counter clockwise because gravity is still affecting the ferrofluid - even if it's floating allmost vertically. At least that is the idea.

[Low-Q]

I have done the experiment. It seems like the ferrofluid is virtually weightless when trapped between two magnets or into a magnet some how. I had a lot of ferrofluid between two magnets and cut out a part of a straw to put inside the ferrofluid. The straw represent a volume of air in the middle of the fluid, but it do not raise according to the buoyancy effect even if the straw itself is pretty easy to move up and down. Here is the pictures of the experiment. As you can see there is a hole right through the ferrofluid which is trapped between two neo-magnets. I thought that gravity was still acting on the ferrofluid in the same way as when it would be inside a enclosed container - without magnets present. But no. Vertical buoyancy is not possible for ferofluids in a magnetic field strong enough to keep the fluid from droping down.

Vidar

[ResinRat2]

Nice try, Vidar. Too bad it didn't work but thanks very much for doing the experiment and posting your results.

RR2

[Blainiac]

Could you try displacing more ferrofluid?  I don't think that would work but maybe Vidar?