Arguing about how many millions of years it will run for seems to be missing the forest for the trees. IMO the real message here is, holy crap magnetic bearings are amazing, now how do we get them into everything else?
By making significant improvements in the material science and manufacturing of paramagnetic and diamagnetic materials. Magnetic bearings are limited by Earnshaw's theorem [1] which states (roughly) that you can't stabilize some regular magnets using only their charge - they have to dynamically respond ti each other or they'll all just fly off. Usually this is done with electromagnets and a control system like in jet engines but its expensive and difficult. The alternative is passive para/diamagnetic materials whose magnetic fields change based on the other fields around them but those are usually rather exotic and have to be precisely engineered. Without that stabilization, the bearings would be worse that useless since they would never be able to prevent the rotor from touching the stator.
> Spinning ferromagnets (such as the Levitron) can—while spinning—magnetically levitate using only permanent ferromagnets
> Pseudo-levitation constrains the movement of the magnets usually using some form of a tether or wall. This works because the theorem shows only that there is some direction in which there will be an instability. Limiting movement in that direction allows levitation with fewer than the full 3 dimensions available for movement (note that the theorem is proven for 3 dimensions, not 1D or 2D).
We already have magnetic bearings in real life fans - the Corsair ML range of computer fans.
They're fantastic, move a lot of air and high static pressure, but the only noise that comes off them is the moving air, they're virtually silent. They also have a huge lifespan compared to fluid dynamic bearings, rifle bearings and sleeve bearings because there's no friction leading to wear on bearings.
I won't say you're wrong, the losses are small. But I guess they remind me of other technologies in the past that were by themselves incremental improvements, but as cost came down and they were put together with other incremental improvements, our capabilities advanced significantly & in ways we may not have expected.
For one, I think bearings wearing out is the main failure mode of most electric motors.
Great example, also from rotating systems, is the harmonic drive gearbox -- a very compact & high gear ratio device that (curiously) uses a deformable metal "cup" (flexspline) rather than a 100% rigid piece of metal like a traditional gear. Huge improvement that is now commonplace in robotics.
This is an opportunity to look at the problem from a different perspective.
Currently, in all mechanical designs bearing losses are small, because if they were not the design would probably be unworkable or unfeasible. But consider, maybe there are new things that could come into existence which are not feasible today because of bearing losses.
The internet, for example, didn't make it newly possible to send mail to people, but it made it so much easier that it changed what it meant to send mail.
