Astronomical seeing is the limiting factor for the resolution of all but the smallest Earthbound telescopes.
Source
Stunning advances in adaptive optics (along with it's predecessor speckle interferometry and it's budget-minded cousin lucky imaging) get around this but only with substantial ...
@Antzi I think your edit here though well-intentioned, does harm, and the reason you gave is not correct. Losses due to friction is a potential problem here, or a potential advantage, depending on the details. The OP mentioned a frictionless solution (damping could be added if advantageous.
But I think you are doing harm by unilaterally taking that out of play like that. It would have been better to leave as a visible comment so people could discuss it openly.
re "In this question, it makes no difference wether there is a physical or magnetic contact."
Teslas speed up nicely, and recover energy when braking due to their magnetic drive. Put a friction-based transmission and clutch in a Tesla and what a mess!
Same with the Hyperloop. Musk originally had it on an air bearing, newer versions use magnetic levitation. Can you imagine using a rack and pinion or screw drive to propel the pods down the tunnel?
My main concern with this post, (and most posts from this users), is that it try to mix lots of unrelated concepts, often poorly understood, often offering only speculative advantage, and adding nothing but complexity to the question
@uhoh I think that's the case here; the magnetic feature is an implementation detail, ass well as the solar vanes, ...
@Antzi I know what you mean about the mixing (both in general, and in this case).
But in this particular case, using passive solar vanes and a near-frictionless motion afforded by magnetic bearings, the possibility exists for a non-driven system; something that doesn't need power.
The OP was potentially clever here, so why remove that forethought from their post?
I think it's usually good to encourage people to think things through, and in this specific instance, I don't see any problem letting the OP keep this bit of detail.
by the way, I "starred as interesting" @geoffc 's comment about me being Mr. Grumpy and someone has double starred it (on the right) -->
How is the magnetic bearing not a marginal improvement in this case ? My understanding is that the vanes attitude can be dynamically changed and that the satellite moves in between on the pole
Reducing friction is always nice; but you're still going to need motors to go up and down, so aside from maybe vibration damping and power reduction, ...
While I think @Uhoh is right that the edit doesn't help. I'm with @Antzi on the fact that the post messes up a number of concepts. I'm not 100% convinced that that user is getting the encouragement to think things through, and is more scattergunning barely understood ideas in the hope some will stick...
@Antzi I think they are young and still learning, but unfortunately they keep posting similar things on various sites and getting suspended, rather than taking guidance like yours on board. I am happy they are obviously enthusiastic, but they need to put in some effort in my opinion
I don't think your initial assertion is accurate. Consider, for example, $f(z)=z^5-z-1$. If you iterate the Newton's method function $N(z) = z-f(z)/f'(z)$ from $z_0=0$, you'll quickly find an attractive orbit of period 3. The basin of attraction of that orbit is a positive measure set with no poi...
Astronomical seeing is the limiting factor for the resolution of all but the smallest Earthbound telescopes.
Source
Stunning advances in adaptive optics (along with it's predecessor speckle interferometry and it's budget-minded cousin lucky imaging) get around this but only with substantial ...
