I need to find unmeasurable dense subset of circle. I think, that I found the unmeasurable set, but I can't show that it is dense. Here is my construction. Let's take $\alpha\in\mathbb{R}\setminus\mathbb{Q}$, consider the irrational rotation of the circle on angle $\alpha$. Let's take orbits of all points on the circle under the rotation, then choose the only one point from every orbit. This is set $X_0$. Then $X_j=X_0+\alpha*j$. So $\forall j$ the set $X_j$ is unmeasurable. I need to find the point of $X_j$ in any neighbourhood of any point on the circle to show that $X_j$ is dense. But I don't know how to do it.
2026-04-26 03:50:50.1777175450
Unmeasurable dense subset of circle
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Take any unmeasurable subset $X$ and add a countable dense subset $Y$, that is take $X \cup Y$.