Is the action of $O(n,\mathbb{R})$ on ${S}^{n-1}$ transitive? I think this is true as orthogonal matrices are supposed to rotate and keep the length fixed, but how do I prove this?
EDIT: Based on Alexander's comment, if $x = (x_{1}, \ldots, x_{n}) \in S^{n-1}$, then I can construct a matrix $A$ whose first row is the vector $x$ and whose other rows can be obtained by completing it to an orthonormal basis. But does it ensure that columns are also orthogonal?
With the said alexander:Let $x$ be a arbitary point in $S^{n-1}$,we know there exist a orthonormal basis in $\mathbb{R^n},\alpha_1,\alpha_2,...,\alpha_n$ and $\alpha_1=x$,now consider the linear map $T:\mathbb{R^n}\to \mathbb{R^n}$ s,t $e_i\mapsto\alpha_i(e_i$is standard basis which is also orthonormal).
Call the matrix of $T$,$A$.$A$ is orthonormal and$A{(1,0,...,0)}^t=x^t$.here PROPOSITION 10C part(b)