Is there an even integer $n$ such that $S^n$ can be topologically embedded in its unit tangent bundle $$T^{1} S^n=\{(x,y)\in S^n \times S^n \mid x.y=0\}$$ What about if we poseAcording to the extra condition thatcomment of Mark Grant and the imageanswer of Ryan Budney, I revise the question:
For what even $S^n$ be$n$, there is a retract embedding of theof $S^n$ in its unit tangent bundle?