**Abstract**

The most famous cat in modern physics must be the Schrodinger's cat, in which he hypothesized that his cat cannot be determined alive or dead until we look into his box, by which the paradox of his half-live cat had been puzzling the quantum physicists over three quarter of a century since Schrödinger disclosed it in a Copenhagen forum in 1935. Since the disclosure, the paradox has been debated by Einstein, Bohr, Schrodinger, and many other renowned physicists, until now. We have found the cause of the paradox, and we will show in this chapter of which the hypothesis of Schrodinger's cat is not a paradox after all. It was the timeless radioactive particle he introduced into the box, since timeless and temporal spaces are mutually exclusive. We will show that the whole quantum world is timeless (i.e., t = 0), since quantum mechanics can be regarded as mathematics.

**Keywords:** Schrödinger's cat, quantum mechanics, superposition principle, timeless subspace, temporal space
