A qubit state can be represented geometrically by Bloch sphere. A Bloch sphere has infinite points and so a single qubit can represent infinite number of states. Qubit state is represented by, Ipsi> = cos(theta/2)I0> + exp(i(phi))sin(theta/2)I1> It is said in the Book on Quantum Computation by Nielsen & Chuang that u can store an infinite text on a single qubit in the infinite binary expansion of theta. How is that possible? Though a single qubit can be in any one of the infinite number of states, how can it represent all the states at the same time? I can understand infinite expansion of theta but what do they mean by infinite binary expansion of theta?