$delta_x$ * $delta_p$ >= $\frac{h}{4*pi}$, where $delta_x$ = uncertainty in position, $delta_p$ = m*$delta_v$ = uncertainty in momentum. This is a fundamental limit, not an experimental limitation. Consequence: the concept of well-defined orbits (Bohr model) is replaced by probability distributions (orbitals). For an electron confined to 1 angstrom: $delta_v$ >= $\frac{h}{4*pi*m*delta_x}$ = 6.626x10^-$$\frac{34}{4 x 3.14 x 9.1x10^-31 x 10^-10} = 5.8 x 10^5 m/s — comparable to the electron's actual velocity. For a 1 kg ball confined to 1 mm: $delta_v$ >= 5.3 x 10^-32 m/s — immeasurably small. This explains why quantum effects are significant for electrons but not macroscopic objects.