In classical physics, physical properties cannot be detached from the object associated to it. If a magnet follows a given trajectory in space and time, its magnetic moment follows it through the same trajectory. However in quantum mechanics, particles can be in a quantum superposition of more than one trajectory previous to measurement. The quantum Cheshire experiments suggests that previous to a measurement, a particle may take two paths, but the property of the particle, like the spin of a massive particle or the polarization of a light beam, travels only through one of the paths, while the particle takes the opposite path. The conclusion is only obtained from an analysis of weak measurements, which consist in interpreting the particle history previous to measurement by studying quantum systems in the presence of small disturbances.