Suppose there are two scientists in a laboratory containing measuring apparatus, and there is a particle whose momentum is unknown to those scientists. (1) Does the particle have momentum before it is measured? Suppose one scientist measures the momentum of the particle, and subsequently the second scientist also measures it. (2) Does the particle have momentum before the second scientist measures it? What if a third scientist, unbeknown to the other two, has measured the momentum of the particle before the first scientist measured it?