Another good metaphor for the indeterminate nature of elementary particles is the game of flipping a coin,
and trying to guess which side, heads or tails, will face upwards when it is caught in one hand and turned
onto the back of the other hand.
The outcome of a flip is of course determined the moment the coin is caught in the hand, but there is no way
of knowing the result until the hand covering the coin is removed. Both those betting on heads and those betting
on tails are in an indeterminate state of neither winning nor losing until the hand is removed, and the coin
revealed. The instant the coin is revealed, winners and losers are decided.
Elementary particles show the same nature. You read earlier how elementary particles display the properties of
both particles and waves. The diagram below is a graphic expression of this idea.
The quantum is a point traveling along the wave, but we cannot know where exactly it is on the wave at any point
in time. In this condition, its wave-like properties stand out. However, if we were able, by some means or other,
to observe the quantum, the wave would collapse into that one point where the particle was observed. In this
situation, it is the particle-like properties that stand out.
In short, until an observation is made of a quantum, it actually exists in several states or locations at once.
The act of measurement then "collapses" the wave function to the particular place where the quantum is actually
found. This understanding of quantum mechanics is known as the Copenhagen Interpretation.
