Is there a hard and fast relationship between uncertainty and entanglement? In other words, if you have one phenomena, you have to have the other. I would think so because of the following example, but I wanted to make sure I understood the relationship. Please let me know if there are better examples or if there is no relationship. There is probably something wrong with my example anyways. Example: Let's say there are two horizontal electron guns facing each other that fire a single electron each at the same time. The electron from the left gun is called the L electron, and the electron from the right gun is called the R electron. The left gun has a filter on it that blocks all but spin up electrons, and the right gun has a filter to blocks all but spin down electrons. In addition, let's say that there are two electron spin detectors: one above (detector A) and below (detector B) the impending collision. Assuming that the electrons collide and that the detectors will record the electrons spin, there will always be two interpretations of the collision before the spin (and what happened) is determined. Interpretation 1: Electron L went to detector A and electron R went to detector B Interpretation 2: Electron L went to detector B and electron R went to detector A Both are equally probable and there is no certain way to determine which happened until the spins are detected. Because of this uncertainty, the two electrons must be entangled. Otherwise, weird cases would result such as electron R being detected in both detectors and electron L disappearing. Or, one observer seeing one thing and another observer seeing another.