Hiya, Another me trying to grasp some physical experiment. I'm working myself through a Dutch popular science book "Snaartheorie" (String Theory) by 'our' professor Marcel Vonk: it's meant to give the reader a maths-less impression of the theories behind string theory. Vonk starts with an explaination of quantum principles: after giving an argumentation to prove the particle-wave duality, he moves on to trajectories in the quantum world. He explains that when we know the start and end position of a particle, we can't know its trajectory (he explains it without argumentation - I'm assuming none exists). Vonk then explains how a double slit experiment (which was previously covered) in which one particle at a time would still cause a pattern of interferention. This is how I think his reasoning works: When the particle arrives, we do not know what trajectory it took: there are equal possibilities of left and right slit. One could therefore interpret, since the trajectory cannot be recovered, that the interpretations of the particle traveling to both slits are equally likely, thus equally valid truths (which reminds me of the different valid truths of SR). The particle therefore travels through both, and interferes with itself. My questions are these: 1. Is my interpretation correct and a valid explaination of what happens when we send individual particles towards the two slits? 2. Other threads on PF show signs that this phenomenon cannot be explained - I have assumed it can be since Vonk makes an attempt. What about this? 3. If I want to get a better grasp on this phenomenon, are there any terms or phenomena I should check out on wikipedia or youtube? Other threads speak of quantum superposition but so far that's just another word for me. Thanks for thinking along!