Parallel Worlds Probably Exist. Here’s Why

a portion of this video was sponsored by Norton 360 classical mechanics is great if you know the state of a system say the position and velocity of a particle then you can use an equation Newton's second law to calculate what that particle will do in the future in quantum mechanics if you know the quantum state of a particle that is its wave function you can use the Schrodinger equation to calculate what that particle will do in the future usually it spreads out over time as it is doing here note to make this animation we really solved the Schrodinger equation so there's a beautiful symmetry here if you know the initial state you can use an equation to evolve that state smoothly and continuously into the future the problem is in quantum mechanics we never actually observe the wave function like this instead when we measure it we find the particle at a single point in space so how are we to reconcile the spread-out wavefunction evolving smoothly under the Schrodinger equation with this point like particle detection now I think it's understandable that when the founders of quantum theory approached this problem they considered the measurement more real than the wavefunction after all the measurement was something we had actually observed and it matches our experience of a world of matter particles it was harder to say what the wavefunction was exactly Schrodinger formulated his wave equation because scientists notably debroglie suspected that matter has wave-like properties but it took a third physicist Max Born to propose how we should interpret the wave function at each point in space the wave function has a complex amplitude essentially just a real number plus an imaginary number Max Born suggested if you take that amplitude and square it you get the probability of finding the particle there the fact that you have to square the amplitude actually appears as a last minute footnote in boran's paper but that is how probability was introduced into the core of our picture of reality that's a pretty big philosophical leap I mean no longer is the universe deterministic this made a lot of scientists especially Einstein uncomfortable but the born rule as it is now called remains at the heart of quantum mechanics because it is spectacularly successful at predicting the outcomes of experiments so the way quantum mechanics came ...