# Heisenberg uncertainty principle and a complete model

Given the Heisenberg uncertainty principle doesn't this mean that to observe the location of something the velocity of the something becomes more uncertain and vice versa now if the universe is deterministic then the state of something at a particular point in time should determine the future and fate of that something. If we have a complete model formed from theories about the observations we have. Given the knowledge of the state of something we should be able to calculate using the model the fate of that something and we would also be able to determine its outcome. However doesn't the the Heisenberg principle mean we can never know with any certainty the actual state of something at any particular point in time thus the information we use in the model would never be able to determine the precise outcome of anything and more over we would never be able to verify the actual future state of that something because of the uncertainty and thus we would be unable to verify the accuracy of the model. If the hiesenberg principle is correct then doesn't this mean that the pursuit of a complete accurate model is potentially unreachable because we will only be able to verify it to within degrees of certainty.

• We will never be able to verify it with any degree of certainty - to be true, that's an oversimplification. Please see a tutorial such as this. The uncertainty in measurements amplifies at microscopic scales and reduces dramatically at macroscopic scales. For instance, given the momentum of a ball (weighing $0.4kg$), the uncertainty in measuring its position is barely to the order of $10^{-25}m$. Jun 11, 2017 at 20:22
• @Dhruv Saxena doesn't the difference you calculate to be the discrepancy in the position you observe and the actual position that the something is and there is a sphere of the something's probable and actual location because of the discrepancy. And maybe yes the perception of this is down to scales Newton's interpretation of his observations were at macroscopic levels and the result of his classical theories describe events at that level and the measurement of the result of those is not very disimilar to what is actually going on so his classical view is actually a good description of the real Jun 11, 2017 at 20:50
• @Dhruv Saxena ality of things is not far from the truth but as you look more closely your observations become probably more different than the actual reality of things and thus the degree of certainty between whats observed and the actual truth becomes greater like you describe I guess what I meant Any like you object to. The degree is dependent upon your level of perspective, Jun 11, 2017 at 21:08
• Personally, I'd think that, for a ball that is about $22 inches$ in length, the discrepancy of $10^{-25}m$ in determining its position is utterly insignificant. It doesn't render the Newtonian mechanics futile. I think the question Is the universe fundamentally deterministic? could address quite a lot of arguments that we can make. Jun 11, 2017 at 22:19
• I really am sleepy your right classical Newtonian mechanics describes a picture if your calculations are correct then the discrepancy is maybe insignificant to judge that theory is an incorrect description of the reality things but it's veryfictation would be impossible because measurabity is uncertain because of the principle and we cannot honest to goodness say for fact that this model is correct and exact description of the reality of things. When u look more closely as u said the discrepancy are greater and a any other model becomes further from the truth than the newton model. Must sleep Jun 11, 2017 at 22:37