How do we know the idea that particles don’t exist in one definitive spot until we measure them, isn’t just our lack of knowledge due to not measuring them yet?

Question

How do we know the idea that particles don’t exist in one definitive spot until we measure them, isn’t just our lack of knowledge due to not measuring them yet?

In: 17

Answer 1

In developing modern science we essentially come up with models that are pure math. Lots of equations from which you can plug in numbers and get out predictions. And these mathematical equations are the most accurate predictive tools humans have ever created. If they were inaccurate to any significant degree, things like computers and GPS wouldn’t exist.

But this creates an issue: what does it all *mean*. And this is where we have a difference between the math and the interpretation of the math. One way of interpreting the math is that the values for location or speed or what have you don’t exist at all until we measure them. Another is that all possible values for location and speed are real, but manifest in infinite multiple worlds. And there are many more different kinds of interpretations beyond those.

In addition, there is the question as to whether it even matters. You see, the math works the same regardless. So some say that what’s “actually” happening doesn’t matter as long as the math works. Since the different interpretations don’t change the underlying math, they are completely irrelevant, or at least completely academic.

To get to your specific question, this is the topic in Quantum Mechanics known as “hidden variables.” It asks the very question you’re asking. And the ultimate, and unsatisfying, answer is: we don’t know. We have different interpretations – none of which affect the underlying math. Some say: no, there aren’t any hidden variables and the universe is fundamentally random*. Other say: yes, there are, and the universe is fundamentally deterministic as a result.

^(* – I say “random” because that’s the ELI5 term. A more accurate term would be “stochastic” which is random in the sense it’s not strictly predictable and doesn’t adhere to a pattern, but also isn’t necessarily uniform (which is a property most people assume when you just say “random”).)