Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

My Thoughts on Quantum Uncertainty

  1. Jan 26, 2008 #1
    So I am just a simple high school student whom, while reading Elegant Universe, came up with an idea that would answer why the quantum world is so unusual. I am not well educated in quantum mechanics or the such, so plz don't be too brutal while shooting down my thoughts, lol. So, while I was reading about extra dimensions curled up microscopically, i came across an idea, and threw the book down to elaborate on this idea. What if these extra dimensions , while too small to effect our macroscopic world, alter the quantum world just slightly in some cases to cause quantum uncertainty. Something only noticeable in this tiny dimension could be affecting the other dimensions or the extra dimension it's self could alter the 3 dimensional particles. These are just my uneducated amateur thoughts, so plz, if they are drastically misdirected, direct them in the correct order.
  2. jcsd
  3. Jan 26, 2008 #2
    Quantum Mechanics could very well be an approximation to a different theory (sort of like how Newtonian mechanics are an approximation of Einsteinian, i.e. relativistic, mechanics).

    I haven't learned anything about extra dimensions and so forth, and I doubt I ever will in any class I am required to take, so I can't help in that regard, though.

    Although, it's not enough for there to be extra dimensions. Something has to be happening in those extra dimensions.

    For example, if you have a magnetic field and a charged particle goes through it, it ends up going in a circular path. If you only saw 2 dimensions, you'd be like "WTF?", but since we know there are 3 and the magnetic field goes in that 3rd dimension, we know what's happening.

    So there would need to be some sort of mechanism proposed to perturb the particles like that. And then you'd have to figure out how to test that vs. just saying their state is undetermined.
  4. Jan 27, 2008 #3
    I'm afraid I don't know anything about string theory beyond what's in the elegant universe and the fabric of the cosmos (2years to go all being well before I can take courses in that :wink:)... but I do know a little more about quantum mechanics. I'm assuming that by "uncertainty" you're referring to Heisenberg's uncertainty principle. This states that certain pairs of variables cannot both be known with abitrary accuracy. Such variables are known as cannonically conjugate variables- the definition of which involves maths you haven't done yet, but don't worry about it. The HUP is an inevitable consequence of standard QM, and you can derive it using either wave mechanics or the original matrix formulation.
    Now for the bit I don't understand :biggrin: In string theory, the answer to poop-loops' criterion that something must "happen" in the extra dimensions is that the fundamental constituents of matter vibrate through that many degrees of freedom. What I don't know is whether or not this leads to quantum mechanics as we know it. If it does, then it is responsible for uncertainty; if, however, QM and GR dictate more precisely how these vibrating systems behave, then uncertainty isn't really anything to do with the extra dimensions at all. Hopefully someone on here can advise us on which of those is nearer the mark!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook