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I do not know much about quantum physics. However, I do know it believes the world is discrete ( has quanta). This seems to contradicts the fact that we can create an object of length root 2 since you can not choose a quanta for an object of root 2 such that the total length sums to root 2. Does quantum physics agree with the fact that root 2 is constructable?

dylan7
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    I'm afraid it is (spectacularly) unclear what your question means. Are you asking if a stick can be infinitely divided, or are you asking if any physical object could have a length of $\sqrt{2}$ i.e. do irrational numbers have any physical meaning, or are you asking something else that I haven't thought of? – John Rennie Mar 03 '15 at 16:31
  • Is this clearer? I know root 2 can be constructed. I am asking how can a statement that the world is discrete allow for the construction of a non-discrte number such as root 2. – dylan7 Mar 03 '15 at 16:38
  • Possible duplicates: http://physics.stackexchange.com/q/52273/2451 , http://physics.stackexchange.com/q/9720/2451 and links therein. – Qmechanic Mar 03 '15 at 16:50
  • @John I'm not asking if it is possible, I know it is. I know root 2 is a constructable number. I am asking how quantum physics agrees with that fact. – dylan7 Mar 03 '15 at 17:01
  • Contrary to popular belief, the crucial point/defining property of quantum physics is not that anything is discretized. – ACuriousMind Mar 03 '15 at 17:06
  • @ACuriousMind Is the world is discrete a deduction from the crucial points/defining properties of quantum physics, or is it not implied by the subject at all? – dylan7 Mar 03 '15 at 17:10
  • To my knowledge, it is not implied at all at any level of rigor by standard quantum field theory/quantum mechanics. – ACuriousMind Mar 03 '15 at 17:12
  • Ah interesting, thank you. That is a popular misconception. – dylan7 Mar 03 '15 at 17:14

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A common misunderstanding of quantum mechanics is the belief that EVERYTHING in the world is quantized, but this is simply not true. For example the position of a free particle is not quantized but may take on any value.

CStarAlgebra
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  • Thank you. However, what critically defining concept of quantum physics led to the name of the subject coming from the word quanta? It seems there is some important concept in the subject that had to do with discrete, or no? – dylan7 Mar 03 '15 at 17:16
  • The word was first used by Planck and Helmholtz in reference to discrete amounts of energy and or heat. – CStarAlgebra Mar 03 '15 at 17:21