• Question: What are the basics of quantum physics

    Asked by anon-245167 to Ondrej, Jordan, Ed, Christine, Alice on 9 Mar 2020.
    • Photo: Edward Banks

      Edward Banks answered on 9 Mar 2020: last edited 9 Mar 2020 3:26 pm

      The very basic part of quantum physics is that energy comes in certain discrete steps, or quanta- hence quantum. This is opposed to classical physics where energy can be any value on a spectrum. Visualise a stairway versus a ramp.
      This packaging of energy into packets (or quanta) leads to lots of interesting effects like the photoelectric effect, or the double slit experiment.

    • Photo: Ondrej Kovanda

      Ondrej Kovanda answered on 10 Mar 2020:

      Imagine a particle. Do you see a solid “ball-like” object, or a wave? Quantum-mechanical objects have properties of both, but are neither. Can you measure position and momentum of a particle at the same time? Well, the better you know one, the less you know the other! If you roll a dice, though the result may seem random, you can, in principle, determine the number you end up with starting from how fast you roll, the shape of the dice and possibly other inputs. In quantum world, however, the outcomes are usually not determined by the initial conditions, and are completely unpredictable. Is this behaviour weird? No, this is the way of Nature! What is truly weird is that if you put billions of billions of billions of these peculiar quantum-mechanical objects together, they start behaving for instance like… a cheese! (or literally any other macroscopic object)

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