Sunday, July 6, 2008

Second video sequence: Schrödinger equation

I just uploaded the second Common Sense Quantum Physics video sequence on youtube, presenting how the Schrödinger equation may be applied to ordinary macroscopic arrows. I have personnally had some difficulties to grasp the physical meaning of the evolution equations of QM when I studied it back in the eighties. I wish someone had tought me QM this way, so I hope it'll help some students.


  1. Hi Arjen,

    As promised I’ve had a more in depth look at your blog and with my first cursory glimpse I remain impressed. You are in a way taking Feynman literally when it comes to his calculation and visualization concepts with extending his diagram approach with a dynamics of sorts. It is also interesting as you look at the particles as beables and yet maintain the Feynman view that the waves are simply our mental manifestation of probability. This of course is more in line with the early Copenhagen perspective rather then the contemporary one where all is simply waves that collapse upon observation to present themselves as particles.

    I would also agree that your view is more intuitive then what we have now, yet would be interested why one cannot imagine both particle and wave as being beables as deBroglie had first imagined and Bohm completed in the non relativistic context. You mentioned the importance of Bell in learning to come to grips with QM and yet you seem to disagree with him in terms of his ontological perspective of QM. This is not meant as a contention simply as a curious query as I do respect your attempt to taking some of the voodoo out of QM, an aspiration I think is not only worthwhile yet as Bell so often pointed out being absolutely necessary if things are to progress.



  2. Hello Phil,

    Thank you for your comment.

    I also believe that the waves are beables. When you have a lot of arrow-like particles flying around, these particles behave collectively as waves. This wave than acts as a pilot-wave. When you detect a rotating arrow-like particle with the help of another arrow-like particle, you get probabilities that are proportional to the square of the intensity of the pilot-wave. I hope to explain that in the fourth or fifth of my video sequences.

    Kind regards.

  3. Hey, I'm just wondering if your a Bohmian/debroglie proponent?

  4. Hello Anonymous,

    I found much inspiration in De Broglie's and Bohm's pilot wave approach. I am a proponent of the fact that the internal motion (spin) of the elementary particles are steered by a wave that has the same phase. I think De Broglie and Bohm missed one important point with regard to their particles: measurements on them are not single-valued, i.e. the particles are not pointlike and their shape confers them multiple possible measurement results.

  5. Can I ask you how your view differs from decoherence / MWI?

    Do you believe particles only have one position and momentum at all times and there is no branching of the wavfunction?

  6. The difference of my "common sense" view with decoherence and MWI is interpretational. In that view, I visualize the quantum vacuum as an ocean of elementary rod-particles that behave in coherence (pilot wave). When a set of those rods aggregate together (through high spinning speeds), they may decohere from the vacuum pilot wave and their motion seems less probabilistic. In that view, there is only one universe, only one configuration of all rods at one instant, only one location for the geometrical center of each rod. However that reality is undetermined by measurement, because when one measures a location, it's the location of the point of impact of the rod-particle, not of the geometrical center of the particle.

    I hope this answers your questions.

  7. Thanks, very great straight forward answer.
    Same with your videos, easy to learn, you should make more.

    I wonder, why do you think people buy into the whole "parallel/splitting universes" now a days?
    It seems like the only realist interpretation that physicist believe may be right