Blog of Veikko M.O.T. Nyfors, Hybrid Quantum ICT consultant

Quantum Mechanics demystified, a try


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Zeno’s paradox

While philosopher Zeno presented his paradox long before quantum mechanics was born, I still categorize it as a quantum paradox. Quantum mechanics gives the best shot to explain the paradox, you see.

In short:
Tortoise and a rabbit decide to run a 100m flat race against each other. Just to make sure for good which one is faster.
Rabbit is confident he runs twice as fast as tortoise and gives a 50m head start. Once rabbit then cathes 50m line, tortoise has already advanced to 87.5m. When rabbit reaches that point, tortoise is again already some way gone. This goes on, tortoise has always moved a bit further and rabbit is not able to overtake tortoise ever.

Sounds reasonable, doesn’t it? Eh, no! We know by experience rabbit would pass tortoise easily.

Human mind has just become accustomed to classical mechanics way of thinking in this matter. In this case infinite series of ever decreasing distances converging to 100m. But in ‘Newtonian math’ newer actually reaching it.

Quantum mechanics brings the relief. Planck’s length 1.616255 × 10-35m designates the smallest possibly perceptible distance. One can’t divide that anymore to halves. This makes the trick. Rabbit passes tortoise at Planck’s scale. Sort of.
Not very intuitive in the end, after all. But so is quantum mechanics in various ways, unintuitive.

Humans sense the world as their perception allows. In a very limited ‘macroscopic’ scale. However, the universe is built up from grains sized in Planck’s scale.
Imagine you are approaching Neitvuori’s national park by boat from lake Saimaa. You first see a big green colored hill in the distance. Once you get closer, you recognize there is a forest with pines, birches and several other kinds of trees on Neitvuori slopes. Once you are on the shore, you see the leaves on the birches and understand why did it look so green from distance. Then you might start to look back on biology lessons from high school, where you had a look on the leave with a microscope. It’s looking like having small vessels among other things. Green color is coming from chlorophyll molecules you were told. Which molecules in turn are built up from atoms, mainly Hydrogen and Carbon ones. Those in turn consist of Protons, Neutrons and Electrons. Two first ones of Quarks in turn. Quarks being still pretty far from Planck’s scale, ~ 10-18m.

One could say, that normal human digest reaches up to the tree leave level. From molecules downwards, special equipment is used to gather information on things. Theories there open up only to deeply involved persons. Common people with their normal senses just do not get it. And even deeply involved people just do not apprehend stuff going on closer to Planck’s scale. Yet.

Similar things comes up in Relativity as well.
E.g. few people, if any, can perceive curved 4D spacetime in a clear intuitive manner, as Einstein presented it. I can’t.
Have seen no intuitive presentation of it. E.g. why does the ball fall down to earth when I drop it? It doesn’t get circulating the earth. As the common visualization of bent membrane with heavy ball in the middle and a smaller one circulating around seems to suggest.
More intuitive approach to gravity gets presented in my article Gravity