Ever since the 1960s Double Slit Experiment (DSE), reality has not been the same. The fact that single electrons shot through a setting of two slits, accumulatively made a wave-pattern on the screen, but when a beam of detector light was put across the slits, the wave function of the electrons collapsed and they behaved as particles again — has led to two conclusions, one that particles have a dual particle/wave behaviour, and the other that electrons or quantum particles change their behaviour when they find an observer/detector in their settings.
In fact, in 1924, De Broglie postulated that E=mc2, that Einstein had postulated in 1905, actually meant that as energy and mass are interchangeable, meaning that like all particles (with masses) can behave as waves, all waves can behave as particle too. Following that, in the Copenhagen Interpretation (1924-27), Neil Bohr and Heisenberg came up with the conclusion that light is neither a particle nor a wave, rather it is the experimental setting that will force it to behave either as a particle (photon) or a wave, and the DSE on electrons further proved this conclusion. It was also concluded that both the wave or particle properties are present in the substance, in the form of probabilities/possibilities, and only ‘one’ of them is exhibited, depending upon the ‘observer’.
This ‘behaviour’ of sub-atomic particles and the photons of light, invites us to think if the aspects of matter that are ‘observable’ and that make the existence of matter ‘real’ for us — like their being particles, having mass and weight, or being waves carrying some form of energy — are all external properties of the real substance! A simple analogy would be like a person has both possibilities of a good or a bad mood in him/her, but only one of the moods is exhibited uniquely to an observer entering the room, probably because it is the observer who is making the person happy or angry — so is what the observer observes, an intrinsic property of the person or just a superfluous ‘behaviour’ caused by the presence of the observer?
In other words, is the mass of a subatomic particle, just a form of its ‘behaviour’ and not a ‘real’ property? Question arises that if the electron passes through the double slits as a wave, what happens to its mass at that moment! One would think that at a moment when the electron was passing the slits, it had turned massless, or one could say that it simply ‘ceased to exist’. Interestingly, in this experiment the electron was made to move with 40% of the speed of the light — though a lot of speed, still it is not enough for the particle to be converted into a wave as predicted by E=mc2. Rather it seems that the electron is at will to keep changing its form from mass to wave and back whenever it deems.
So, if ‘mass’ is a relative thing, what is the reality of the ‘real world’? Perhaps, the urge to ascertain the ‘real’ has led physicists to come up with the Standard Model, which does not look so much like a chart of subatomic particles, but rather a chart of their observed properties or behaviours. Physicists have often said that ‘nobody understands quantum mechanics,’ that must be true, because before we could know what it actually means, it has branched into several branches that have made the comprehension of the ideas within it even more cumbersome — as if the more physicists try to find simpler solutions, the more they are entangled deeper in the paradoxical world of the quantum! Nevertheless, the human mind urges to comprehend phenomenon even when empirical evidence is not there.
One can say that many times physics works with reverse-engineering — like, if mass is not an intrinsic property of the subatomic particles, and perhaps if it appears with some sort of interaction with something else, and if that something is as widely distributed as all matter in the universe, then perhaps that something should be a field, spread throughout. That field was mathematically constructed as the Higgs Field, a field of force-carrying waves that should exist throughout space. And somehow when this fields interacts with that of the electrons, their wave-function collapses and they come to acquire mass — and all this would be happening in the measure of plank lengths, which is on scale of 10-35 of a metre. And the discovery of the Higgs Boson in 2012 stamped on the validity of the theory.
So, a conceptual world that arises from all this, is a world of wave-fields, that are always in motion, because a wave is nothing but a movement of massless energy; and a world of interacting fields, as one field passes through another; and a world of mass-creation wherever the waves collapse due to interaction! Surely, as much as the theory and its math may be complex, it is a long way from explaining all the permanent massive structures in the universe, that seem to be unaffected by fields that may be passing through them all the time.
All this reductionism, which has been the attempt to find reality at its most elementary basis, and which was promising to find the simple ‘theory of everything’ that would explain everything throughout the sciences — seems to be getting more and more befuddled in its own perplexities — and seems very far from explaining ‘reality’ that seems to be playing very differently at different levels of experience! The laws of physics are totally different at the astronomical level from what they are at the quantum level, and from how things work at the human-level sizes. They are completely different for the chemical world from what they are for the biological world — and so far, the chemists, the biologists and the physicists have no grounds in common.
The de-substantiation of mass, however, does drag us into the thought that the material world, with all its sensibility, is just a figment of our perception, our imagination! If my mass is there just because all my electrons have to behave that way, because they are being observed by certain observers, and may behave completely differently in other observer-settings, then is this observer-setting the permanent, eventual, ‘reality’ that scientists are endeavouring to find?
Published in The Express Tribune, June 18h, 2021.