Why the inter-atomic world only approximates the macroscopic properties of matter.

In a previous posting, I wrote that the microscopic world, in this case implying inter-atomic distances, generates an approximation of the macroscopic, mechanical properties of matter.

What any alert reader should notice, is that in order for this theory to be true, it actually needs to lead to an exact result at some point, and not just to approximate results. And so the question which should follow is, ‘Why only an approximation, the way it was described?’

There is a family of answers to that question, which starts with the fact that not all solids are covalent solids. I was taught that there exist essentially three types of solids:

  1. Molecular Solids,
  2. Covalent Solids,
  3. Ionic Solids.

I feel that the WiKiPedia article I linked to in this list, gives a good explanation for what Molecular Solids are, and also gives links to the other types of solids. If the reader has serious questions, I recommend he read that WiKi next; they explain certain details better than I can.

At the same time, solids which I was taught were covalent solids, are really just a combination of molecular and covalent solids, due to the way molecules could be linked in certain directions, but not linked in other directions, in 3D. This is why the WiKi describes those types of solids as ‘mesh-solids’.

Organic polymers are extreme examples of meshes, while certain structural materials such as beryllium are completely different, being highly covalent, and being much stronger therefore, than organic polymers.

Another reason for which my first description is only an approximation, is the existence of thermal agitation. This means that individual nuclei are always in motion, even if the macroscopic body is not noticeably in motion. Furthermore, due to the involvement of Quantum Mechanics, heat can take the form of transitions between discrete states, instead of all the heat being stored, just as the continuous agitation of the nuclei. Hence, molecules which have a greater number of QM states to occupy, at any given temperature, will also store more heat, as their temperature changes, and will therefore also have greater specific heat. If heat was just the kinetic energy of the nuclei, we should find that all matter have very predictable properties of specific heat, just a function of atomic density, when in fact this is not so.

And, the velocities associated with thermal agitation at room temperature, are often underestimated. They can be enough to break the bonds between molecules by themselves, which is also a reason ‘why ice melts at room temperature’.

Continue reading Why the inter-atomic world only approximates the macroscopic properties of matter.

Quantum Mechanics is Falsifiable.

One concept which exists in Science, is that certain theories are Falsifiable. This means that a given hypothesis will predict some sort of experimental outcome, which other theories would not predict, and then an experiment can be performed to test whether this outcome is according to the theory. If it is not, then this test will break the theory, and will thus falsify it.

Quantum Mechanics is often Falsifiable. If the reader thinks it is not, then maybe the reader is confusing Quantum Mechanics with String Theory, which is supposedly not falsifiable? And thinking that String Theory is just the same thing as Quantum-Mechanics, is a bit like thinking that Cosmology is just the same thing as Astronomy.

(Edit 02/03/2018 :

There is an aspect to a theory being Falsifiable, which I did not spell out above, assuming that the reader could infer it. But certain conversations I’ve had with people I personally know, suggest that those people do not understand this concept.

The result of a physical experiment can easily be, that the outcome is according to the theory. Just as much as the inverse situation would falsify the theory, such an outcome can eventually confirm the theory, and without confirming the theory, there is no real way in which Scientists can know, whether a new theory is in fact valid.

There is no specific imperative to prove a theory wrong, in the theory being Falsifiable. )

(Edit 02/15/2018 :

One aspect to how this posting should be read, which some readers might infer, but which other readers might not infer, is that it begins by stating a hypothesis. At first, I declared this hypothesis as distinct from several other theoretical explanations of light.

But it would break the flow of a blog-posting, if every paragraph which I wrote after that, began with a redeclaration, stating that the truth of the paragraph depends on the initial hypothesis.

This dependency should be assumed, and belongs to my intended meaning. )

According to Quantum Mechanics, light can be polarized, just as it can according to the classical, wave-based theory of light. Only, because according to Quantum-Mechanics light is driven by particles – by photons – its explanation of polarization is quite different from polarized light, according to the classical, electrodynamic explanation.

According to wave-based light, plane-polarized light is the primary phenomenon, and circular-polarized light is secondary. Circular-polarized light would follow, when waves of light are polarized in two planes at right-angles to each other, but when these waves also have a 90⁰ phase-shift.

(Edit 02/20/2018: A Hypothesis which I’ve just disproved, but which this whole posting’s validity depends on.) According to Quantum-Mechanics, the photon is in itself a circular-polarized quantum of light, of which there can trivially be left- and right-handed examples. According to Quantum-Mechanics, plane-polarized light forms, when left- and right-handed photons pair up, so that their electrostatic components form constructive interference in one plane, while canceling at right-angles to that plane.

From a thermodynamic point of view, there is little reason to doubt that photons could do this, since the particles which make up matter are always agitated, and since the photons in an original light-source also have some random basis. So a conventional plane-polarizing filter, of the kind that we used to attach to our film-cameras, would not be so hard to explain. It would just need to phase-shift the present left-handed photons in one way, while phase-shifting the present right-handed ones oppositely, until they line up.

But there exists one area in which the predictions of Quantum-Mechanics do not match those of classical wave-mechanics. If we are given a digital camera that accepts lens-attachments, we will want to attach circular polarizing filters, instead of plane-polarizing filters. And the classical explanation of what a circular polarizer does, is first to act as a plane-polarizer, which thereby selects a plane of polarization which we want our camera to be sensitive to, but the output of which is next circularly-polarized, so that light reaches the autofocus mechanism of the camera, which is still not plane-polarized. Apparently, fully plane-polarized light will cause the autofocus to fail.

This behavior of a polarizer is easily explained according to Quantum-Mechanics. The plane-polarized light which is at first admitted by our filter, already possesses left- and right-handed photons. After that, we could visualize sorting out the photons that are circular-polarized in the wrong direction.

But the opposite behavior of a filter would not be predicted by Quantum-Mechanics. According to that, if we first pass randomly-polarized light through a circular polarizer, and if we then pass the resulting beam into a plane-polarizer, we should not be able to obtain plane-polarized output from the last polarizer.

According to the classical explanation of light, this should still be an easy thing to do. Our circularly-polarized light is supposed to have two components at right-angles, and our plane-polarizer should only allow vibration in one plane. But according to Quantum-Mechanics, if the incident beam is already circularly-polarized, it should only consist of either left-handed or right-handed photons, and then a simple filter should not be able to conjure photons that are not present in the original beam. And so our circularly-polarized light should not be convertible into plane-polarized light.

Continue reading Quantum Mechanics is Falsifiable.

About Why the output of a Laser is so Wavelike

The subject of wave-particle duality continues to mystify commoners, while the ultimate explanation given by experts, who need to be schooled in Quantum-Mechanics for years, before they are exposed to these secrets, seem to defy some common-sense reasoning. More specifically, the way in which Quantum-Mechanics mainly explains it, is that the wave-phenomena, specifically those that take place in a vacuum, only exist as being secondary to the existence of particles. We think we can see many examples in our practical world, where waves ‘seem real’.

One such example is the beam of light output by a Laser, that is both monochromatic and coherent, that is highly parallel, and that only seems to make its wave-nature obvious. It is this ultra-high consistency of the wave-nature of a Laser-beam, that also makes it useful for creating holograms – aside from the fact that the beams output from these devices have many more uses today.

But in a way that might disappoint some skeptical thinkers, this nature of the light output from a Laser is actually predicted by Quantum-Mechanics, and fails to provide a contradiction to it. And I will explain why.

Quantum Mechanics is largely built around the Heisenberg Uncertainty Principle, although Heisenberg did not dare to assign complex numbers to his probability clouds yet. Those probability clouds are supposed to represent the superposed states of a particle, with the additional detail that they can be phase-shifted according to understanding today, which means that they seem to conserve a two-component number – i.e. a complex number.

What the uncertainty principle seems to state, is that the precision with which the position of a particle can be known, is inversely proportional to the precision with which its momentum-vector can be known, and vice-versa.

Photons are understood to have momentum vectors, even though when the photon-energy is low, such as for visible light, that momentum-vector also has low magnitudes. But the momentum-vector of a photon is supposed to follow entirely from the direction-vector it is traveling with, as well as being inversely proportional in magnitude, to its wavelength. The energy of the photon is also inversely proportional to its wavelength.

Because of the nature of the light output by a Laser, all the variables needed to know the momentum-vector of its photons are known – and are exactly equal. So the precision of their momentum-vectors is actually zero – i.e. their momentum vectors should have a variance of zero, based on the fact that they are parallel and fully monochromatic.

And so it would only seem to follow from the Uncertainty Principle, that the variance with which their position-vectors should be knowable, should be off-the-scale. By that logic, the position-vector of any one photon in the beam, cannot be knowable.

And so we seem to obtain a beam of light, only the wave-nature of which is knowable.

Dirk

 

About Massive Bosons

Most Bosons do not have mass. Photons are an example of that. But in some cases they do. For example, nuclei are thought to consist of quarks, which cannot exist as singletons. But quarks are thought to be held together by gluons, which are thought to be Bosons that have mass.

When they have non-zero rest-mass, Bosons actually resemble matter, more than Bosons do with zero rest-mass. Helium-4 is the Bose particle, that gives rise to the best-known example of a superfluid. Helium-3 is the corresponding Fermi particle, that gives rise to Thermal Superconductivity, which contrasts sharply with that Helium-4 does at cryogenic temperatures.

Dirk