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Quantum Physics

 Cosmology also involves physics. In the pursuit of a 'theory of everything' quantum physics also comes up along with cosmology.
This is my interpretation of their relationship.


Chemistry is the scientific discipline involved with elements and compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.

In the scope of its subject, chemistry occupies an intermediate position between physics and biology. It is sometimes called the central science because it provides a foundation for understanding both basic and applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant chemistry (botany), the formation of igneous rocks (geology), the properties of the soil on the moon (astrophysics).

Chemistry addresses topics such as how atoms and molecules interact via chemical bonds to form new chemical compounds. There are four types of chemical bonds: covalent bonds, in which compounds share one or more electron(s); ionic bonds, in which a compound donates one or more electrons to another compound to produce ions (cations and anions); hydrogen bonds; and Van der Waals force bonds.

The periodic table, also known as the periodic table of elements, is a tabular display of the chemical elements, which are arranged by atomic number, electron configuration, and recurring chemical properties. The structure of the table shows periodic trends. The seven rows of the table, called periods, generally have metals on the left and non-metals on the right. The columns, called groups, contain elements with similar chemical behaviours.  Also [included is] the filling of different atomic orbitals.'
The elements in this table used only 3 subatomic particles: electron, neutron, proton. Each element was defined by the number of protons. The unionized atom would have one electron, so the positive charged nucleus was balanced by the negative charged electron. A different number of neutrons in the nucleus would create an isotope for that element; neutrons have no charge and about the same mass as the proton; electrons have a very small mass. If an electron attained sufficient energy it could leave the atom resulting in a positive charged ion. Each element would have its electrons organized in shells.
With this foundation chemists could define behaviors of elements and the configuration of compounds formed by the combination of elements, into a molecule.
 
Quantum mechanics or quantum physics has no effect on chemistry and its description and its understanding of matter.

classical mechanics describes basic physics:
a body has mass; a body can have a velocity or a change in its position over time.
A change in velocity is acceleration.
a body with velocity has momentum; the product of mass and velocity.
applying a force to a body (with mass) results in acceleration.

Most people can have an intuitive understanding of classical mechanics. Many things have 3 dimensions, like depth, height, length. The relationship between force and motion, like starting/stopping in a car or on a roller coaster during turns, is also commonly noted. The force of gravity gives a person his/her weight. Having seen astronauts walk lightly on the moon most people recall a person weighs less on the moon because its force of gravity is less.

According to Isaac Newton gravity is a force; it arises mutually between bodies with mass.

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The force of gravity was first measured in 1797



Online references about gravity imply Newton's theory of gravity is replaced by Einstein's theory of space time.
from Wikipedia:
'
Gravity is most accurately described by the general theory of relativity (proposed by Albert Einstein in 1915) which describes gravity not as a force, but as a consequence of the curvature of spacetime caused by the uneven distribution of mass. The most extreme example of this curvature of spacetime is a black hole.
'

A black hole is only theoretical (I posted about it 2/28) because a mass cannot have zero radius, so it is not any example, even extreme. To say 'most accurately' is to just say this is dogma that must be believed without question.
The following references indicate the theories of quantum mechanics are based on Einstein's theories including Einstein's space time.




from that wiki reference:
'
Isaac Newton described the effects of gravity, but didn't propose a mechanism for how it worked.
Albert Einstein proposed that massive objects warp and curve the universe, resulting in other objects moving on or orbiting along those curves—and that this is what we experience as gravity.
In its current form, general relativity is incompatible with quantum mechanics — signaling that a shift in our understanding may be on the horizon.
'

I find that a very interesting trailing comment about sciences being incompatible - even in Wikipedia.

Classical physics explains several forces, like gravity and electromagnetic fields. Equations explained how these forces worked but not on the subatomic level. The force of gravity remains unexplained by quantum physics but progress has been made toward other forces like those in the nucleus holding protons and neutrons together

Newton's force of gravity is calculated for the  two masses using their distance.
On the Earth there is another interpretation of gravity, called free fall, using a uniform gravitational field. This force for an acceleration( on earth, 9.8 m/s^2), does not depend on the second mass but only on Earth. This free fall acceleration was demonstrated on the moon by an Apollo astronaut in 1971 where the free fall rate is slower there due to the Moon's smaller mass.

from wikipedia:

'
It can be said that two objects in space orbiting each other in the absence of other forces are in free fall around each other, e.g. that the Moon or an artificial satellite "falls around" the Earth, or a planet "falls around" the Sun. Assuming spherical objects means that the equation of motion is governed by Newton's Law of Universal Gravitation, with solutions to the gravitational two-body problem being elliptic orbits obeying Kepler's laws of planetary motion.
'

Initially (1618) Kepler's third law of motion did not require the mass of the body in the elliptical orbit.
However the ratio changed for a different mass than the Sun at the focus.
Isaac Newton (1687) modified this law to include the two masses.

A gravitational field is part of the basis for relativity.
from wikipedia:

'
Einstein stated it thus: we [...] assume the complete physical equivalence of a gravitational field and a corresponding acceleration of the reference system.— Einstein, 1907
'

Quantum physics attempts to describe forces at the subatomic particle level.

Classical physics explains several forces, like gravity and electromagnetic fields. Equations explained how these forces worked but not on the subatomic level. The force of gravity remains unexplained by quantum physics but I assume some progress has been made toward other forces like those in the nucleus holding protons and neutrons together.

Quantum physics deals with subatomic particles. With high energy collisions a standard particle like the proton could be broken into smaller particles that normally don't exist for long. The proton was found to break into two subparticles, called quarks. An electron can't be broken. A neutron is created by the combination of a proton and electron and that pair is usually what the neutron pieces are after breaking.

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Beginning with that pair of quarks the standard model now defines many subatomic particles; many of these have never been observed, even in colliders.

from wikipedia list of particles:
'
Elementary particles are particles with no measurable internal structure; that is, it is unknown whether they are composed of other particles.
'
There are 12 types of these elementary particles of unknown composition; being elementary one could assume they are critical. Quantum physics remains primarily theoretical.

Quantum mechanics is an evolving set of theories that arose when scientists attempted to model an atom.

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One of the main reasons for this branch of physics is: subatomic particles can have both a wave nature and a particle nature. This observed behavior cannot be managed by classical mechanics.
the 3 revolutionary principles of quantum mechanics:

quantized properties
particles of light
waves of matter

In an early theory of an atom, the electron particles had an orbit around the nucleus; then later they orbited in a cloud.
'
Let's consider an electron as a cloud (only one electron, not a cloud of many; the term ' electron cloud' could be confusing);

If the electron cloud collides with something the electron cloud behave like a particle (a solid body hitting a solid body).

If the cloud encounters a wall with a narrow slit the electron cloud passes through  the slot  like a wave.
'
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Quantum electrodynamics (QED) is the quantum field theory of the interactions of charged particles with the electromagnetic field. It describes mathematically not only all interactions of light with matter but also those of charged particles with one another.

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or on youtube:
Richard Feynman Lecture on Quantum Electrodynamics: QED series of 8 segments
This lecture is about: though light is electromagnetic radiation of one or more frequencies (light is visible but other frequencies on that spectrum are not), Feynman's experiments confirm light is a particle, called a photon, not a wave.

this QED theory lead to the weak nuclear force and electroweak theory EWT

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"
 the electroweak interaction is the unified description of two of the four known fundamental interactions of nature: electromagnetism and the weak interaction. Although these two forces appear very different at everyday low energies, the theory models them as two different aspects of the same force.
"
then strong nuclear force followed, using quantum chromoodynamics QCD

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'
quantum chromodynamics (QCD) is the theory of the strong interaction between quarks and gluons, the fundamental particles that make up composite hadrons such as the proton, neutron and pion.

The combination of QED+EWT+QCD became the standard model, also called QFT quantum field theory
'
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From Wikipedia:
"
QFT is a theoretical framework that combines classical field theory, special relativity, and quantum mechanics and is used to construct physical models of subatomic particles.
"
Because this not my specialty, I was not aware that initially some of these quantum mechanics theories had a serious problem , where some equations would generate a result of infinity. This result cannot be acceptable. A solution, called renormalization, attempted to get rid of these infinities in the equations.
from Wiki:
"
Many theorists believed, in the few years after 1949, that QFT could soon provide an understanding of all microscopic phenomena, not only the interactions between photons, electrons, and positrons. Contrary to this optimism, QFT entered yet another period of depression that lasted for almost two decades.

The first obstacle was the limited applicability of the renormalization procedure. In perturbative calculations in QED, all infinite quantities could be eliminated by redefining a small (finite) number of physical quantities (namely the mass and charge of the electron). Dyson proved in 1949 that this is only possible for a small class of theories called "renormalizable theories", of which QED is an example. However, most theories, including the Fermi theory of the weak interaction, are "non-renormalizable". Any perturbative calculation in these theories beyond the first order would result in infinities that could not be removed by redefining a finite number of physical quantities.
'

Renormalization had to deal with the consequences of a cloud of virtual particles and a description of space-time as a continuum. These contributed to the problem of infinities.

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QFT has failed to produce a quantum theory of gravity. That has been the goal for a long time. If relativity space-time superseded gravity then a theory based on one lacking gravity might have trouble describing it.
Lately string theory (where particles are replaced by one-dimensional objects called strings) has been considered to help make progress.

I posted (2/06) my skepticism about string theory and its ten dimensions, where some dimensions cannot be tested.

Last updated (03/05/2019)


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