Systems / Physics

This page in itself is a complicated subject, as it goes over science that is indeed **real**, having countless points & topics to discuss, and wording which may be confusing to those who haven't gotten educated or can understand more complex systems.
In addition, most of the information you will find here is taken from websites such as *Brittania* and *Wikipedia*, with attempts to remove any real identities due to being used in a fictional work (it's just selective hypocrisy, really).
As such, user's discretion is advised.

## Physics

A scientific model of An atom, the main building block of everything... or is it?

## Concept info

### TLDR

Physics is the branch of science that deals with the structure of matter and how the fundamental constituents of the universe interact.

Physics is the branch of science that deals with the structure of matter and how the fundamental constituents of the universe interact. It studies objects ranging from the very small using quantum mechanics to the entire universe using general relativity... In Alphatale: Redux, Physics is an important barrier that is broken or circumvented in various different ways, however it still governs the Universe within both the Biosphere & transvoid.

## So what even are physics?

* Physics is the basic physical science. Until rather recent times *physics* and *natural philosophy* were used interchangeably for the science whose aim is the discovery and formulation of the fundamental laws of nature. As the modern sciences developed and became increasingly specialized, physics came to denote that part of physical science not included in astronomy, chemistry, geology, and engineering. Physics plays an important role in all the natural sciences, however, and all such fields have branches in which physical laws and measurements receive special emphasis, bearing such names as astrophysics, geophysics, biophysics, and even psychophysics. Physics can, at base, be defined as the science of matter, motion, and energy. Its laws are typically expressed with economy and precision in the language of mathematics.

* **Physics** is the natural science of matter, involving the study of matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves. A scientist who specializes in the field of physics is called a physicist.

* Physics is one of the oldest academic disciplines and, through its inclusion of astronomy, perhaps *the* oldest. Over much of the past two millennia, physics, chemistry, biology, and certain branches of mathematics were a part of natural philosophy, but during the Scientific Revolution in the 17th century these natural sciences emerged as unique research endeavors in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms studied by other sciences and suggest new avenues of research in these and other academic disciplines such as mathematics and philosophy.

* Advances in physics often enable new technologies. For example, advances in the understanding of electromagnetism, solid-state physics, and nuclear physics led directly to the development of new products that have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus (the mathematical study of continuous change).

* Natural philosophy has its origins in Greece during the Archaic period (650 BCE – 480 BCE), when pre-Socratic philosophers rejected non-naturalistic explanations for natural phenomena and proclaimed that every event had a natural cause. They proposed ideas verified by reason and observation, and many of their hypotheses proved successful in experiment; for example, atomism was found to be correct approximately 2000 years after it was proposed by Leucippus and his pupil Democritus.

* The ultimate aim of physics is to find a unified set of laws governing matter, motion, and energy at small (microscopic) subatomic distances, at the human (macroscopic) scale of everyday life, and out to the largest distances (e.g., those on the extragalactic scale). This ambitious goal has been realized to a notable extent. Although a completely unified theory of physical phenomena has not yet been achieved (and possibly never will be), a remarkably small set of fundamental physical laws appears able to account for all known phenomena. The body of physics developed up to about the turn of the 20th century, known as classical physics, can largely account for the motions of macroscopic objects that move slowly with respect to the speed of light and for such phenomena as heat, sound, electricity, magnetism, and light. The modern developments of relativity and quantum mechanics modify these laws insofar as they apply to higher speeds, very massive objects, and to the tiny elementary constituents of matter, such as electrons, protons, and neutrons.

### Mechanics

Mechanics is generally taken to mean the study of the motion of objects (or their lack of motion) under the action of given forces. Classical mechanics is sometimes considered a branch of applied mathematics. It consists of kinematics, the description of motion, and dynamics, the study of the action of forces in producing either motion or static equilibrium (the latter constituting the science of statics). The 20th-century subjects of quantum mechanics, crucial to treating the structure of matter, subatomic particles, superfluidity, superconductivity, neutron stars, and other major phenomena, and relativistic mechanics, important when speeds approach that of light, are forms of mechanics that will be discussed later in this section.

In classical mechanics the laws are initially formulated for point particles in which the dimensions, shapes, and other intrinsic properties of bodies are ignored. Thus in the first approximation even objects as large as Earth and the Sun are treated as pointlike—e.g., in calculating planetary orbital motion. In rigid-body dynamics, the extension of bodies and their mass distributions are considered as well, but they are imagined to be incapable of deformation. The mechanics of deformable solids is elasticity; hydrostatics and hydrodynamics treat, respectively, fluids at rest and in motion.

The three laws of motion set forth by Isaac Newton form the foundation of classical mechanics, together with the recognition that forces are directed quantities (vectors) and combine accordingly. The first law, also called the law of inertia, states that, unless acted upon by an external force, an object at rest remains at rest, or if in motion, it continues to move in a straight line with constant speed. Uniform motion therefore does not require a cause. Accordingly, mechanics concentrates not on motion as such but on the change in the state of motion of an object that results from the net force acting upon it. Newton’s second law equates the net force on an object to the rate of change of its momentum, the latter being the product of the mass of a body and its velocity. Newton’s third law, that of action and reaction, states that when two particles interact, the forces each exerts on the other are equal in magnitude and opposite in direction. Taken together, these mechanical laws in principle permit the determination of the future motions of a set of particles, providing their state of motion is known at some instant, as well as the forces that act between them and upon them from the outside. From this deterministic character of the laws of classical mechanics, profound (and probably incorrect) philosophical conclusions have been drawn in the past and even applied to human history. Lying at the most basic level of physics, the laws of mechanics are characterized by certain symmetry properties, as exemplified in the aforementioned symmetry between action and reaction forces. Other symmetries, such as the invariance (i.e., unchanging form) of the laws under reflections and rotations carried out in space, reversal of time, or transformation to a different part of space or to a different epoch of time, are present both in classical mechanics and in relativistic mechanics, and with certain restrictions, also in quantum mechanics. The symmetry properties of the theory can be shown to have as mathematical consequences basic principles known as conservation laws, which assert the constancy in time of the values of certain physical quantities under prescribed conditions. The conserved quantities are the most important ones in physics; included among them are mass and energy (in relativity theory, mass and energy are equivalent and are conserved together), momentum, angular momentum, and electric charge.

### The study of gravitation

This field of inquiry has in the past been placed within classical mechanics for historical reasons, because both fields were brought to a high state of perfection by Newton and also because of its universal character. Newton’s gravitational law states that every material particle in the universe attracts every other one with a force that acts along the line joining them and whose strength is directly proportional to the product of their masses and inversely proportional to the square of their separation. Newton’s detailed accounting for the orbits of the planets and the Moon, as well as for such subtle gravitational effects as the tides and the precession of the equinoxes (a slow cyclical change in direction of Earth’s axis of rotation), through this fundamental force was the first triumph of classical mechanics. No further principles are required to understand the principal aspects of rocketry and space flight (although, of course, a formidable technology is needed to carry them out).

The modern theory of gravitation was formulated by Albert Einstein and is called the general theory of relativity. From the long-known equality of the quantity “mass” in Newton’s second law of motion and that in his gravitational law, Einstein was struck by the fact that acceleration can locally annul a gravitational force (as occurs in the so-called weightlessness of astronauts in an Earth-orbiting spacecraft) and was led thereby to the concept of curved space-time. Completed in 1915, the theory was valued for many years mainly for its mathematical beauty and for correctly predicting a small number of phenomena, such as the gravitational bending of light around a massive object. Only in recent years, however, has it become a vital subject for both theoretical and experimental research. (Relativistic mechanics refers to Einstein’s special theory of relativity, which is not a theory of gravitation.)

### The study of heat, thermodynamics, and statistical mechanics

Heat is a form of internal energy associated with the random motion of the molecular constituents of matter or with radiation. Temperature is an average of a part of the internal energy present in a body (it does not include the energy of molecular binding or of molecular rotation). The lowest possible energy state of a substance is defined as the absolute zero (−273.15 °C, or −459.67 °F) of temperature. An isolated body eventually reaches uniform temperature, a state known as thermal equilibrium, as do two or more bodies placed in contact. The formal study of states of matter at (or near) thermal equilibrium is called thermodynamics; it is capable of analyzing a large variety of thermal systems without considering their detailed microstructures.

1. First law: The first law of thermodynamics is the energy conservation principle of mechanics (i.e., for all changes in an isolated system, the energy remains constant) generalized to include heat.
2. Second law: The second law of thermodynamics asserts that heat will not flow from a place of lower temperature to one where it is higher without the intervention of an external device (e.g., a refrigerator). The concept of entropy involves the measurement of the state of disorder of the particles making up a system. For example, if tossing a coin many times results in a random-appearing sequence of heads and tails, the result has a higher entropy than if heads and tails tend to appear in clusters. Another formulation of the second law is that the entropy of an isolated system never decreases with time.
3. Third law: The third law of thermodynamics states that the entropy at the absolute zero of temperature is zero, corresponding to the most ordered possible state.And then there are statistical mechanics: The science of statistical mechanics derives bulk properties of systems from the mechanical properties of their molecular constituents, assuming molecular chaos and applying the laws of probability. Regarding each possible configuration of the particles as equally likely, the chaotic state (the state of maximum entropy) is so enormously more likely than ordered states that an isolated system will evolve to it, as stated in the second law of thermodynamics. Such reasoning, placed in mathematically precise form, is typical of statistical mechanics, which is capable of deriving the laws of thermodynamics but goes beyond them in describing fluctuations (i.e., temporary departures) from the thermodynamic laws that describe only average behaviour. An example of a fluctuation phenomenon is the random motion of small particles suspended in a fluid, known as Brownian motion.

Quantum statistical mechanics plays a major role in many other modern fields of science, as, for example, in plasma physics (the study of fully ionized gases), in solid-state physics, and in the study of stellar structure. From a microscopic point of view the laws of thermodynamics imply that, whereas the total quantity of energy of any isolated system is constant, what might be called the quality of this energy is degraded as the system moves inexorably, through the operation of the laws of chance, to states of increasing disorder until it finally reaches the state of maximum disorder (maximum entropy), in which all parts of the system are at the same temperature, and none of the state’s energy may be usefully employed. When applied to the universe as a whole, considered as an isolated system, this ultimate chaotic condition has been called the “heat death.”

### The study of electricity and magnetism

Although conceived of as distinct phenomena until the 19th century, electricity and magnetism are now known to be components of the unified field of electromagnetism. Particles with electric charge interact by an electric force, while charged particles in motion produce and respond to magnetic forces as well. Many subatomic particles, including the electrically charged electron and proton and the electrically neutral neutron, behave like elementary magnets. On the other hand, in spite of systematic searches undertaken, no magnetic monopoles, which would be the magnetic analogues of electric charges, have ever been found.

The field concept plays a central role in the classical formulation of electromagnetism, as well as in many other areas of classical and contemporary physics. Einstein’s gravitational field, for example, replaces Newton’s concept of gravitational action at a distance. The field describing the electric force between a pair of charged particles works in the following manner: each particle creates an electric field in the space surrounding it, and so also at the position occupied by the other particle; each particle responds to the force exerted upon it by the electric field at its own position.

Classical electromagnetism is summarized by the laws of action of electric and magnetic fields upon electric charges and upon magnets and by four remarkable equations formulated in the latter part of the 19th century by the Scottish physicist James Clerk Maxwell. The latter equations describe the manner in which electric charges and currents produce electric and magnetic fields, as well as the manner in which changing magnetic fields produce electric fields, and vice versa. From these relations Maxwell inferred the existence of electromagnetic waves—associated electric and magnetic fields in space, detached from the charges that created them, traveling at the speed of light, and endowed with such “mechanical” properties as energy, momentum, and angular momentum. The light to which the human eye is sensitive is but one small segment of an electromagnetic spectrum that extends from long-wavelength radio waves to short-wavelength gamma rays and includes X-rays, microwaves, and infrared (or heat) radiation.

### Optics

Because light consists of electromagnetic waves, the propagation of light can be regarded as merely a branch of electromagnetism. However, it is usually dealt with as a separate subject called optics: the part that deals with the tracing of light rays is known as geometrical optics, while the part that treats the distinctive wave phenomena of light is called physical optics. More recently, there has developed a new and vital branch, quantum optics, which is concerned with the theory and application of the laser, a device that produces an intense coherent beam of unidirectional radiation useful for many applications.
The formation of images by lenses, microscopes, telescopes, and other optical devices is described by ray optics, which assumes that the passage of light can be represented by straight lines, that is, rays. The subtler effects attributable to the wave property of visible light, however, require the explanations of physical optics. One basic wave effect is interference, whereby two waves present in a region of space combine at certain points to yield an enhanced resultant effect (e.g., the crests of the component waves adding together); at the other extreme, the two waves can annul each other, the crests of one wave filling in the troughs of the other. Another wave effect is diffraction, which causes light to spread into regions of the geometric shadow and causes the image produced by any optical device to be fuzzy to a degree dependent on the wavelength of the light. Optical instruments such as the interferometer and the diffraction grating can be used for measuring the wavelength of light precisely (about 500 micrometres) and for measuring distances to a small fraction of that length.

### Atomic & chemical physics

One of the great achievements of the 20th century was the establishment of the validity of the atomic hypothesis, first proposed in ancient times, that matter is made up of relatively few kinds of small, identical parts—namely, atoms. However, unlike the indivisible atom of Democritus and other ancients, the atom, as it is conceived today, can be separated into constituent electrons and nucleus. Atoms combine to form molecules, whose structure is studied by chemistry and physical chemistry; they also form other types of compounds, such as crystals, studied in the field of condensed-matter physics. Such disciplines study the most important attributes of matter (not excluding biologic matter) that are encountered in normal experience—namely, those that depend almost entirely on the outer parts of the electronic structure of atoms. Only the mass of the atomic nucleus and its charge, which is equal to the total charge of the electrons in the neutral atom, affect the chemical and physical properties of matter.

Although there are some analogies between the solar system and the atom due to the fact that the strengths of gravitational and electrostatic forces both fall off as the inverse square of the distance, the classical forms of electromagnetism and mechanics fail when applied to tiny, rapidly moving atomic constituents. Atomic structure is comprehensible only on the basis of quantum mechanics, and its finer details require as well the use of quantum electrodynamics (QED).

Atomic properties are inferred mostly by the use of indirect experiments. Of greatest importance has been spectroscopy, which is concerned with the measurement and interpretation of the electromagnetic radiations either emitted or absorbed by materials. These radiations have a distinctive character, which quantum mechanics relates quantitatively to the structures that produce and absorb them. It is truly remarkable that these structures are in principle, and often in practice, amenable to precise calculation in terms of a few basic physical constants: the mass and charge of the electron, the speed of light, and Planck’s constant (approximately 6.62606957 × 10−34 joule∙second), the fundamental constant of the quantum theory.

### Condensed-matter physics

This field, which treats the thermal, elastic, electrical, magnetic, and optical properties of solid and liquid substances, grew at an explosive rate in the second half of the 20th century and scored numerous important scientific and technical achievements, including the transistor. Among solid materials, the greatest theoretical advances have been in the study of crystalline materials whose simple repetitive geometric arrays of atoms are multiple-particle systems that allow treatment by quantum mechanics. Because the atoms in a solid are coordinated with each other over large distances, the theory must go beyond that appropriate for atoms and molecules. Thus conductors, such as metals, contain some so-called free electrons, or valence electrons, which are responsible for the electrical and most of the thermal conductivity of the material and which belong collectively to the whole solid rather than to individual atoms. Semiconductors and insulators, either crystalline or amorphous, are other materials studied in this field of physics.

### Nuclear Physics

This branch of physics deals with the structure of the atomic nucleus and the radiation from unstable nuclei. About 10,000 times smaller than the atom, the constituent particles of the nucleus, protons and neutrons, attract one another so strongly by the nuclear forces that nuclear energies are approximately 1,000,000 times larger than typical atomic energies. Quantum theory is needed for understanding nuclear structure.

Like excited atoms, unstable radioactive nuclei (either naturally occurring or artificially produced) can emit electromagnetic radiation. The energetic nuclear photons are called gamma rays. Radioactive nuclei also emit other particles: negative and positive electrons (beta rays), accompanied by neutrinos, and helium nuclei (alpha rays).

A principal research tool of nuclear physics involves the use of beams of particles (e.g., protons or electrons) directed as projectiles against nuclear targets. Recoiling particles and any resultant nuclear fragments are detected, and their directions and energies are analyzed to reveal details of nuclear structure and to learn more about the strong force. A much weaker nuclear force, the so-called weak interaction, is responsible for the emission of beta rays. Nuclear collision experiments use beams of higher-energy particles, including those of unstable particles called mesons produced by primary nuclear collisions in accelerators dubbed meson factories.

### Particle physics

One of the most significant branches of contemporary physics is the study of the fundamental subatomic constituents of matter, the elementary particles. This field, also called high-energy physics, emerged in the 1930s out of the developing experimental areas of nuclear and cosmic-ray physics. Initially investigators studied cosmic rays, the very-high-energy extraterrestrial radiations that fall upon Earth and interact in the atmosphere (*see below* The methodology of physics). However, after World War II, scientists gradually began using high-energy particle accelerators to provide subatomic particles for study. Quantum field theory, a generalization of QED to other types of force fields, is essential for the analysis of high-energy physics. Subatomic particles cannot be visualized as tiny analogues of ordinary material objects such as billiard balls, for they have properties that appear contradictory from the classical viewpoint. That is to say, while they possess charge, spin, mass, magnetism, and other complex characteristics, they are nonetheless regarded as pointlike.

During the latter half of the 20th century, a coherent picture evolved of the underlying strata of matter involving two types of subatomic particles: fermions (baryons and leptons), which have odd half-integral angular momentum (spin 1/2, 3/2) and make up ordinary matter; and bosons (gluons, mesons, and photons), which have integral spins and mediate the fundamental forces of physics. Leptons (e.g., electrons, muons, taus), gluons, and photons are believed to be truly fundamental particles. Baryons (e.g., neutrons, protons) and mesons (e.g., pions, kaons), collectively known as hadrons, are believed to be formed from indivisible elements known as quarks, which have never been isolated.

Quarks come in six types, or “flavours,” and have matching antiparticles, known as antiquarks. Quarks have charges that are either positive two-thirds or negative one-third of the electron’s charge, while antiquarks have the opposite charges. Like quarks, each lepton has an antiparticle with properties that mirror those of its partner (the antiparticle of the negatively charged electron is the positive electron, or positron; that of the neutrino is the antineutrino). In addition to their electric and magnetic properties, quarks participate in both the strong force (which binds them together) and the weak force (which underlies certain forms of radioactivity), while leptons take part in only the weak force.

Baryons, such as neutrons and protons, are formed by combining three quarks—thus baryons have a charge of −1, 0, or 1. Mesons, which are the particles that mediate the strong force inside the atomic nucleus, are composed of one quark and one antiquark; all known mesons have a charge of −2, −1, 0, 1, or 2. Most of the possible quark combinations, or hadrons, have very short lifetimes, and many of them have never been seen, though additional ones have been observed with each new generation of more powerful particle accelerators.

The quantum fields through which quarks and leptons interact with each other and with themselves consist of particle-like objects called quanta (from which quantum mechanics derives its name). The first known quanta were those of the electromagnetic field; they are also called photons because light consists of them. A modern unified theory of weak and electromagnetic interactions, known as the electroweak theory, proposes that the weak force involves the exchange of particles about 100 times as massive as protons. These massive quanta have been observed—namely, two charged particles, W+ and W−, and a neutral one, W0.

In the theory of the strong force known as quantum chromodynamics (QCD), eight quanta, called gluons, bind quarks to form baryons and also bind quarks to antiquarks to form mesons, the force itself being dubbed the “colour force.” (This unusual use of the term colour is a somewhat forced analogue of ordinary colour mixing.) Quarks are said to come in three colours—red, blue, and green. (The opposites of these imaginary colours, minus-red, minus-blue, and minus-green, are ascribed to antiquarks.) Only certain colour combinations, namely colour-neutral, or “white” (i.e., equal mixtures of the above colours cancel out one another, resulting in no net colour), are conjectured to exist in nature in an observable form. The gluons and quarks themselves, being coloured, are permanently confined (deeply bound within the particles of which they are a part), while the colour-neutral composites such as protons can be directly observed. One consequence of colour confinement is that the observable particles are either electrically neutral or have charges that are integral multiples of the charge of the electron. A number of specific predictions of QCD have been experimentally tested and found correct.

### Quantum mechanics

Although the various branches of physics differ in their experimental methods and theoretical approaches, certain general principles apply to all of them. The forefront of contemporary advances in physics lies in the submicroscopic regime, whether it be in atomic, nuclear, condensed-matter, plasma, or particle physics, or in quantum optics, or even in the study of stellar structure. All are based upon quantum theory (i.e., quantum mechanics and quantum field theory) and relativity, which together form the theoretical foundations of modern physics. Many physical quantities whose classical counterparts vary continuously over a range of possible values are in quantum theory constrained to have discontinuous, or discrete, values. Furthermore, the intrinsically deterministic character of values in classical physics is replaced in quantum theory by intrinsic uncertainty.

According to quantum theory, electromagnetic radiation does not always consist of continuous waves; instead it must be viewed under some circumstances as a collection of particle-like photons, the energy and momentum of each being directly proportional to its frequency (or inversely proportional to its wavelength, the photons still possessing some wavelike characteristics). Conversely, electrons and other objects that appear as particles in classical physics are endowed by quantum theory with wavelike properties as well, such a particle’s quantum wavelength being inversely proportional to its momentum. In both instances, the proportionality constant is the characteristic quantum of action (action being defined as energy × time)—that is to say, Planck’s constant divided by 2π, or ℏ.

In principle, all of atomic and molecular physics, including the structure of atoms and their dynamics, the periodic table of elements and their chemical behaviour, as well as the spectroscopic, electrical, and other physical properties of atoms, molecules, and condensed matter, can be accounted for by quantum mechanics. Roughly speaking, the electrons in the atom must fit around the nucleus as some sort of standing wave (as given by the Schrödinger equation) analogous to the waves on a plucked violin or guitar string. As the fit determines the wavelength of the quantum wave, it necessarily determines its energy state. Consequently, atomic systems are restricted to certain discrete, or quantized, energies. When an atom undergoes a discontinuous transition, or quantum jump, its energy changes abruptly by a sharply defined amount, and a photon of that energy is emitted when the energy of the atom decreases, or is absorbed in the opposite case.

Although atomic energies can be sharply defined, the positions of the electrons within the atom cannot be, quantum mechanics giving only the probability for the electrons to have certain locations. This is a consequence of the feature that distinguishes quantum theory from all other approaches to physics, the uncertainty principle of the German physicist Werner Heisenberg. This principle holds that measuring a particle’s position with increasing precision necessarily increases the uncertainty as to the particle’s momentum, and conversely. The ultimate degree of uncertainty is controlled by the magnitude of Planck’s constant, which is so small as to have no apparent effects except in the world of microstructures. In the latter case, however, because both a particle’s position and its velocity or momentum must be known precisely at some instant in order to predict its future history, quantum theory precludes such certain prediction and thus escapes determinism.

The complementary wave and particle aspects, or wave–particle duality, of electromagnetic radiation and of material particles furnish another illustration of the uncertainty principle. When an electron exhibits wavelike behaviour, as in the phenomenon of electron diffraction, this excludes its exhibiting particle-like behaviour in the same observation. Similarly, when electromagnetic radiation in the form of photons interacts with matter, as in the Compton effect in which X-ray photons collide with electrons, the result resembles a particle-like collision and the wave nature of electromagnetic radiation is precluded. The principle of complementarity, asserted by a Danish physicist, who pioneered the theory of atomic structure, states that the physical world presents itself in the form of various complementary pictures, no one of which is by itself complete, all of these pictures being essential for our total understanding. Thus both wave and particle pictures are needed for understanding either the electron or the photon. Although it deals with probabilities and uncertainties, the quantum theory has been spectacularly successful in explaining otherwise inaccessible atomic phenomena and in thus far meeting every experimental test. Its predictions, especially those of QED, are the most precise and the best checked of any in physics; some of them have been tested and found accurate to better than one part per billion.

## Metaphysics & Pataphysics

### What are Metaphysics

**Metaphysics** is the branch of philosophy that studies the fundamental nature of reality. This includes the first principles of: being or existence, identity, change, space and time, cause and effect, necessity, actuality, and possibility.

Metaphysics is considered one of the four main branches of philosophy, along with epistemology, logic, and ethics. It includes questions about the nature of consciousness and the relationship between mind and matter, between substance and attribute, and between potentiality and actuality.

Metaphysics studies questions related to what it is for something to exist and what types of existence are there. Metaphysics seeks to answer, in an abstract and fully general manner, the questions of: What is *it* that exists; and What *it* is like. The term was misread by other medieval commentators, who thought it meant "the science of what is beyond the physical". Following this tradition, the prefix *meta-* has more recently been prefixed to the names of sciences to designate higher sciences dealing with ulterior and more fundamental problems: hence metamathematics, metalinguistics, metaphysiology, etc. A person who creates or develops metaphysical theories is called a *metaphysician*.

Common parlance also uses the word *metaphysics* for a different referent from that of those already mentioned, namely for beliefs in arbitrary non-physical or magical entities. For example, "metaphysical healing" to refer to healing by means of remedies that are magical rather than scientific. This usage stemmed from the various historical schools of speculative metaphysics which operated by postulating all manner of physical, mental and spiritual entities as bases for particular metaphysical systems. Metaphysics as a subject does not preclude beliefs in such magical entities but neither does it promote them. Rather, it is the subject which provides the vocabulary and logic with which such beliefs might be analyzed and studied, for example to search for inconsistencies both within themselves and with other accepted systems such as science.

Metaphysical study is conducted using deduction from that which is known *a priori*. Like foundational mathematics (which is sometimes considered a special case of metaphysics applied to the existence of number), it tries to give a coherent account of the structure of the world, capable of explaining our everyday and scientific perception of the world, and being free from contradictions. In mathematics, there are many different ways to define numbers; similarly, in metaphysics, there are many different ways to define objects, properties, and Goals, for it to become concepts of its Nature, and other entities that are claimed to make up the world. While metaphysics may, as a special case, study the entities postulated by fundamental science such as atoms and superstrings, its core topic is the set of categories such as object, property and causality which those scientific theories assume. For example: claiming that "electrons have charge" is espousing a scientific theory; while exploring what it means for electrons to be (or at least, to be perceived as) "objects", charge to be a "property", and for both to exist in a topological entity called "space", is the task of metaphysics.

There are two broad stances about what is "the world" studied by metaphysics. According to metaphysical realism, the objects studied by metaphysics exist independently of any observer so that the subject is the most fundamental of all sciences. Metaphysical anti-realism, on the other hand, assumes that the objects studied by metaphysics exist inside the mind of an observer, so the subject becomes a form of introspection and conceptual analysis. This position is of more recent origin. Some philosophers, notably Kant, discuss both of these "worlds" and what can be inferred about each one. Some, such as the logical positivists, and many scientists, reject the metaphysical realism as meaningless and unverifiable. Others reply that this criticism also applies to any type of knowledge, including hard science, which claims to describe anything other than the contents of human perception, and thus that the world of perception *is* the objective world in some sense. Metaphysics itself usually assumes that some stance has been taken on these questions and that it may proceed independently of the choice—the question of which stance to take belongs instead to another branch of philosophy, epistemology.

### Ontology (being)

*Ontology* is the branch of philosophy that studies concepts such as existence, being, becoming, and reality. It includes the questions of how entities are grouped into basic categories and which of these entities exist on the most fundamental level. Ontology is sometimes referred to as the *science of being*. It has been characterized as *general metaphysics* in contrast to *special metaphysics*, which is concerned with more particular aspects of being. Ontologists often try to determine what the *categories* or *highest kinds* are and how they form a *system of categories* that provides an encompassing classification of all entities. Commonly proposed categories include substances, properties, relations, states of affairs and events. These categories are characterized by fundamental ontological concepts, like *particularity* and *universality*, *abstractness* and *concreteness* or *possibility* and *necessity*. Of special interest is the concept of *ontological dependence*, which determines whether the entities of a category exist on the *most fundamental level*. Disagreements within ontology are often about whether entities belonging to a certain category exist and, if so, how they are related to other entities.

### Identity & change

Identity is a fundamental metaphysical concern. Metaphysicians investigating identity are tasked with the question of what, exactly, it means for something to be identical to itself, or – more controversially – to something else. Issues of identity arise in the context of time: what does it mean for something to be itself across two moments in time? How do we account for this? Another question of identity arises when we ask what our criteria ought to be for determining identity, and how the reality of identity interfaces with linguistic expressions.

The metaphysical positions one takes on identity have far-reaching implications on issues such as the mind–body problem, personal identity, ethics, and law. Identity, sometimes called numerical identity, is the relation that a thing bears to itself, and which no thing bears to anything other than itself (cf. sameness).

A modern philosopher who made a lasting impact on the philosophy of identity was Leibniz, whose *law of the indiscernibility of identicals* is still widely accepted today. It states that if some object *x* is identical to some object *y*, then any property that *x* has, *y* will have as well.

However, it does seem that objects can change over time. Two rival theories to account for the relationship between change and identity are *perdurantism*, which treats objects as a series of object-stages, and *endurantism*, which maintains that the organism—the same object—is present at every stage in its history.

By appealing to intrinsic and extrinsic properties, endurantism finds a way to harmonize identity with change. Endurantists believe that objects persist by being strictly numerically identical over time. However, if Leibniz's law of the indiscernibility of identicals is used to define numerical identity here, it seems that objects must be completely unchanged in order to persist. Discriminating between intrinsic properties and extrinsic properties, endurantists state that numerical identity means that, if some object *x* is identical to some object *y*, then any *intrinsic* property that *x* has, *y* will have as well. Thus, if an object persists, *intrinsic* properties of it are unchanged, but *extrinsic* properties can change over time. Besides the object itself, environments and other objects can change over time; properties that relate to other objects would change even if this object does not change.

Perdurantism can harmonize identity with change in another way. In four-dimensionalism, a version of perdurantism, what persists is a four-dimensional object which does not change although three-dimensional slices of the object may differ.

### Space & time

**Philosophy of space and time** is the branch of philosophy concerned with the issues surrounding the ontology and epistemology of space and time. While such ideas have been central to philosophy from its inception, the philosophy of space and time was both an inspiration for and a central aspect of early analytic philosophy. The subject focuses on a number of basic issues, including whether time and space exist independently of the mind, whether they exist independently of one another, what accounts for time's apparently unidirectional flow, whether times other than the present moment exist, and questions about the nature of identity (particularly the nature of identity over time).

To put it, simply, Space-time philosophy is a matter of trying to comprehend time & space in itself, thus, answering the following; Objects appear to us in space and time, while abstract entities such as classes, properties, and relations do not. How do space and time serve this function as a ground for objects? Are space and time entities themselves, of some form? Must they exist prior to objects? How exactly can they be defined? How is time related to change; must there always be something changing in order for time to exist?

The position of conventionalism states that there is no fact of the matter as to the geometry of space and time, but that it is decided by convention. One person in particular proposed this whilst reacting to the creation of the new non-Euclidean geometry, & argued that which geometry applied to a space was decided by convention, since different geometries will describe a set of objects equally well, based on considerations from the idea of a "sphere-world" model. Coordinative definition has two major features. The first has to do with coordinating units of length with certain physical objects. This is motivated by the fact that we can never directly apprehend length. Instead we must choose some physical object, say the Standard Metre at the Bureau International des Poids et Mesures (International Bureau of Weights and Measures), or the wavelength of cadmium to stand in as our unit of length. The second feature deals with separated objects. Although we can, presumably, directly test the equality of length of two measuring rods when they are next to one another, we can not find out as much for two rods distant from one another. Even supposing that two rods, whenever brought near to one another are seen to be equal in length, we are not justified in stating that they are always equal in length. This impossibility undermines our ability to decide the equality of length of two distant objects. Sameness of length, to the contrary, must be set by definition.

One solution to this problem takes a metaphysical view, in which the direction of time follows from an asymmetry of causation. We know more about the past because the elements of the past are causes for the effect that is our perception. We feel we can't affect the past and can affect the future because we *can't* affect the past and *can* affect the future. There are two main objections to this view. First is the problem of distinguishing the cause from the effect in a non-arbitrary way. The use of causation in constructing a temporal ordering could easily become circular. The second problem with this view is its explanatory power. While the causation account, if successful, may account for some time-asymmetric phenomena like perception and action, it does not account for many others.

However, asymmetry of causation can be observed in a non-arbitrary way which is not metaphysical in the case of a human hand dropping a cup of water which smashes into fragments on a hard floor, spilling the liquid. In this order, the causes of the resultant pattern of cup fragments and water spill is easily attributable in terms of the trajectory of the cup, irregularities in its structure, angle of its impact on the floor, etc. However, applying the same event in reverse, it is difficult to explain why the various pieces of the cup should fly up into the human hand and reassemble precisely into the shape of a cup, or why the water should position itself entirely within the cup. The causes of the resultant structure and shape of the cup and the encapsulation of the water by the hand within the cup are not easily attributable, as neither hand nor floor can achieve such formations of the cup or water. This asymmetry is perceivable on account of two features: i) the relationship between the agent capacities of the human hand (i.e., what it is and is not capable of and what it is for) and non-animal agency (i.e., what floors are and are not capable of and what they are for) and ii) that the pieces of cup came to possess exactly the nature and number of those of a cup before assembling. In short, such asymmetry is attributable to the relationship between i) temporal direction and ii) the implications of form and functional capacity.

The application of these ideas of form and functional capacity only dictates temporal direction in relation to complex scenarios involving specific, non-metaphysical agency which is not merely dependent on human perception of time. However, this last observation in itself is not sufficient to invalidate the implications of the example for the progressive nature of time in general.

The second major family of solutions to this problem, and by far the one that has generated the most literature, finds the existence of the direction of time as relating to the nature of thermodynamics. The answer from classical thermodynamics states that while our basic physical theory is, in fact, time-reversal symmetric, thermodynamics is not. In particular, the second law of thermodynamics states that the net entropy of a closed system never decreases, and this explains why we often see glass breaking, but not coming back together. But in statistical mechanics things become more complicated. On one hand, statistical mechanics is far superior to classical thermodynamics, in that thermodynamic behavior, such as glass breaking, can be explained by the fundamental laws of physics paired with a statistical postulate. But statistical mechanics, unlike classical thermodynamics, is time-reversal symmetric. The second law of thermodynamics, as it arises in statistical mechanics, merely states that it is *overwhelmingly* likely that net entropy will increase, but it is not an absolute law. Current thermodynamic solutions to the problem of the direction of time aim to find some further fact, or feature of the laws of nature to account for this discrepancy.

A third type of solution to the problem of the direction of time, although much less represented, argues that the laws are not time-reversal symmetric. For example, certain processes in quantum mechanics, relating to the weak nuclear force, are not time-reversible, keeping in mind that when dealing with quantum mechanics time-reversibility comprises a more complex definition. But this type of solution is insufficient because 1) the time-asymmetric phenomena in quantum mechanics are too few to account for the uniformity of macroscopic time-asymmetry and 2) it relies on the assumption that quantum mechanics is the final or correct description of physical processes.

### Casuality

Classical philosophy recognized a number of causes, including teleological final causes. In special relativity and quantum field theory the notions of space, time and causality become tangled together, with temporal orders of causations becoming dependent on who is observing them. The laws of physics are symmetrical in time, so could equally well be used to describe time as running backwards. Why then do we perceive it as flowing in one direction, the arrow of time, and as containing causation flowing in the same direction? Causality is linked by many philosophers to the concept of counterfactuals. To say that A caused B means that if A had not happened then B would not have happened. Causality is usually required as a foundation for philosophy of science if science aims to understand causes effects and make predictions about them.

### Cosmology

Metaphysical cosmology is the branch of metaphysics that deals with the world as the totality of all phenomena in space and time. Historically, it formed a major part of the subject alongside ontology, though its role is more peripheral in contemporary philosophy. It has had a broad scope, and in many cases was founded in religion. The ancient Greeks drew no distinction between this use and their model for the cosmos. However, in modern times it addresses questions about the Universe which are beyond the scope of the physical sciences. It is distinguished from religious cosmology in that it approaches these questions using philosophical methods (e.g. dialectics). Cosmogony deals specifically with the origin of the universe. Modern metaphysical cosmology and cosmogony try to address questions such as:

* What is the origin of the Universe? What is its first cause? Is its existence necessary?
* What are the ultimate material components of the Universe?
* What is the ultimate reason for the existence of the Universe?

### Mind & Matter:

Accounting for the existence of mind in a world largely composed of matter is a metaphysical problem which is so large and important as to have become a specialized subject of study in its own right, philosophy of mind.

Substance dualism is a classical theory in which mind and body are essentially different, with the mind having some of the attributes traditionally assigned to the soul, and which creates an immediate conceptual puzzle about how the two interact. This form of substance dualism differs from the dualism of some eastern philosophical traditions (like Nyāya), which also posit a soul; for the soul, under their view, is ontologically distinct from the mind. Idealism postulates that material objects do not exist unless perceived and only as perceptions. Adherents of panpsychism, a kind of property dualism, hold that everything *has* a mental aspect, but not that everything exists *in* a mind. Neutral monism postulates that existence consists of a single substance that in itself is neither mental nor physical, but is capable of mental and physical aspects or attributes – thus it implies a dual-aspect theory. For the last century, the dominant theories have been science-inspired including materialistic monism, type identity theory, token identity theory, functionalism, reductive physicalism, nonreductive physicalism, eliminative materialism, anomalous monism, property dualism, epiphenomenalism and emergentism.

### And so what are pataphysics?

according to countless sources, One definition of 'pataphysics' is that it is "a branch of philosophy or science that examines imaginary phenomena that exist in a world beyond metaphysics; it is the science of imaginary solutions." It was originally meant to be a form of mock-science in the late 1800s, though it in itself has brought quite a bit of speculation in itself. It is in itself, a lie, but it has many theories in itself, in spite of its satire nature:

* **Clinamen:** Clinamen is the unpredictable swerve of atoms that one could call "... the smallest possible aberration that can make the greatest possible difference."
* **Anomaly:** An anomaly represents the exception. One poet has noted that, "Pataphysics will examine the laws governing exceptions."
* **The absolute:** The absolute is the idea of a transcended reality... there is no other way to put it.
* **Antinomy:** An antinomy is the mutually incompatible. It represents the duality of things, the echo or symmetry, the good and the evil at the same time. It is in itself a paradox, the antonym of something, and so as long as something exists, there will be an opposite.

## Trivia

* In terms of learning on this subject, monsters may have had more complicated time trying to comprehend physics due to the presence of magic. Ofcourse, it was worth a shot for the royal scientists, and perhaps began study when it was run by Dr. WD Gaster (since thermodynamics undeniably involved in the creation of the CORE), so it would turn out that magic seems less like a reason to deny it and moreso the exception to the rules, and thus a real example of pataphysics.
	+ Nobody in the transvoid, aside from Ten, her peers or Himmsworth, had a clue about physics until knowledge was beginning to spread. That being said, the Transvoid itself exists as a world where physics are continuously altered, due to constant distortions in reality... the Transvoid is an anomaly in itself.
* (Author's note:) The world of UNDERTALE is not meant to be entirely realistic, and is moreso akin to a cartoon, albeit with more real situations... however, Alphatale: Redux brings in physics to further establish the affects of magic & other principles, such as determination, which physics cannot prove due to their 'abnormal' traits. That isn't to say that UNDERTALE doesn't reference science at all or has referenced physics before (particularly quantum physics), this page is rather meant to be an introduction to physics for those who haven't heard of them before outside of mentions of the space-time continuum.