This glossary contains a vocabulary used by CPER concerning the overall site, regarding: meaning of scientific words, useful definitions, short explanations of some concepts, and references to reliable external sources of information on the Internet or on paper.

Browse the glossary using this index

Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | ALL





  • Entropy is defined as a thermodynamic parameter representing the state of disorder of a system at the atomic, ionic, or molecular level.
  • Entropy is a thermodynamic property which serves as a measure of how close a system is to equilibrium.
  • Entropy is a measure of disorder in a system; the higher the entropy the greater the disorder. In the context of entropy, "perfect internal disorder" is synonymous with "equilibrium".
  • Entropy is a measure of the unavailability of a system’s energy to do work; Thus, thermodynamic entropy is a measure of the amount of energy in a physical system that cannot be used to do work.
  • Entropy is a measure of the dispersal of energy; how much energy is spread out in a process, or how widely spread out it becomes, at a specific temperature.
  • Entropy is the capacity factor for thermal energy that is hidden with respect to temperature.
  • Entropy is a measure of disorder in the universe.
  • Entropy is the tendency of a system, that is left to itself, to descend into chaos.

Second Law of Thermodynamics

According to the second law of thermodynamics the entropy of an isolated system never decreases. An isolated system will spontaneously evolve toward thermodynamic equilibrium, the configuration with maximum entropy.
Systems that are not isolated may decrease in entropy, provided they increase the entropy of their environment by at least that same amount.
Since entropy is a state function, the change in the entropy of a system is the same for any process that goes from a given initial state to a given final state, whether the process is reversible or irreversible.


The idea of "irreversibility" is central to the understanding of entropy. Most people have an intuitive understanding of irreversibility (a dissipative process): if one watches a movie of everyday life running forward and in reverse, it is easy to distinguish between the two. The movie running in reverse shows impossible things happening: water jumping out of a glass into a pitcher above it, smoke going down a chimney, water "unmelting" to form ice in a warm room, crashed cars reassembling themselves, and so on.
The intuitive meaning of expressions such as "you can't unscramble an egg", "don't cry over spilled milk" or "you can't take the cream out of the coffee" is that these are irreversible processes. There is a direction in time by which spilled milk does not go back into the glass (see: The arrow of time).
In thermodynamics, one says that the "forward" processes – pouring water from a pitcher, smoke going up a chimney, etc. – are "irreversible": they cannot happen in reverse, even though, on a microscopic level, no laws of physics would be violated if they did. This reflects the time-asymmetry of entropy.
All real physical processes involving systems in everyday life, with many atoms or molecules, are irreversible. For an irreversible process in an isolated system, the thermodynamic state variable known as entropy is always increasing.
The reason that the movie in reverse is so easily recognized is because it shows processes for which entropy is decreasing, which is physically impossible.

Entropy as energy dispersal

Entropy can also be described in terms of "energy dispersal" and the "spreading of energy", while avoiding all mention of "disorder", "randomness" and "chaos". In this approach, the second law of thermodynamics is introduced as: "Energy spontaneously disperses from being localized to becoming spread out if it is not hindered from doing so."

This explanation can be used in the context of common experiences such as a rock falling, a hot frying pan cooling down, iron rusting, air leaving a punctured tyre and ice melting in a warm room. Entropy is then depicted as a sophisticated kind of "before and after" yardstick: Measuring how much energy is spread out over time as a result of a process such as heating a system, or how widely spread out the energy is after something happens in comparison with its previous state, in a process such as gas expansion or fluids mixing (at a constant temperature).

The equations are explored with reference to the common experiences, with emphasis that in chemistry the energy that entropy measures as dispersing is the internal energy of molecules.

Chemical reactions

The second law of thermodynamics, states that a closed system has entropy which may increase or otherwise remain constant. Chemical reactions cause changes in entropy and entropy plays an important role in determining in which direction a chemical reaction spontaneously proceeds.

Systems ecology and Negentropy

Nowadays, many biologists use the term 'entropy of an organism', or its antonym 'negentropy', as a measure of the structural order within an organism.

Historical frame

The term entropy was coined in 1865 by the German physicist Rudolf Clausius, who stated that: “The entropy of the universe tends to a maximum.”.


Unlike many other functions of state, entropy cannot be directly observed but must be calculated. Entropy can be calculated for a substance as the standard molar entropy from absolute zero temperature (also known as absolute entropy).
Entropy has the dimension of energy divided by temperature, which has a unit of joules per kelvin (J/K) in the International System of Units.
While these are the same units as heat capacity, the two concepts are distinct. Entropy is not a conserved quantity: for example, in an isolated system with non-uniform temperature, heat might irreversibly flow and the temperature become more uniform such that entropy increases.

The arrow of time

Entropy is the only quantity in the physical sciences that seems to imply a particular direction of progress, sometimes called an arrow of time. As time progresses, the second law of thermodynamics states that the entropy of an isolated system never decreases (but rather will increase). Hence, from this perspective, entropy measurement is thought of as a kind of clock (an isolated system has low entopy in the past, and high entropy in the future).
The Second Law of Thermodynamics allows for the entropy to remain the same regardless of the direction of time. If the entropy is constant in either direction of time, there would be no preferred direction. However, the entropy can only be a constant if the system is in the highest possible state of disorder, such as a gas that always was (and always will be) uniformly spread out in its container.
The existence of a thermodynamic arrow of time implies that the system is highly ordered (i.e. low entropy) in one time direction only, which would by definition be the "past". Thus this law is about the boundary conditions rather than the equations of motion of our world.

Linguistic derivation

The term Entropy is derived from the Ancient Greek word entropía (ἐντροπία) meaning “a turning towards”.
This is a combination of the prefix en- (ἐν) meaning "in", and the word tropḗ (τροπή) meaning "a turning", in analogy with energy.

External sources









▲ Top ▲



In biology, epigenetics is the study of cellular and physiological traits that are not caused by changes in the DNA sequence. Epigenetics describes the study of stable, long-term alterations in the transcriptional potential of a cell. Some of those alterations are heritable. Unlike simple genetics based on changes to the DNA sequence (the genotype), the changes in gene expression or cellular phenotype of epigenetics have other causes, thus use of the term epi-genetics.

Relation between Genotype and Phenotype with Epigentic target

The term also refers to the changes themselves: functionally relevant changes to the genome that do not involve a change in the nucleotide sequence. Examples of mechanisms that produce such changes are DNA methylation and histone modification, each of which alters how genes are expressed without altering the underlying DNA sequence. Gene expression can be controlled through the action of repressor proteins that attach to silencer regions of the DNA. These epigenetic changes may last through cell divisions for the duration of the cell's life, and may also last for multiple generations even though they do not involve changes in the underlying DNA sequence of the organism; instead, non-genetic factors cause the organism's genes to behave (or "express themselves") differently.

Epigenetic mechanisms

One example of an epigenetic change in eukaryotic biology is the process of cellular differentiation. During Morphogenesis, totipotent stem cells become the various pluripotent cell lines of the embryo, which in turn become fully differentiated cells. In other words, as a single fertilized egg cell – the zygote – continues to divide, the resulting daughter cells change into all the different cell types in an organism (including neurons, muscle cells, epithelium, endothelium of blood vessels, etc.) by activating some genes while inhibiting the expression of others.

Influence of Epigenetics on Metamorphosis of butterfly

Linguistic derivation

The term Epigenetics is derived from the ancient Greek prefix epi (επί-) meaning "over, outside of, around, on top of" and the word genetics from genesis (γένεσις) meaning "origin", "source", or "birth".




Eugenics is also called Eugenetics.


Eugenics is the theory and practice of improving the genetic quality of the human population. It is a social philosophy advocating the improvement of human genetic traits through the promotion of higher reproduction of people with desired traits (positive eugenics), and reduced reproduction of people with less-desired or undesired traits (negative eugenics).


CPER's standpoint

CPER propagates the fundamental human right of Positive Intrinsic Eugenics (PIE), which belief is based on the following conditions:

  • It is a basic democratic human right to choose yourself (at free will) with whom you want to procreate in a natural way, for whatever reason you find fit. No one may forbid you to marry the reproduction partner of your own choice, (when your are an adult)!
  • A heterosexual man or woman may seek a reproduction partner with whom he/she hopes to create children that may display an improved ratio/combination of both their desired parental traits (physical or mental).
  • People hope, by procreating with the partner of choice, to increase the chances that, in the random combination of genetic traits at fertilization, their offspring become better adapted towards surviving the circumstances of life. This way, parents strive for a better biological Quality of Life for their future offspring.

Some examples of possible improved outcome (as perceived by the procreating partners) of intrinsic positive 'breeding' are:
Improved physical qualities: tallness, strength, agility, speed, physical endurance, improved immune system, longevity, beauty. Also: (striving for) offspring with normal health by avoiding having children from a partner with an illness caused by certain genetic factors, for example: some forms of cancer.
Improved mental competences: higher IQ or EQ, such as: photographic memory, numeracy skills, verbal fluency, perfect musical hearing/pitch, caring love, social communication talent, emotional stability, mental hardiness, stress resistance, leadership qualities.

CPER's definition of PIE (within humans):
Positive Intrinsic Eugenics is: the tendency for genetic improvement within a species, by means of natural procreation, caused by the inner (human) drive/impulse to seek a particular reproduction partner to increase the chance of desirable qualities in their communal offspring.
PIE is therefore the inner drive to seek positive qualities from a potential reproduction partner, with the hope of creating children equipped with survival characteristics, that are desired by both parents.

Opposite formulation:
Tendency of people to strive for offspring with a normal healthy constitution by avoiding creating children with a partner who carries an illness caused by certain inherited genetic factors, for example: some forms of cancer, or enzyme deficiencies.

Future evolution of mankind:
CPER states that, because of the accelerating human overpopulation, the struggle for life will become harder and harder worldwide. Thus people will do anything to produce offspring that has a better chance of surviving harsh reality.


Linguistic derivation

The term Eugenics is derived from the ancient Greek words eu- (εὖ), meaning "good/well", and -genes (γένος), meaning "born" or "race".


External sources






Biological Evolution is the change in the inherited characteristics of biological populations over successive generations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins. All life on Earth is descended from a last universal ancestor that lived approximately 3.8 billion years ago. Repeated speciation and the divergence of life can be inferred from shared sets of biochemical and morphological traits, or by shared DNA sequences. These homologous traits and sequences are more similar among species that share a more recent common ancestor, and can be used to reconstruct evolutionary histories, using both existing species and the fossil record. Existing patterns of biodiversity have been shaped both by speciation and by extinction.

Historical frame

Charles Darwin (12 Feb. 1809 – 19 Apr. 1882 †) was the first to formulate a scientific argument for the theory of evolution by means of natural selection. Evolution by natural selection is a process that is inferred from three facts about populations: 

  1. More offspring are produced than can possibly survive.
  2. Traits vary among individuals, leading to different rates of survival and reproduction.
  3. Trait differences are heritable.

Thus, when members of a population die they are replaced by the progeny of parents that were better adapted to survive and reproduce in the environment in which natural selection took place. This process creates and preserves traits that are seemingly fitted for the functional roles they perform. Natural selection is the only known cause of adaptation, but not the only known cause of evolution. Other, non-adaptive causes of evolution include mutation and genetic drift.
In the early 20th century, genetics was integrated with Darwin's theory of evolution by natural selection through the discipline of population genetics. The importance of natural selection as a cause of evolution was accepted into other branches of biology. Moreover, previously held notions about evolution, such as orthogenesis (J.B. Lamarck) and "progress" became obsolete. Scientists continue to study various aspects of evolution by forming and testing hypotheses, constructing scientific theories, using observational data, and performing experiments in both the field and the laboratory.  Biologists agree that descent with modification is one of the most reliably established facts in science. Discoveries in evolutionary biology have made a significant impact not just within the traditional branches of biology, but also in other academic disciplines (e.g., anthropology and psychology) and on society at large.


CPER's standpoint

Members of CPER differ in their belief system about Biological Evolution from mainstream scientific agreements, in the following way: CPER acknowledges that, when an intelligent animal species emerges from millennial evolutional processes in nature, this species (at the moment: Human Being) can manipulate the outcome of evolutional tendencies. This way, the 'humanimal' starts giving accelerated direction to Progressive Evolution of its own life form, and eventually of future life in general.


Linguistic derivation

The term Evolution is derived from the Latin word ēvolūtiō, meaning "unfolding" or "unrolling".


External sources

http://en.wikipedia.org/wiki/Evolution .