Sciences
Scienze Esatte Fisiche E Naturali · 109 articles · Principal contributors · All subjectsParticular Questions (Questioni particolari)
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Acoustics (ACUSTICA)
ACOUSTICS. - As a science it deals with all the qualities of sound in itself or in relation to certain places where the sounds themselves… -
Age of Man (GENERE UMANO, ETÀ DEL)
AGE OF MAN. - The problem of the age of the h. r. remains one of the most difficult and controversial, since its solution is bound up with… -
Age of the Earth (TERRA, ETÀ DELLA)
AGE OF THE EARTH. - The methods used until a few decades ago to determine the age of the earth are revealed today as totally lacking in… -
Aging, The Biological Problem of (SENESCENZA, PROBLEMA BIOLOGICO DELLA)
AGING, The Biological Problem of. - The problem of the senescence of organisms is linked to the condition of the life cycle (v. BIOLOGICAL… -
Astronomy (ASTRONOMIA)
ASTRONOMY. - Among ancient peoples, astrology (v.) was the mother of astronomy. Since, according to the common opinion, the destiny of men… -
Atomic Nucleus (NUCLEO ATOMICO)
ATOMIC NUCLEUS. - The study undertaken to discover the intimate constitution of chemical atoms led to the conclusion that every atom really… -
Bacteriophage (BATTERIOFAGO)
BACTERIOPHAGE. - The discovery of the b. is due to the French bacteriologist d'Hérelle, who in 1917 described in the fecal filtrate of… -
Bathybius Haeckelii
BATHYBIUS HAECKELII. - A gelatinous slime dredged from the bottom of the Atlantic, which T. H. Huxley named thus, identifying in it the… -
Biocenosis (BIOCENOSI)
BIOCENOSIS. - The term b., or biological association, introduced by Moebius in 1877, defines the entire complex of living beings that… -
Biochemistry (BIOCHIMICA)
BIOCHEMISTRY. - Biochemistry is that part of physiology which studies the chemical composition and the chemical-physical properties of… -
Biogenetic Law (BIOGENETICA, LEGGE)
BIOGENETIC LAW. - The original formulation given by E. Haeckel (v.) in ch. 20 of the work Generelle Morphologie der Organismen (1866), 41st… -
Biological Cycles (CICLI BIOLOGICI)
BIOLOGICAL CYCLES. - There is no fundamental difference from the concept of rhythm. Life manifests itself rhythmically (v. BIORHYTHMS):… -
Biological Differentiation (DIFFERENZIAMENTO BIOLOGICO)
BIOLOGICAL DIFFERENTIATION. - The phenomena of b. d. are diverse, but all share the common condition of a gradual evolution of specific… -
Biological Environments (AMBIENTI BIOLOGICI)
BIOLOGICAL ENVIRONMENTS. - By biological environments are meant the various habitats in which conditions sufficient to permit the life of… -
Biometry (Anthropometry) (BIOMETRIA (ANTROPOMETRIA))
BIOMETRY (ANTHROPOMETRY). - I. ORIGINI E DEFINIZIONE. - Biometrics was born at the historical moment when, in the life sciences in general,… -
Bioregulators (BIOREGOLATORI)
BIOREGULATORS. - The individual functions of the organism are not carried out in isolation, but are coordinated with one another so that,… -
Biorhythms (BIORITMI)
BIORHYTHMS. - By b. are meant the rhythmic activities of living beings. In reality every vital phenomenon is rhythmic: the life itself of a… -
Biosphere (BIOSFERA)
BIOSPHERE. - From the Greek βίος (= life) and σφαῖρα (= sphere). It was intended to call b. the spherical corpuscle further indivisible,… -
Biotype (BIOTIPO)
BIOTYPE. - In genetics, a b. is understood as a complex of individuals identical to one another in their endowment of hereditary… -
Biotypology (BIOTIPOLOGIA)
BIOTYPOLOGY. - Science that studies the human individual in all his vital manifestations, in order to determine, in the most complete… -
Brain (CERVELLO)
BRAIN. - The encephalon (from Gr. ἐγκέφαλος) constitutes the most important center of the entire nervous system and is located in the… -
Carbon (CARBONIO)
CARBON. - Chemical element with atomic number 6 and atomic weight 12, one of the most important in nature as an essential component of… -
Catalepsy (CATALISI)
CATALEPSY. - Some substances increase the speed of certain chemical reactions when they are present in the environment in which these take… -
Cellula
CELLULA. - In biology, this is the name given to the smallest vital unit, capable of autonomous life and of reproduction of the metozoa and… -
Cellular, Theory (CELLULARE, TEORIA)
CELLULAR, THEORY. - With the discovery of the cell, the idea of the cellular constitution of all animals and plants matured. However, only… -
Chemistry (CHIMICA)
CHEMISTRY. - I. DEFINITIONS AND DIVISIONS. - The word c. may derive from the Egyptian or Coptic terms "km.t" or "Kèmi" having the meanings… -
Chlorophyllian Photosynthesis (FOTOSINTESI CLOROFILLIANA)
CHLOROPHYLLIAN PHOTOSYNTHESIS. - The suggestive process of foliar nutrition in plants has been clarified in its fundamental outlines ever… -
Chromosome (CROMOSOMA)
CHROMOSOME. - Characteristic formations that are resolved from the nuclear substances of animal and plant cells when these enter into… -
Circulation (CIRCOLAZIONE)
CIRCULATION. - By c. is meant that complex of structures and functions suited to make a current of liquid circulate incessantly from the… -
Classification (CLASSIFICAZIONE)
CLASSIFICATION.— It is the operation by which a multitude of related objects is arranged in a hierarchical system of groupings, for the… -
Colloids (COLLOIDI)
COLLOIDS. - The colloidal state of matter is of particular interest both because it is the condition of many industrial products of very… -
Comet (COMETA)
COMET. - The typical form of a c. (from the Greek κομήτης) consists of a head or coma, which surrounds a brighter nucleus, and of a tail… -
Cranium (CRANIO)
CRANIUM. - The bony head is made up of two distinct portions: the cerebral cranium, which contains the brain (v. BRAIN), and the facial… -
Crystal (CRISTALLO)
CRYSTAL. - The chemical elements and compounds, inorganic and organic, when they originate in the solid state, can assume the form of… -
Electricity (ELETTRICITÀ)
ELECTRICITY. - About the essence of this most important subject among those that constitute our physical universe, very little is known,… -
Electrochemistry (ELETTROCHIMICA)
ELECTROCHEMISTRY. - In any chemical reaction, from the simplest to the most complex, there always takes place a variation in the spatial… -
Electrology (ELETTROLOGIA)
ELECTROLOGY. - Under this denomination is understood the systematic and, as far as possible, logical development of the science of… -
Electrotechnics (ELETTROTECNICA)
ELECTROTECHNICS. - After the discovery of electromagnetic, electrothermal and electrochemical phenomena, no one could doubt the possibility… -
Embryology (EMBRIOLOGIA)
EMBRYOLOGY. - Considered in the strict sense, embryology should deal with the development of the organism until it is contained within the… -
Emotion (EMOZIONE)
EMOTION. - I. PSYCHOLOGY. - It is the reaction to a sensation, or image, that comes to disturb our organic or psychic equilibrium, a… -
Endocrine, Glands (ENDOCRINE, GLANDOLE)
ENDOCRINE, GLANDS. - In contrast to the glands of external secretion, which elaborate ferments with biochemical activity (secreta) or… -
Energy (ENERGIA)
ENERGY. - In general it means activity, action, power, force. In its technical meaning, the concept, specifically defined by science,… -
Enzymes (ENZIMI)
ENZYMES. - The name e., which means "in yeast," from the Greek ἐν Ῥυμῇ, was proposed by Kühne in 1878. Together with vitamins and hormones,… -
Ether (ETERE)
ETHER. - A real entity, extended, but lacking the most common qualities of sensible material entities, such as weight, impenetrability,… -
Eugenics (EUGENICA)
EUGENICS. - Name used for the first time in 1833 (Eugenics) by Francis Galton, distinguished English statesman (1822-1911), to indicate… -
Evolution (EVOLUZIONE)
EVOLUTION. - Evolutionism (transformism, phylogeny, descent theory) is the scientific doctrine that affirms the natural derivation of… -
Fecundation (FECONDAZIONE)
FECUNDATION. - It is the union of the male germ cell with the female germ cell, that is, of two gametes of different sex. In most… -
Ferments and Fermentation (FERMENTI E FERMENTAZIONE)
FERMENTS AND FERMENTATION. - Ferments or enzymes are catalysts produced by living organisms that perform their work in the metabolism (v.… -
Galvanoplasty (GALVANOPLASTICA)
GALVANOPLASTY. - A process based on the laws of electrolysis, by means of which objects are reproduced by depositing a metal onto a mold… -
Gene
GENE. - It is the structural and functional unit of the hereditary patrimony contained in the nucleus, that is, the smallest portion of… -
Genetics (GENETICA)
GENETICS. - Genetics is defined as the science of heredity, that is, the doctrine of the phenomena concerning the reappearance of the same… -
Geochemistry (GEOCHIMICA)
GEOCHEMISTRY. - From γῆ, "earth," and γυμνῆ, "chemistry." It is the science that studies the physical-chemical composition of the earth.… -
Geology (GEOLOGIA)
GEOLOGY. - The introduction (1603) of the term g. (from γῆ earth and λόγος discourse, treatise, history) is attributed to the great… -
Gravitation (GRAVITAZIONE)
GRAVITATION. - I. GENERALITIES. - In the study of natural phenomena, over the course of the centuries, the opportunity has repeatedly… -
Growth (ACCRESCIMENTO)
GROWTH. - It is the biological problem of the increase in volume of organisms during development. As regards mammals and man, it takes… -
Habitability of Worlds (ABITABILITÀ DEI MONDI)
HABITABILITY OF WORLDS. - 1. SECONDO LA SCIENZA. - By h. of worlds is meant a complex of conditions suited to the forms of life existing on… -
Heredity (EREDITARIETÀ)
HEREDITY. - Transmission from parents to children of the characteristics proper to the species, the race, the individual. This transmission… -
Lethargy (LETARGO)
LETHARGY. - It is a phenomenon characteristic of certain mammals (rodents, insectivores, bats, carnivores, etc.), consisting in the… -
Magnetism (MAGNETISMO)
MAGNETISM. - Since remote antiquity it had been observed that certain iron minerals possess the singular property that, when pieces of them… -
Malaria
MALARIA. - The generic term malaria denotes a group of infections of humans and animals caused by protozoa of the genus Plasmodium.… -
Man, Origin of (UOMO, ORIGINE DELL')
MAN, ORIGIN OF. - The problem of human origins is the principal object of research in human paleontology and has been a source of… -
Mathematics (MATEMATICA)
MATHEMATICS. - Arithmetic and geometry are the two great trunks of mathematics, from which numerous other branches have sprung forth to… -
Matter, Constitution of (MATERIA, COSTITUZIONE DELLA)
MATTER, Constitution of. - The problem of the constitution of matter is undoubtedly one of the fundamental scientific problems: indeed,… -
Mechanics (MECCANICA)
MECHANICS. - Mechanics has as its object the study of the phenomena of material bodies that take place without altering either their… -
Meiosis (MEIOSI)
MEIOSIS. - Meiosis (a term introduced by Farmer and Moore, 1905) is the mechanism of reduction of the chromosomes (v. CHROMOSOME) from the… -
Metabolism (METABOLISMO)
METABOLISM. - The term m. denotes the whole set of chemical transformation processes that the materials introduced from the environment… -
Meteorology (METEREOLOGIA)
METEOROLOGY. - The etymology of the word indicates that originally it referred to the study, or at least the observation, of all… -
Microbiology (MICROBIOLOGIA)
MICROBIOLOGY. - Microbiology studies living beings that are extremely small, invisible to the naked eye and visible only by means of… -
Mineralogy (MINERALOGIA)
MINERALOGY. - The science of minerals. Its principal task was originally to describe and identify them; today it tends above all toward a… -
Moon (LUNA)
MOON. - Satellite of the Earth, from which it probably originated through the division of the still-fluid terrestrial mass (v. COSMOGONY).… -
Mutation (MUTAZIONE)
MUTATION. - This term is commonly used to indicate the sudden appearance of a new hereditary character, and as such the word was introduced… -
Nervous System (Of Man) (NERVOSO, SISTEMA (DELL'UOMO))
NERVOUS SYSTEM (Of Man). - I. GENERALITIES. - It is a general property of protoplasm to be excitable, that is, to perceive stimuli of… -
Parasitism (PARASSITISMO)
PARASITISM. - It denotes that form of association between organisms of different species in which one of the two associates (the parasite)… -
Pharmacology (FARMACOLOGIA)
PHARMACOLOGY. - The word, introduced into the medical vocabulary in the 1600s, in its etymology means the study of drugs (medicaments and… -
Phylogeny (FILOGENESI)
PHYLOGENY. - Within the framework of the theory of evolution, it denotes the historical order according to which the various groups of… -
Physical Indeterminism (INDETERMINISMO FISICO)
PHYSICAL INDETERMINISM. - Physical i. depends on the uncertainty principle, the foundation of atomic mechanics, due to W. Heisenberg. In… -
Physical Laws and Statistical Laws (LEGGI FISICHE E LEGGI STATISTICHE)
PHYSICAL LAWS AND STATISTICAL LAWS. - In the complex of natural phenomena that form the object of scientific research, two groups can be… -
Physical Theories (TEORIE FISICHE)
PHYSICAL THEORIES. - By physical theory is meant, in the most general sense, a rational explanation of a phenomenon or of a set of physical… -
Physics (FISICA)
PHYSICS. - From the Greek φύσις (nature). This is the name given to the science that studies the generic properties of matter and of the… -
Physiology (FISIOLOGIA)
PHYSIOLOGY. - From the Greek φύσις = nature and λογέω = I investigate, physiology is the science of the functioning of the living organism.… -
Probability, Calculus of (PROBABILITÀ, CALCOLO DELLE)
PROBABILITY, CALCULATION OF. - Science that deals, both from the theoretical and from the practical point of view, with the study of causal… -
Psychoanalysis (PSICANALISI)
PSYCHOANALYSIS. - It is a system of dynamic psychology, that is, one that studies in particular the forces of propulsion and direction of… -
Quanti, Hypotheses and Theory of (QUANTI, IPOTESI E TEORIA DEI)
QUANTA, HYPOTHESIS AND THEORY OF. - The hypothesis of quanta is the first, in order of time and importance, of the two singular hypotheses… -
Radar
RADAR. - This name is generally used to designate a considerable series of criteria, methods and devices designed to detect, even at night… -
Radioactivity (RADIOATTIVITÀ)
RADIOACTIVITY. - Atoms, according to the suggestive model proposed by Rutherford, are made up of a nucleus and satellite electrons (e.).… -
Radiocommunications (RADIOCOMUNICAZIONI)
RADIOCOMMUNICATIONS. - I. EARLY DEVELOPMENTS. - The scientific basis of this means of various transmissions lies, as is well known, in… -
Regeneration (Science) (RIGENERAZIONE (SCIENZA))
REGENERATION (SCIENCE). - One of the general properties of living organisms is regulation (v.), a property that allows the preservation of… -
Relativity, Theory of (RELATIVITÀ, TEORIA DELLA)
RELATIVITY, Theory of. - I. PHYSICAL SPACE AND TIMES. - This theory, like the almost contemporary theory of "quanta" (v.), is one of the… -
Reproduction (RIPRODUZIONE)
REPRODUCTION. - Reproduction, or the faculty of generating new organisms similar to themselves, is the most typical and fundamental… -
Respiration (RESPIRAZIONE)
RESPIRATION. - This term refers to the exchange between the organism and the external environment of those substances that are found in the… -
Science of Nutrition (SCIENZA DELL'ALIMENTAZIONE)
FOOD SCIENCE. - It is the study of man's dietary needs and, in a broader sense, also of those of animals and plants, and of the ways in… -
Solar System (SOLARE, SISTEMA)
SOLAR, SYSTEM. — It is the whole of the Sun and of the celestial bodies (planets and their satellites, minor planets, comets and certain… -
Sound (SUONO)
SOUND. - I. PHYSICAL GENESIS OF ACOUSTIC STIMULI. - The energy adequate to stimulate the auditory apparatus is a particular form of… -
Species (SPECIE)
SPECIES. - A biological entity which, through physiological isolation, on the one hand allows the complex of characters inherited from its… -
Statistics (STATISTICA)
STATISTICS. - This term derives, most probably, from the Latin status, which means state, position, condition, manner of being. It was used… -
Stratigraphy (STRATIGRAFIA)
STRATIGRAPHY. - Stratigraphy, also called stratigraphic geology or historical geology, reconstructs the chronological order of deposition… -
Symbiosis (SIMBIOSI)
SYMBIOSIS. - From the Greek σύν (= together) and βίος (= life). This term, introduced by A. de Bary in 1879, denotes the intimate and… -
Tectonics (TETTONICA)
TECTONICS. - It is that part of geology (v.) which deals with: a) the conditions of position (attitude), form and mutual relations of the… -
Terminology (TERMOLOGIA)
TERMINOLOGY. - It is the branch of physics that systematically studies phenomena in which heat plays a predominant part. Everyone has some… -
Thermodynamics (TERMODINAMICA)
THERMODYNAMICS. - Thermodynamics is the most important chapter of physics which, going far beyond the limit that its name would seem to… -
Tropisms (TROPISMI)
TROPISMS. - The phenomenon of tropisms is closely connected with that of the excitability of living matter. Excitability is a fundamental… -
Twins (GEMELLI)
TWINS. - Twins are children born in the same birth and from the eggs of a single laying. In particular cases more than one individual can… -
Unity and Physical Dimensions (UNITÀ E DIMENSIONI FISICHE)
UNITY AND PHYSICAL DIMENSIONS. - The notion of the measurement of certain quantities, in particular of lengths, areas, weights, and hence… -
Virus (Ultravirus, Infravirus, Filterable Viruses) (VIRUS (ULTRAVIRUS, INFRAVIRUS, VIRUS FILTRABILI))
VIRUS (Ultravirus, Infravirus, Filterable Viruses). - They are particular agents of diseases of man, animals and plants, characterized by… -
Vita Latent (VITA LATENTE)
LATENT LIFE. - Latent life falls within the field of biological adaptations. It is to be understood as a reduction to a minimum of every… -
Viventian Age (VIVENTI, ETÀ DEI)
VIVENTIAN AGE. - The enormous span of time that elapses between the solidification of the first terrestrial crust and the Cambrian (the… -
Vulcan (VULCANO)
VULCAN. - In common usage, volcanoes are elevations of the earth's crust through which, during periods of eruption, incandescent materials… -
Water (ACQUA)
WATER. - I. A. IN THE SCIENCES. - Every form of life, including human life, unfolds in an aqueous environment. Some animals, such as… -
Zoology (ZOOLOGIA)
ZOOLOGY. - The science whose object is the study of animals. This very broad definition, which makes the expression "z." a synonym of…