Science in the context of Underwater habitat

Cosmology (from Ancient Greek κόσμος (cosmos) 'the universe, the world' and λογία (logia) 'study of') is a branch of physics and metaphysics dealing with the nature of the universe, the cosmos. The term cosmology was first used in English in 1656 in Thomas Blount's Glossographia, with the meaning of "a speaking of the world". In 1731, German philosopher Christian Wolff used the term cosmology in Latin (cosmologia) to denote a branch of metaphysics that deals with the general nature of the physical world. Religious or mythological cosmology is a body of beliefs based on mythological, religious, and esoteric literature and traditions of creation myths and eschatology. In the science of astronomy, cosmology is concerned with the study of the chronology of the universe.

Physical cosmology is the study of the observable universe's origin, its large-scale structures and dynamics, and the ultimate fate of the universe, including the laws of science that govern these areas. It is investigated by scientists, including astronomers and physicists, as well as philosophers, such as metaphysicians, philosophers of physics, and philosophers of space and time. Because of this shared scope with philosophy, theories in physical cosmology may include both scientific and non-scientific propositions and may depend upon assumptions that cannot be tested. Physical cosmology is a sub-branch of astronomy that is concerned with the universe as a whole. Modern physical cosmology is dominated by the Big Bang Theory which attempts to bring together observational astronomy and particle physics; more specifically, a standard parameterization of the Big Bang with dark matter and dark energy, known as the Lambda-CDM model.

Philosophy (from Ancient Greek philosophía lit. 'love of wisdom') is a systematic study of general and fundamental questions concerning topics like existence, knowledge, mind, reason, language, and value. It is a rational and critical inquiry that reflects on its methods and assumptions.

Historically, many of the individual sciences, such as physics and psychology, formed part of philosophy. However, they are considered separate academic disciplines in the modern sense of the term. Influential traditions in the history of philosophy include Western, Arabic–Persian, Indian, and Chinese philosophy. Western philosophy originated in Ancient Greece and covers a wide area of philosophical subfields. A central topic in Arabic–Persian philosophy is the relation between reason and revelation. Indian philosophy combines the spiritual problem of how to reach enlightenment with the exploration of the nature of reality and the ways of arriving at knowledge. Chinese philosophy focuses principally on practical issues about right social conduct, government, and self-cultivation.

Aristotle (Attic Greek: Ἀριστοτέλης, romanized: Aristotélēs; 384–322 BC) was an ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, and the arts. As the founder of the Peripatetic school of philosophy in the Lyceum in Athens, he began the wider Aristotelian tradition that followed, which set the groundwork for the development of modern science.

Little is known about Aristotle's life. He was born in the city of Stagira in northern Greece during the Classical period. His father, Nicomachus, died when Aristotle was a child, and he was brought up by a guardian. At around eighteen years old, he joined Plato's Academy in Athens and remained there until the age of thirty seven (c. 347 BC). Shortly after Plato died, Aristotle left Athens and, at the request of Philip II of Macedon, tutored his son Alexander the Great beginning in 343 BC. He established a library in the Lyceum, which helped him to produce many of his hundreds of books on papyrus scrolls.

Alexandria is a major city in Egypt. Lying at the western edge of the Nile River Delta, it extends about 40 km (25 mi) along the country's northern coast. It is Egypt's principal seaport, the second largest city after Cairo, and the largest city on the Mediterranean coast. Founded in 331 BC by Alexander the Great, Alexandria is one of the largest and most important cities of antiquity and a leading hub for science, culture, and scholarship.

Nicknamed the "Bride of the Mediterranean" and "Pearl of the Mediterranean Coast", the city is a popular tourist destination and a major industrial centre. It is the sixth-largest city in the Arab world and in the Middle East, and the eleventh-largest city and urban area in Africa. Alexandria was established originally near an ancient Egyptian settlement named Rhacotis, which later became its Egyptian quarter. The city was made the capital of the Ptolemaic Kingdom and became the foremost commercial, intellectual, and cultural centre for much of the Hellenistic age and late antiquity; at one time, it was the most populous city in the ancient world. Alexandria was best known for the Lighthouse of Alexandria (Pharos), one of the Seven Wonders of the Ancient World; its Great Library, the largest in the ancient world; and the Catacombs of Kom El Shoqafa, one of the Seven Wonders of the Middle Ages.

Humans, scientifically known as Homo sapiens, are primates that belong to the biological family of great apes and are characterized by hairlessness, bipedality, and high intelligence. Humans have large brains compared to body size, enabling more advanced cognitive skills that facilitate successful adaptation to varied environments, development of sophisticated tools, and formation of complex social structures and civilizations.

Humans are highly social, with individual humans tending to belong to a multi-layered network of distinct social groups – from families and peer groups to corporations and political states. As such, social interactions between humans have established a wide variety of values, social norms, languages, and traditions (collectively termed institutions), each of which bolsters human society. Humans are also highly curious: the desire to understand and influence phenomena has motivated humanity's development of science, technology, philosophy, mythology, religion, and other frameworks of knowledge; humans also study themselves through such domains as anthropology, social science, history, psychology, and medicine. As of 2025, there are estimated to be more than 8 billion living humans.

Reason is the capacity of consciously applying logic by drawing valid conclusions from new or existing information, with the aim of seeking truth. It is associated with such characteristically human activities as philosophy, religion, science, language, and mathematics, and is normally considered to be a distinguishing ability possessed by humans. Reason is sometimes referred to as rationality, although the latter is more about its application.

Reasoning involves using more-or-less rational processes of thinking and cognition to extrapolate from one's existing knowledge to generate new knowledge, and involves the use of one's intellect. The field of logic studies the ways in which humans can use formal reasoning to produce logically valid arguments and true conclusions. Reasoning may be subdivided into forms of logical reasoning, such as deductive reasoning, inductive reasoning, and abductive reasoning.

Early Islamic philosophy or classical Islamic philosophy is a period of intense philosophical development beginning in the 2nd century AH of the Islamic calendar (early 9th century CE) and lasting until the 6th century AH (late 12th century CE). The period is known as the Islamic Golden Age, and the achievements of this period had a crucial influence in the development of modern philosophy and science. For Renaissance Europe, "Muslim maritime, agricultural, and technological innovations, as well as much East Asian technology via the Muslim world, made their way to western Europe in one of the largest technology transfers in world history." This period starts with al-Kindi in the 9th century and ends with Averroes (Ibn Rushd) at the end of 12th century. The death of Averroes effectively marks the end of a particular discipline of Islamic philosophy usually called the Peripatetic Arabic School, and philosophical activity declined significantly in Western Islamic countries, namely in Islamic Spain and North Africa, though it persisted for much longer in the Eastern countries, in particular Persia and India where several schools of philosophy continued to flourish: Avicennism, Illuminationist philosophy, Mystical philosophy, and Transcendent theosophy.

Intellectual innovations, achievements, and advancements of this period included, within jurisprudence, the development of ijtihad, a method or methodological approach to legal reasoning, interpretation, and argument based on independent inquiry and analogical deduction; within science and the philosophy of science, the development of empirical research methods emphasizing controlled experimentation, observational evidence, and reproducibility, as well as early formulations of empiricist epistemologies; commentaries and developments in Aristotelian logic, as well as innovations in non-Aristotelian temporal modal logic and inductive logic; and developments in research practice and methodology, including, within medicine, the first documented peer review process and within jurisprudence and theology, a strict science of citation, the isnad or "backing".

Technology is the application of conceptual knowledge to achieve practical goals, especially in a reproducible way. The word technology can also mean the products resulting from such efforts, including both tangible tools such as utensils or machines, and intangible ones such as software. Technology plays a critical role in science, engineering, and everyday life.

Technological advancements have led to significant changes in society. The earliest known technology is the stone tool, used during prehistory, followed by the control of fire—which in turn contributed to the growth of the human brain and the development of language during the Ice Age, according to the cooking hypothesis. The invention of the wheel in the Bronze Age allowed greater travel and the creation of more complex machines. More recent technological inventions, including the printing press, telephone, and the Internet, have lowered barriers to communication and ushered in the knowledge economy.

The history of science covers the development of science from ancient times to the present. It encompasses all three major branches of science: natural, social, and formal. Protoscience, early sciences, and natural philosophies such as alchemy and astrology that existed during the Bronze Age, Iron Age, classical antiquity and the Middle Ages, declined during the early modern period after the establishment of formal disciplines of science in the Age of Enlightenment.

The earliest roots of scientific thinking and practice can be traced to Ancient Egypt and Mesopotamia during the 3rd and 2nd millennia BCE. These civilizations' contributions to mathematics, astronomy, and medicine influenced later Greek natural philosophy of classical antiquity, wherein formal attempts were made to provide explanations of events in the physical world based on natural causes. After the fall of the Western Roman Empire, knowledge of Greek conceptions of the world deteriorated in Latin-speaking Western Europe during the early centuries (400 to 1000 CE) of the Middle Ages, but continued to thrive in the Greek-speaking Byzantine Empire. Aided by translations of Greek texts, the Hellenistic worldview was preserved and absorbed into the Arabic-speaking Muslim world during the Islamic Golden Age. The recovery and assimilation of Greek works and Islamic inquiries into Western Europe from the 10th to 13th century revived the learning of natural philosophy in the West. Traditions of early science were also developed in ancient India and separately in ancient China, the Chinese model having influenced Vietnam, Korea and Japan before Western exploration. Among the Pre-Columbian peoples of Mesoamerica, the Zapotec civilization established their first known traditions of astronomy and mathematics for producing calendars, followed by other civilizations such as the Maya.

A scientist is a expert who conducts scientific research to advance knowledge in science.

In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophical study of nature called natural philosophy. Though Thales (c. 624–545 BC) was arguably the first scientist for describing how cosmic events may be seen as natural, not necessarily caused by gods, it was not until the 19th century that the term scientist came into regular use: it was coined by the theologian, philosopher, and historian of science William Whewell in 1833 to describe Mary Somerville.

European science in the Middle Ages comprised the study of nature, mathematics and natural philosophy in medieval Europe. Following the fall of the Western Roman Empire and the decline in knowledge of Greek, Christian Western Europe was cut off from an important source of ancient learning. Although a range of Christian clerics and scholars from Isidore and Bede to Jean Buridan and Nicole Oresme maintained the spirit of rational inquiry, Western Europe would see a period of scientific decline during the Early Middle Ages. However, by the time of the High Middle Ages, the region had rallied and was on its way to once more taking the lead in scientific discovery. Scholarship and scientific discoveries of the Late Middle Ages laid the groundwork for the Scientific Revolution of the Early Modern Period.

According to Pierre Duhem, who founded the academic study of medieval science as a critique of the Enlightenment theory of a 17th-century anti-Aristotelian and anticlerical scientific revolution, the various conceptual origins of that alleged revolution lay in the 12th to 14th centuries, in the works of churchmen such as Thomas Aquinas and Buridan.

Medicine is the science and practice of caring for patients, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness. Contemporary medicine applies biomedical sciences, biomedical research, genetics, and medical technology to diagnose, treat, and prevent injury and disease, typically through pharmaceuticals or surgery, but also through therapies as diverse as psychotherapy, external splints and traction, medical devices, biologics, and ionizing radiation, amongst others.

Medicine has been practiced since prehistoric times, and for most of this time it was an art (an area of creativity and skill), frequently having connections to the religious and philosophical beliefs of local culture. For example, a medicine man would apply herbs and say prayers for healing, or an ancient philosopher and physician would apply bloodletting according to the theories of humorism. In recent centuries, since the advent of modern science, most medicine has become a combination of art and science (both basic and applied, under the umbrella of medical science). For example, while stitching technique for sutures is an art learned through practice, knowledge of what happens at the cellular and molecular level in the tissues being stitched arises through science.

The English-speaking world comprises the 88 countries and territories in which English is an official, administrative, or cultural language. In the early 2000s, between one and two billion people spoke English, making it the largest language by number of speakers, the third largest language by number of native speakers and the most widespread language geographically. The countries in which English is the native language of most people are sometimes termed the Anglosphere. Speakers of English are called Anglophones.

Early Medieval England was the birthplace of the English language; the modern form of the language has been spread around the world since the 17th century, first by the worldwide influence of England and later the United Kingdom, and then by that of the United States. Through all types of printed and electronic media of these countries, English has become the leading language of international discourse and the lingua franca in many regions and professional fields, such as science, navigation and law.

Oswald Arnold Gottfried Spengler (29 May 1880 – 8 May 1936) was a German philosopher whose areas of interest included history, philosophy, mathematics, science, and art, as well as their relation to his organic theory of history. He is best known for his two-volume work The Decline of the West (Der Untergang des Abendlandes), published in 1918 and 1922, covering human history. Spengler's model of history postulates that human cultures and civilizations are akin to biological entities, each with a limited, predictable, and deterministic lifespan.

Spengler predicted that about the year 2000, Western civilization would enter the period of pre‑death emergency which would lead to 200 years of Caesarism (extra-constitutional omnipotence of the executive branch of government) before Western civilization's final collapse.

Humanities are important academic disciplines that study aspects of human society and culture, including certain fundamental questions asked by humans. During the Renaissance, the term "humanities" referred to the study of classical literature and language, as opposed to the study of religion, or "divinity". The study of the humanities was a key part of the secular curriculum in universities at the time. Today, the humanities are more frequently defined as any fields of study outside of natural sciences, social sciences, formal sciences (like mathematics), and applied sciences (or professional training). They use methods that are primarily critical, speculative, or interpretative and have a significant historical element—as distinguished from the mainly empirical approaches of science.

The humanities include the academic study of philosophy, religion, history (sometimes considered part of the social sciences instead), language arts (literature, writing, oratory, rhetoric, poetry, etc.), the performing arts (theater, music, dance, etc.), and the visual arts (painting, sculpture, photography, filmmaking, etc.).

Truth or verity is the property of being in accord with fact or reality. In everyday language, it is typically ascribed to things that aim to represent reality or otherwise correspond to it, such as beliefs, propositions, and declarative sentences.

True statements are usually held to be the opposite of false statements. The concept of truth is discussed and debated in various contexts, including philosophy, art, theology, law, and science. Most human activities depend upon the concept, where its nature as a concept is assumed rather than being a subject of discussion, including journalism and everyday life. Some philosophers view the concept of truth as basic, and unable to be explained in any terms that are more easily understood than the concept of truth itself. Most commonly, truth is viewed as the correspondence of language or thought to a mind-independent world. This is called the correspondence theory of truth.

Platonism is the philosophy of Plato and philosophical systems closely derived from it, though later and contemporary Platonists do not necessarily accept all of Plato's own doctrines. Platonism has had a profound effect on Western thought. At the most fundamental level, Platonism affirms the existence of abstract objects, which are asserted to exist in a third realm distinct from both the sensible external world and from the internal world of consciousness, and is the opposite of nominalism. This can apply to properties, types, propositions, meanings, numbers, sets, truth values, and so on (see abstract object theory). Philosophers who affirm the existence of abstract objects are sometimes called Platonists; those who deny their existence are sometimes called nominalists. The terms "Platonism" and "nominalism" also have established senses in the history of philosophy. They denote positions that have little to do with the modern notion of an abstract object.

In a narrower sense, the term might indicate the doctrine of Platonic realism, a form of mysticism. The central concept of Platonism, a distinction essential to the Theory of Forms, is the distinction between the reality which is perceptible but unintelligible, associated with the flux of Heraclitus and studied by the likes of physical science, and the reality which is imperceptible but intelligible, associated with the unchanging being of Parmenides and studied by the likes of mathematics. Geometry was the main motivation of Plato, and this also shows the influence of Pythagoras. The Forms are typically described in dialogues such as the Phaedo, Symposium and Republic as perfect archetypes of which objects in the everyday world are imperfect copies. Aristotle's Third Man Argument is its most famous criticism in antiquity.

Western esotericism, also known as the Western mystery tradition, is a wide range of loosely related ideas and movements that developed within Western society. These ideas and currents are united since they are largely distinct both from orthodox Abrahamic religion and Age of Enlightenment rationalism. It has influenced, or contributed to, various forms of Western philosophy, mysticism, religion, science, pseudoscience, art, literature, and music.

The idea of grouping a wide range of Western traditions and philosophies together under the term esotericism developed in 17th-century Europe. Various academics have debated numerous definitions of Western esotericism. One view adopts a definition from certain esotericist schools of thought themselves, treating "esotericism" as a perennial hidden inner tradition. A second perspective sees esotericism as a category of movements that embrace an "enchanted" worldview in the face of increasing disenchantment. A third views Western esotericism as encompassing all of Western culture's "rejected knowledge" that is accepted neither by the scientific establishment nor orthodox religious authorities.

Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides a description of the largest-scale structures and dynamics of the universe and allows study of fundamental questions about its origin, structure, evolution, and ultimate fate. Cosmology as a science originated with the Copernican principle, which implies that celestial bodies obey identical physical laws to those on Earth, and Newtonian mechanics, which first allowed those physical laws to be understood.

Physical cosmology, as it is now understood, began in 1915 with the development of Albert Einstein's general theory of relativity, followed by major observational discoveries in the 1920s: first, Edwin Hubble discovered that the universe contains a huge number of external galaxies beyond the Milky Way; then, work by Vesto Slipher and others showed that the universe is expanding. These advances made it possible to speculate about the origin of the universe, and allowed the establishment of the Big Bang theory, by Georges Lemaître, as the leading cosmological model. A few researchers still advocate a handful of alternative cosmologies; however, most cosmologists agree that the Big Bang theory best explains the observations.