Main article: Chemistry (word)The word chemistry comes from the word alchemy, an earlier set of practices that encompassed elements of chemistry, metallurgy, philosophy, astrology, astronomy, mysticis ...
Chemistry, a branch of physical science, is the study of the composition, structure, properties and change of matter. Chemistry is chiefly concerned with atoms and their interactions with other atoms ...
Although the scientific discipline of astronomy has made tremendous strides in understanding the nature of the universe and its contents, there remain some important unanswered questions. Answers to t ...
Astronomy is one of the sciences to which amateurs can contribute the most.Collectively, amateur astronomers observe a variety of celestial objects and phenomena sometimes with equipment that they bui ...
Astronomy and astrophysics have developed significant interdisciplinary links with other major scientific fields. Archaeoastronomy is the study of ancient or traditional astronomies in their cultural ...
Cosmology (from the Greek κ?σμο? (kosmos) "world, universe" and λ?γο? (logos) "word, study" or literally "logic") could be considered the study of the universe as a whole.Observations of th ...
The study of objects outside our galaxy is a branch of astronomy concerned with the formation and evolution of Galaxies; their morphology (description) and classification; and the observation of activ ...
Our solar system orbits within the Milky Way, a barred spiral galaxy that is a prominent member of the Local Group of galaxies. It is a rotating mass of gas, dust, stars and other objects, held togeth ...
The study of stars and stellar evolution is fundamental to our understanding of the universe. The astrophysics of stars has been determined through observation and theoretical understanding; and from ...
Planetary science is the study of the assemblage of planets, moons, dwarf planets, comets, asteroids, and other bodies orbiting the Sun, as well as extrasolar planets. The Solar System has been relati ...
At a distance of about eight light-minutes, the most frequently studied star is the Sun, a typical main-sequence dwarf star of stellar class G2 V, and about 4.6 billion years (Gyr) old. The Sun is not ...
Theoretical astronomers use several tools including analytical models (for example, polytropes to approximate the behaviors of a star) and computational numerical simulations. Each has some advantages ...
One of the oldest fields in astronomy, and in all of science, is the measurement of the positions of celestial objects. Historically, accurate knowledge of the positions of the Sun, Moon, planets and ...
In addition to electromagnetic radiation, a few other events originating from great distances may be observed from the Earth.In neutrino astronomy, astronomers use heavily shielded underground facilit ...
Gamma ray astronomy is the study of astronomical objects at the shortest wavelengths of the electromagnetic spectrum. Gamma rays may be observed directly by satellites such as the Compton Gamma Ray Ob ...
