2025年1月14日 · This article traces the development over time of humanity’s perception of the universe, from prehistoric observations of the night sky to modern calculations on the recessional velocity of galaxies. For articles on component parts of the universe, see solar system, star, galaxy, and nebula.

universe, Whole cosmic system of matter and energy of which Earth is a part. Its main constituents are the galaxies , within which are star s and stellar groupings and nebulae ( see nebula ). Earth’s Sun is one star among the billions of stars in the Milky Way Galaxy .

Astronomy - Cosmology, Universe, Stars: Cosmology is the scientific study of the universe as a unified whole, from its earliest moments through its evolution to its ultimate fate. The currently accepted cosmological model is the big bang.

2025年1月31日 · Science, any system of knowledge that is concerned with the physical world and its phenomena and that entails unbiased observations and systematic experimentation. In general, a science involves a pursuit of knowledge covering general truths or the operations of fundamental laws.

2025年1月31日 · Space exploration - Astronomy, Technology, Discovery: In the decades following the first Sputnik and Explorer satellites, the ability to put their instruments into outer space gave scientists the opportunity to acquire new information about the natural universe, information that in many cases would have been unobtainable any other way.

The universe is also called the cosmos. Cosmology is the branch of science that studies the universe as a whole. It brings together the natural sciences, particularly astronomy and physics, in a joint effort to understand such aspects as the universe’s origin, …

2025年1月10日 · Expanding universe, dynamic state of the extragalactic realm, the discovery of which transformed 20th-century cosmology. The development of general relativity and its application to cosmology, along with the detection of extragalactic redshift, led to the realization in the 1920s that all galaxies are receding.

The universe is everything that exists, including objects and energy, throughout time and space. Earth, the Sun, and the rest of the solar system are only a very small part of the universe. The size of the universe is difficult to imagine.

4 天之前 · Observable universe, the region of space that humans can actually or theoretically observe with the aid of technology. The observable universe, which can be thought of as a bubble with Earth at its centre, is differentiated from the entirety of the universe, which is the whole cosmic system of

2024年11月17日 · Astronomy, science that encompasses the study of all extraterrestrial objects and phenomena. Since the late 19th century, astronomy has expanded to include astrophysics, the application of physical and chemical knowledge to an …