गुरुत्वाकर्षणRelated word or term.gravityRelated word or term.
General relativityTheory of gravitation as curved spacetime Slow motion computer simulation of the black hole binary system GW150914, during 0.33 s of its final inspiral, merge, and ringdown. The star field behind the black holes is being heavily distorted and appears to rotate and move, due to extreme gravitational lensing, as spacetime itself is distorted and dragged around by the rotating black holes. General relativity G μ ν + Λ g μ ν = κ T μ ν {\displaystyle G_{\mu u }+\Lambda g_{\mu u }={\kappa }T_{\mu u }} Introduc...
SpacetimeIn physics, spacetime, or the space-time continuum, is a mathematical model that fuses the three dimensions of space and the one dimension of time into a single four-dimensional continuum. Spacetime diagrams are useful in visualizing and understanding relativistic effects, such as how different observers perceive where and when events occur. Until the turn of the 20th century, the assumption had been that the three-dimensional geometry of the universe (its description in terms of locations, shapes, distances, an...
Fundamental interactionIn physics, the fundamental interactions or fundamental forces are interactions in nature that appear not to be reducible to more basic interactions. There are four fundamental interactions known to exist: gravity, electromagnetism, weak interaction, and strong interaction. The gravitational and electromagnetic interactions produce long-range forces whose effects can be seen directly in everyday life. The strong and weak interactions produce forces at subatomic scales and govern nuclear interactions inside atoms...
ForceIn physics, a force is an action that can cause an object to change its velocity or its shape, or to resist other forces, or to cause changes of pressure in a fluid. In mechanics, force makes ideas like pushing or pulling mathematically precise. Because the magnitude and direction of a force are both important, force is a vector quantity (force vector). The SI unit of force is the newton (N), and force is often represented by the symbol F. Force plays an important role in classical mechanics. The concept of forc...
Black holeA black hole is an astronomical body so compact that its gravity prevents anything, including light, from escaping. Albert Einstein's theory of general relativity, which describes gravitation as the curvature of spacetime, predicts that any sufficiently compact mass will form a black hole. The boundary of no escape is called the event horizon. In general relativity, crossing a black hole's event horizon traps an object inside but produces no locally detectable change. General relativity also predicts that every ...
CurvatureMathematical measure of how much a curve or surface deviates from flatnessA migrating wild-type Dictyostelium discoideum cell whose boundary is colored by curvature. Scale bar: 5 μm.In mathematics, curvature is any of several strongly related concepts in geometry that intuitively measure the amount by which a curve deviates from being a straight line or by which a surface deviates from being a plane. If a curve or surface is contained in a larger space, curvature can be defined extrinsically relative to the amb...
UniverseEverything in space and time UniverseThe Hubble Ultra-Deep Field image shows some of the most remote galaxies visible to present technology (diagonal is ~1/10 apparent Moon diameter)Age13.787 ± 0.020 billion yearsObservable diameter8.8×1026 m (28.5 Gpc or 93 Gly)Average density (with energy)9.9×10−27 kg/m3Average temperature2.72548 K(−270.4 °C, −454.8 °F)Main contentsOrdinary (baryonic) matter (4.9%)Dark matter (26.8%)Dark energy (68.3%)ShapeFlat with 0.4% error margin Part of a series onPhysical cosm...
Star formationStar formation is the process by which dense regions within molecular clouds in interstellar space—sometimes referred to as "stellar nurseries" or "star-forming regions"—collapse and form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astro...
Physical objectIn natural language and physical science, a physical object or material object (or simply an object or body) is a collection of matter, usually contiguous, with a defined boundary, that exists in space and time. It is usually contrasted with abstract objects and mental objects. Also in common usage, an object is not constrained to consist of the same collection of matter. Atoms or parts of an object may change over time. An object is usually meant to be defined by the simplest representation of the boundary cons...
Albert EinsteinPersonalHousePolitical viewsReligious viewsFamilyBrainBlackboardRefrigeratorOppenheimer relationshipPhysicsGeneral relativityMass–energy equivalenceBrownian motionPhotoelectric effectWorksArchivesScientific publicationsAnnus Mirabilis papers (1905)"Investigations on the Theory ofBrownian Movement" (1905)Relativity: The Special andthe General Theory (1916)The World as I See It (1934)"Why Socialism?" (1949)Russell–Einstein Manifesto (1955)LegacyIn popular cultureEinsteiniumAwards and honorsEponymous thingsPape...
Dark matterUnsolved problem in physicsWhat is dark matter? How was it generated?More unsolved problems in physics
HydrogenHydrogen is a chemical element; it has the symbol H and atomic number 1. It is the lightest and most abundant chemical element in the universe, constituting about 75% of all normal matter. Under standard conditions, hydrogen is a gas of diatomic molecules with the formula H2, called dihydrogen, or sometimes hydrogen gas, molecular hydrogen, or simply hydrogen. Dihydrogen is colorless, odorless, non-toxic, and highly combustible. Stars, including the Sun, mainly consist of hydrogen in a plasma state, while on Ear...
Coalescence (physics)Coalescence is the process by which two or more droplets, bubbles, or particles merge during contact to form a single daughter droplet, bubble, or particle. Coalescence manifests itself from a microscopic scale in meteorology to a macroscopic scale in astrophysics. For example, it is seen in the formation of raindrops as well as planetary and star formation. In meteorology, its role is crucial in the formation of rain. As droplets are carried by the updrafts and downdrafts in a cloud, they collide and coalesce t...*As an Amazon Associate I earn from qualifying purchases.