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href="/browse/Science">Science</a> </span> <span class="breadcrumb-item "> Physics </span> </nav> <h1 class="font-serif mt-30 mb-20">Physics</h1> <div class="font-serif grid"> <div class="col-sm-70 col-sm-offset-15"> What’s the matter? Matter is the material substance that constitutes our whole observable universe, and it is the subject of study of physics. Physics, the basic physical science, studies objects ranging from the very small (using quantum mechanics) to the entire universe (using general relativity). It deals with the structure of matter and how the fundamental constituents of the universe interact.</div> </div> <div class="text-hr text-hr-right border-navy font-12 text-uppercase font-weight-bold mt-30 ls-lg">Browse Subcategories</div> <div class="slider js-slider position-relative d-inline-flex align-items-center mw-100 mt-20 category-snap-slider"> <div class="slider-container js-slider-container overflow-hidden d-flex font-14 overflow-hidden text-nowrap mx-5"> <a href="/browse/Matter-Energy" class="link-white mr-20 mr-sm-30">Matter & Energy</a> <a href="/browse/Physicists" class="link-white ">Physicists</a> </div> <button disabled class="prev-button js-prev-button position-absolute btn btn-circle shadow btn-blue " aria-label="Previous"> <span class="material-icons md-24" data-icon="keyboard_arrow_left"></span> </button> <button disabled class="next-button js-next-button position-absolute btn btn-circle shadow btn-blue " aria-label="Next"> <span class="material-icons md-24" data-icon="keyboard_arrow_right"></span> </button> </div> </div> </div> <div class="container"> <h2 class="label my-30">Physics Encyclopedia Articles</h2> <div class="grid top g-10 mb-40"> <div class="col-33 col-sm-20 col-md-16 col-lg-10"> <div class="border shadow p-10 text-center "> <a class="font-weight-bold font-14 " href="/browse/Physics/1">ABE-GRA</a> </div> </div> <div class="col-33 col-sm-20 col-md-16 col-lg-10"> <div class="border shadow p-10 text-center "> <a class="font-weight-bold font-14 " href="/browse/Physics/2">GRA-SEI</a> </div> </div> <div class="col-33 col-sm-20 col-md-16 col-lg-10"> <div class="border shadow p-10 text-center "> <a class="font-weight-bold font-14 " href="/browse/Physics/3">SEI-YEL</a> </div> </div> </div> <h2 class="label my-30 text-center">Featured Articles</h2> <div class="js-pinboard grid gy-20"> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/technology/mineral-processing" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/34/1534-004-5BBDA0CA/diagram-flotation-separation-cell.jpg?w=400&h=225&c=crop" alt="Schematic diagram of a flotation separation cell." class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/technology/mineral-processing" class="font-weight-bold font-16 lh-sm">mineral processing</a> <div class="font-serif mt-10 font-14"> Mineral processing, art of treating crude ores and mineral products in order to separate the valuable minerals from the waste rock, or gangue. It is the first process that most ores undergo after mining... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/relativity" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/80/222280-138-41E211F6/Your-Daily-Equation-01-E-mc2.jpg?w=400&h=225&c=crop" alt="Explaining E = mc2" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/relativity" class="font-weight-bold font-16 lh-sm">relativity</a> <div class="font-serif mt-10 font-14"> Relativity, wide-ranging physical theories formed by the German-born physicist Albert Einstein. With his theories of special relativity (1905) and general relativity (1915), Einstein overthrew many assumptions... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/mechanics-of-solids" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/01/2501-004-36E343DA/position-vector-velocity-v-material-point-element.jpg?w=400&h=225&c=crop" alt="Figure 1: The position vector x and the velocity vector v of a material point, the body force fdV acting on an element dV of volume, and the surface force TdS acting on an element dS of surface in a Cartesian coordinate system 1, 2, 3 (see text)." class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/mechanics-of-solids" class="font-weight-bold font-16 lh-sm">mechanics of solids</a> <div class="font-serif mt-10 font-14"> Mechanics of solids, science concerned with the stressing, deformation, and failure of solid materials and structures. What, then, is a solid? Any material, fluid or solid, can support normal forces. These... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/ultrasonics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/98/185498-138-E45D47C3/sound-bubbles-sonoluminescence.jpg?w=400&h=225&c=crop" alt="Understand the concept of sonoluminescence which is a phenomenon of turning sound into light" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/ultrasonics" class="font-weight-bold font-16 lh-sm">ultrasonics</a> <div class="font-serif mt-10 font-14"> Ultrasonics, vibrations of frequencies greater than the upper limit of the audible range for humans—that is, greater than about 20 kilohertz. The term sonic is applied to ultrasound waves of very high... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/light" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/30/27030-050-EA86AA82/spectrum-wavelengths-longest-lines-diagram-elements-Fraunhofer.jpg?w=400&h=225&c=crop" alt="visible spectrum of light" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/light" class="font-weight-bold font-16 lh-sm">light</a> <div class="font-serif mt-10 font-14"> Light, electromagnetic radiation that can be detected by the human eye. Electromagnetic radiation occurs over an extremely wide range of wavelengths, from gamma rays with wavelengths less than about 1... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/sound-reception" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/43/54943-050-CC13D6E8/mechanisms-insects-mosquito-ear-organ-Magicicada-septendecim.jpg?w=400&h=225&c=crop" alt="auditory mechanisms in insects" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/sound-reception" class="font-weight-bold font-16 lh-sm">sound reception</a> <div class="font-serif mt-10 font-14"> Sound reception, response of an organism’s aural mechanism, the ear, to a specific form of energy change, or sound waves. Sound waves can be transmitted through gases, liquids, or solids, but the hearing... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/principles-of-physical-science" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/93/3493-004-B74CF884/Data-table-experiment-Galileo-tangent-curve.jpg?w=400&h=225&c=crop" alt="Galileo experiment" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/principles-of-physical-science" class="font-weight-bold font-16 lh-sm">principles of physical science</a> <div class="font-serif mt-10 font-14"> Principles of physical science, the procedures and concepts employed by those who study the inorganic world. Physical science, like all the natural sciences, is concerned with describing and relating to... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/fluid-mechanics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/08/2508-004-2696813B/representations-manometer-barometer-Torricellian.jpg?w=400&h=225&c=crop" alt="differential manometer, Torricellian barometer, and siphon" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/fluid-mechanics" class="font-weight-bold font-16 lh-sm">fluid mechanics</a> <div class="font-serif mt-10 font-14"> Fluid mechanics, science concerned with the response of fluids to forces exerted upon them. It is a branch of classical physics with applications of great importance in hydraulic and aeronautical engineering,... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/gravity-physics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/50/21250-004-7E580D28/lens-Hubble-Space-Telescope-field-picture-copies.jpg?w=400&h=225&c=crop" alt="gravitational lens" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/gravity-physics" class="font-weight-bold font-16 lh-sm">gravity</a> <div class="font-serif mt-10 font-14"> Gravity, in mechanics, the universal force of attraction acting between all bodies of matter. It is by far the weakest known force in nature and thus plays no role in determining the internal properties... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/technology/mirror-optics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/80/164580-050-D0D0223D/mirror-Arnolfini-Portrait-van-Eyck.jpg?w=400&h=225&c=crop" alt="Gothic mirror, detail from The Marriage of Giovanni Arnolfini and Giovanna Cenami by Jan van Eyck, 1434; in the National Gallery, London." class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/technology/mirror-optics" class="font-weight-bold font-16 lh-sm">mirror</a> <div class="font-serif mt-10 font-14"> Mirror, any polished surface that diverts a ray of light according to the law of reflection. The typical mirror is a sheet of glass that is coated on its back with aluminum or silver that produces images... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/cosmology-astronomy" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/00/185400-138-6E452A70/universe.jpg?w=400&h=225&c=crop" alt="Examine the observable universe's place within the whole universe" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/cosmology-astronomy" class="font-weight-bold font-16 lh-sm">cosmology</a> <div class="font-serif mt-10 font-14"> Cosmology, field of study that brings together the natural sciences, particularly astronomy and physics, in a joint effort to understand the physical universe as a unified whole. The “observable universe”... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/liquid-state-of-matter" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/95/2395-004-4F69A001/Phase-diagram-argon.jpg?w=400&h=225&c=crop" alt="Figure 1: Phase diagram of argon." class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/liquid-state-of-matter" class="font-weight-bold font-16 lh-sm">liquid</a> <div class="font-serif mt-10 font-14"> Liquid, in physics, one of the three principal states of matter, intermediate between gas and crystalline solid. The most obvious physical properties of a liquid are its retention of volume and its conformation... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/heat" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/73/151073-138-DA1730BF/Explanation-heat-transfer.jpg?w=400&h=225&c=crop" alt="How heat transfers from one object to another" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/heat" class="font-weight-bold font-16 lh-sm">heat</a> <div class="font-serif mt-10 font-14"> Heat, energy that is transferred from one body to another as the result of a difference in temperature. If two bodies at different temperatures are brought together, energy is transferred—i.e., heat flows—from... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/physics-science" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/49/54449-050-9200B218/Daniel-Bernoulli-particles-gas-pressure-model-motion.jpg?w=400&h=225&c=crop" alt="Bernoulli model of gas pressure" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/physics-science" class="font-weight-bold font-16 lh-sm">physics</a> <div class="font-serif mt-10 font-14"> Physics, science that deals with the structure of matter and the interactions between the fundamental constituents of the observable universe. In the broadest sense, physics (from the Greek physikos) is... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/seismograph" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/12/66812-004-13F2C800/Charles-F-Richter-torsion-pendulum-seismograph-diagram-1924.jpg?w=400&h=225&c=crop" alt="Anderson-Wood torsion pendulum seismograph" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/seismograph" class="font-weight-bold font-16 lh-sm">seismograph</a> <div class="font-serif mt-10 font-14"> Seismograph, instrument that makes a record of seismic waves caused by an earthquake, explosion, or other Earth-shaking phenomenon. Seismographs are equipped with electromagnetic sensors that translate... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/geomagnetic-field" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/73/473-004-A997D846/magnetic-field-bar-magnet-dipole-configuration-approximation.jpg?w=400&h=225&c=crop" alt="magnetic field of a bar magnet" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/geomagnetic-field" class="font-weight-bold font-16 lh-sm">geomagnetic field</a> <div class="font-serif mt-10 font-14"> Geomagnetic field, magnetic field associated with Earth. It is primarily dipolar (i.e., it has two poles, the geomagnetic North and South poles) on Earth’s surface. Away from the surface the dipole becomes... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/mechanics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/65/2465-050-F05D1DFE/vector-difference-sum-C-B-A-component.jpg?w=400&h=225&c=crop" alt="vector mathematics" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/mechanics" class="font-weight-bold font-16 lh-sm">mechanics</a> <div class="font-serif mt-10 font-14"> Mechanics, science concerned with the motion of bodies under the action of forces, including the special case in which a body remains at rest. Of first concern in the problem of motion are the forces that... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/acoustics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/92/147292-050-33BD89A2/sound-source-chamber.jpg?w=400&h=225&c=crop" alt="Acoustics" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/acoustics" class="font-weight-bold font-16 lh-sm">acoustics</a> <div class="font-serif mt-10 font-14"> Acoustics, the science concerned with the production, control, transmission, reception, and effects of sound. The term is derived from the Greek akoustos, meaning “heard.” Beginning with its origins in... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/relativistic-mechanics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/96/2496-004-0B81948F/speed-world-line-particle-light.jpg?w=400&h=225&c=crop" alt="Figure 1: The world line of a particle traveling with speed less than that of light." class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/relativistic-mechanics" class="font-weight-bold font-16 lh-sm">relativistic mechanics</a> <div class="font-serif mt-10 font-14"> Relativistic mechanics, science concerned with the motion of bodies whose relative velocities approach the speed of light c, or whose kinetic energies are comparable with the product of their masses m... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/technology/holography" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/48/3248-004-BAEE18D6/Gabor-method-holograms.jpg?w=400&h=225&c=crop" alt="hologram graphic" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/technology/holography" class="font-weight-bold font-16 lh-sm">holography</a> <div class="font-serif mt-10 font-14"> Holography, means of creating a unique photographic image without the use of a lens. The photographic recording of the image is called a hologram, which appears to be an unrecognizable pattern of stripes... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/metallurgy" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/39/1539-004-7C917766/hearth-Catalan-smelting-iron-ore-times-fuel.jpg?w=400&h=225&c=crop" alt="Catalan hearth or forge used for smelting iron ore until relatively recent times. 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It also concerns the chemical,... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/technology/lubrication" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/63/126263-050-9EB6D2AC/Motor-oil-lubricant-automobile-engines.jpg?w=400&h=225&c=crop" alt="motor oil" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/technology/lubrication" class="font-weight-bold font-16 lh-sm">lubrication</a> <div class="font-serif mt-10 font-14"> Lubrication, introduction of any of various substances between sliding surfaces to reduce wear and friction. Nature has been applying lubrication since the evolution of synovial fluid, which lubricates... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/quantum-mechanics-physics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/87/222287-138-E460E7C6/Your-Daily-Equation-08-Photoelectric-Effect.jpg?w=400&h=225&c=crop" alt="photoelectric effect: Einstein's Nobel Prize-winning discovery" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/quantum-mechanics-physics" class="font-weight-bold font-16 lh-sm">quantum mechanics</a> <div class="font-serif mt-10 font-14"> Quantum mechanics, science dealing with the behaviour of matter and light on the atomic and subatomic scale. It attempts to describe and account for the properties of molecules and atoms and their constituents—electrons,... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/technology/scanning-tunneling-microscope" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/mendel-resources/3-133/images/shared/default3.png?v=3.133.36" class="default col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/technology/scanning-tunneling-microscope" class="font-weight-bold font-16 lh-sm">scanning tunneling microscope</a> <div class="font-serif mt-10 font-14"> Scanning tunneling microscope (STM), type of microscope whose principle of operation is based on the quantum mechanical phenomenon known as tunneling, in which the wavelike properties of electrons permit... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/biophysics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/mendel-resources/3-133/images/shared/default3.png?v=3.133.36" class="default col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/biophysics" class="font-weight-bold font-16 lh-sm">biophysics</a> <div class="font-serif mt-10 font-14"> Biophysics, discipline concerned with the application of the principles and methods of physics and the other physical sciences to the solution of biological problems. The relatively recent emergence of... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/physical-science" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/76/100076-050-696FA9C8/magnet-Compact-Muon-Solenoid-Large-Hadron-Collider-2007.jpg?w=400&h=225&c=crop" alt="Large Hadron Collider" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/physical-science" class="font-weight-bold font-16 lh-sm">physical science</a> <div class="font-serif mt-10 font-14"> Physical science, the systematic study of the inorganic world, as distinct from the study of the organic world, which is the province of biological science. Physical science is ordinarily thought of as... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/multiverse" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/59/185559-138-BA08F650/lesson-universe-distinction.jpg?w=400&h=225&c=crop" alt="Discover the difference between the observable universe and the whole universe" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/multiverse" class="font-weight-bold font-16 lh-sm">multiverse</a> <div class="font-serif mt-10 font-14"> Multiverse, a hypothetical collection of potentially diverse observable universes, each of which would comprise everything that is experimentally accessible by a connected community of observers. The observable... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/technology/microscope" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/50/114750-050-06EEB5F0/compound-microscope.jpg?w=400&h=225&c=crop" alt="compound microscope" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/technology/microscope" class="font-weight-bold font-16 lh-sm">microscope</a> <div class="font-serif mt-10 font-14"> Microscope, instrument that produces enlarged images of small objects, allowing the observer an exceedingly close view of minute structures at a scale convenient for examination and analysis. Although... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/technology/electronics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/54/216554-138-870AA8A9/Screen-printable-electronic-ink-for-flexible-electronics.jpg?w=400&h=225&c=crop" alt="Conductors and insulators in flexible electronics" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/technology/electronics" class="font-weight-bold font-16 lh-sm">electronics</a> <div class="font-serif mt-10 font-14"> Electronics, branch of physics and electrical engineering that deals with the emission, behaviour, and effects of electrons and with electronic devices. Electronics encompasses an exceptionally broad range... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/anthropic-principle" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/37/111337-050-538D9761/Hubble-Deep-Field-galaxies-image-observation-result.jpg?w=400&h=225&c=crop" alt="Hubble Deep Field" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/anthropic-principle" class="font-weight-bold font-16 lh-sm">anthropic principle</a> <div class="font-serif mt-10 font-14"> Anthropic principle, in cosmology, any consideration of the structure of the universe, the values of the constants of nature, or the laws of nature that has a bearing upon the existence of life. Clearly,... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/atomic-physics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/mendel-resources/3-133/images/shared/default3.png?v=3.133.36" class="default col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/atomic-physics" class="font-weight-bold font-16 lh-sm">atomic physics</a> <div class="font-serif mt-10 font-14"> Atomic physics, the scientific study of the structure of the atom, its energy states, and its interactions with other particles and with electric and magnetic fields. Atomic physics has proved to be a... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/radioactivity" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/52/6052-004-FA9B043E/decay-electron-capture.jpg?w=400&h=225&c=crop" alt="decay of beryllium-7" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/radioactivity" class="font-weight-bold font-16 lh-sm">radioactivity</a> <div class="font-serif mt-10 font-14"> Radioactivity, property exhibited by certain types of matter of emitting energy and subatomic particles spontaneously. It is, in essence, an attribute of individual atomic nuclei. An unstable nucleus will... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/thermodynamics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/14/227614-050-1AC65CC4/German-physicist-mathematician-Rudolf-Julius-Emanuel-Clausius.jpg?w=400&h=225&c=crop" alt="Rudolf Clausius" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/thermodynamics" class="font-weight-bold font-16 lh-sm">thermodynamics</a> <div class="font-serif mt-10 font-14"> Thermodynamics, science of the relationship between heat, work, temperature, and energy. In broad terms, thermodynamics deals with the transfer of energy from one place to another and from one form to... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/optics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/35/187035-138-7FE57388/researchers-attempts-invisibility.jpg?w=400&h=225&c=crop" alt="Are invisibility cloaks possible in reality?" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/optics" class="font-weight-bold font-16 lh-sm">optics</a> <div class="font-serif mt-10 font-14"> Optics, science concerned with the genesis and propagation of light, the changes that it undergoes and produces, and other phenomena closely associated with it. There are two major branches of optics,... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/gas-state-of-matter" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/16/103416-050-01DAF575/Heat-air-bottle-space-balloon.jpg?w=400&h=225&c=crop" alt="heated air expands" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/gas-state-of-matter" class="font-weight-bold font-16 lh-sm">gas</a> <div class="font-serif mt-10 font-14"> Gas, one of the three fundamental states of matter, with distinctly different properties from the liquid and solid states. The remarkable feature of gases is that they appear to have no structure at all.... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/plasma-state-of-matter" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/86/179686-138-C038EAA6/PHELIX-laser-GSI-Helmholtz-Centre-for-Heavy.jpg?w=400&h=225&c=crop" alt="How scientists use lasers to learn about the universe" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/plasma-state-of-matter" class="font-weight-bold font-16 lh-sm">plasma</a> <div class="font-serif mt-10 font-14"> Plasma, in physics, an electrically conducting medium in which there are roughly equal numbers of positively and negatively charged particles, produced when the atoms in a gas become ionized. It is sometimes... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/celestial-mechanics-physics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/36/137736-050-C05FC854/diagram-Ptolemaic-Harmonia-Macrocosmica-Andreas-Cellarius-system-1660.jpg?w=400&h=225&c=crop" alt="geocentric system" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/celestial-mechanics-physics" class="font-weight-bold font-16 lh-sm">celestial mechanics</a> <div class="font-serif mt-10 font-14"> Celestial mechanics, in the broadest sense, the application of classical mechanics to the motion of celestial bodies acted on by any of several types of forces. By far the most important force experienced... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/science/solid-state-of-matter" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/65/63065-050-26594B0B/States-matter.jpg?w=400&h=225&c=crop" alt="states of matter" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/science/solid-state-of-matter" class="font-weight-bold font-16 lh-sm">solid</a> <div class="font-serif mt-10 font-14"> Solid, one of the three basic states of matter, the others being liquid and gas. (Sometimes plasmas, or ionized gases, are considered a fourth state of matter.) A solid forms from liquid or gas because... </div> </div> </div> </div> </div> <div class="p-10 d-inline-flex js-pin col-100 col-sm-33 col-md-25 "> <div class="card text-normal col-100 "> <div class="card-media position-relative"> <a href="https://www.britannica.com/technology/lens-optics" style="--aspect-ratio: 16/9"> <img loading="lazy" src="https://cdn.britannica.com/01/189401-138-9C338E27/video-lenses-images-light.jpg?w=400&h=225&c=crop" alt="How lenses and mirrors affect light and vision" class="col-100" /> </a> </div> <div class="col"> <div class="card-body text-hyphenate"> <a href="https://www.britannica.com/technology/lens-optics" class="font-weight-bold font-16 lh-sm">lens</a> <div class="font-serif mt-10 font-14"> Lens, in optics, piece of glass or other transparent substance that is used to form an image of an object by focusing rays of light from the object. 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