Vijay Shankar Sharma
Textbook physics terms. Not a BFUT reinterpretation. 371 terms. Textbook meanings only.
20 terms. Page 1 of 1.
quantum · intermediate
The range of energy levels in a solid material where no electron states can exist, lying between the valence band, which is normally filled with electrons, and the conduction band, where electrons can move freely and conduct electricity. The size of the band gap determines whether a material behaves as an insulator, semiconductor, or conductor. Semiconductors like silicon have a moderate band gap, exploited in transistors and solar cells.
waves · intermediate
The range of frequencies contained within a signal or that a system can transmit or process effectively, usually expressed in hertz. A wider bandwidth allows more information to be carried per unit time, which is why higher-bandwidth channels support faster data transmission. The concept applies broadly, from radio communication to the frequency range a wave packet spans in quantum mechanics.
particle · intermediate
A category of subatomic particle made of three quarks bound together by the strong force. Protons and neutrons, the particles that make up atomic nuclei, are the most familiar baryons. Baryons belong to a broader family called hadrons, and every baryon has a corresponding antibaryon made of three antiquarks. The total number of baryons minus antibaryons, called baryon number, is conserved in essentially all known particle interactions.
cosmology · intermediate
Also called: BAO
A subtle, regular pattern in the large-scale distribution of galaxies throughout the universe, left behind as a fossil imprint of the same sound waves that produced the acoustic peaks seen in the cosmic microwave background. This pattern provides a standard ruler, a distance scale of known physical size, that astronomers use to measure cosmic distances and track the universe's expansion history across billions of years.
waves · intro
The periodic variation in amplitude heard when two sound waves of slightly different frequencies overlap, produced by their alternating constructive and destructive interference. The beat frequency equals the difference between the two original frequencies. Musicians use beats to tune instruments, listening for the beating to slow and disappear as two notes are brought into exact agreement.
nuclear · intro
A type of radioactive decay in which a neutron in an atomic nucleus converts into a proton, or a proton converts into a neutron, emitting an electron or positron along with a neutrino or antineutrino. This process changes the atomic number of the nucleus by one while leaving the mass number unchanged, effectively transforming the atom into a different element. Beta decay is driven by the weak nuclear force.
cosmology · intro
The standard cosmological model describing the early universe as an extremely hot, dense state that has been expanding and cooling ever since. It is supported by several independent lines of evidence, including the cosmic microwave background radiation, the observed abundances of light elements, and the recession of distant galaxies. The Big Bang describes the expansion history of the observable universe rather than an explosion into pre-existing space.
astro · intro
A system of two stars gravitationally bound together, orbiting a common center of mass. Binary stars are common in the galaxy, and studying their orbits allows astronomers to measure stellar masses directly, since the orbital period and separation depend on the combined mass of the pair through Kepler's laws. Some binaries eventually interact through mass transfer, sometimes ending in dramatic events like a nova or supernova.
nuclear · intermediate
The energy required to completely separate the components of a bound system, such as the protons and neutrons in an atomic nucleus, or an electron orbiting an atom. A higher binding energy means the system is more stable, since more energy would need to be supplied to break it apart. Nuclear binding energy is the source of the enormous energy released in nuclear fission and fusion reactions.
relativity · intro
A region of spacetime where gravity is so strong that nothing, not even light, can escape once it crosses the boundary known as the event horizon. Black holes form when massive stars collapse at the end of their lives, or through the merger of smaller black holes and neutron stars. Their existence is confirmed through observations of orbiting stars, gravitational waves, and direct imaging of the shadow they cast.
thermo · intermediate
The electromagnetic radiation emitted by an idealized object, called a blackbody, that absorbs all radiation falling on it and re-emits energy based purely on its temperature. The spectrum of this radiation follows a characteristic curve described by Planck's law, with hotter objects emitting more strongly at shorter wavelengths. Blackbody radiation explains why heated metal glows red, then orange, then white as its temperature rises.
astro · intro
A shift of light or other electromagnetic radiation toward shorter, bluer wavelengths, caused by relative motion of the source toward the observer, or by a gravitational field decreasing along the light's path. It is the counterpart to redshift and follows the same Doppler and gravitational principles. Blueshift is observed, for example, in the light from stars orbiting close to the center of the galaxy.
quantum · intro
An early model of the atom, proposed by Niels Bohr in 1913, in which electrons orbit the nucleus only in specific allowed circular paths with fixed energy levels, rather than at arbitrary distances. Electrons emit or absorb light of specific wavelengths when jumping between these levels. Although superseded by the more complete quantum mechanical model of the atom, the Bohr model successfully predicted the spectral lines of hydrogen.
thermo · intermediate
A fundamental physical constant that relates the average kinetic energy of particles in a gas to its temperature, with a value of about 1.38 times ten to the minus twenty-three joules per kelvin. It bridges the microscopic world of individual particle motion and the macroscopic quantity we measure as temperature. The constant is named after Austrian physicist Ludwig Boltzmann, a founder of statistical mechanics.
quantum · intermediate
A foundational rule of quantum mechanics, proposed by physicist Max Born in 1926, stating that the probability of finding a quantum system in a particular state upon measurement is given by the square of the magnitude of the system's wavefunction at that state. The Born rule provides the crucial link between the abstract mathematical wavefunction, which itself has no direct physical interpretation, and the concrete, measurable probabilities of experimental outcomes.
particle · intermediate
A category of particle that follows Bose-Einstein statistics and can occupy the same quantum state as other identical bosons in unlimited numbers. Force-carrying particles such as photons, gluons, and the Higgs boson fall into this category, distinguishing them from matter particles called fermions, which cannot share a quantum state. Bosons generally have integer values of a quantum property called spin.
thermo · intro
A gas law stating that, at constant temperature, the pressure of a fixed amount of gas is inversely proportional to its volume: as volume decreases, pressure increases proportionally, and vice versa. Formulated by Robert Boyle in the seventeenth century, it is one of the earliest quantitative gas laws and forms part of the broader ideal gas law used throughout thermodynamics.
thermo · intro
The random, jittery movement of small particles suspended in a fluid, caused by countless collisions with the fluid's molecules. First observed in pollen grains by botanist Robert Brown, it was later explained theoretically by Albert Einstein as direct evidence for the existence of atoms and molecules. Brownian motion is a foundational example of a random walk process, used across physics, finance, and biology.
mechanics · intermediate
A measure of a material's resistance to uniform compression, defined as the ratio of an applied pressure change to the resulting fractional change in volume. Materials with a high bulk modulus, like steel, are difficult to compress, while gases have a much lower bulk modulus and compress easily. It is one of several elastic moduli used to describe how materials respond to stress.
mechanics · intro
The upward force exerted by a fluid on an object partly or fully submerged in it, arising because fluid pressure increases with depth. This force allows objects less dense than the surrounding fluid to float, and is quantified by Archimedes' principle. Buoyancy explains why a steel ship can float while a solid steel block sinks, since the ship's shape displaces a much larger volume of water.