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Ferdinand Kurlbaum
Ferdinand Kurlbaum (1857–1927) was a German experimental physicist at the Physikalisch-Technische Reichsanstalt whose blackbody radiation measurements, including work with Heinrich Rubens, gave Planck the experimental foundation for quantum theory in 1900.
Ferdinand Schmidt-Kaler
Ferdinand Schmidt-Kaler, born 1962 in Bonn, is a German experimental physicist working on trapped-ion quantum computing who led the 2003 realization of the Cirac–Zoller controlled-NOT gate and heads the QUANTUM section at Mainz.
Ferdinand Vandeveer Hayden
Ferdinand Vandeveer Hayden (1829–1887) was an American geologist who led the surveys of the western territories from 1867 to 1879 and helped persuade Congress to create Yellowstone National Park.
Ferdinand von Lindemann
Ferdinand von Lindemann, born 1852 in Hannover, was a German mathematician whose 1882 proof that π is transcendental settled squaring the circle; he also supervised David Hilbert.
Ferdinand von Richthofen
Ferdinand von Richthofen (1833–1905) was a German geologist and geographer who made seven survey expeditions to China from 1868 to 1872 and introduced the term Silk Road into scholarly use.
Ferdinand Zirkel
Ferdinand Zirkel (1838–1912) was a German mineralogist and petrographer who established thin-section microscopy as petrography's principal method, and professor of mineralogy at Leipzig from 1870 to 1909.
Ferenc Krausz
Ferenc Krausz, born 1962 in Mór, Hungary, is a Hungarian-Austrian physicist who pioneered attosecond physics, measuring light pulses short enough to watch electrons move, and shared the 2023 Nobel Prize in Physics.
Feringa's light-driven molecular motor
Feringa's light-driven molecular motor is a synthetic molecule, first reported by Ben Feringa in 1999, that rotates unidirectionally under light and earned part of the 2016 Nobel Prize in Chemistry.
Fermat number
A Fermat number is an integer of the form 2^(2^n) + 1, named after Pierre de Fermat. Only the first five, 3 through 65537, are known to be prime.
Fermat pseudoprime
A Fermat pseudoprime to a base is a composite number that satisfies Fermat's little theorem, so it passes the Fermat primality test; the smallest base-2 example is 341.
Fermat's Last Theorem
Fermat's Last Theorem, also called Wiles' theorem, states that xⁿ + yⁿ = zⁿ has no positive integer solutions for n > 2, proved by Andrew Wiles in 1995.
Fermat's little theorem
Fermat's little theorem is a number theory result stating that a^(p-1) ≡ 1 mod p for any prime p not dividing a. Fermat stated it in 1640.
Fermat's principle
Fermat's principle, also called the principle of least time, is the statement of geometrical optics that light takes the path whose travel time is stationary, from which reflection and Snell's law follow.
Fermat's theorem on sums of two squares
Fermat's theorem on sums of two squares, also called Fermat's Christmas Theorem, states that an odd prime is a sum of two squares exactly when it is 1 modulo 4.
Fermi acceleration
Fermi acceleration is the process by which charged particles gain energy through repeated reflections from moving magnetic structures, proposed by Enrico Fermi in 1949 to explain cosmic rays.
Fermi arc
A Fermi arc is an open, arc-shaped segment of the Fermi surface on a Weyl semimetal, connecting surface projections of two Weyl nodes of opposite chirality, first observed in TaAs in 2015.
Fermi arcs
Fermi arcs are open, arc-shaped segments of a material's Fermi surface, seen most prominently on Weyl semimetals, where each arc topologically connects two Weyl nodes of opposite chirality.
Fermi Bubbles
The Fermi Bubbles are two giant lobes of gamma-ray emission spanning about 50,000 light-years above and below the Milky Way's center, discovered in 2010 by NASA's Fermi telescope.
Fermi constant
The Fermi constant, written G_F, is the coupling constant that sets the strength of the low-energy weak interaction, introduced in Enrico Fermi's 1934 beta decay theory.
Fermi energy
The Fermi energy is the energy of the highest occupied electron state in a system of fermions at absolute zero, typically a few eV in metals.
FERMI free-electron laser
FERMI (Free Electron laser Radiation for Multidisciplinary Investigations) is a seeded free-electron laser facility in Trieste, Italy, emitting extreme-ultraviolet and soft X-ray light from 100 to 4 nm.
Fermi Gamma-ray Space Telescope
The Fermi Gamma-ray Space Telescope, launched as GLAST in 2008 and named for physicist Enrico Fermi, is a NASA observatory that surveys the whole sky in gamma rays.
Fermi gas
A Fermi gas, or fermion gas, is a system of identical fermions occupying quantum states under the Pauli exclusion principle, governed by the Fermi-Dirac distribution.
Fermi interaction
The Fermi interaction, proposed by Enrico Fermi in 1934, is a four-fermion contact interaction that described nuclear beta decay and remains the weak interaction's low-energy description.
Fermi level
The Fermi level is the chemical potential of electrons in a solid or electrolyte, the energy with a 50 percent probability of occupation at thermal equilibrium.
Fermi level pinning
Fermi level pinning is the fixing of a semiconductor's Fermi level at an interface with a metal, making the Schottky barrier height independent of the metal used.
Fermi liquid theory
Fermi liquid theory, or Landau's Fermi-liquid theory, is a framework formulated by Lev Landau in 1956 and 1957 that describes interacting fermion systems, such as liquid helium-3 and metals, via long-lived quasiparticles.
Fermi paradox
The Fermi paradox, also called the Fermi-Hart paradox, is the conflict between the expected abundance of alien civilizations and the total lack of evidence for them.
Fermi polaron
A Fermi polaron is a quasiparticle formed when a mobile impurity interacts with and is modified by a surrounding degenerate Fermi gas, studied widely in ultracold atoms.
Fermi problem
A Fermi problem, also called a Fermi estimate, is an estimation problem solved by breaking a quantity into parts estimated from general knowledge, to within an order of magnitude.