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Attosecond
An attosecond (abbreviated as as) is a unit of time in the International System of Units (SI) equal to 10−18 or 1⁄1 000 000 000 000 000 000 (one quintillionth) of a second. An attosecond is to a second, as a second is to approximately 31.69 billion years. The attosecond is a tiny unit, but it has various potential applications: it can observe oscillating molecules, the chemical bonds formed by atoms in chemical reactions, and other extremely tiny and extremely fast things. One attosecond is equal to 1000 zeptoseconds, or 1/1000 femtosecond. Because the next SI unit is 1000 times larger, measurements of 10−17 and 10−16 second are typically expressed as tens or hundreds of attoseconds. Common measurements * 0.247 attoseconds: travel time of a photon across "the average bond length of molecular hydrogen" * 24.189... attoseconds: the atomic unit of time * 43 attoseconds: the shortest pulses of laser light yet created * 53 attoseconds: the shortest electron laser pul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anne L'Huillier
Anne Geneviève L'Huillier (; born 16 August 1958) is a French physicist. She is a professor of atomic physics at Lund University in Sweden. She leads an attosecond physics group which studies the movements of electrons in real time, which is used to understand chemical reactions on the atomic level. Her experimental and theoretical research are credited with laying the foundation for the field of attochemistry. In 2003 she and her group beat the world record for the shortest laser pulse, of 170 attoseconds. L'Huillier became a member of the Royal Swedish Academy of Sciences in 2004. She has received various physics awards including the Wolf Prize in Physics in 2022 and the Nobel Prize in Physics in 2023. Life Education Anne L'Huillier was born in Paris in 1958. She was awarded a double master's degree in theoretical physics and mathematics, but switched for her doctorate degree to experimental physics at Pierre and Marie Curie University. Her dissertation was on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre Agostini
Pierre Agostini (; born 23 July 1941) is a French experimental physicist and Emeritus professor at the Ohio State University in the United States, known for his pioneering work in strong-field laser physics and attosecond science. He is especially known for the observation of above-threshold ionization and the invention of the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) technique for characterization of attosecond light pulses. He was jointly awarded the 2023 Nobel Prize in Physics. Education and career Pierre Agostini was born in Tunis, in the French protectorate of Tunisia, in 1941. He obtained his ''baccalauréat'' at the Prytanée national militaire school in 1959 in La Flèche, France. Agostini studied physics at Aix-Marseille University, where he subsequently received a B.Ed. degree (''licence d'enseignement'') in physics in 1961, and an M.A.S. degree (''diplôme d'études approfondies'') in 1962. In 1968 he completed a d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferenc Krausz
Ferenc Krausz (born 17 May 1962) is a Hungaro-Austrian physicist working in Attosecond physics, attosecond science. He is a director at the Max Planck Institute of Quantum Optics and a professor of experimental physics at the Ludwig Maximilian University of Munich in Germany. His research team has generated and measured the first attosecond pulse (physics), light pulse and used it for capturing electrons' motion inside atoms, marking the birth of attophysics. In 2023, jointly with Pierre Agostini and Anne L'Huillier, he was awarded the Nobel Prize in Physics. Academic career From 1981 until 1985 Krausz studied theoretical physics at Eötvös Loránd University and electrical engineering at the Technical University of Budapest in Hungary. From 1987 to 1991 he graduated with a Doctor of Philosophy, PhD at the Technical University of Vienna, in Austria, and from 1991 to 1993 he also did his habilitation there. 1996–1998 he became associate professor, from 1999 until 2004 profess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orders Of Magnitude (time)
An order of magnitude of time is usually a decimal prefix or decimal order-of-magnitude quantity together with a base unit of time, like a microsecond or a million years. In some cases, the order of magnitude may be implied (usually 1), like a "second" or "year". In other cases, the quantity name implies the base unit, like "century". In most cases, the base unit is seconds or years. Prefixes are not usually used with a base unit of years. Therefore, it is said "a million years" instead of "a megayear". Clock time and calendar time have duodecimal or sexagesimal orders of magnitude rather than decimal, e.g., a year is 12 months, and a minute is 60 seconds. The smallest meaningful increment of time is the Planck time―the time light takes to traverse the Planck distance, many decimal orders of magnitude smaller than a second. The largest realized amount of time, based on known scientific data, is the age of the universe, about 13.8 billion years—the time sin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time
Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequence events, to compare the duration of events (or the intervals between them), and to quantify rates of change of quantities in material reality or in the qualia, conscious experience. Time is often referred to as a fourth dimension, along with Three-dimensional space, three spatial dimensions. Time is one of the seven fundamental physical quantities in both the International System of Units (SI) and International System of Quantities. The SI base unit of time is the second, which is defined by measuring the electronic transition frequency of caesium atoms. General relativity is the primary framework for understanding how spacetime works. Through advances in both theoretical and experimental investigations of spacetime, it has been shown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unit Of Time
A unit of time is any particular time interval, used as a standard way of measuring or expressing duration. The base unit of time in the International System of Units (SI), and by extension most of the Western world, is the second, defined as about 9 billion oscillations of the caesium atom. The exact modern SI definition is " he secondis defined by taking the fixed numerical value of the cesium frequency, , the unperturbed ground-state hyperfine transition frequency of the cesium 133 atom, to be when expressed in the unit Hz, which is equal to s−1." Historically, many units of time were defined by the movements of astronomical objects. * Sun-based: the year is based on the Earth's orbital period around the sun. Historical year-based units include the Olympiad (four years), the lustrum (five years), the indiction (15 years), the decade, the century, and the millennium. * Moon-based: the month is based on the Moon's orbital period around the Earth. * Earth-based: the da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second
The second (symbol: s) is a unit of time derived from the division of the day first into 24 hours, then to 60 minutes, and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of Units (SI) is more precise: The second ..is defined by taking the fixed numerical value of the caesium frequency, Δ''ν''Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be when expressed in the unit Hz, which is equal to s−1. This current definition was adopted in 1967 when it became feasible to define the second based on fundamental properties of nature with caesium clocks. As the speed of Earth's rotation varies and is slowing ever so slightly, a leap second is added at irregular intervals to civil time to keep clocks in sync with Earth's rotation. The definition that is based on of a rotation of the earth is still used by the Universal Time 1 (UT1) system. Etymology "Minute" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femtosecond
A femtosecond is a unit of time in the International System of Units (SI) equal to 10 or of a second; that is, one quadrillionth, or one millionth of one billionth, of a second. A femtosecond is to a second, as a second is to approximately 31.69 million years. For context, a ray of light travels approximately 0.3 μm (micrometers) in 1 femtosecond, a distance comparable to the diameter of a virus.Compared with overview in: The first to make femtosecond measurements was the Egyptian Nobel Laureate Ahmed Zewail, for which he was awarded the Nobel Prize in Chemistry in 1999. Professor Zewail used lasers to measure the movement of particles at the femtosecond scale, thereby allowing chemical reactions to be observed for the first time. The word ''femtosecond'' is formed by the SI prefix ''femto'' and the SI unit ''second''. Its symbol is fs. A femtosecond is equal to 1000 attoseconds, or 1/1000 picosecond. Because the next higher SI unit is 1000 times larger, times of 10� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Nobel Laureates In Physics
The Nobel Prize in Physics () is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of physics. It is one of the five Nobel Prizes established by the 1895 will and testament, will of Alfred Nobel (who died in 1896), awarded for outstanding contributions in physics. As dictated by Nobel's will, the award is administered by the Nobel Foundation and awarded by the Royal Swedish Academy of Sciences. The award is presented in Stockholm at an annual ceremony on 10 December, the anniversary of Nobel's death. Each recipient receives a medal, a diploma and a monetary award prize that has varied throughout the years. Statistics The Nobel Prize in Physics has been awarded to 226 individuals as of 2024. The first prize in physics was awarded in 1901 to Wilhelm Röntgen, Wilhelm Conrad Röntgen, of Germany, who received 150,782 Swedish krona, SEK. John Bardeen is the only laureate to win the prize twice—in 1956 and 1972. Lawrence Bragg, Willi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pion
In particle physics, a pion (, ) or pi meson, denoted with the Greek alphabet, Greek letter pi (letter), pi (), is any of three subatomic particles: , , and . Each pion consists of a quark and an antiquark and is therefore a meson. Pions are the lightest mesons and, more generally, the lightest hadrons. They are unstable, with the charged pions and decaying after a mean lifetime of 26.033 nanoseconds ( seconds), and the neutral pion decaying after a much shorter lifetime of 85 attoseconds ( seconds). Charged pions most often particle decay, decay into muons and muon neutrinos, while neutral pions generally decay into gamma rays. The exchange of virtual particle, virtual pions, along with vector meson, vector, rho meson, rho and omega mesons, provides an explanation for the nuclear force, residual strong force between nucleons. Pions are not produced in radioactive decay, but commonly are in high-energy collisions between hadrons. Pions also result from some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up quark, up and down quark, down quarks. Electrons are extremely lightweight particles that orbit the positively charged atomic nucleus, nucleus of atoms. Their negative charge is balanced by the positive charge of protons in the nucleus, giving atoms their overall electric charge#Charge neutrality, neutral charge. Ordinary matter is composed of atoms, each consisting of a positively charged nucleus surrounded by a number of orbiting electrons equal to the number of protons. The configuration and energy levels of these orbiting electrons determine the chemical properties of an atom. Electrons are bound to the nucleus to different degrees. The outermost or valence electron, valence electrons are the least tightly bound and are responsible for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulse
In medicine, the pulse refers to the rhythmic pulsations (expansion and contraction) of an artery in response to the cardiac cycle (heartbeat). The pulse may be felt ( palpated) in any place that allows an artery to be compressed near the surface of the body close to the skin, such as at the neck ( carotid artery), wrist (radial artery or ulnar artery), at the groin (femoral artery), behind the knee ( popliteal artery), near the ankle joint ( posterior tibial artery), and on foot (dorsalis pedis artery). The pulse is most commonly measured at the wrist or neck for adults and at the brachial artery (inner upper arm between the shoulder and elbow) for infants and very young children. A sphygmograph is an instrument for measuring the pulse. Physiology Claudius Galen was perhaps the first physiologist to describe the pulse. The pulse is an expedient tactile method of determination of systolic blood pressure to a trained observer. Diastolic blood pressure is non-palpable and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
