The history of quantum mechanics is a fundamental part of the history of modern physics. The major chapters of this history begin with the emergence of quantum ideas to explain individual phenomena—blackbody radiation, the photoelectric effect, solar emission spectra—an era called the Old or Older quantum theories. [1]Quantum is an open-access peer-reviewed journal for quantum science and related fields. Quantum is non-profit and community-run: an effort by researchers and for researchers to make science more open and publishing more transparent and efficient. Sign up for our monthly digest of papers and other news.Mar 15, 2022 · 1. The quantum world is lumpy. (Image credit: getty) The quantum world has a lot in common with shoes. You can’t just go to a shop and pick out sneakers that are an exact match for your feet ... This textbook, now in an expanded third edition, emphasizes the importance of advanced quantum mechanics for materials science and all experimental techniques which employ photon absorption, emission, or scattering. Important aspects of introductory quantum mechanics are covered in the first seven chapters to make the subject self-contained …If you have a copy of Griffiths, he has a nice discussion of this in the delta function potential section. In summary, if the energy is less than the potential at $-\infty$ and $+\infty$, then it is a bound state, and the spectrum will be discrete: $$ \Psi\left(x,t\right) = \sum_n c_n \Psi_n\left(x,t\right). $$ Otherwise (if the energy is greater than the potential at $-\infty$ …What God, Quantum Mechanics and Consciousness Have in Common. Theories that try to explain these big metaphysical mysteries fall short, making agnosticism the only sensible stance. In my 20s, I ...Quantum Mechanics: The Theoretical Minimum – Buy Now. Source: Leonard Susskind, Art Friedman/Amazon. Theoretical Minimum is a rare New York Times’ bestseller on quantum mechanics, written by ...The quantum harmonic oscillator is the quantum-mechanical analog of the classical harmonic oscillator. Because an arbitrary smooth potential can usually be approximated as a harmonic potential at the vicinity of a stable equilibrium point, it is one of the most important model systems in quantum mechanics.Instead, classical mechanics is now considered an approximate theory to the more general quantum mechanics. Emphasis has shifted to understanding the fundamental forces of nature as in the Standard Model and its more modern extensions into a unified theory of everything. Classical mechanics is a theory useful for the study of the motion …The latest news on quantum physics, wave particle duality, quantum theory, quantum mechanics, quantum entanglement, quantum teleportation, and quantum computing.MIT 8.04 Quantum Physics I, Spring 2013View the complete course: http://ocw.mit.edu/8-04S13Instructor: Allan AdamsIn this lecture, Prof. Adams discusses a se...It turns out that we can just as easily formulate quantum mechanics using the momentum-space wavefunction, ϕ(p, t) ϕ ( p, t), as the real-space wavefunction, ψ(x, t) ψ ( x, t). The former scheme is known as the momentum representation of quantum mechanics. In the momentum representation, wavefunctions are the Fourier …Sep 15, 2014 · View full lesson: http://ed.ted.com/lessons/particles-and-waves-the-central-mystery-of-quantum-mechanics-chad-orzelOne of the most amazing facts in physics i... The history of quantum mechanics is a fundamental part of the history of modern physics. The major chapters of this history begin with the emergence of quantum ideas to explain individual phenomena—blackbody radiation, the photoelectric effect, solar emission spectra—an era called the Old or Older quantum theories. [1]QUANTUM MECHANICS An innovative approach to quantum mechanics that seamlessly combines textbook and problem-solving book into one Quantum Mechanics: Concepts and Applications provides an in-depth treatment of this fundamental theory, combining detailed formalism with straightforward practice. Thoroughly integrating close to seven hundred …Lecture 1: An overview of quantum mechanics. L1.1 Quantum mechanics as a framework. Defining linearity (17:46) L1.2 Linearity and nonlinear theories. Schrödinger’s equation … Quantum Mechanics. Argonne maintains a wide-ranging science and technology portfolio that seeks to address complex challenges in interdisciplinary and innovative ways. Below is a list of all articles, highlights, profiles, projects, and organizations related specifically to quantum mechanics. 1. The quantum world is lumpy. (Image credit: getty) The quantum world has a lot in common with shoes. You can’t just go to a shop and pick out sneakers that are an exact match for your feet ...MIT 8.04 Quantum Physics I, Spring 2013View the complete course: http://ocw.mit.edu/8-04S13Instructor: Allan AdamsIn this lecture, Prof. Adams discusses a se...Quantum mechanics offers us a way to describe the atomic world to a surprising degree of precision. Its predictions often defy our intuition of the world. All of the remarkable and surprising quantum phenomena come from the fact that probability is at the heart of quantum mechanics. We can never know what will happen for sure.Quantum Mechanics (QM) and Semiconductor Physics are the foundations of modern technology. They are taught in core courses in science and engineering disciplines such as electrical engineering, chemistry, and material science and engineering. However, educators face major challenges because of the abstract, non-experiential, and counter ...Provided to YouTube by Back Lot MusicQuantum Mechanics · Ludwig GöranssonOppenheimer (Original Motion Picture Soundtrack)℗ 2023 Back Lot Music, a Division of...Figure 2.1: In quantum mechanics the right hand side of the Schrödinger equation is written shortly as ˆHΨ(x, t), so (2.2) can be written as. iℏ∂Ψ ( x, t) ∂t = ˆHΨ(x, t) (2.3) This notation has a deeper reason, which is explained here shortly. The operation − ℏ2 2m ∂2Ψ ( x, t) ∂x2 + V(x)Ψ(x, t) can be considered as a ... In this quantum physics introduction for beginners, we will explain quantum physics, also called quantum mechanics, in simple terms. Quantum physics is possibly the most fascinating part of physics that exists. It is the amazing physics that becomes relevant for small particles, where the so-called classical physics is no longer valid. Quantum Mechanics is a set of mathematical rules upon which physical theories are constructed. Applying the rules of quantum mechanics, it is possible to calculate the observables of an isolated physical system, at any instant in …Instead, classical mechanics is now considered an approximate theory to the more general quantum mechanics. Emphasis has shifted to understanding the fundamental forces of nature as in the Standard Model and its more modern extensions into a unified theory of everything. Classical mechanics is a theory useful for the study of the motion …Quantum computing uses specialized technology—including computer hardware and algorithms that take advantage of quantum mechanics—to solve complex problems that classical computers or supercomputers can’t solve, or can’t solve quickly enough. Today, IBM Quantum makes real quantum hardware—a tool that scientists only began to … This 9 week course aims to teach quantum mechanics to anyone with a reasonable college-level understanding of physical science or engineering. Quantum mechanics was once mostly of interest to physicists, chemists and other basic scientists. Now the concepts and techniques of quantum mechanics are essential in many areas of engineering and science such as materials science, nanotechnology ... The Principles of Quantum Mechanics is an influential monograph on quantum mechanics written by Paul Dirac and first published by Oxford University Press in 1930. Dirac gives an account of quantum mechanics by "demonstrating how to construct a completely new theoretical framework from scratch"; "problems were tackled top-down, …Quantum mechanics. Download RSS feed: News Articles / In the Media / Audio. Displaying 1 - 15 of 53 news articles related to this topic. Show: News Articles. In the Media. Audio. MIT researchers discover “neutronic molecules” Study shows neutrons can bind to nanoscale atomic clusters known as quantum dots. ...The Principal Quantum Number (\(n\)) The principal quantum number, \(n\), designates the principal electron shell. Because n describes the most probable distance of the electrons from the nucleus, the larger the number n is, the farther the electron is from the nucleus, the larger the size of the orbital, and the larger the atom is.n can be any positive …This course presents the fundamental concepts of quantum mechanics: wave properties, uncertainty principles, the Schrödinger equation, and operator and matrix methods. Key topics include commutation rule definitions of scalar, vector, and spherical tensor operators; the Wigner-Eckart theorem; and 3j (Clebsch-Gordan) coefficients. In addition, we deal …Lecture 22: Metals, Insulators, and Semiconductors. video. 263 MB. Lecture 23: More on Spin. video. 265 MB. Lecture 24: Entanglement: QComputing, EPR, and Bell's Theorem. MIT OpenCourseWare is a web based publication of virtually all MIT course content. OCW is open and available to the world and is a permanent MIT activity.Current Weather. 8:54 PM. 71° F. RealFeel® 67°. Air Quality Unhealthy. Wind WNW 12 mph. Wind Gusts 13 mph. Partly cloudy More Details. An interpretation of quantum mechanics is an attempt to explain how the mathematical theory of quantum mechanics might correspond to experienced reality. Although quantum mechanics has held up to rigorous and extremely precise tests in an extraordinarily broad range of experiments, there exist a number of contending schools of thought over ... Mass defect and binding energy. Nuclear stability and nuclear equations. Half-life plot. Exponential decay and semi-log plots. This unit is part of the Physics library. Browse videos, articles, and exercises by topic. Manufacturing Engineer at Schlumberger Company, Cameron | SPD First Rank Winner (Aramco Project) l KFUPM Mechanical Engineer Alumni l Interned in NESR | SCE … Quantum mechanics - Applications, Particles, Waves: As has been noted, quantum mechanics has been enormously successful in explaining microscopic phenomena in all branches of physics. The three phenomena described in this section are examples that demonstrate the quintessence of the theory. The kaon (also called the K0 meson), discovered in 1947, is produced in high-energy collisions between ... Lecture 22: Metals, Insulators, and Semiconductors. video. 263 MB. Lecture 23: More on Spin. video. 265 MB. Lecture 24: Entanglement: QComputing, EPR, and Bell's Theorem. MIT OpenCourseWare is a web based publication of virtually all MIT course content. OCW is open and available to the world and is a permanent MIT activity.Quantum mechanical laws are usually only found to apply at very low temperatures. Quantum computers, for example, currently operate at around -272°C. At higher temperatures, classical mechanics ...Unlike quantum mechanics which has a canonical mathematical framework in terms of von Neumann’s Hilbert space formulation, QFT has no canonical mathematical framework. Even though there is a canonical mathematical framework for quantum mechanics, there are many interpretations of that framework, e.g., many-worlds, GRW, …Quantum mechanics, science dealing with the behavior of matter and light on the atomic and subatomic scale. It attempts to describe and account for the properties of molecules and atoms and …In this quantum physics introduction for beginners, we will explain quantum physics, also called quantum mechanics, in simple terms. Quantum physics is possibly the most fascinating part of physics that exists. It is the amazing physics that becomes relevant for small particles, where the so-called classical physics is no longer valid.In both classical and quantum mechanical systems, angular momentum (together with linear momentum and energy) is one of the three fundamental properties of motion. Prerequisites. Chapters 1 and 2. Angular momentum and its conservation in classical mechanics. Spherical coordinates, elements of vector analysis.May 12, 2015 · Leonard Susskind is the Felix Bloch Professor in Theoretical Physics at Stanford University. He is the author of Quantum Mechanics (with Art Friedman) and The Theoretical Minimum (with George Hrabovsky), among other books. He lives in Palo Alto, California. Art Friedman is a data consultant who previously spent fifteen years at Hewlett-Packard ... Quantum mechanics Abstract Although complex numbers are essential in mathematics, they are not needed to describe physical experiments, as those are expressed in terms of probabilities, hence real ... An interpretation of quantum mechanics is an attempt to explain how the mathematical theory of quantum mechanics might correspond to experienced reality. Although quantum mechanics has held up to rigorous and extremely precise tests in an extraordinarily broad range of experiments, there exist a number of contending schools of thought over ... of his research is in electrodynamics and quantum mechanics. He is the author of over fty arti-cles and four books: Introduction to Electrodynamics (4th edition, Cambridge University Press, 2013), Introduction to Elementary Particles (2nd edition, Wiley-VCH, 2008), Introduction to Quantum Mechanics (2nd edition, Cambridge, 2005), and This 9 week course aims to teach quantum mechanics to anyone with a reasonable college-level understanding of physical science or engineering. Quantum mechanics was once mostly of interest to physicists, chemists and other basic scientists. Now the concepts and techniques of quantum mechanics are essential in many areas of engineering and ... His record of successful theoretical research with undergraduate students was recognized in 2011 when he was named as a KITP-Anacapa scholar. AI generated results by. Discover Introduction to Quantum Mechanics, 3rd Edition, David J. Griffiths, HB ISBN: 9781107189638 on Higher Education from Cambridge. 1.1: Why Quantum Mechanics is Necessary; 1.2: The Schrödinger Equation and Its Components; 1.3: The Born-Oppenheimer Approximation One of the most important approximations relating to applying quantum mechanics to molecules and molecular ions is known as the Born-Oppenheimer (BO) approximation. 1.4: Free Particle Motions in More …David Tong: Lectures on Topics in Quantum Mechanics. This is an advanced course on quantum mechanics. It covers a wide range of topics, including an introduction to atomic physics, quantum foundations and scattering theory. Please do email me if you find any typos or mistakes. PostScript PDF. Content.Quantum Mechanics (QM) and Semiconductor Physics are the foundations of modern technology. They are taught in core courses in science and engineering disciplines such as electrical engineering, chemistry, and material science and engineering. However, educators face major challenges because of the abstract, non-experiential, and counter ...Quantum mechanics works completely di erently, as can be seen by repeating the double-slit experiment for electrons. What one observes is that electrons still reach the detector in \lumps", but now P 12(x) 6= P 1(x) + P 2(x). Moreover, the observed probability distribution looks suspiciously like the interferenceAccording to the postulates of quantum mechanics, if the wavefunction defined in Equation \ref{2} is an eigenfunction of this Hamiltonian, every time we measure the total energy of the electron we will measure the corresponding eigenvalue. In other words, if this is true: \(\hat H \psi = a \psi\), then the constant \(a\) is the energy of one ...Lecture 22: Metals, Insulators, and Semiconductors. video. 263 MB. Lecture 23: More on Spin. video. 265 MB. Lecture 24: Entanglement: QComputing, EPR, and Bell's Theorem. MIT OpenCourseWare is a web based publication of virtually all MIT course content. OCW is open and available to the world and is a permanent MIT activity.If you have a copy of Griffiths, he has a nice discussion of this in the delta function potential section. In summary, if the energy is less than the potential at $-\infty$ and $+\infty$, then it is a bound state, and the spectrum will be discrete: $$ \Psi\left(x,t\right) = \sum_n c_n \Psi_n\left(x,t\right). $$ Otherwise (if the energy is greater than the potential at $-\infty$ …Chapter 2: 1D Wave Mechanics. Chapter 3: Higher Dimensionality Effects. Chapter 4: Bra-ket Formalism. Chapter 5: Some Exactly Solvable Problems. Chapter 6: Perturbation Theories. Chapter 7: Open Quantum Systems. Chapter 8: Multiparticle Systems. Chapter 9: Introduction to Relativistic Quantum. Chapter 10: Making Sense of Quantum …Quantum mechanics has played an important role in photonics, quantum electronics, and micro-electronics. But many more emerging technologies require the understanding of quantum mechanics; and hence, it is important that scientists and engineers understand quantum mechanics better. One area is nano-technologies due … Lecture 1: An overview of quantum mechanics. Quantum mechanics as a framework. Defining linearity (17:46) Linearity and nonlinear theories. Schrödinger’s equation (10:01) The nature of superposition. Mach-Zehnder interferometer (14:30) Lecture 2: Overview of quantum mechanics (cont.). Interaction-free measurements. The variational principle states, quite simply, that the ground-state energy, E0 E 0, is always less than or equal to the expectation value of H H calculated with the trial wavefunction: that is, E0 ≤ ψ|H|ψ . (13.1.2) (13.1.2) E 0 ≤ ψ | H | ψ . Thus, by varying ψ ψ until the expectation value of H H is minimized, we can obtain ... Course Description. Together, this course and 8.06 Quantum Physics III cover quantum physics with applications drawn from modern physics. Topics covered in this course include the general formalism of quantum mechanics, harmonic oscillator, quantum mechanics in three-dimensions, angular momentum, spin, and addition of angular momentum. …. In quantum mechanics with complex numbers, the particles Alice and Charlie receive don’t need to be entangled with each other. No real-number description, however, can replicate the pattern of correlations that the three physicists will measure. The new paper shows that treating the system as real requires introducing extra information that ...1. Key Features of Quantum Mechanics: Linearity of the Equations of Motion, Complex Numbers are Essential, Loss of Determinism, Quantum Superpositions, Entanglement (PDF) 2. Experiments with Photons: Mach-Zehder Interferometer, Elitzur-Vaidman Bombs (PDF) 3. Particle Nature of Light and Wave Nature of Matter: Photoelectric Effect, …Quantum mechanics explains how the universe works with things that are even smaller than atoms. It is also called quantum physics or quantum theory. Mechanics is the part of physics that explains how things move and quantum is the Latin word for 'how much'. A quantum of energy is the least amount possible (or the least extra amount), and ...A brief overview of the history and basic concepts of quantum mechanics, the study of physics on very small length scales. Learn how quantum mechanics is related to …This course presents the fundamental concepts of quantum mechanics: wave properties, uncertainty principles, the Schrödinger equation, and operator and matrix methods. Key topics include commutation rule definitions of scalar, vector, and spherical tensor operators; the Wigner-Eckart theorem; and 3j (Clebsch-Gordan) coefficients. In addition, we deal …Quantum mechanics was developed by the young. In 1923 Pauli, Heisenberg, Dirac and Jordan were in their 20s; de Broglie and Schrödinger, in their 30s, were late bloomers 1 — in the spirit of ...start, in Chapter 3, by examining how many of the central ideas of quantum mechanics are a direct consequence of wave-particle duality—i.e., the concept that waves sometimes act as particles, and particles as waves. We shall then proceed to investigate the rules of quantum mechanics in a more systematic fashion in Chapter 4. Quantum mechanics isThe quantum mechanical model of the atom (Opens a modal) Heisenberg uncertainty principle (Opens a modal) Quantum numbers (Opens a modal) Quantum numbers for …The history of quantum mechanics is a fundamental part of the history of modern physics. The major chapters of this history begin with the emergence of quantum ideas to explain individual phenomena—blackbody radiation, the photoelectric effect, solar emission spectra—an era called the Old or Older quantum theories. [1]Quantum mechanics is a hypothesis in material science that gives a depiction of the actual properties of nature at the size of atoms and subatomic particles. It is the foundation of all quantum material science including quantum science, quantum field hypothesis, quantum innovation, and quantum data science. This is the first course in the undergraduate Quantum Physics sequence. It introduces the basic features of quantum mechanics. It covers the experimental basis of quantum physics, introduces wave mechanics, Schrödinger's equation in a single dimension, and Schrödinger's equation in three dimensions. The lectures and lecture notes for this course form the basis of Zwiebach’s textbook ... Jan 10, 2021 · Quantum mechanics is more right, but most of the time classical mechanics is good enough. What I find fascinating is that "good enough" increasingly isn’t. Much of the technology developed in ... Quantum mechanics opens the doors for Quantum Engineers to leverage quantum physics to deliver unprecedented solutions to engineering problems. Quantum Engineers specialise in how high-frequency, nanometer-scale electronics can be made to harness quantum nature. When you study Quantum Engineering at UNSW, you'll develop the …Postulate 3. For every observable property of a system there is a quantum mechanical operator. The operator for position of a particle in three dimensions is just the set of coordinates x x, y y, and z z, which is written as a vector. The operator for a component of momentum is. P^x = −iℏ ∂ ∂x (3.9.4) (3.9.4) P ^ x = − i ℏ ∂ ∂ x.There are 3 modules in this course. Course 2 of Statistical Thermodynamics presents an introduction to quantum mechanics at a level appropriate for those with mechanical or aerospace engineering backgrounds. Using a postulatory approach that describes the steps to follow, the Schrodinger wave equation is derived and simple solutions obtained ...quantum mechanics, Branch of mathematical physics that deals with atomic and subatomic systems. It is concerned with phenomena that are so small-scale that they cannot be described in classical terms, and it is formulated entirely in terms of statistical probabilities. Considered one of the great ideas of the 20th century, quantum …That theory is known as quantum mechanics, and it is now the basic framework for understanding atomic, nuclear, and subnuclear physics, as well as condensed-matter (or ”solid-state”) physics. The laws of motion (due to Galileo, Newton,...) which preceded quantum theory are referred to as classical mechanics.These special wavefunctions are called eigenstates, and the multiples are called eigenvalues. Thus, if. Aψa(x) = aψa(x), (3.8.1) (3.8.1) A ψ a ( x) = a ψ a ( x), where a a is a complex number, then ψa ψ a is called an eigenstate of A A corresponding to the eigenvalue a a. Suppose that A A is an Hermitian operator corresponding to some ...
Postulate 3. For every observable property of a system there is a quantum mechanical operator. The operator for position of a particle in three dimensions is just the set of coordinates x x, y y, and z z, which is written as a vector. The operator for a component of momentum is. P^x = −iℏ ∂ ∂x (3.9.4) (3.9.4) P ^ x = − i ℏ ∂ ∂ x.. I breviary
Quantum physics is the result of applying the framework of quantum mechanics to di erent physical phenomena. We thus have Quantum Electrodynamics, when quantum mechanics is applied to electromagnetism, Quantum Optics, when it is applied to light and optical devices, or Quantum Gravity, when it is applied to gravitation.Quantum 101. What is quantum? Quantum mechanics is the physics of the very small. It explains and predicts the behaviour of atoms and molecules in a way that redefines our understanding of nature. It is the most precise description that we have of the world, and yet, it predicts surprising, often counter-intuitive behaviours. This 9 week course aims to teach quantum mechanics to anyone with a reasonable college-level understanding of physical science or engineering. Quantum mechanics was once mostly of interest to physicists, chemists and other basic scientists. Now the concepts and techniques of quantum mechanics are essential in many areas of engineering and ... In quantum mechanics with complex numbers, the particles Alice and Charlie receive don’t need to be entangled with each other. No real-number description, however, can replicate the pattern of correlations that the three physicists will measure. The new paper shows that treating the system as real requires introducing extra information that ...The old quantum theory is a collection of results from the years 1900–1925 which predate modern quantum mechanics. The theory was never complete or self-consistent, but was rather a set of heuristic corrections to classical mechanics. The theory is now understood as a semi-classical approximation to modern quantum mechanics.Feb 10, 2022 · 🌎 Get Our Merch designed with https://www.youtube.com/channel/UCNYaxPiba3oxmeL_3jKxnYA/store💫Get 10% off Under Lucky Stars and enjoy our star maps comple... A fundamental concept in quantum mechanics is that of randomness, or indeterminacy. In general, the theory predicts only the probability of a certain result. Consider the case of radioactivity. Imagine a box of atoms with identical nuclei that can undergo decay with the emission of an alpha particle. In a given time interval, a certain fraction ... Quantum Mechanics Concepts and Applications Second Edition Nouredine Zettili Jacksonville State University, Jacksonville, USA A John Wiley and Sons, Ltd., PublicationThe Principles of Quantum Mechanics is an influential monograph on quantum mechanics written by Paul Dirac and first published by Oxford University Press in 1930. Dirac gives an account of quantum mechanics by "demonstrating how to construct a completely new theoretical framework from scratch"; "problems were tackled top-down, …In his estimation, quantum mechanics is a broad-brush theory that expresses the overall behavior of nature’s building blocks but lacks the resolution to capture individual cases. A deeper, more ...Notes 1: The Mathematical Formalism of Quantum Mechanics, pdf format. Notes 2: The Postulates of Quantum Mechanics, pdf format. Notes 3: The Density Operator, pdf format. Notes 4: Spatial Degrees of Freedom, pdf format. Notes 5: Time Evolution in Quantum Mechanics, pdf format. Notes 6: Topics in One-Dimensional …View full lesson: http://ed.ted.com/lessons/particles-and-waves-the-central-mystery-of-quantum-mechanics-chad-orzelOne of the most amazing facts in physics i...Quantum Mechanics (QM) and Semiconductor Physics are the foundations of modern technology. They are taught in core courses in science and engineering disciplines such as electrical engineering, chemistry, and material science and engineering. However, educators face major challenges because of the abstract, non-experiential, and counter ...Manufacturing Engineer at Schlumberger Company, Cameron | SPD First Rank Winner (Aramco Project) l KFUPM Mechanical Engineer Alumni l Interned in NESR | SCE …1. Key Features of Quantum Mechanics: Linearity of the Equations of Motion, Complex Numbers are Essential, Loss of Determinism, Quantum Superpositions, Entanglement (PDF) 2. Experiments with Photons: Mach-Zehder Interferometer, Elitzur-Vaidman Bombs (PDF) 3. Particle Nature of Light and Wave Nature of Matter: Photoelectric Effect, …Decoherence Theory This is not an interpretation, but it is an important element of the modern understanding of quantum mechanics. It expands upon the kind of mathematical analysis that led ...First published Sun Mar 24, 2002; substantive revision Thu Aug 5, 2021. The Many-Worlds Interpretation (MWI) of quantum mechanics holds that there are many worlds which exist in parallel at the same space and time as our own. The existence of the other worlds makes it possible to remove randomness and action at a distance from quantum theory ... Quantum mechanics. Quantum mechanics is the best tool we have to understand how the universe works on its smallest scales. Everything we can see around us, from far-off galaxies to our own bodies ... .