Measurement in quantum mechanics
The framework of quantum mechanics requires a careful definition of measurement. The issue of measurement lies at the heart of the problem of the interpretation of quantum mechanics, for which there ...
Physicists Can Finally Peek at Schrödinger's Cat Without Killing It Forever
There may be a way of sneaking a peak at Schrödinger's cat — the famous feline-based thought experiment that describes the mysterious behavior of subatomic particles — without permanently killing the ...
A quantum experiment suggests there’s no such thing as objective reality - MIT Technology Review
Physicists have long suspected that quantum mechanics allows two observers to experience different, conflicting realities. Now they’ve performed the first experiment that proves it.
Pilot Wave Theory and Quantum Realism
There’s one interpretation of the meaning of quantum mechanics that manages to skip a lot of the unphysical weirdness of the mainstream interpretations: it's...
Schrödinger’s cat just got even weirder (and even more confusing)
The researchers hope their findings will help make quantum computers a reality.
Single particle creates interference after double slit
Oil droplet exhibits properties reminiscent of an elementary particle
A Different Picture Of Quantum Surrealism
With its ideas of particles zipping in and out of existence, quantum mechanics is probably the kookiest-sounding theory in science. And our understanding of it is little helped by the mysterious “pro...
These Bouncing Droplets Could Help Resolve a 90-Year Mystery of Quantum Mechanics
The drops of silicone oil bobbing in this mesmerizing video do more than create aesthetically satisfying ripples across a slick surface. They could be indirect evidence of an alternate solution to a n...
Quantum "Weeping Angel" Effect Freezes Atoms In Place
The paradox of Schroedinger’s Cat famously demonstrates that a quantum cat sealed in a box is both alive and dead at the same time until we look inside, at which point it becomes one or the other. Suc...
The Race To Prove 'Spooky' Quantum Connection May Have a Winner
Particles don’t obey the same rules as people. Poke a particle, and another one far away can instantly respond the touch -- without any messages passing through the space between, as if the two partic...
Reality Doesn’t Exist Until We Measure It, Quantum Experiment Confirms
Australian scientists have recreated a famous experiment and confirmed quantum physics's bizarre predictions about the nature of reality, by proving that reality doesn't actually exist until we measur...
Physicists show 'quantum freezing phenomenon' is universal
Physicists who work on quantum technologies are always looking for ways to manage decoherence, which occurs when a quantum system unavoidably interacts with the surrounding environment. In the past fe...
Many Interacting Worlds theory: Scientists propose existence and interaction of parallel worlds
Griffith University academics are challenging the foundations of quantum science with a radical new theory based on the existence of, and interactions between, parallel universes. In a paper published...
Delayed choice quantum eraser - Experiment
Commentary on a delayed choice quantum eraser experiment with entangled photons.
Observable
In physics, particularly in quantum physics, a system observable is a measurable operator, or gauge, where the property of the system state can be determined by some sequence of physical operations. ...
Wave function collapse
In quantum mechanics, wave function collapse is said to occur when a wave function—initially in a superposition of several eigenstates—appears to reduce to a single eigenstate (by "observation"). It i...
Density matrix
A density matrix is a matrix that describes a quantum system in a mixed state, a statistical ensemble of several quantum states. This should be contrasted with a single state vector that describes a q...
Principle of locality
In physics, the principle of locality states that an object is only directly influenced by its immediate surroundings. A physical theory is said to be a local theory if it is consistent with the prin...
Quantum nonlocality
In theoretical physics, quantum nonlocality is the phenomenon by which the measurements made at a microscopic level necessarily refute one or more notions (often referred to as local realism) that are...
Interpretations of quantum mechanics
An interpretation of quantum mechanics is a set of statements which attempt to explain how quantum mechanics informs our understanding of nature. Although quantum mechanics has held up to rigorous and...
Hidden variable theory
Historically, in physics, hidden variable theories were espoused by some physicists who argued that the state of a physical system, as formulated by quantum mechanics, does not give a complete descrip...
Quantum nondemolition measurement
Quantum nondemolition (QND) measurement is a special type of measurement of a quantum system in which the uncertainty of the measured observable does not increase from its measured value during the su...
Physicists Can Finally Peek at Schrödinger's Cat Without Killing It Forever
There may be a way of sneaking a peak at Schrödinger's cat — the famous feline-based thought experiment that describes the mysterious behavior of subatomic particles — without permanently killing the ...
A quantum experiment suggests there’s no such thing as objective reality - MIT Technology Review
Physicists have long suspected that quantum mechanics allows two observers to experience different, conflicting realities. Now they’ve performed the first experiment that proves it.
Ghirardi-Rimini-Weber theory
The Ghirardi–Rimini–Weber theory, or GRW, is a collapse theory in quantum mechanics. GRW differs from other collapse theories by proposing that wave function collapse happens spontaneously. GRW is an ...
De Broglie–Bohm theory
The de Broglie–Bohm theory, also known as the pilot-wave theory, Bohmian mechanics, the Bohm or Bohm's interpretation, and the causal interpretation, is an interpretation of quantum theory. In additio...
Complementarity (physics)
In physics, complementarity is a fundamental principle of quantum mechanics, closely associated with the Copenhagen interpretation. It holds that objects have complementary properties which cannot be...
Consistent histories
In quantum mechanics, the consistent histories approach is intended to give a modern interpretation of quantum mechanics, generalising the conventional Copenhagen interpretation and providing a natura...