Quantum theory Definition and 222 Threads

what do most physicists today believe in?

No existing quantum mechanics or theory need be thought to sufficiently explain how it is that the subatomic of matter or photons of radiation can be detected and described as possessing their properties of behaviour called wave and spin or as being entangled in composite or singlet states, none...

Michio Kaku appeared on Part 1 of Einstein's Unfinished Symphony with the following interpretation of probabilities in quantum mechanics: Wouldn’t this be impossible, even in principle? Mars at its closest is at a distance of 55.7 million km, and if particles are limited by the speed of...

How do lasers make use of the quantum theory of the atom. I tried to look it up but I couldn't understand what they were saying. :confused:

In the transition from "basic" quantum theory to quantum field theory, both in the derivation of the Gordon-Klein and of the Dirac-equations, there is a big problem with solutions with negative energies. Can anyone explain me why this is being considered a big problem in the first place (it...

A very naive question from a beginner: I only know a very limited amount of string theory, and as far as I know it, it is a quantum theory in the strictest sense, namely that we still have a state in Hilbert space which evolves unitarily ; it is just the "theory to be quantized" that changes...

Hi. I have a problem with this quantum theory, that is going to make me crazy!: Why we are allowed to renormalize every function after we find the solution. I mean, how we are sure that we have found all the solution exists. Thanks in advance. Somy :smile:

Can quantum theory be explained? Is it possible to look at quantum theory and say "this calculation works because in terms of physics..."? (even if the physics does not entirely correlate with classical ideas) Eg - is it possible to explain in physics terms why electrons can only exist...

If someone could kindly spare some time and point out how to do these questions, most greatful. 1.After learning about de Broglie's hypothesis that particles of momentum, p, have wave characteristics with wavelength, h/p, a 76.00 kg student has grown concerned about being diffracted when...

Question from an amateur: I often read that Quantum Theory can explain very accurately the very small but not the big, General Relativity very accurate for the big but not for the very small. How "wide is the band" in which both overlap, being both accurate? i.e how big is the size of...

Mathematically speaking, the existence of a "dual" vector space, abstractly reflects the relationship between row vectors (1×n) and column vectors (n×1). The construction can also take place for infinite-dimensional spaces and gives rise to important ways of looking at different...

As I understand, QFT is formulated on a Minkowski background spacetime. This spacetime is not dynamical. So, what a priori reason is there for formulating QFT on a flat background spacetime? Is it a question of empirical evidence? Or of mathematical utility? Or both, something else? I have...

Can "direction" be quantized? That is the main question of this thread. At the outset, we need to clarify (hopefully come to some sorts of agreement) the meaning of the word "direction" for two groups of people, (1) the mathematicians and (2) the physicists. I am considering myself...

[SOLVED] Quantum theory of gravity Does anyone know if the same field theory approach that was applied to the electromagnetic force (resulting in QED) has been attempted with gravity. This would entail ignoring GR and trying to develop a quantum field theory of gravity from scratch. Any insights?

New Markopolou/Smolin: "Quantum Theory from Quantum Gravity" http://arxiv.org./gr-qc/0311059 "Planck's constant turns out to be a derived quantity"

I have just finished reading the ghost in the atom by P Davis and was intrigued by John Wheeler's interpretation of quantum theory where the wave function collapses when it enters the conciousness of an observer. I was wondering if since the book was published any progress has been made on this...

When Maxwell showed that light was an electromagnetic wave it was necessary to identify some oscillator of atomic proportions to account for these waves. Henri Lorentz , considered that electrons which are normally held in an equilibrium position are capable of vibration when displaced under...

I was just wondering what is wrong the quantum theory? What are its drawbacks?

dear reader, can anyone tell me what is quantum theory? and what is time sciendifically?

dear reader, could anyone say what is quantum theory exactly??[?] [?]

i have found this link, the other one returned to german for some reason, http://quantumtheory.de/en.html i can't follow the math so can somone explain please ?

Polarization and Quantum Theory -- confused This is what I'm getting hung up on: If you take a piece of vertically polarized glass and place it in front of a piece of horizontally polorized galss then NO light passes through the second glass because the light is at 90 degrees to the...