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Questions related from Sofia D. Wechsler
I am dealing with an experiment on atoms in the "Circular Rydberg State" (CRS) - see the picture. These are alkali atoms (a single electron of valence) highly excited, e.g. with the principal...
01 July 2021 8,134 0 View
This question is connected with the so-called wave-particle duality. We know experiments which can be explained only if we assume that the quantum objects are waves. However, are there experiments...
22 May 2021 8,536 6 View
I don't see this limit - I never saw a proof of it. Can somebody indicate a proof? Typically, at high velocities the number of particles is not well defined. QM works with a defined number of...
28 March 2021 1,187 16 View
An experiment that I propose contains a beam-splitter for protons. There is plenty of articles in the literature, about atoms interferometry. But, except for electron interferometry, I don't see...
23 November 2020 7,364 3 View
There are different proofs that the quantum nechanics (QM), more exactly the quantum formalism (that was NEVER contradicted by experiment), does not admit a substructure of particles following...
20 November 2018 6,886 96 View
I read in Internet about a very old and advanced civilazation on a continent, Atlantida, which seems to have been swept away by the ocean water. Archeologists hold that techniques of building of...
15 November 2018 3,773 19 View
Imagine that a quantum object, what we call (non-rigorously) a "particle", is described by a wave-function which is non-null in two regions of the space, but in between it is null. Could it be...
19 October 2018 5,028 50 View
Assume that an atom is irradiated with photons of energy E0, fit for raising an electron to a level of energy zero - recall that the bound levels in atoms are negative, s.t. a level of energy zero...
12 October 2018 9,563 31 View
Look at the following process: a photon wave-packet is split by a beam-splitter into the superposition ~ |a> + i|b>. In continuation, each one of the wave-packets |a> and |b>, passes through a...
13 August 2018 4,929 6 View
(This question is not mine, I copied here an issue raised by Hans van Leunen in one of my threads. I think it is worth of a separate discussion.) Here are some of the problems Hans van Leunen...
01 August 2018 5,995 23 View
An example of density of Lagrangian of a scalar field ϕ(x), is (1) L = ½(∂ϕ/∂t)2 - ½(∇ϕ)2. (From this density of Lagrangian, one derives the Klein-Gordon equation). I miss the...
22 July 2018 8,627 13 View
My question is posed in two ways: A. Within the effort to extend the Ghirardi-Rimini-Weber to become a relativistic theory, many trials were made. In one of the articles engaging in this...
18 June 2018 8,153 99 View
The standard form of the quantum mechanics (SQM) is considered by many people unsatisfactory, as it leaves many open questions. The fact that it contradicts the classical physics, both Newtonian...
08 June 2018 773 88 View
The standard QM offers no explanation for the collapse postulate. By the Bohmian mechanics (BM) there is no collapse, there exists a particle following some trajectory, and and detector fires if...
03 June 2018 1,891 31 View
The "collapse" postulate says that if part of the wave-function produces a click in a detector, the rest of the wave-function disappears. In the experiment described here, it is shown that no part...
01 January 2018 1,247 17 View
I am bringing in this question elements from a couple of domains of the physics. 1. It is known that the cosmological constant predicted by the general relativity (GR) is by cca. 40 orders of...
31 December 2017 1,506 3 View
I am bringing in this question approached from different domains of the physics: 1. In cosmology we have the problem that the cosmological constant calculated with the tools of the general...
31 December 2017 4,186 5 View
The entanglement of two macroscopic bodies, M1 and M2, consisting, each one, in many parts, is not a relation directly between the parts, but, first of all between the movements of the two bodies...
28 October 2017 9,217 6 View
In the Hanbury Brown and Twiss experiment - see picture - we write the wave-function as follows (1) Ψ ~ |rD1A|-1|rD2B|-1 exp{2πι(|rD1A| + |rD2B|)/λ} + |rD1B|-1|rD2A|-1 exp{2πι(|rD1B| +...">
18 October 2017 7,070 13 View
As basic issues I mention: 1. The uncertainty principle says that if we measure with precision an observable A corresponding to an Â, then an observable B corresponding to an operator B̂...
13 October 2017 2,091 51 View
A non-absorbing detector is supposed, at least in theory, to report that a particle passes through it, though, the particle is allowed to exit the detector, s.t. we can do additional tests on it....
23 September 2017 1,167 8 View
Consider the following experiment with pairs of down-conversion photons: the idler-photon is detected by a detector I, while the signal-photon enters an apparatus that splits it into three copies...
21 September 2017 5,857 38 View
I am working with the Hanbury-Brown and Twiss experiment, and I noticed a property of this experiment, similar to tunnelling. Consider a pair of particles, A and B, the particle A passing through...
21 August 2017 7,090 4 View
For understanding my question I invite everybody to read the example. In the Bohmian mechanics (BM) the velocity formula gives an infinite value to the velocity of the Bohmian particle at points...
10 August 2017 5,797 17 View
Weak measurement are a relatively new trend in quantum experiment. They mean to determine the so-called Bohmian velocity, but in fact they measure the average linear momentum while disturbing very...
03 July 2017 7,729 14 View
I saw in some articles that the quantum tunneling involves crossing a potential bsrrier in a time-interval equal to zero. arXiv:quant-ph/9710046v2, "Can a falling tree make a noise in two forests...
24 December 2016 9,914 39 View
Relativistic quantum mechanics (RQM) deals, among other things, with the transformation of the wave-function from one frame of coordinates to another one. However, it seems to me that with...
05 December 2016 4,637 23 View
Do we get from the most distant galaxies mostly the spectral lines of heavy elements or of light elements? The thought behind my question is that on our time axis, the nuclear reactions on bodies...
29 October 2016 9,993 36 View
Assume two identical fermions, e.g. 3He, and polarized with the same spin projection, e.g. z-polarized. The fermions are sent from afar to the same detector - see attached picture. The dimensions...
28 October 2016 2,672 14 View
Dear friends, I am interested in the Stern-Gerlach experiment, with spin 1 atoms. I see in pictures that the apparatus contains two long magnets, typically, of 13 cm length. I am interested to...
06 October 2016 2,474 14 View
Assume that the particles in the system don't react among themselves and don't undergo any change of the type of particle. Assume also that their energies are not very high, i.e. we don't have...
01 October 2016 2,901 19 View
The realism hypothesis in QM says that results of measurements on quantum systems, are completely determined by subquantal parameters (hidden or detectable, local or non-local). These parameters...
12 June 2016 7,188 50 View
Imagine two fermion wave-packets of Gaussian form, whose paths cross one another, see figure. The blue circles represent the two wave-packets at different times. At a certain time the wave-packets...
11 May 2016 6,492 84 View
I was told repeatedly and I saw in different places the statement that the quantum field theory (QFT) doesn't admit a fix number of particles. But I didn't succeed to understand why. I am familiar...
05 May 2016 5,267 29 View
Atom optics is typically done in the last years with gratings of light. These gratings successfully implement mirrors and beam-splitters. Two counter-propagating laser beams cross one another, and...
24 March 2016 2,346 5 View
What is the meaning of the uncertainty relation ΔE Δt ≥ ħ during the energy measurement of a particle? My understanding is that Δt should be the time-window of the detector. But I am not sure....
13 March 2016 8,368 4 View
I think that inside a reactor one can obtain neutrons of different energies. My question is if it is possible to create two sources as in the picture?
29 February 2016 6,189 1 View
I think that there exist neutronic stars, but do they emit? Do we receive neutron radiation from those stars? If not, are there other sources of fermions?
21 February 2016 9,809 4 View
The principle of the Hanbury-Brown and Twiss experiment (see picture) says that the joint amplitude of probability that a particle from the source A be detected in the detector 1 and a particle...
07 February 2016 6,771 9 View
Consider a gas of identical boson-particles, e.g. atoms of a noble element. Let the gas be at a low temperature, s.t. the mean kinetic energy of the atoms is low. I think that during their...
30 January 2016 3,968 5 View
In the B-E formula for the average number of identical bosons that can occupy a single particle state ψj , out of a set of such states ‹n›j = 1/{exp[β(ϵj – μj)] – 1} there appears the chemical...
30 January 2016 6,494 6 View
There is disagreement between scientists about the reversibility of the spontaneous decay. There is analogy between the de-excitation of an excited atom (with emission of a photon) and the decay...
27 December 2015 2,186 41 View
All that I have about the Bose-Einstein distribution is the statistics of the occupation number n of the j-th energy level, (1) = 1/{exp[(μj - ϵj)/kBT] - 1} where μj is the chemical...
21 December 2015 5,638 5 View
In the light that we get from stars we discern certain lines belonging to the most abundant elements in those stars. Assume that we would pass the light from a star through a prism in order to...
01 December 2015 9,886 3 View
I am no specialist in the topic of neutrino flavor oscillations, but I examined a lot of articles, theoretical and experimental, on this topic. And the result is that I remained with doubts on...
21 June 2015 1,425 80 View
Assume two opposite charges at a big distance from one another, and placed in vacuum. The charges are in relative movement with constant velocity. At a certain moment the charges "feel" one the...
21 March 2015 5,103 4 View
This question is a reaction to the fact that some authors hold that the interaction between a microscopic object with a macroscopic object, leads to an entanglement between the states of the...
01 January 1970 8,865 55 View
I need help about a problem which seems trivial, but I would like to see material with experimental evidence. It is clear that for a single-particle wave-function of, say, an electron, e.g. (1)...
01 January 1970 6,296 8 View
The CSL model of collapse was constructed by Ghirardi, Pearle, and Rimini. The model takes the reduction of the wave-function as a real phenomenon. Do you believe that it is a correct view?...
01 January 1970 7,734 60 View
Asher Peres: VARIABILITY OF FUNDAMENTAL CONSTANTS "Are universal fundamental constants really constant over cosmological times? Recent observations of the fine structure of spectral lines in the...
01 January 1970 4,333 97 View
NOTE: In consequence of some answers of users due to whom part of the issues become clarified, I do from time to time MODIFICATIONS in this question stressing the remaining questions. Shan Gao,...
01 January 1970 7,736 48 View
Here is a citation from a letter wrote by Einstein to Born on 12 May 1952 ("The Born–Einstein Letters", Macmillan, 1971, p. 192.) Einstein asked Born: "Have you noticed that Bohm believes (as de...
01 January 1970 8,484 49 View
We understand mass in the practical life, as an amount of substance. About light we say that it has no rest mass. But substance it has in a way, I mean, it carries electromagnetic...
01 January 1970 6,925 65 View
I "heard" people saying that Feynman had the opinion that nobody understands QM. But what does that mean? Does it mean that we are not smart enough? Or, alternatively, does it mean that QM...
01 January 1970 6,506 13 View
How can we establish the age of a black hole? I think that black holes are the oldest and the most massive objects in the Universe. Am I right? Since nothing gets out from a black hole we cannot...
01 January 1970 4,687 9 View
The behavior of macroscopic objects is dictated by the principle of least action, or, its equivalent form, the laws of Newton. In the thermodynamics, the heat equation is a law for the spreading...
01 January 1970 4,264 60 View
I tried to publish a proof by which the Bohm interpretation of QM is problematic, The End of Bohm's Mechanics? -A variant of the Tan-Walls-Col... in a journal, and the editors claimed that...
01 January 1970 1,233 10 View
A user, Richard Lewis, proposes as basic principles of the quantum mechanics (QM), the following: - wave / particle duality - the uncertainty principle - the correspondence principle - quantum...
01 January 1970 6,151 26 View
In my article The Wave Function Cannot be a Real Wave -Then, Can We Speak ... I show that the most popular interpretations of the quantum mechanics (QM) fail to reproduce the quantum...
01 January 1970 4,252 60 View
There is an opinion that the wave-function represents the knowledge that we have about a quantum (microscopic) object. But if this object is, say, an electron, the wave-function is bent by an...
01 January 1970 969 97 View
Does that mean that in each trial of an experiment there is a different number of particles? Or, alternatively, does it mean that in any given trial the number of particles is undefined? If the...
01 January 1970 4,932 25 View
What is the axiomatic difference between Feynman's path integral, Schrodinger's equation, and Heisenberg's matrixial picture on QM? Is there something that Feynman's path integral assumes, and the...
01 January 1970 3,601 3 View
NOTE : This question is connected with another one, at...
01 January 1970 3,755 26 View
(The issue behind this question is the possibility of shortening the flight time in space travels. One possibility is great velocity, but I am asking here about another means.) In the flat space,...
01 January 1970 582 29 View
Here is the equation (1) Rμν - ½Rgμν + Λgμν = 8πGc-4 Tμν . Since Tμν represents sources, e.g. masses, this tensor should vanish in void - this is a claim that I saw in different places. Next, as...
01 January 1970 3,310 100 View
Consider an experiment in which we prepare pairs of electrons. In each trial, one of the two electrons - let's name it the 'herald' - is sent to a detector C, and the other - let's name it...
01 January 1970 9,544 16 View
Consider the wave-function representing single electrons (1) α|1>a + β|1>b , with both |α|2 < 1 and |β|2 < 1. On the path of the wave-packet |a> is set a detector A. The question is what...
01 January 1970 859 67 View
Consider the polarization singlet of two photons 1 and 2 (1) |ψ> = (1/√2) ( |H>1 |H>2 + |V>1 |V>2 . Let's represent the photon 2 in another base than { |H>, |V>}, e.g { |B>, |C>} the...
01 January 1970 3,022 34 View
A photon is a wave-packet which can be Fourier expanded as (1) Σp exp[i(pr - Et)/ħ] The phase velocity, i.e. the velocity of propagation of the phase, is obtained for each Fourier component by...
01 January 1970 2,526 34 View
In his work "The Consistent Histories Approach to Quantum Mechanics" publish in the Stanford Encyclopedia of Philosophy, Griffiths claims that this approach overcomes the problem of the...
01 January 1970 8,069 3 View
