What exactly said J. von Neumann about the wave-function "collapse"?

I wasn't able to get von Neumann's book "Mathematical Foundations of Quantum Mechanics". But I saw many descriptions on his scheme of measurement, all of them saying the same things. What I was...

11 December 2018 5,509 21 View

Could this be a NO-GO of the quantum mechanics?

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...

10 November 2018 3,557 97 View

I am interested in processes of absorption and coherent delayed re-emission. Can somebody indicate references?

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...

07 August 2018 8,003 7 View

How sure we are that the photon is a particle? How big is a photon of radio frequency?

08 September 2017 5,047 4 View

What you think about weak measurements? Can we trust them?

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...

06 July 2017 5,351 15 View

What in fact did Sidney Coleman wanted to say in his lecture "Quantum mechanics in your face?

In his lecture https://www.youtube.com/watch?v=EtyNMlXN-sw Sidney Coleman, a famous physicist in the quantum theory and famous lecturer in the domain, tried to explain at a simple level the...

04 May 2017 4,221 86 View

A relativistic puzzle: can somebody solve it?

Assume two space-stations at rest with respect to one another. In one station works the experimenter Alice, and in the other, the experimenter Bob. Consider that at the time t0 by the clock of...

11 December 2016 6,283 18 View

What happens to the spin of a particle when passing from one frame of coordinates to another frame in relative movement?

09 October 2016 6,616 18 View

What happens with the linear momentum of two identical fermions identically polarized and sent to the same detector?

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...

09 October 2016 4,226 15 View

What is the "resonance of two photons of 750 GeV"?

08 September 2016 7,618 10 View

flexibility of polymers chain

effect of double bond on the flexibility of polymers

07 April 2021 0 0 View

Formulation of polymer color flakes

I am writing to request some information for making polymer color flakes. I would appreciate the help.

17 March 2021 0 0 View

Physics: Why do we describe light by referring to its wavelength, but microwaves and radar pulses by referring to their frequency?

In physics, the description of the properties of light generally refers to its wavelength (nm), while in the range of microwaves and radio waves we refer to the frequency of a signal (e.g. kHz or...

03 March 2021 1,682 3 View

What is your perception on using visual analysis or quantitative approaches to evaluate data from single-case research designs (n of 1 trials)?

Results of single-case research designs (i.e., n-of-1 trials) are often evaluated by visually inspecting the time-series graph and computing quantitative indices. A question our research team is...

03 March 2021 687 1 View

Resistor definition in Piezoelectric bimorph with ANSYS workbench

Hello, good day! I am trying to simulate similar bimorph piezoelectric harvester with below commands. However, the output power doesn't change with resistor value. Please help to find the reason. ET,10,CIRCU94,0 !SET UP RESISTOR R,1,100000 !RESISTANCE VALUE TYPE,10 !SET ELEMENT TYPE E,1,2 !CREATE RESISTOR BETWEEN NODES 1 AND 2 Thanks in advance Regards,

02 March 2021 0 0 View

Why are the velocities so high in my Boussinesq approximation Fluent simulation?

Hello, I have a mechanism where air rises due to convective flows. In this simulation, nothing is driving the air except this. I understand that the Boussinesq approximation only works for small...

02 March 2021 4,910 3 View

What is the characteristic length to determine the Reynolds number for the scattered turbulent fluid flow?

Dear all, I just saw this example in FB on the difference between laminar flow and turbulent flow. The flow from a pipe hits the sink and scattered. The flow from the pipe is characterized as...

02 March 2021 1,999 5 View

Why almost every element would be metallized in sufficiently high pressure and low temperature?

(This statement is from wikipedia, BTW). What is so special about metallic bond that is limiting high-P low-T state of a matter (as long as individual atoms exist, not white dwarf of neutron star...

02 March 2021 3,309 2 View

Why Austenite grains in steel show much more twinning than ferrite grains?

It is oftentimes said to be a distinctive metallographic trait that differentiates a fully austenitic and a fully felly ferritic steel without etching that might distinguish between two. Why...

02 March 2021 728 2 View

How Relativistic effects is one reason for lanthanide contraction?

The Lanthanide contraction which is the decrease in ionic radii of the elements in the lanthanide series from atomic number 57, lanthanum, to 71, lutetium, is due to poor shielding of the 4f...

01 March 2021 2,272 4 View