# All Questions

15 views

### Experiments / theory of digitizers mixed with wave mechanics [on hold]

Classical waves arise in a wide variety of situations and are often/usually/typically measured with analog measurements. However, combining use of a digitizer can complicate the analysis. I am ...
39 views

### Kinetic energy during 1 minute - wrong? [on hold]

I've come across this IEEE paper whilst researching for a project I've undertaken regarding a bicycle generator. This paper concerns an exercise bike powered electric generator. Essentially they have ...
133 views

### Is there a time operator in quantum mechanics?

The question in the title has been asked many times on this site before, of course. Here's what I found: Time as a Hermitian operator in QM? in 2011. Answer states time is a parameter. Is there an ...
15 views

### Systems evolving towards equilibrium

I believe that in quantum transport the states in contacts are forced to be in equilibrium (can someone comment on it? the boundary conditions used (ansatz) essentially suggest that states in contacts ...
28 views

69 views

### Why are harmonic oscillators quantized? [on hold]

What physical reason is there for a mass on a spring to have discrete energy levels? And why are those energy levels equally spaced, i.e. why is $E \ \alpha \ f$? Personal background and ...
20 views

### Is there a relationship between kinetic energy of emitted electron and photoelectric current?

I know that photoelectric current is dependent upon intensity of incident light. But it should also be dependent upon kinetic energy of emitted electron because mathematically $I=Q/T$. So if kinetic ...
14 views

### Cooldown of a 1 meter wide sphere of water at 10C° in space [on hold]

I am wondering how long would it take for such a sphere of water to totally be under 0C°. Let's suppose that the surface tension is enough to keep the topology of the sphere intact an that it will ...
27 views

### Meaning of components of Maxwell's stress tensor $T_{ij}$

I am learning about Maxwell's stress tensor and what I understood is that the components, say $T_{ij}$ is something like a force parallel to the $j$th-direction acting on the surface with its normal ...
89 views

### Quantum Mechanics in your face

In this lecture Quantum Mechanics in your face by Sidney Coleman http://www.youtube.com/watch?v=EtyNMlXN-sw Does he state that there's only evolution according to Schrodinger's equation in QM and it ...
24 views

### when does normal force equal to mg?

Can someone once and for all explain when does normal force equal to mg? I know for sure that when there is no friction, normal force will be equal to mg. But, i encountered some questions when there ...
22 views

### Incident angle and refracted angle

I came across this picture while studying about Huygens' principle and Laws of Refraction.In my book I saw that it is mentioned $\theta_1$ is the incident angle and $\theta_2$ is the refracted ...
14 views

### Why does the current decrease when the battery is disconnected despite the supplying of energy by induced emf?

When the battery is disconnected from an LR circuit, the current decreases to zero. But why does it happen so? The inductor is constantly feeding up energy to the current to compensate the ...
18 views

### Does matter shrink due to energy radiation and does it have anything to do with dark matter and dark energy?

Is matter shrinking? Is shrinking the cause of concentrated dark matter that makes up matter moving from concentration to unconcentration. Does dark energy and expansion of the universe come from this ...
20 views

### Does Coriolis force effect a particle that has only a tangential velocity in a rotating frame?

Imagine a disc rotating at an angular velocity $\omega$, a particle on the disc which is attached to the disc so its also rotating at an angular velocity $\omega$. Now the particle has tangential ...
19 views

### How do quantum particles interact with each other? [on hold]

Does infinite expansion of particles become finite when the smallest stuff that makes up matter interact with each other? Would then those particles be in the form of shapes,such as platonic solids ...