# All Questions

65 views

### Assymptotic freedom significance

So I have read a bit on this, and get the idea and mathematical machinery leading up to this. I get that it sheds light on the relationship between coupling strengths and length scales. Can someone ...
312 views

### Clarifying constraint forces in Lagrangian dynamics

In the Lagrangian formulation, the addition of constraint forces that are unknown can be done with Lagrange multipliers, which allows for the forces to be found. Taking $k$ constraints of the form ...
602 views

### Difference between $SU(2)$ and $SU(2)$ gauge transformations?

I hear this jargon all the time, so what is the difference? (Of course this is nothing special to $SU(2)$, but rather I just took it as an example)
161 views

### Work and its nature?

Suppose we have a constant force $\overrightarrow{F}$ and in the direction of force we have 2 point $x_1$ and $x_2$ in that order. And we have to calculate work done on moving frok $x_1$ to $x_2$ and ...
162 views

### Physical meaning of uncertainty principle + question on symmetry

A question on the Uncertainty principle. So we know that it says (for position and momentum) that: $$\Delta x \Delta p \ge \hbar/2$$. Where $\Delta p = \sqrt {<p^2> - <p>^2 }$ and ...
531 views

### Spin orbit coupling and fine structure of the Hydrogen atom

At university we have just derived the expression for the energy split due to spin-orbit coupling in the Hydrogen atom, i.e. what is known as the FINE structure of Hydrogen. To do this, we ...
3k views

### HEPA vs. water filter in vacuum cleaning [closed]

What is the difference between air being filtered with HEPA or water? Which one performs better within a non-allergic home environment? Does water filter have a meaning still when common vacuum ...
162 views

### Mass in terms of special relativity

According to special relativity mass doesnt add up like we think it does. That is, a system of 2 protons might not necessarily have a system mass of 2*(mass of one proton). If the protons are ...
51 views

### Capacitance of a free conductor

Consider a ideal conductor in free space.For all purposes here,the zero of the potential is taken at infinity. Suppose I give a charge $Q$ to the conductor.As a result,the conductor will have a ...
139 views

### Change of QM Momentum operator under coordinate transformation

Can any one please let me know what is the general procedure to construct the momentum operator under some coordinate transformation? For example, I understand that if ...
1k views

### Why doesn't current flows in reverse biased diode?

Consider this reverse biased diode : I read that no or very small current flows in reverse biased diode as depletion layers get widened and huge resistance is offered so no electrons can cross it. ...
105 views

### A question about the numerical simulation on classical three-body gravitional system

Related to this post Just out of curiosity, I have a question about the current status of classical (Newtonian) three-body gravitional numerical simulation. I found wikipedia is relatively limited on ...
146 views

### What is use of inertial frames

In class of Newton's laws of motion, it was explained that Newton's second law is valid only in inertial frames. Teacher give us a example by considering a lift which is going downwards with ...
140 views

Regarding the future applications of terahertz technology, I thought we already knew the entire electromagnetic spectrum. In fact we do not, terahertz lies between microwaves and infrared radiation. ...