533 reputation
112
bio website
location India
age
visits member for 1 year, 8 months
seen 5 hours ago

1d
comment What is the meaning of spin two?
Hi you have discussed spin-0 particle as the quanta of scalar field, spin-1 particle as the quanta of vector field and spin-2 particle as the quanta of tensor field. But what about spin-1/2 particles? What do we call the field of spin-1/2 particles?
Oct
12
comment Jarlskog Invariant and its mathematical origin
@LubošMotl, The quotation in my comment is from your answer (see just below the definition of J) where you have mentioned if any of the sines or cosines of the angles is zero then the U matrix can be brought to real. But from standard parametrization, we see that if $s_{13}=0$, then only U matrix is real.
Oct
12
comment Jarlskog Invariant and its mathematical origin
@LubošMotl, Is this really true "or if any of the sines or cosines of the angles vanish in which case it's also possible to bring the matrix into a real form." ? I thought it is possible only when $s_{13}$=0. Can you give some reference ?
Sep
25
revised Why doesn't current flow when the wire is open?
added 1 character in body
Aug
30
comment Finding the direction of the magnetic force acting on a conducting wire
The Lorentz force acting on the wire is given by $\vec{F}=q(\vec{v} \times \vec{B})$. If you don't know how to find the direction of the cross-product of the two vectors, please refer to this wiki article
Aug
28
comment Why there is a time gap between the news presenter and the field reporter?
@MikeDunlavey, In that case it would be better to mention your guess in few words too so that everybody knows what maybe a possible answer.
Aug
27
comment Why there is a time gap between the news presenter and the field reporter?
@MikeDunlavey "So the field reporter would hear the question sooner if he simply watched the channel!" .It is not necessarily true. Suppose anchor says XYZ at 12:00:00 and time required to reach the signal(XYZ) to reporter and return back to the anchor is 1 second. Then anchor sees the signal(XYZ) come from the reporters cell phone at 12:00:01. But that does not necessarily mean you are also watching these at the same time. Maybe the signal takes 5 seconds,say, to reach you. so you are hearing anchor's question at 12:00:05 and the reporter's cell phone at 12:00:06.
Aug
21
comment Does centrifugal force exist?
@dmckee, do you still have that view about the answer after the EDIT part having the example of turning the bus? But I don't know how the animation is showing centrifugal force and maybe this is what you are talking about in your comment.
Aug
21
comment Are voltages discrete when we zoom in enough?
Okay maybe I couldn't make you understand my question. I wanted to ask from where you get these information: "Capacitance is a function of the shape, size and distance between objects". Do you use C=$\frac{Q}{V}$ to get these information? Or can they be known from something else? In the latter case I am OK with your answer. But if we need C=$\frac{Q}{V}$ to get those information I think Floris' answer is better.
Aug
20
comment Are voltages discrete when we zoom in enough?
I think C is defined in terms of Q and V (maybe I am wrong, and in that case I seek clarifications). And from that you get these informations: "Capacitance is a function of the shape, size and distance between objects". Again you are using these informations to tell something about V? I think Floris' answer is better.
Aug
14
revised Doubt regarding Ampere's Circuital Law
added 3 characters in body
Aug
13
revised Doubt regarding Ampere's Circuital Law
added 1 character in body
Aug
12
answered Doubt regarding Ampere's Circuital Law
Aug
12
comment Doubt regarding Ampere's Circuital Law
I think you are getting this inconsistency as you are breaking continuity equation by taking only a finite current carrying wire alone.
Aug
12
comment Doubt regarding Ampere's Circuital Law
see the magnetic field is still tangential. And I agree with you that in the case of finite wire the magnitude of the $\vec{B}$ depends on z also. But it doesn't depend on $\phi$ which is important in this case of line integral. As it doesn't depend on $\phi$ you can still take the magnetic field out of the integral and you have B(r,z)=$\frac{\mu_0 I}{2\pi r}$. But this is inconsistent as left hand side shows dependence on Z (so our intuition is) but right hand side shows no dependence on Z. I think this is what OP's question is.
Aug
12
comment Doubt regarding Ampere's Circuital Law
"where it is obvious that the B-field should not just depend on the radial coordinate, so our simple calculation fails": I think if you apply Biot-Savart law you can see toward the end too it is still tangential to the circular loop. And that is where I think OP's question is. I think the probable answer is: we can't take only finite straight current carrying wire without violating continuity equation.
Aug
10
comment Unitarity of PMNS matrix
Let us continue this discussion in chat.
Aug
10
comment Unitarity of PMNS matrix
I don't know whether you are getting my question or not. I want to ask whether Hamiltonian is Unitary always. DO you mean $H^{\dagger}H=I$? Then again $H^{\dagger}=H$ ,so that $H^2=I$? And you know the consequences of this. All the eigenvectors are degenerate, moreover all the vectors are eigenvector of $H^2$.
Aug
10
comment Unitarity of PMNS matrix
I knew the Hamiltonian must have to be Hermitian. But should it be Unitary also?
Aug
10
comment Unitarity of PMNS matrix
Do you really mean this: "The Hamiltonian for any system must be unitary"?