# Recent content by say_cheese

1. ### I Can someone expand (curlA.del)(curlA)

is there a simpler expansion of ((∇xA).∇)(∇xA). This is a common term in fluid equations.
2. ### I Quantum Entanglement-Susskind-lecture 4&5

In Lecture 5 on quantum entanglement, Susskind calculates the Bell's inequality terms using projection operator (a difficult concept and a tedious derivation). However, I believe the following I obtained the result on the Bell's inequality using the probability of spin of an electron prepared...
3. ### A Nonlinear first order Differential equation

Good questions. My present mesh sizes are about 5% of the variation length of the driving term A. The driving term is sinusoidal in theta and phi with a mild radial dependence. (180,50,50) mesh. There is a sharper variation in one area and I have remeshed there 5 times. It is quite possible...
4. ### I Descriptiveness of this term

One way to look at it is that it is the momentum imparted through the electromagnetic force, Momentum wikipedia - The classical Hamiltonian ℋ for a particle in any field equals the total energy of the system – the kinetic energy T = p2/2m (where p2 = p · p, see dot product) plus the potential...
5. ### A Nonlinear first order Differential equation

I will try this, but that is only one term in (v.∇)v. The parameters have 3 components and the components of the equation have other component terms such as vr∂vθ/∂r.
6. ### A Nonlinear first order Differential equation

The theta and phi coordinates are cyclic (v(0)=v(2*pi)), v=0, dv/dr=0 at v=0 and a.
7. ### A Nonlinear first order Differential equation

I need to solve the well known momentum equation in 3D cylindrical coordinates: ρ(∂v/∂t +(v.∇)v)=A where A and the velocity v are both local vector variables. I am actually looking for the stationary solution to the equation, i.e. no ∂/∂t term) I have tried evolving the velocity and tried...
8. ### Flux surface average for a tokamak

I am trying to figure out the flux surface average of a 3D perturbation in a tokamak. For example what is the flux surface average of cos(m*theta+n*phi) at a given flux surface. (Theta and phi being poloidal and toroidal angles respectively?
9. ### Don't quite Understand the terminology -- Local gauge

I hope someone with a deep conceptual understanding of terminologies would help me out here. I am having starting problems in understanding the approach of gauge theories. I have read suggested threads and I am still at a loss. I am an experimental physicist and know basics of electrodynamics...
10. ### Hard Science Fiction

Ditto on the Martian. Did you know that it was a manuscript rejected by publishers and the author published on the web and became an instant hit and in a year or so, the moviee is going to be out soon. Hilarious, serious, "down to Mars" movie with everything in it from present day NASA science.
11. ### Consequence of Making a Higgs particle

I am still puzzled by this question. I admit that the Higgs decays, but only in a finite time such that, for example, energy has to be conserved. In the case of creating quarks etc., there are clear conservation laws. In the case of Higgs production there must be a consequence,a ripple and...
12. ### Consequence of Making a Higgs particle

I apologize, I did mean Higgs Field but also a boson associated with it. Yes, I am wondering if the appearance of the Higgs boson changes the Higgs field locally and what is the consequence.
13. ### Consequence of Making a Higgs particle

Now we are presumably creating (?) Higgs Bosons in the collider. But the universe is permeated already by the Higgs field and Higgs bosons. When the colliders make an "artificial" Higgs, what conservation laws (in addition to energy, momentum, charge, isospin, baryon number etc.)are obeyed? In...
14. ### Velocity Cone in expanding universe

Thanks. I do see the figures and see the agreement with Jorrie's calculator. Great!
15. ### Velocity Cone in expanding universe

The figures in http://www.astro.virginia.edu/class/whittle/astr553/Topic16/t16_light_cones.html are very useful in understanding the various world lines in concordant diagrams. Is there any easy way to see how a velocity cone (at the observer's worldline) from a later time than the Big Bang...