862 reputation
11339
bio website axiomsofchoice.org
location
age
visits member for 3 years
seen 9 hours ago

A duck walks into a bar. Animal control is promptly called and the duck is released into a near by park.


Mar
13
suggested suggested edit on Do batteries lose charge?
Mar
13
revised Why do noble gases stabilize plasma discharges?
added 19 characters in body
Mar
13
answered Why do noble gases stabilize plasma discharges?
Mar
12
comment Can Somebody give me Questions
You misinterpreted the Q&A concept.
Mar
10
comment Why quantising gravity necessarily give us gravitons?
Do you know if there is any hypotetical way of tweaking the spin degrees of freedom and make the graviton a fermion? Are there physical arguments against that?
Mar
9
revised Tensor product of Hadamard Operators
suggestion to make it parsable
Mar
9
suggested suggested edit on Tensor product of Hadamard Operators
Mar
8
revised What is an effective and efficient way to read research papers?
added 134 characters in body
Mar
8
answered What is an effective and efficient way to read research papers?
Mar
7
comment How to find different operator representations in QM?
@DepeHb: i.imgur.com/IchgG0c.png Momentum is that which is conserved if you translate the system. Turns out the operator $T_d$ which shifts a function $f(x)$ by $d$ can be written as $\exp\left(i\hbar\,d\,\left(\frac{1}{i\hbar}\frac{\partial}{\partial x}\right)\right)$. The generator is the momentum operator $\propto\frac{\partial}{\partial x}$ and so as function of $x$, the eigenstates $\left|p\right\rangle$ of that operator must be $\mathrm{e}^{cpx}$.
Mar
7
revised Naive visualization of space-time curvature
added 5 characters in body
Mar
7
comment Naive visualization of space-time curvature
@StanLiou: Then you are assuming you can explain the notion of a local interial frame to a layman.
Mar
7
answered Naive visualization of space-time curvature
Mar
5
answered Do Dirac Gamma Matrices act like Tensors?
Mar
5
comment Is there a limit to acceleration?
@Carterini: Not that a factor of 2 is of any relevance if we're already speaking of $10^{51}$, but no, $2.2$ is the value you get if you plug in "(speed of light)^(7/2)/((Plancks constant)*(Gravitational constant))^(1/2)" into wolframapha and so here I bet against your back of the envelope calculuation. And I say it again, I'd just sit down and see how fast momentum can translate between two particles, say with a $\left|r_1(t)-r_2(t)\right|^{-2}$.
Mar
4
comment Is there a limit to acceleration?
Afaik, there is no slogan about maximal acceleration. You could cook up a Planckian acceleration $c^{3.5}/(\hbar G)^{0.5}\approx 2.2\,10^{51}m^2/s$, but I don't see the use for that here. Seems the latter must ask for r'' vs. W. We should maybe make it a little more concrete. Consider a particle at rest with $r_1=0$ at some time and set up a potential $V(|r_1-r_2|)$ with another particle. You can consider a) a free collision (where total momentum is constant) and compute $r_1''(t)$. b) try to compute the energy cost it takes to move the second particle in some way to push the other one.
Feb
27
revised Group of translations in two dimensions - A weird treatment
check it out
Feb
27
suggested suggested edit on Group of translations in two dimensions - A weird treatment
Feb
27
comment What's the real fundamental definition of energy?
...and call this the Lagrangian, for the map $t\mapsto q(t)$ it should read action there, alternatively you can speak about the image of that map.
Feb
26
comment Why do we use $\psi$ instead of a straightforward probability?
This thread should answer the question.