A general quick and dirty formula
Consider the equation for the density:
\rho=\frac{An}{N_AZ}
Where
\rho = the density
n = the density of electrons in the conduction band
A = atomic mass, consider this to be a constant
N_A= Avogadro´s number
Z = valence, consider this to be...
Can someone explain why the compton wavelength and event horizon are used to determine the uncertainty in what we can see if we were to look back in time to the big bang. (We can only see back to 10^-43 seconds after the big bang.)
Here's a website that derives this time (Planck time)...
Thank you so much for your reply, Physics Monkey.
You are correct about the direction of the vector potential, I made a mistake in its direction. It should be in the y-direction and I've edited my original post to correct it.
I've also gone back and replaced full derivatives which...
The problem (From Electromagnetism by Pollack and Stump, exercise 11.34)
A stationary charge of charge e and mass m encounters a electromagnetic wave with vector potential
\vec{A}=\vec{j}f(x-ct)
where
\vec{j}
is the unit vector in the y-direction. The scalar potential is zero...