Recent content by neobaud

He was not talking about an eternal wave. His example started at the pair annihilation. You can't have an EM wave plane or no come from nowhere. Can you give more info about how to modify my equation at the scale of the entire universe?

If an em wave came from nowhere, that would violate conservation of energy.

Thanks so in the equation $$\mathbf{F} = q_1 \left[ \frac{1}{4\pi\epsilon_0} \frac{q_2}{r^2} \hat{\mathbf{r}} + \mathbf{v}_1 \times \left( \frac{\mu_0}{4\pi} \frac{q_2 (\mathbf{v}_2 \times \hat{\mathbf{r}})}{r^2} \right) \right]$$ There is an additional factor? I get the fact that there may...

One of the main things I am trying to learn is if r in this equation is the r at time t-r/c, does this equation become correct?

Sorry what is an eternal space time? I was assuming spacetime originated at the big bang. Is this not the case?

Oh ya. But the wave originated from a charge at some point right? So if I wanted to figure out the total force between two charges it would be Static force+Magnetic force+wave force? So in my equation above I need one more term for the wave part?

Oh ya I had amended my original question in the thread. The equation for the force would be $$\mathbf{F} = q_1 \left[ \frac{1}{4\pi\epsilon_0} \frac{q_2}{r^2} \hat{\mathbf{r}} + \mathbf{v}_1 \times \left( \frac{\mu_0}{4\pi} \frac{q_2 (\mathbf{v}_2 \times \hat{\mathbf{r}})}{r^2} \right)...

Ok interesting. How can there be a field potential without a charge? That is where the field comes from isn't it?

Ok I just looked up Liénard-Wiechert potential and that approach is exactly what I am asking. So I guess the answer is yes

Ok right the equation is wrong. Let me adjust that then. There is some more complicated equation for the force between two charges that is a factor of their distance and velocity. If I applied that equation to each charge for it's distance at time t-r/c, does this account for special...

So Coulomb's law is this simple formula for calculating the force between two charges. Kq1*q2/(r^2) (Disclaimer: I know this computation is not actually possible I was just wondering if it would give the correct result) I was wondering if it is valid to sum the force vector from every charge...

Right. I am skeptical of her experiment because it is hard to say if it was a limitation of the sensors. She is using her cell phone and some cheap distance finder from a hardware store. What if the SNR was just not high enough to detect the return beam. A detector like this would most...

Yes this is exactly what I am wondering. Is this just a very small amount (immeasurable?)

So what do you think? Will any part of the original light exit the medium at time d/c? Dale seems to think it won't (or at least a measurable amount) and everyone else seems uncommitted. Maybe it's too complicated to know for sure without a really good experiment?

Ya that figure shows exactly what I was wondering about. At t_start the original wave starts ramping up. The transmitted wave doesn't actually get going until a bit later right? So it seems like some of the original wave should get to the edge of the material before the cancelling phase can...