Recent content by radonballoon

So then would I be on the right track if I found the phase difference between each pair and then added them to get the final phase difference?

Homework Statement There are three slits in a screen, with one aligned with the source at z=0, one a distance a above 0, and one a distance b below 0. Another screen is at a distance d >> a,b from the first. What is the periodicity of fringes on the screen? Homework Equations \Delta \phi =...

thanks, that clears it up. I figured that's what would happen, but I wasn't sure. To other poster: The poynting vector can be pointing in say the z direction and have the electric vector pointing in -x direction (magnetic field in -y direction). Then if the waveguide (two parallel planes)...

So we just went over waveguides in my class, in particular the TE and TEM modes (for a perfect conductor with two infinite planes for waveguides). I know that according to boundary conditions (assuming perfect conductor), the transverse electric field components must be zero at the boundary...

I know that it's a pseudo force that arises when you use a non-inertial reference frame. However, say there is nothing but vacuum and a hollow donut if you will, and an object floating in the vacuum inside the donut. The object is not touching the donut, and then it begins to spin. In an...

Ok thinking about it some more, I think I understand. Obviously if someone was floating nothing would happen, but if he then collided with one of the walls he would be accelerated in the direction they were moving, and then this happens again and again until he is moving with the same speed as...

The people inside the car feel the force of the turn only because they are attached to the car in some way (in this case by gravity/seatbelts), the people in the space station would be floating before the station spun, they would not be attached in any way to the station. The air in the space...

Ok, so I'm having trouble imagining why a "centrifugal force" would exist for a rotating space station. As I understand it if there was only vacuum inside the station then anyone inside it would not move toward the "floor" (outer wall), so I can only imagine that it would be the air inside the...

Haha wow this seems like so long ago. I couldn't find the dot for dot product, so thanks for that :D

Thanks for that last link, it has cleared up a whole mess of confusion. I think I finally have it this time: a^{\mu '} = \Lambda^{\mu '}{}_{\mu}a^{\mu} b_{\mu '} = \Lambda^{\mu}{}_{\mu '}b_{\mu} Since it's covariant, use inverse matrix. Then: a^{\mu '}b_{\mu '} = \Lambda^{\mu...

Ok I think I've got it! My professor didn't explain it quite like that, the way you put it makes much more sense. So this is what I've got: a'^{\mu} = \Lambda^{\mu}{}_{\nu}a^{\nu} \text{ and } b'_{\mu} = \Lambda^{\mu}_{\nu}b_{\nu} a'^{\mu}b'_{\mu} =...

Thanks for all the help, but I'm still confused. I don't see how I can assume that \Lambda^{\mu}{}_{\nu}\Lambda^{\sigma}{}_{\mu} = \delta^{\sigma}{}_{\nu}. I could see how I can assume this if what I'm trying to prove is true, but I can't assume this if I'm trying to prove it. How am I supposed...

It's a problem in my textbook, assigned by my professor. I wasn't even really sure what the problem was asking either. Looking around on google, a similar problem was solved on planeyphysics: http://planetphysics.org/encyclopedia/SpacetimeIntervalIsInvariantForALorentzTransformation.html So...

Thanks for the reply. Ok so I guess it should have been a'^{\mu}b'_{\mu} = \Lambda^{\mu}_{\nu}a^{\nu}b_{\nu}. I'm aware that the initial equation is a scalar, I was merely turning it into a vector so I could easily transform it. I then squared each component, negated the first and summed...

Homework Statement Show that a^{\mu}b_{\mu} \equiv -a^0b^0 + \vec{a} \bullet \vec{b} is invariant under Lorentz transformations. Homework Equations \Lambda_{\nu}^{\mu} \equiv \left( \begin{array}{cccc} \gamma & -\beta \gamma & 0 & 0 \\ -\beta \gamma & \gamma & 0 & 0 \\ 0 & 0 & 1 &...