Recent content by cavalier3024

This is really more of a philosophical question.. But i think that what they meant is this: according to copenhagen interpretation, the wavefunction will collapse to either state at a 50% chance, so the person may or may not die. But according to the many worlds interpretation the wavefunction...

not after you correct the light delay.. as i said before - take a look at http://upload.wikimedia.org/math/c/0/f/c0ff5f091774a86621f711d11e7c0068.png" (t is the time in one reference frame, and t' is the time in a frame moving at speed V relative to it). now let's look at a situation where a...

what i meant is that if he will look towards the direction opposite to his movement, the farther away he will look the more he will see into the past. but if he will look forward, towards where he is moving, the farther he will look the more into the future he will see. (all the times of course...

why not? let's ignore the delay caused by light. even now, two observers moving relative to each other will 'see' the same event happen at different times (lets assume that both observers are currently at the same position and that the event occurs at a different position). and the difference...

exactly! what i tried to say is that: the fact that each measures the other to be younger is NOT just a consequence of the fact that light takes some time to travel between them. i don't know why you thought that i thought the opposite.. but anyway thanks for clarifying my case..

yep. that's true, but still, only one can happen - either the two clocks are at the same location when they start, or they are at the same location some time after they start, when they measure each other. in either case there is a point in time where the two clocks are at different locations...

if i understand you correctly, the purpose of this hypothetical device is to help synchronize the two clocks A and B? if so, it doesn't really provide a solution, and to explain why i need to first see if we agree about relative simultaneity. what i say is that if from A's point of view two...

ok, so first, you can't define an absolute speed since there is no such thing as 'speed relative to C'. that is because no matter how fast you are moving, you will always see the light moving at the same speed, C. about the paradox - its really simple. So you say that there are two clocks, A...

thanks alot! i hope this will help me to pass my final exam two days from now btw this formula is taken from ashcroft, they didnt say there that it applies only to cubic symmetry but I am not sure. do you have the general form of this formula, or can refer me to a site\book?

i have a question regarding calculating the thermal expansion parameter \alpha it is given by: \alpha = \frac{1}{L} \frac{\partial L}{\partial T} = \frac{1}{3B} \sum \frac{\partial(hw)}{\partial V} \frac{\partial n}{\partial T} now, I am not quite sure how i calculate d(hw)/dV. how is w...

sure. and according to bloch's theorem: \epsilonn(k)=\epsilonn(k+G) where G is any reciprocal lattice vector. this means that at the same band (n) the energy is periodic over k. regarding the extended zone scheme, I am not sure but as far as i understand it will be the same as the...

well, if I'm not mistaken, bloch oscillations are based on the assumption that the dispersion relation is periodic [something like - e(k)=B+A*cos(a*k)]. when you derive the speed from this energy [by v=(1/h)*de(k)/dk] you get a sine - a periodic speed. the reason that the dispersion relation is...

you said that 'when one energy band is filled, electrons start filling the next one', but that's not always the case. sometimes bands overlap and one band may start filling before the previous one finished, giving two partially filled bands. you can see what i mean at page 224 (chapter 12)...

In the semi-classical model, i noticed that all the electrons with values of k that are in the same brillouin zone are considered to be at the same energy band, but i can't quite understand why it is so. i know that in each brillouin zone the number of allowed states (of k) is the same as the...