Recent content by EHT

@chrisbaird during the silence of this thread, I already upgraded my understanding. Now I understand that in the wave point of view, the light is not absorbed, the light is just interfering with the new light waves emitted by the atoms that result in delayed light(advanced in phase),this can...

I have read it, but it doesn't really answering my question. I already agree that the absorption-emission process isn't related with the atomic transition. I was thinking that the media is a fluid, I thought that there will be no such fine pattern as in the solid, therefore the phonons' effect...

Some textbooks that I read explain it in a way kind of like this: In a material the photons is absorbed by an atom and then re-emitted a short time later, it then travels at a short distance to the next atom and get absorbed&emitted again and so on. How quickly the atoms in a material can...

@Astronuc: I already know the results and I won a prize. I mean there should be a certificate that indicates that I really won something, I need it for university application. Thanks anyway

Did anyone won a prize in the 2010 Rudolf Ortvay Competition? If you did, did you get any diploma/certificate for it? I got an email from one of the organizer (Gyula David) around 5 months ago, he said that they will send me an official diploma. But till now I haven't get one yet. Does anybody...

Finally! Check it!

I haven't give up yet I already got my result from the organizer, but not the complete one. I guess we should contact someone from hungary, are u from hungary?

you can still join the problem competition, http://www.wopho.org/competition-detail.php?id=1 I'll pm you

I've sent another email, but no reply till now. Check this out: http://www.wopho.org/selection.php

Hi Ico, I got an email from the organizer, he said that the result will be posted in around this week

@Born2bwire: for the induct-tor, you are using negatively charged rod in the first case and positively charged conductor in the second case. Which is compltely different, if we use the same induct-tor it doesn't matter where do we put the grounding cable on the sphere. The negatively charged...

as in the other thread, the ampere law that I mentioned is the one without displacement current correction in it

Yes, Ampere's Law that I mentioned in my previous post is the one without maxwell's correction, therefore we need to add the effect of dispacement current due to the changing of charge density in both end of the wire to calculate the field The application of this law implicitly relies on the...

No, ampere's law can't be used here. You can always change the length of the wire and get the same answer. This absolutely can't be true The derivation of Ampere's law requires that \nabla.J=0 everywhere. On the other hand Biot-Savart can be used anytime

if you add up the total energy of a flat universe, the result is precisely zero. How can this be? When you include the effects of gravity, energy comes in two forms. Mass corresponds to positive energy, but the gravitational attraction between massive objects can correspond to negative energy...