Recent content by yosofun

I am considering offering Windows netMeeting (software is free) and email based online prep courses for the GRE Physics Exam. Tentative Plan 1 A Friday A Week --- Starts 3/10 at 6 PM PST. $100 for 4 one-hour lectures on Friday nights (and one on Thursday night) and strategized problem sets...

further comments?

hi, there have been 1-photon-at-a-time interference experiments. by 1 photon-at-a-time, i mean an antibunched photon source, as in P. Grangier, G. Roger and A. Aspect. \emph{Europhys. Lett.}, \textbf{1} (1986), 173. since antibunched photons do NOT display interference effects, one can...

Hi, I believe photon bunching also occurs for coherent light, since although the coherence function is 1 for coherent states, the coherent states are also prone to arrive randomly, as per the Poisson Distribution. Thus, even for low intensity, the coherent sources are likely to produce bunched...

i have read through a mathematical description of the quantization of the electric field through the simple harmonic oscillator raising/lowering operators. what is the physical interpretation and justification for this? what if one assumes that photons do not behave like simple harmonic...

to preserve commutation relations in the quantized field operators (basically simple harmonic oscillator raising/lowering operators), a vacuum mode must be introduced in the case of a usual 50-50 beam splitter. thus, one has 4 modes: vacuum incident mode reflected mode transmited...

The Hanbury Brown Twiss effect, aka the photon bunching effect, states that photons (from a thermal or coherent source) arrive in pairs instead of individually. The experimental setup consists of having a source go through a 50-50 beam splitter, where one path goes through a variable time...

Hi, I am confused about the electric dipole selection rules. Delta l = +/- 1 Delta m_l = 0, +/- 1 but are there rules for Delta j and Delta m_s and Delta n? Is there a (semi-rigorous) way to conceptually understand selection rules? Thanks.

what about delta j and delta n?

Hi, I have a question on selection rules for electric dipole transitions. It has to do with a GRE Physics exam question that's confusing a number of students at grephysics.net ... if any of the quantum guru's here would like to help, please check it out at...

Hi, I'm trying to understand Griffiths' (Introduction to Quantum Mechanics) argument that shadows can't transmit information. In his Afterword, he mentions that there are many things that travel faster than light, to quote, "If a bug flies across the beam of a movie projector, the speed of...

if one assumes that energy is conserved only "on the average," then it would be possible (for you) to walk through a solid concrete wall -- extremely unlikely, but still possible. this really worries me.

explain in more detail please...

I've been reading Giancoli (Physics for Scientists and Engineers, 3rd Ed) and Griffiths (Intro to QM). There seems a contradiction on the applications of the Energy-time uncertainty principle between the two. Griffiths claims that energy is always conserved, even though mathematically...