Gap Definition and 267 Threads

I need some clarification on what is meant by the energy gap of a superconductor. From my own understanding, is is caused by the manifestation of cooper pair, and hence can not obey fermi-dirac statistics, but abides with bose-einstein statistics. However, I feel that this reasoning is...

Hi , I have two problem with which I am stuck: 1- Given the family of curves y=1/(x+C). Find the family of orthogonal trajectories. For this problem, I took the first derivative of y---> y'=-1/(x+C)^2. from here, I cannot find the value of C since (x+C)^2=-1/y' which is impossible...

The conductivity of pure germanium increases by 50% when the temperature is increased from 20 degree C to 30 degree C. What is the energy gap E_g between the conduction and the valence bands of germanium? b) For silicon E_g = 1.1eV, what is the percentage change in the conductivity for the...

Try talking about astro phys to *the man in the street*, and there is no interest whatsoever, how can this be redressed ? i can tell you the black eyed peas are more of interest to the GP.

I'm asked to prove that the condition for the existence of an energy gap at the boudnry of the Brillouin zone on a 1D lattice is equivalent to the condition for Bragg refraction. I don't understand this question. Doesn't an energy gap arise solely when there is a potential? Meanwhile, Bragg...

I am trying to costruct a proof relating to the tangent space of SL(n). I'm almost there but all I need to show that if B is an arbitary constant traceless nxn matrix then there exists an A(t) (nxn) with the following properties: i) detA = 1 ii) A'(0) = B. Just a tip in the right direction...

When neurotransmitters are released into the synaptic gap, do they bind with receptors only once and then disengage once, or do they bind and disengage repeatedly? Thanks.

I stumbled across this book while browsing the shelves at my local library. The book is , which I read years ago and which greatly influenced my thinking (it was Sagan who persuaded me to quit watching programs about crop circles and the Loch Ness monster that I was so fond of as a child)...

Hey i was wondering if anyone had any sites on how to build a Spark Gap Radio Transmitter, i need to do this for history to show how marconi invented the radio. Thanks- Andrew

Hi, i live in the UK and currently studying physics at A-level. I have chosen to investigate EMP and its effect on electrical systems for a project. How would i build a generator? Am i right in saying all i would need is a fairly large capacitor and a spark gap? What sized voltage are we talking...

in one of my electronics classes, as a group we have to design and build a transmitter and receiver to transmit and receive morse code. we can only use a tesla coil and/or a spark gap for transmission. since we have 3 in our group... i am making the spark gap, someone else - a tesla coil, and...

Could someone rephrase in a short and casual manner the famous Millenium Problem of the Clay Math institute ? http://www.claymath.org/millennium/Yang-Mills_Theory/ Thank you for help !

Hello, I am in the middle of revising topics for the materials section of myend of year exam. For some reason my department give out past papers but do not give out answers. Any answers to any of the follwing questions would be very helpful. I don't think too much detail is required just a...

http://www.biomedcentral.com/news/20040405/03

I’m not sure if this is the right forum for my question so this was my best guess since it deals with photons. I’ve only gone through my first few physics classes that explain the classic structure of the atom, electromagnetic spectrum and the likes. I’ve also read a few books on physics on my...

This question may sound stupid, but I really don't know what to think. You see, it has been my understanding that energy is just an expression of the movement of physical things (this is simplifying, but it suffices). However, I had also believed that matter was just congealed energy. I hadn't...

This theory is fundamental physics theory.I tried to describe spacetime from new approach.I also tried to link General Theory of Relativity and Quantum Mechanics. I'm really sorry for the wrong translation in the first sentence of the manuscript ... It should be:I think that spacetime behaves...