Recent content by Cemre

  1. C

    Center of mass of tetrahedron with uniform density

    Hi, I have 4 non-planar points P1 = ( x1 , y1 , z1 ) P2 = ( x2 , y2 , z2 ) P3 = ( x3 , y3 , z3 ) P4 = ( x4 , y4 , z4 ) what is the coordinate of center of mass of the object ( tetrahedron ) whose vertices are P1 P2 P3 and P4? ( uniform density ) Thanks
  2. C

    QED functions E(a to b) and P(a to b)

    The video lectures are not very clear but I found it in the book... thanks... it is as follows. P(A to B) is ; E(A to B) is ;
  3. C

    QED functions E(a to b) and P(a to b)

    Hi again, I think I found something... at wikipedia : http://en.wikipedia.org/wiki/Path_integral_formulation --> given by the time integral of the "Lagrangian" along the corresponding path also another wiki article has information about QED Lagrangian. "Quantum electrodynamic Lagrangian" ...
  4. C

    QED functions E(a to b) and P(a to b)

    Feynman says in his lecture that P(e1,e2) is almost equivalent to E(e1,e2)... where e1 and e2 are event1 and event2 in fact P(e1,e2) is E(e1,e2) where rest mass is set to zero. But he doesn't give the open formula for E(e1,e2) I would appreciate very much if someone could give me the open...
  5. C

    QED functions E(a to b) and P(a to b)

    Hi, yes, yes, I know that E and P are functions that take a couple of positions and time, one for location 1 , one for location 2, and give out a complex number which is the probability amplitute. I know about probability amplitutes. path-Integrating complex functions E and P gives the...
  6. C

    QED functions E(a to b) and P(a to b)

    Hello all... I confess, I didn't make much googling about this, so if this question is already answered :) just show me the link to answer... In his famous video lectures about quantum electro dynamics, Richard Feynman is talking about electron and photon functions E and P. And whole...
  7. C

    P orbitals and single electron atoms

    Hello, does hydrogen atom with a single electron have p orbitals? when the single electron of the hydrogen atom is excited, can it go to the 2p orbital? are "p orbitals" consequence of electrons interacting with nucleus ( protons ) ? or are "p orbitals" consequence of electrons interacting...
  8. C

    Magnetic field of a moving point charge

    Hi, I'm writing a small simulator where two objects apply force on each other inversely proportional to square of distance between them. ( like gravty ) in terms of gravity, I think this is the only force that I have to take into consideration. but I'm confused about electrical and magnetic...
  9. C

    Is the Sum of Two Periodic Functions Always Periodic?

    Hello, correct me if I am wrong, but as far as I know if 2 functions f(x) and g(x) are periodic with Tf and Tg periods. f(x)+g(x) is also periodic with least common multiple of Tf and Tg. But; what if that least common multiple doesn't exist? is "sin(x) + sin(pi*x)" periodic? there...
  10. C

    Centrifugal force around planets

    Hello, When I thought about centrifugal force, gravity came into my mind... When we tie a rope around a ball and rotate it in the air, rope gets some tension ( small displacement between atoms of rope ) and we feel this as centrifugal force. This force occurs because we apply an...
  11. C

    Does the Quantum Eraser Experiment Truly Erase Information or Alter Causality?

    Hello, info about quantum eraser experiment is at wikipedia and at http://grad.physics.sunysb.edu/~amarch/ I want to express my view of last part of this experiment and want to discuss whether there really is an "erasure" or a breakdown of causality even in the delayed case. the way the...
  12. C

    Probability of Toy Car in nth Box Given 9/n-1 Boxes Have Toy Cars

    Let's say we have 10 boxes and I open each of them one by one... I open the 1st box, there is a toy car in it. I open the 2nd box, there is also a toy car in it. I open the 3rd box, there is also a toy car in it. ... I open the 9th box, there is also a toy car in it. :) wow, I got 9 toy...
  13. C

    Negative Energy/Negative Matter

    Correct me if I am wrong: but as i had learned, any attractive force field ( gravity field, opposite sign electric field ) has negative energy : -km/d for negative matter: negativity must be defined: if you are talking about electromagnetic force, negative matter of electron would be...
  14. C

    What speed is something moving at right before it stops?

    In my opinion: things never completely stop. matters have heat and heat is an energy related to motion, and as I know: harmonic ( sinusodial ) motion ( vibration ) so all derivatives of this motion related to heat are also sinusodials. when the object is moving with high speed, a big...
Back
Top