Recent content by sancharsharma

@mathman, But the wavelength of light is not merely a distance between two points. As a support it doesn't follow lorentz length contraction. It is distance per cycle. So are you sure that it is a valid argument to say that wavelength expands as universe expands?

Can anyone please explain the physical reason of why is light losing energy as universe is expanding?

yeh, annihilation and creation operator was a nice idea. thankx. I think the definition given is pretty much mathematical than the quantum mechanics would require. if we imagine a situation where say only a few positions are allowed (lets say the situation of an electron in a lattice where...

I am new to quantum physics. Is there is any operator in quantum physics that does not show eigenvalue property? Give example please, thankx...

We may use the method introduced by Feynman, that will make it shorter. See Feynman Vol2, derivation of Poynting's Vector. There he describes a handy method to use the operator like a normal vector, and everythig else follows directly...

But classical physics doesn't predict any vacuum polarisation... So how can we find a function which is non existent?? i failed to understand your question probably...

well, i don't think we start with classical physics... look at this approach, we start with quantum amplitudes. postulate1: probability is mod of amplitude squared then we call everything that changes amplitudes as operators. we define energy, momentum and all... till now was...

thankyou... but I am still not able to grasp that why is candela a fundamental unit if it can be derived from power and angles. explain please...

I cannot get a feel of what is luminosity physically... Can anyone explain me the difference between energy transfer in terms of brightness (which is measured in Watts) and luminosity (which requires a new definition of units, candela)??