Blackbody radiation Definition and 110 Threads

we have a hollow cubical box with sides of length a with perfectly conducting walls, such that the electric field tangential to the surfaces of the walls must be zero. we need to show that the system of standing waves: Ex = Ax*cos(Kx*x)*sin(Ky*y)*sin(Kz*z)*exp(iwt) Ey =...

I am to show Planck's blackbody radiation formula without the stimulated emission: level n is the upper energy level, level m is the lower energy level: N_m B u(\lambda,T)=N_n A \frac{N_n}{N_m}=\frac{B u(\lambda,T)}{A} N_n=ce^{-E_n /kT} N_m=ce^{-E_m /kT} \frac{N_n}{N_m}=e^{-h...

Even by taking low numbers for the surface area and emissivity of the plasma, the radiation would be extremely high due to high temepreatures in magnetic confinement fusion. So how is blackbody radiation countered in magnetic confinement?

Can someone point out any information (derivation or where it comes from) about this equation: S = v\int_0^\infty\phi(\rho,\nu)d\nu \nu is frequency of radiation. \rho(\nu) is radiation energy, v is volume. I'm getting this from Einstein's photoelectric effect paper. Thanks a lot!

What is the rate of energy radiation per unit area of a blackbody at a temperature of 260K ? Where's the tricky part in this question? Surely the answer to this question can't be just stefans constant * T^4 ie. 5.67x10^-8 * 260^4 = 259.105 W/m^2

This is actually a homework question, but its probably better suited for this forum. Gas accreting onto burned-out stars like white dwarfs, neutron stars, and black holes can often be seen in the X-ray part of the EM spectrum, at energies of about 10 keV. What temperature does this suggest...

Can someone help me with this please? B(f) = [(2hf^3)/c^2]{1/[exp (hf/kT) - 1]} - Planck law in terms of frequency. "Derive expressions for B(f) for the cases i. hf << kT, ii. hf >> kT". I've done the first bit, that's just using a Taylor expansion. The second bit is where I'm stuck. In...

Sorry if my physics isn't so good. I only go to High school. Anywayz here is what i understand about blackbody radiation. A blackbody is an object that completely absorbs all the radiation of any wavelength. right. Then blackbody radiation means that a blackbody emitting radiation. Here is what...

when we derive a formula for blackbody radiation, we say that each electromagnetic mode has energy nhf, n is an integer, h is Planck's constant f is the frequency of the radiation. We interpret n as the number of photons per mode. However, a deeper QM analysis involves replacing the...

I'm reading an astronomy textbook, and I'm not sure about some things. The textbook says the EM waves are caused by accelerating charges. I don't understand how this is. I'm not sure, but my memory and intuition tells me that only charges moving in a sinuosidal (can never spell it) manner...