https://nbeaver.github.io/interactive-electromagnetic-spectrum-calculator
- An interactive version of an electromagnetic spectrum chart (nomogram).
- Order of magnitude calculations.
- Quickly calculates some scalar quantities for a single photon (frequency, wavelength, energy, wavenumber, momentum, and "temperature").
This is intended to be an extension of the electromagnetic spectrum charts, so it focuses on spectroscopic quantities of a single photon. This limits the scope and avoids the introduction of additional parameters to vary.
For example, another variable of interest for X-ray physics would be the final wavelength of a photon after Compton scattering:
\lambda - \lambda' = \frac{h}{m_e c} (1 - \cos{\theta})
but would require introducing another variable: the scattering angle \theta.
Cosmic background microwave radiation:
I'm looking at the physical properties of blackbodies. The graph shows the max of the CMB curve at about 2mm. The Wien displacement law claims T = k/λ, so T(Kelvin) ≃ 2.9/λ(mm). Therefore the CMB Temperature is 1.4 Kelvin. What's the trick here?
[ . . . ]
What Wien's law tells you explicitly is where the energy emitted per unit time per unit area per unit wavelength peaks. This quantity is usually called "intensity". When you deal with intensity you are free decide whether you want to use wavelength units or frequency units
http://www.astro.ubc.ca/people/scott/faq_email.html
- http://halas.rice.edu/conversions
- http://scienceprimer.com/electromagnetic-spectrum
- http://www.ilpi.com/msds/ref/energyunits.html
- https://acswebcontent.acs.org/chemistry-in-context/suite/applets/ElectromagneticSpectrum/photonEMWapplet3.html
- https://convert.impopen.com/index.php
- https://www.olympus-lifescience.com/en/microscope-resource/primer/java/wavebasics/
- https://www.powertechnology.com/calculators