Topics T1–T3 · ≈16 min

The Oblong on the Wall

A visible photon carries a few electron-volts — inline, E=hνE = h\nu — and in display form,

E=hcλ1240 eV⋅nmλ.E = \frac{hc}{\lambda} \approx \frac{1240\ \text{eV·nm}}{\lambda}.
EM-spectrum locator: a scale-of-ten zoom that shrinks the visible band to a sliver of the whole electromagnetic spectrum.