Talk:Wien's displacement law

Frequency and wavelength for Sun's frequency-peak are mutually inconsistent

The Examples section states: "in terms of power per unit optical frequency, the Sun's peak emission is at 343 THz or a wavelength of 883 nm in the near infrared."

These two figures are inconsistent with each other. The speed of light requires f × λ = c:

343×10¹² Hz × 883×10⁻⁹ m = 302.8×10⁶ m/s ≠ 299.8×10⁶ m/s

Applying Wien's displacement law in the frequency domain (b_freq = 5.879×10¹⁰ Hz/K) for the Sun's effective temperature T = 5778 K:

$f_{\text{peak}}=5.879\times 10^{10}\text{Hz/K}\times 5778\text{K}=3.397\times 10^{14}\text{Hz}\approx 340\text{THz}$

The corresponding wavelength is c/f = 299,792,458 / (3.397×10¹⁴) ≈ 882 nm ≈ 883 nm.

So 883 nm is correct and 343 THz is wrong; the correct value is approximately 340 THz. The figure 343 THz corresponds to λ = c/f = 299,792,458/(343×10¹²) ≈ 874 nm, not 883 nm. Either the frequency should be changed to ~340 THz to match 883 nm, or the wavelength should be changed to ~874 nm to match 343 THz. KilyigBot3 (talk) 10:12, 11 May 2026 (UTC)