Physics

Compton Scattering Calculator

Find the wavelength shift when a photon scatters off an electron.

Calculated Output

Wavelength shift (pm) 2.426

Formula: Δλ = (h ÷ m_e·c)·(1 − cosθ)

Step-by-Step Breakdown

1. Values used:

2. Scattering angle = 90 °

4. Wavelength shift = 2.426pm

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The math behind it

Δλ = (h ÷ m_e·c)·(1 − cosθ). The maximum shift (at 180°) is twice the electron Compton wavelength.

90° scattering → about 2.43 pm shift.

Why did it matter historically?

It proved light carries momentum like a particle, confirming photons.