Mercury's 43 Arcseconds

Plate 31 speaks for itself: “Newton missed 43 arcseconds a century.”

The Physics

Mercury's perihelion advances slightly faster than the planets' Newtonian pulls explain. General relativity supplies the missing 43 arcseconds per century.

Δφ = 6π G M / (c² a (1 − e²))

• Δφ: perihelion advance per orbit, rad
• G: gravitational constant, m³ kg⁻¹ s⁻²
• M: solar mass, kg
• c: speed of light, m s⁻¹
• a: semi-major axis, m
• e: eccentricity, dimensionless

GR predicts 42.98″ per century. Einstein, 1915.

Sources

• A. Einstein, Sitzungsber. Preuss. Akad. Wiss., 831 (1915).
• C. M. Will, Living Rev. Relativ. 17, 4 (2014).

On the poster

Plate 031, “Mercury's 43 Arcseconds”: the pixel-art plate with its slogan “Newton missed 43 arcseconds a century.”, the key equation and the facts panel shown above. Pixelated Physics. Physics. Personified.