Eötvös' Balance
Plate 032 Physics Poster
Plate 32 speaks for itself: “Snakewood and platinum fall alike.”
The Physics
Eötvös used a torsion balance to compare how gravity and Earth's rotation act on different materials. Any difference between inertial and gravitational mass would twist the beam; none was seen.
η < 10⁻⁸
- η: fractional difference in acceleration of two materials, dimensionless
1889: equal to 1 part in 20 000 000. Full paper 1922; work shown in 1909.
Honest caveat: The η < 10⁻⁸ bound is conservative: the 1889 work reached 1 part in 2×10⁷ (5×10⁻⁸), and the 1922 Eötvös–Pekár–Fekete paper tightened it to a few parts in 10⁹.
Sources
- R. v. Eötvös, D. Pekár, E. Fekete, Ann. Phys. 373, 11 (1922).
- C. M. Will, Living Rev. Relativ. 17, 4 (2014).
On the poster
Plate 032, “Eötvös' Balance”: the pixel-art plate with its slogan “Snakewood and platinum fall alike.”, the key equation and the facts panel shown above. Pixelated Physics. Physics. Personified.
Shipping calculated at checkout by destinationMade to order, ships in 2–5 business days
Field notes
查看全部-
How Did Rømer Measure the Speed of Light with Io?
In 1676, at the Paris Observatory, Ole Rømer noticed that eclipses of Jupiter’s moon Io came late when Earth was moving away from Jupiter and early when it was approaching....
How Did Rømer Measure the Speed of Light with Io?
In 1676, at the Paris Observatory, Ole Rømer noticed that eclipses of Jupiter’s moon Io came late when Earth was moving away from Jupiter and early when it was approaching....
-
What Is the Born Rule, and Why Is Probability |...
Quantum mechanics describes a particle with a wavefunction ψ, but experiments record definite clicks. The Born rule is the bridge: the probability of finding the particle is the squared magnitude...
What Is the Born Rule, and Why Is Probability |...
Quantum mechanics describes a particle with a wavefunction ψ, but experiments record definite clicks. The Born rule is the bridge: the probability of finding the particle is the squared magnitude...
-
Is There a Theory of Everything, and What Would...
Physics has a tested theory for three forces and a separate one for gravity, but no accepted theory joining them. The graviton, gravity’s hypothetical carrier particle, has never been seen....
Is There a Theory of Everything, and What Would...
Physics has a tested theory for three forces and a separate one for gravity, but no accepted theory joining them. The graviton, gravity’s hypothetical carrier particle, has never been seen....
