Galileo Galilei

Key discoveries

Astronomical discoveries with the telescope — discovered mountains on the Moon, sunspots, the four largest moons of Jupiter (Galilean moons), the phases of Venus, which proved its rotation around the Sun.

Law of falling bodies — showed that in the absence of air resistance, bodies fall with the same acceleration regardless of mass.

Principle of relativity (Galilean transformations) — stated that the laws of mechanics are the same in all inertial frames of reference.

Invention of the thermoscope — a precursor to the thermometer.

Theory of tides — attempted (incorrectly) to explain tides by the motion of the Earth.

The Kick That Stops Molecules: A New Cold Record

Scientists used a precise laser pulse—a delta-kick—to cool molecules almost to a standstill. The molecules' internal vibrations don't mess with their motion, so they stay intact. Supercold molecules will open the door to ultra-precise tests of gravity.

arXiv:2502.09437 · 2025-02-13

Quantum Test of Falling Bodies

The equivalence principle states: all objects fall at the same rate because the mass that creates gravity equals the mass that resists acceleration. To test this at the quantum level, scientists place weights in a state where their mass is as if blurred. Supersensitive torsion balances capture not o

arXiv:2512.06333 · 2025-12-06

Gravity and Charge: Physics' Blind Spot

New work exposes a gap: the effect of charge on gravity has never been systematically studied. The authors predict a tiny change in acceleration depending on the charge-to-mass ratio and propose modifying a torsion balance to illuminate this blind spot for the first time. Surprise: for the electron,

arXiv:2601.16325 · 2026-01-22

All Atoms Fall Alike: A Cosmic Verdict

The idea that all objects fall equally underpins Einstein's theory. On the Chinese space station, physicists compared the fall of two types of rubidium atoms. The result matched the prediction with an error of a few ten-millionths.

arXiv:2603.22981 · 2026-03-24

The Silent String of Gravity: Hunting for κ

The weak equivalence principle has been tested with fantastic precision, but always with grounded samples — as if one string of the gravitational violin is deliberately muted. The κ parameter quantifies whether acceleration depends on electric charge: it is the ratio of the difference in acceleratio

arXiv:2605.12246v2 · 2026-05-12