Gravité vs. pesanteur vs. gravitation

The words 'gravité', 'gravitation', and 'pesanteur' are French terms commonly associated with the concept of gravity. Despite their similar contexts, they convey slightly different nuances related to the force that attracts bodies towards the center of a celestial body like Earth.

Gravité

'Gravité' refers to the serious nature or significance of something, often used figuratively beyond just physical gravity. In scientific contexts, it can also mean gravity, though less frequently than 'pesanteur'.
La gravité de la situation nécessite une action immédiate.
(The seriousness of the situation requires immediate action.)
Nous sous-estimons parfois la gravité des conséquences de nos actes.
(We sometimes underestimate the gravity of the consequences of our actions.)

Gravitation

'Gravitation' specifically refers to the phenomenon by which all things with mass or energy are brought toward one another, including the cosmic force that is responsible for this attraction. It is often used in scientific and astronomical contexts.
La loi de la gravitation universelle a été formulée par Isaac Newton.
(The law of universal gravitation was formulated by Isaac Newton.)
La gravitation explique comment les planètes restent en orbite autour du soleil.
(Gravitation explains how planets stay in orbit around the sun.)

Pesanteur

'Pesanteur' specifically refers to the force of gravity as experienced on a celestial body such as Earth; it's synonymous with the weight force acting on objects. It is more commonly used in everyday French to speak about physical gravity rather than 'gravité'.
En apesanteur, les astronautes ne ressentent pas la pesanteur.
(In microgravity, astronauts do not feel the weight force (gravity).)
La pesanteur sur Mars est environ un tiers de celle sur Terre.
(Gravity on Mars is about one-third of that on Earth.)

Summary

While 'gravité' can refer both to seriousness and occasionally to physical gravity, 'gravitation' is used specifically in scientific contexts relating to cosmic forces, and 'pesanteur' describes the experience or sensation of gravity on a celestial body. These nuanced differences result in different uses in both everyday and academic French language expressions related to gravity and its effects.