gravity

Everyday

1. The force that pulls things towards each other, especially the pull of the Earth that makes things fall and gives them weight. tree →
2. Seriousness: «the gravity of the situation» (formal). tree →

In the lessons

In science: gravity pulls everything down towards the centre of the Earth; it keeps the Moon going round the Earth and the planets round the Sun; on the Moon gravity is about one sixth of Earth's, so you would weigh less; Isaac Newton described it (the story of the falling apple). In space astronauts float because they are falling around the Earth all the time. Phrases: the force of gravity, pull of gravity, zero gravity, low gravity, centre of gravity.

Examples

• Gravity makes the ball fall back down. tree →
• The Moon's gravity is weaker than Earth's. tree →
• Gravity keeps the planets moving around the Sun. tree →
• Without gravity we would float away. tree →
• Isaac Newton studied gravity. tree →
• Water flows downhill because of gravity. tree →
• Astronauts feel almost weightless in space. tree →
• A low centre of gravity helps you balance. tree →

Note

Uncountable: no «a gravity». Gravity is a force (a pull); weight is how hard gravity pulls on you. Mass stays the same on the Moon; weight gets smaller. Myth: there is gravity in space — astronauts float because they are falling around Earth, not because gravity is gone. Myth: heavy and light things fall at the same speed without air.