Ten things you never knew about... gravity

The confirmation last week of Einstein’s prediction of gravitational waves is expected to lead to huge advances in our understanding of the universe, so let’s see if we can catch up on gravity.

1. Our understanding of gravity began with the work of Galileo at the end of the 16th century.

2. Before that everyone since Aristotle thought that heavy objects fall faster than lighter ones.

3. Galileo showed that light ones fell more slowly because of air resistance but the gravitational effect was the same on everything.

4. This led to Newton in 1687 showing that the force causing an apple to drop was the same as the

force keeping the Moon in orbit around the Earth.

5. A problem with Newton’s theory was the orbit of Mercury which his theory could not explain.

6. In 1915 Einstein resolved the problem, seeing gravity as a consequence of space- time curvature.

7. His general relativity saw gravity not as a force but a warping of space caused by energy and mass.

8. All we know of the universe is from detection of electromagnetic waves such as light. Gravitational waves let us look further back in time and space.

9. The 2013 film Gravity won seven Oscars. The new discovery is tipped to win a Nobel Prize.

10. The apple that inspired Newton’s theory is thought to have been the “Flower of Kent” variety.