On Sky News this morning:
"Back in 1611, Johannes Kepler said that the most efficient way to stack spheres such as oranges and melons was in a pyramid formation.
Now, 403 years later, academics have finally confirmed that his theory is correct.
Professor Thomas Hales from the University of Pittsburgh, Pennsylvania, thought he had cracked the problem back in 1998.
A 300-page proof was developed, which took 12 reviewers four years to check for errors.
But even then, it could only prove the theory was 99% correct.
So, in 2003, he began to create a computational tool to check the proof beyond all doubt.
Called the Flyspeck project, it uses two pieces of formal verification software. Given enough time, it can check the logic of complex mathematical theories.
This week, Prof Hales and his team announced that his 1998 proof had been scrutinised by the software, and proven correct.
He told New Scientist: "I suddenly feel 10 years younger.""