How the pendulum swings

(ANSA) - Rome, October 4 - Foucault's Pendulum, one of the most famous scientific experiments in history, will be recreated in Bologna on Saturday with the help of Italian philosopher and author Umberto Eco .

The experiment, whose name provided the title for one of Eco's best-selling novels, proves that the earth turns on a north-south axis, completing one rotation each day .

It was first performed by French physicist Jean Bernard Foucault in Paris's Pantheon in 1851. He hung a 28-kg sphere at the end of an 11-metre pendulum from the ceiling and gave it a push .

The pendulum swung backwards and forwards across a point on the floor for several hours, making lines in piles of sand left there for this purpose. Instead of always following the same track, as non-scientists expected, the lines gradually twisted around .

The experiment finally demonstrated unequivocally something that physicists had long worked out but been unable to prove - that the earth spins as it flies through space. Some 155 years later, Eco will set a similar pendulum in motion in Bologna's Basilica of St Petronas. He will introduce the stunt with the same words that Foucault used in Paris: "You are invited to witness the earth turn around." The recreation of the experiment is part of a four-day initiative organised by Bologna city hall and the city's university in a bid to help popularise scientific studies .
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Read the complete article Umberto Eco proves the earth spins from ANSA.it.

I have not yet read the book, but I'm sure I will one of these days. The recreation of this experiment is an interesting look at science at time when concepts we take for granted today were still considered mere theory.

It's funny though. The 'theories' of relativity and evolution are mere theories, possible explanations that could be true and seem to be true in observing nature. Physicists take Einstein and work to prove him right or wrong, constantly coming up with new experiments to test the theory of relativity. Yet there are so many people out there who accept evolution as a 'law' without blinking an eye, even scientists who ought to know the scientific method better. When was the last time you read about a nifty experiment proving evolution in a controlled experiment?