Before Eden

I've visited Cornwall's Eden Project quite a few times in the past couple of decades. But back in 2000, I was lucky to get a tour of the site during construction.

The one fact I remember that most gobsmacked me during the tour was the that each dome weighs the same as the volume of air contained inside it.

That's pretty extraordinary, isn't it?

And it reminded me of a fact that was in my second published book, Connectoscope:

'We don’t think of air as having weight but, of course, it does. It's made of atoms and atoms have mass. And anything that has mass within a gravity field, has weight. That's why we can feel the wind when it blows. And it's how an airplane can fly - the weight of air being pushed downwards forces the plane to stay up.

But how heavy is air? 

If we could make a close-fitting cylinder large enough to encase the Eiffel Tower, the volume of air within would weigh more than the tower itself. 

It's true.

The Eiffel Tower is 1,063 feet high and sits on a square base with sides of 410 feet. It would, therefore, fit inside a cylinder with a radius of around 288 feet and a volume of 35.3 million cubic feet. That much air would weigh just over 11,000 tons. The tower weighs around 7,300 tons.'

As I've said before - every day is a school day!