‘That’s it. Her direction changes the whole time as she paces around the circle, but that makes no difference to the speed she’s moving at, and the relativistic distortion. We watch her lay down that shrunken rod, over and over, as she paces around a circumference that looks unchanged to us. And so she must put it down a lot more than six or seven times before she gets back to her starting point.’ She studied their faces. ‘You see where I’m going with this? Our surveyor down on the Wheel is in a spacetime distorted by the Wheel’s motion. She can measure that distortion, directly. Just by counting the number of times she lays down those sticks. She finds that the circumference of her circle is bigger than what Euclid said it should be . . . She would get the wrong answer for pi . . .’
‘How much bigger?’
‘Given our measure of how close the c-floor has approached the speed of light, the ultimate limit – we figure five million times.’
Nicola actually gasped. ‘So let me get this right. This two-light-year-diameter Wheel has a circumference that isn’t a mere six light years, a walk past Alpha Centauri, like you say. It’s more like thirty million light years.’
Asher grinned. ‘A walk that would take you out of the Galaxy. Out of the local group—’
‘All jammed into this diddly hoop?’
‘You got it.’
-Xeelee: Redemption, Ch. 40