‘It seems logical but still, how can we admire Archimedes’s theory whilst discrediting one of the concepts that underpins it?’

‘The strongest argument comes straight from the word of God in the Book of Joshua, wherein the Sun is ordered to stop its movement and stand still.’ Friar Bartolomeo’s voice had changed, it was firmer, deeper, as if he was speaking from the pulpit. ‘Stand still, O Sun at Gabhaon, O Moon, in the valley of Aialon! And the Sun stood still, and the Moon stayed, whilst the nation took vengeance on its foe. Thus said Joshua in the presence of Israel.’ He paused, as if for effect. ‘The Holy Scriptures show us the truth.’ His voice shifted once more into the melody of recitation. ‘O Lord, my God, Thou art great indeed. Thou fixed the Earth upon its foundations, not to be moved for ever.’ Then he reverted to his normal voice. ‘It could not be more explicit—Psalm 103.’

Luna repeated the words ‘O Sun at Gabhaon, O Moon, in the valley of Aialon’, for they sounded wild and prophetic on her lips, and Friar Bartolomeo nodded approvingly.

‘This is a matter of faith, and so it would be heretical to say that Abraham did not have two children and Jacob twelve, as well as to say that Christ was not born of a virgin, because both are said by the Holy Spirit through the mouths of prophets and apostles.’

Luna nodded, even though the friar had not really answered her question.

The idea that the Earth moved through space was surely madness, but it was rooted in her mind, perhaps because it was so extraordinary. Luna looked up at the tall bookshelves. The friar was right of course; if the Earth moved then all these books would slide one way and then the other.

‘Now more than ever you must not stray from the word of God.’ He spoke firmly and Luna nodded. ‘We must all tread carefully in the gaze of the preacher Savonarola and I say to you again, Leonarda, your voice puts you in danger.’

She mulled over what she’d read as she followed Friar Bartolomeo from the library, first returning the volume from the Almagest. The Sun-centred theory was a madness, but it had been printed and accepted as useful to a degree, at least by the Greeks, and Luna knew her father’s contemporaries at the Academy held Archimedes in the highest regard. Her curiosity was not about to let go of the idea.

*