It is a beautiful night, clear and unseasonably warm. I’m standing outside a pub in South London with the sober voice of reason, gazing into the heavens. We are watching the lunar eclipse.
‘It’s magical,’ she observes.
‘Just you wait,’ I respond, eager to demonstrate my extensive knowledge of the cosmic ballroom. ‘We’re in the penumbral phase now, but the real fun begins when the moon enters the numbral shadow. It’s all about planetary alignment, you see.’
She looks at me sceptically. ‘So what casts the numbral shadow, then?’
‘Er, well, Mercury, obviously.’
‘Or the Earth, perhaps?’