“What a lovely moon,” The Family said as I took the featured photo of clouds at sunset. Often we do not agree about the proper scale of things. I was looking at ephemeral sunlight on passing clouds, things which would fade in two minutes. She was looking at things which change slowly, and would take two weeks to come to fruition. I scanned the sky. Moon? I looked at her, followed the direction of her gaze, and asked “What? Where?” “Right there, where I’m pointing.” I looked along her arm and shook my head “No.” She took my head in her hands, turned it, port to starboard, then a little adjustment horizon to zenith. “There. You see it now?” “Mmm. Oh yes. Nice.”
I fixed that bearing in my mind and zoomed a little to see that wonderful sliver of the new moon. Such a constant in our lives: the periodic unchanging appearance of the new moon. But actually, the earth, the moon, and the sun dance a slow dance, mediated by tides and gravity. If we had enough time, say about 50 billion years, the earth and moon would be tidally locked: the day would be about 1130 hours long, and the moon would stand still above a single place on earth. Unfortunately this will never happen, because in a mere 5 billion years the sun will eat the earth. Tidal friction is that small! The length of the day has increased by about 1/4 of a minute in the last 100,000 years. That is the time from which we have the oldest human architectural remains.
I zoomed a little more. The constancy of astronomy has been the way wandering armies and ships have told direction and time from as long as our records tell us. When you continue the imaginary line between the poles of the earth, it points towards Polaris, the pole star, today. But this direction moves in a little circle every 26000 years or so. As a result, the direction towards the rising sun on the day of the equinox changes with the same period. The Babylonians had found that this direction points towards the constellation of Aries. By the late years of republican Rome, the direction had moved to the constellation of Pisces. This was a shock to the Romans, and gave an impetus to the spread of the imported Indo-Persian religious cult of Mithra (मित्र, Mitra, the Vedic god of sunrise). All the trappings of conspiracy theories of today (secrets which can be discovered merely by looking, cabals and secret handshakes, governments keen to hide facts) come from that history, a sign of the trauma caused by the knowledge that the skies are changing. This fact is forgotten again and again. Shakespeare had Julius Caesar declare “I am as constant as the Northern Star.” Ironical, since this particular lack of constancy was creating an immense ferment in his armies. Even otherwise, this is an anachronism, since there was no pole star in Caesar’s day. By Shakespeare’s time, when the earth’s axis had moved to Polaris, the equinox had moved further towards Aquarius, and the pole towards Polaris. Not so constant, after all, and much faster than tidal locking. Two million times faster!
I put the dust cap back on my camera and we resumed walking. The deeply peaceful surroundings, and the view of the Panchgani plateau on one side, can make your mind wander. But my time was here and now, and The Family said we should walk back to the hotel before dark, “Time for tea,” she said. Our meals are as constant as the moon and the tides; we seem to change daily, but we are more constant than the Northern Star, in our own ephemeral way.