First you are told that, however crooked
A meter rule may be, or any line
Drawn by a hand, tending to an arc,
At least there is light. It doesn’t get
Any more straight that a beam of light, you’re told.
Romans, after all, would devise their famously
Parallel roads by the aid of candlelight.
Nothing more straight-laced, straight-up or direct,
My lad, nothing as honest as light.
Well there’s light in water, of course, there’s always
An exception to the rule: a stick will seem
To bend in it. Refraction: also how
White sun turns blue in a sky suspiciously
Full of nitrogen – riddled with nitrogen –
So in those senses, it isn’t always the same.
But otherwise yes, light is implacable,
Perfect, true and incorruptible.
Apart from reflection or refraction, true:
But otherwise the universe’s yardstick.
And at last you are told that light is relative
And everything more or less is relative
In such a way that, basically, gravity
Curves the movement and even the speed of this
Former universal constant, and as such:
If light itself, if light itself
Is open to persuasion; if the metaphor
For goodness in every school and book and song
Itself is pliable, politic, subject to
A caveat or two; can also be
A bent cop, crooked cop, poorly-drawn line,
Well: in relative terms, why shouldn’t I?
Even light itself subject to influences. That’s an observed natural phenomenon. Odd, when considered as a metaphor, isn’t it?