'(1) Of light. The change of direction
that a ray undergoes when it enters
another transparent medium.'
Penguin Dictionary of Physics
There is more blue up here. This is good. There is
more light careening in the air. The haloes are in form.
Light floods the cerebral cortex all day long; the
toughest wildest physicists acknowledge this, agree with this.
And certainly the angels know and watch the light flood into
certain minds. This is something they do when they tire
of aetherial tag and aerial dogfights and general angel
larrikinism. They take their cortex watching seriously.

The brain is a cabbage with a bit of electrical wiring
and a few computer chips thrown in. But mainly it’s a cabbage.
That is to say a vegetable, a plant. So photosynthesis occurs, of course.
The Cortex Gate for chlorophyl is opened up to let in light:
the psyche glows a phosphorescent green, I walk the heat
down Pitt St and my glowing is like arsenic to the rats that nibble souls.