The frozen pond, still, silent,
reflects sky and tree,
doing what ice does.
The stone at my feet holds
the earth, quiet,
doing what stones do.
I pick up the the rock, and fling it
skittering across the ice.
The sound is otherworldly,
the pew pew pew of a
space battle, the twangggg
of a giant metal slinky,
the warbling chirp of
a prehistoric bird.
It’s called acoustic dispersion,
this phenomenon.
Stone impacts ice,
ice becomes a vibrating plate.
Waves that normally travel together
now bend and separate,
higher frequencies
racing to reach the ear
before lower ones,
sound no longer working in unison.
That, alone, is fascinating. But here’s
another interesting thing.
If you stand near the place
rock meets ice you can’t hear
the split. There is just
one sound.
So much depends on where
you choose to stand.
