The atmosphere blows around and around, but the pattern
stays the same, like an eddy in a river. A standing wave 'stays
still' even if the medium is moving. The wave isn't a 'thing'
so much as a pattern of interactions of things. When waves
moving in opposite directions meet each other, some waves
cancel each other; others reinforce each other. This is what
the physicists call 'wave interference', even where the waves
are reinforced and not canceled. Standing waves don't have
to go around in a circle. Waves travelling along a string
or air column reflect back when they reach an end. Standing
waves in vibrating strings or columns of air settle into the
harmonic series, which we hear as musical tones.
Much of what follows draws on the resonance section of Rod
Nave's invaluable Hyperphysics site. Resonance is self-organizing.
When you first pluck a guitar string, it begins to vibrate
in a tumbling complexity of different modes. But the guitar
has been careful designed to 'want' to vibrate at its resonant
frequencies, and the nonmusical vibrations swiftly die out,
while the musical ones reinforce themselves.
All
m atter and energy behave in some ways like standing waves
at the ultra-tiny scale. Science textbooks usually show
subatomic particles as little marbles, a good enough approximation
in some ways but fundamentally misleading. There's something
vibrational and musical happening at the quarks
and gluons level, something the physicists have been circling
around since Einstein. All subatomic
particles, and even entire atoms, have wavelike qualities.
The mathematical techniques that quantum physicists use to
understand the vibrations of protons and neutrons are largely
the same ones that describe guitar strings. It
came as no surprise to me that Einstein was an enthusiastic
amateur musician.
A standing wave isn't a 'thing'. It's the emergent result
of many things interacting. Some physicists think that space
itself may not be a 'thing' either, that it's the emergent
result of many small discrete interactions. From
Lee Smolin's book Three Roads To Quantum Gravity:
[O]ur world cannot be understood as a collection of independent
entities living in a fixed, static background of space and
time. Instead, it is a network of relationships, the properties
of every part of which are determined by its relationships
to the other parts ... [T]he relations that make up the
world are causal relations. This means that the world is
not made of stuff, but of processes by which things happen.
Elementary particles are not static objects just sitting
there, but processes carrying little bits of information
between events at which they interact, giving rise to new
processes. They are much more like the elementary operations
in a computer than the traditional picture of an eternal
atom.
Look around and imagine that you see each object as a consequence
of photons having just travelled from it to you. Each object
you see is the result of a process by which information
travelled to you in the shape of a collection of photons.
The farther away the object is, the longer it took the photons
to travel to you. So when you look around you do not see
space - instead, you are looking back through the history
of the universe. What you are seeing is a slice through
the history of the world. Everything you see is a bit of
information brought to you by a process which is a small
part of that history.
The whole history of the world is then nothing but the
story of huge numbers of these processes, whose relationships
are continually evolving. We cannot understand the world
we see around us as something static. We must see it as
something created, and under continual recreation, by an
enormous number of processes acting together.
Music is the same way. It's an algorithm for producing vibrations
detectable by the human body and thereby
affecting changes to our emotional state. No human bodies,
no music, at least not of the human variety.
