Sue:
<snip>
Is there any explanation as to why two pendulums should come into phase?
<snip>
I can't go much further than 'yes'. Except to say that vectors are involved:
the weights of the pendulums and the directions of their swinging, plus the
magnitude of the vibrations caused and the path they take through some
medium such as a shelf. To make that a bit more concrete, the effect first
observed by Huygens in the 17th C (two clocks whose pendulums moved in
precisely opposite phase to one another) happened when the clocks were hung
next to one another on the same wall. When they were placed on opposite
sides of the same room it dissipated.
It's more complicated (or more abstract) with say, two or more electronic
oscillators. However, the principle is the same: direction plus amplitude.
And there is a mathematics to all this. Which I'd better leave well alone.
For an illustration of just how important phasing is in (for example) how
sound is both rendered and perceived, let me mention the Hafler effect. You
can get an approximation to surround-sound out of an ordinary stereo signal
by adding two extra speakers wired in anti-phase (rear left = L-R and rear
right = R-L) to produce difference signals.
<snip>
Do you think people can be more or less expert at entraining?
<snip>
Entrainment itself just happens, which is what I meant by its being more
basic than any basic skill. But there is, of course, more to say. The
varying capabilities of our sensory apparatus, since we are not only not all
the same but also only as good as what we perceive; our attention; the
degree and types of interference, and the extent to which we are able to
reflect (more or less self consciously) on those percepts. All these are
important.
There's a nice description in Svevo's *...Zeno* of how self entrainment can
come adrift. Zeno has a limp induced by self consciousness, and his attempts
to master the violin are vitiated (even though 'the lowest being, when he
knows what triplets and groups of four or six notes are, can pass from one
to the other with rhythmic exactness') because 'with me, on the other hand,
when I play one of these figures it clings to me and I can't get rid of it
again, so that it sneaks into the following figure and makes it out of
time.' So one can be one's own worst enemy, as it were.
And there are obviously social influences on how we parse what we hear. We
learn the prosody of our first language before we learn its vocabulary. We
hear music most readily (ie: distinguish it from noise) through forms we've
already heard. And our reading of metrical and quasi metrical poetry seems
to me to proceed (and with luck more successfully than Zeno's efforts with
the violin) through our (re)constructing rhythmic forms from textual cues,
by which we then (self) entrain.
As it happens there's a debate about metre on one of the other lists in
which someone has stated poetry to be 'a volitional human, rather than a
non-volitional natural, thing.' To my mind it is both.
CW
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'I might have known you'd choose the easy way'
(Franz Kline's mother)
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