Michael wrote:
> I am teaching Cognitive Psychology this summer and while discussing
> Sensory input and perception,a student asked:
> "if a tree falls in the forest and there is no one around,
> does it still make a sound?"
>
> I assume yes because a tape recorder could be left there to monitor
> the forest activity.
But that would be a quantum sound, Michael, not a single one.
Consider the Schrodinger's [sp?] cat analogy. He suggests that if we place
a cat in a box with a mechanism that will, completely randomly, either
release or not release poison into the chamber at a given time, until the
box is opened to determine the outcome the cat cannot be thought of either
alive _or_ dead. At the instant the box is opened, two separate universes
come into existance, one in which the cat is alive and one in which it is
not (actually, four would be created--those plus one where the experiment
was not conducted and one in which the box was never opened, but . . .).
Now consider the falling tree. It will displace air and create a wave
within the spectrum of human hearing as a result of the displacement. But
assuming that no living thing (after all, wild animals can hear sound and
react to it as well) is within audio range of the tree, the definitive
aspect of sound--vibration of the inner ear and transmission of the
resultant electrical signal to the brain--will not occur and there will be,
by definition, no sound.
Next add your tape recorder. Suddenly, instead of a question of
psychophysiology it becomes one of quantum mechanics. By the introduction of
this device you have replicated Schrodinger's box (sort of like a Skinner
box for philosophers, isn't it?). Now the question of whether or not a sound
occurred is based on a set of new variables--will the tape be replayed, and
if so, will it have recorded the sound or failed in its function. As a
result, the following complete universes will have been created:
(1) A universe in which the tape was never played, and therefore no sound
was made.
(2) A universe in which the tape was played, and the sound heard, and
therefore a sound was made.
(3) A universe in which the tape was played, but did not record the sound
(which could be broken into sub-sets, including those in which the tape was
defective, the recorder failed to function, etc., each of which necessitates
the creation of a new, complete, universe), and therefore no sound was made.
(4) A universe in which you did not conduct this stupid experiement, and
therefore no sound was made.
Since at least three of the four universes stipulate that no sound was
made, you can tell your student that according to quantum mechanics--the
most sophisticated form of modern physics--there is a .75 probability that a
sound was not made.
Hmmmm . . .
The next time a physicist tells you _psychology_ isn't scientific . . .
Rick <CLEARLY on a break between semesters>
