Posted on 05/30/2003 6:13:25 AM PDT by TroutStalker
Edited on 04/22/2004 11:49:03 PM PDT by Jim Robinson. [history]
What if stalactites could talk? If these icicle-shaped mineral deposits somehow preserved the sound waves that impinged on them as they grew, drop by drop, from the ceilings of caves, and if scientists figured out how to recover the precise characteristics of those waves, then maybe they would also be able to use stalactites like natural voice recorders and recover the conversations of ancient cave dwellers. Is it more far-fetched than recovering conversations from magnetized particles on an audio tape?
(Excerpt) Read more at online.wsj.com ...
The very first any freshman in any scientific field learns is how easily we reach the limits of human knowledge. The second thing he or she learns is how difficult it is to actually tell where it is with any precision. But it isn't really the limits of knowledge that is the issue here, it is the adequacy or inadequacy of existing mental models to incorporate new knowledge, and the necessity of modifying them to incorporate it or discard them in favor of models that do - that is the work of science.
The citation of Heisenberg's Uncertainty Principle is a case in point - there's nothing wrong with the mental models we term "position" and "momentum," but when we discover that we cannot in practice measure both simultaneously the first explanation that comes to mind is the one most often heard - that it is the act of observation that is the problem. Underlying this is the hopeful assumption that a new, non-invasive method of measurement will get us out of this difficulty.
That is a limit of technology, not a limit of the mental models of "position" and "momentum." And it is very likely not true. What is really implied here is more fundamental than that - that the actual information carried by a subatomic particle may be inadequate to satisfy the mental models described by the words "position" and "momentum" simultaneously - that the problem isn't techniques of observation, but an inherent limitation of that way of looking at things.
Professional physicists will, of course, correct my interpretation if it is in error (God bless FR!) but IMHO here is one place where epistemology and scientific observation close the loop and become one. But it is profoundly unsettling to have concepts as intuitive as "position" and "momentum" challenged. Unfortunately, shutting down one's brain won't make the problem go away. I've tried it.
Perhaps my ignorance and mental limitations blind me to the obvious but the answer to this problem seems to be in the semantics. For a particle to have a position it must be fixed in space, not moving. If it is fixed it has no momentum. Therefore, momentum and position are mutually exclusive.
...whether the universe has to be the way it is because the laws of nature can exist only in their current form, or if other physics are possible.
Now this gets more into the area you are talking about, epistemology, but it still seems to me to be a problem of properly stating the conditions of a circumstance, or semantics, rather than logically or mathematically solving a problem. Sounds like wistfulness to me, not science.
How bizarre is this?
Several years ago I literally dreamed this. It was so vivid, and stayed with me so indelibly, that I cast it into the form of a sonnet:
Echo and Narcissus
I dreamt last night that scientists had found
Encoded into metal, rock, and glass,
An unexpected form of "fossil sound",
Which cooling solids captured in their mass.
Numerical reagents were applied,
Precipitating meaning from the noise,
Roman blacksmiths from their shackles cried,
The Glass Harmonica held Franklin's voice.
Three seconds long! Yet Franklin's trifling quote
So captivated man's nostalgic heart,
It prompted him, enraptured, to devote
The world's resources towards his new-found art.
And yet, for all the effort that it spurred,
Nothing more of note was ever heard.
For those of you who don't know, the Glass Harmonica was a musical instrument invented by Benjamin Franklin.
In my dream, the cries of dinosaurs were also pulled from igneous rocks, but that refused to fit the meter.
For the record, I don't think such a thing is possible, but for a long time after my dream I could not shake the notion of "fossil sound" out of my head!
This is the territory of philosophy, not natural science.
There's an old SF book, I can't recall the title or author, about a future where technology can recover the sight and sound of past events that (so the premise goes) are naturally imbedded in molecular vibrations of all matter. The story involved crime detection, and how the main character, knowing his every movement would be watched, managed to pull off a perfect crime.
Not always. The Heisenberg Uncertainty Principle and black hole "no-hair" theorems come immediately to mind. Even the 2nd Law of Thermodynamics implies hard scientific limits on knowledge (i.e. the impossibility proofs of Maxwell's Daemon).
Why do scientists earn a PhD, Doctor of Philosophy? One would think there is some philosophy involved along the way.
No, extended bodies have position whether or not their momentum is nonzero. A car, travelling down the highway, has a position - it's somewhere at all times, right?
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