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May 25, 2005 09:21

The Heisenberg uncertainty principle shows that there is an assymetry relation between measurements of objects. Some of these assymetry relations are between the measurement ( Read more... )

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demoivre May 25 2005, 17:15:56 UTC
Keeping in mind that the Uncertainty Principle, as originally formulated, is a *macroscopic* concept, applying to the measurement of any object, using it for *any* measurements makes sense. But also keep in mind what causes the uncertainty in measurement: the observer ( ... )

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dangerzooey May 25 2005, 17:23:31 UTC
I don't like the Feynman formulation and observer-centered views of the problem. I don't think it has to be the observer that causes the problem. (See the Overview section of wikipedia's Uncertainty Principle article.) I think the problem is just a limit of measurement. You can't verify a process down to the tiniest bit, but instead have to make some assumptions that the process is continuous (think of Zeno's paradoxes). I see no problem with making such assumptions.

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demoivre May 25 2005, 22:46:13 UTC
Uh, hmmm. You've lost me. The whole point of the observer-centered view IS the measurement process. I guess what I need to ask is "what do you mean by measurement?" Things don't measure themselves--at least in my view--and it is the very act of measuring them that disturbs them, thus causing uncertainty. Then again, as I've said before, I haven't gotten *that* far into quantum so I could be wrong. Oh well.

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Ah.... demoivre May 25 2005, 23:08:49 UTC
Wait, I think is see the misunderstanding. As I learned it--and as Feynman was actually talking about it, as near as I can figure--the "observer" is the measuring device (whatever that happens to be) not an actual person observing something. (Even the wikipedia link above mentions "observables" meaning, as I learned it, "measurable things") Is that what you mean?

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my two cents overmann84 May 26 2005, 05:39:37 UTC
We should remember that the reason that the uncertainty relationships arise is due to the wave nature of 'particles'. For all types of waves, the position can only be determined at the expense of knowledge of its wavelength. Particles are represented in terms of the addition of many sine waves to yield a wave packet.
Using the defintion of momentum, we get that uncertainty relation of position and momentum. Another relation is that of energy and time. Scroedinger's wave equation actually yeilds the same measurments of uncertainty as the Heisenberg relationships.
As far as interpreations and implications of this, and if you can apply it to other relationships, thats all you Kevin. As for what its used for, its useful in, catch this, the precision of measurements in the lab, but I think that it is more a statement about measurement rather than a tool. You should really go and talk to one of the Physics professors here about this stuff.

this is will from phil club by the way . . .

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Re: my two cents dangerzooey May 26 2005, 22:21:20 UTC
It sounds like you're agreeing with me. Am I wrong? I too think the UP isn't really a tool, and hence my qualms at attributing fault to some observer. UP is about a part of human evidence and explanation, and nothing more.

Good to see you here, feel free to stay awhile.

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Re: my two cents overmann84 May 27 2005, 00:09:09 UTC
Yeah, I'm with you in that I guess you could call it a 'meta-law' or something ( ... )

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Re: my two cents dangerzooey May 27 2005, 01:21:06 UTC
I don't think people have believed there'd be a winner in particle/wave duality for a long time. Some of my conversations with lyght over this issue have pointed towards that. What's unfortunate is that high school teachers teach it that way, so those of us who go on to study the issues are surprised to find out that we're all perfectly happy with the wave-particle being a single thing having wave-properties and particle-properties, which can't be precisely measured together.

I think mental measurements could only apply to the UP by analogy though, just due to the nature of its derivation.

How so? What nature is that?

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