In the address below http://en.wikipedia.org/wiki/Measurement_in_quantum_mechanics it's written:
For pedagogic reasons, the measurement [in quantum mechanics] is usually assumed to be ideally accurate. What's the meaning?
$\begingroup$
$\endgroup$
5
-
1$\begingroup$ all of our measurements are subject to some margin of error $\endgroup$– user81619Commented Jul 7, 2015 at 19:45
-
$\begingroup$ Is it saying quantum principles are based on this ideal assumption? Like when the state collapses into an eigenstate due to measurement. $\endgroup$– N.S.Commented Jul 7, 2015 at 19:51
-
1$\begingroup$ I am open to correction on this, but to me it's nothing to do with wavefunction collapse. it's more like doing dynamics problems (or thermodynamics and using ideal gases) and ignoring air resistance, because if they were to include that, the problem would be too messy. To me the quote above just means, "we will ignore the fact that we can't actually measure things precisely", so just assume we can while we teach you this. $\endgroup$– user81619Commented Jul 7, 2015 at 19:57
-
$\begingroup$ ideally accurate should mean something like "all errors eliminated but quantum uncertainty". That is grad student performing experiment is sober and temperature in room is exactly 24C and constant. And we are in spherical vacuum. $\endgroup$– aaaaa says reinstate MonicaCommented Jul 7, 2015 at 20:23
-
$\begingroup$ It simply means that you won't learn anything about quantum mechanics from putting a layer of error calculation on top of real experiments. Once you enter the real world, of course, that simplification is gone. $\endgroup$– CuriousOneCommented Jul 8, 2015 at 0:59
Add a comment
|
1 Answer
$\begingroup$
$\endgroup$
I don't think there is any great meaning to this statement - I think the author(s) are indicating how measurement is treated in QM formalism, rather than any practical issues introduced by measuring such systems.
Because this is dangerously close to the topic of the uncertainty principle / observer effect, it's worth stating that quantum uncertainty is not a result of a measurement process, but rather intrinsic to conjugate variables. Historically, this has been mistaken many times.
