Can one speak of the wave function of a object measured?

Click For Summary
SUMMARY

The discussion centers on the interpretation of wave functions in quantum mechanics, specifically regarding measured objects and their relationship to measuring devices. It establishes that for von Neumann measurements, the wave function of the measured object corresponds to the definite state of the measuring device, affirming option (a). In contrast, for measurements of the second kind, the measured object's state post-measurement does not reflect the measured state due to the detector's back action, as referenced in the provided Stanford resource.

PREREQUISITES
  • Understanding of quantum mechanics principles, particularly wave functions
  • Familiarity with von Neumann measurement theory
  • Knowledge of measurement types in quantum mechanics (first and second kind)
  • Basic grasp of quantum decoherence concepts
NEXT STEPS
  • Study the implications of wave function collapse in quantum mechanics
  • Explore the differences between von Neumann and Pauli measurement theories
  • Research quantum back action and its effects on measurement outcomes
  • Examine the concept of quantum decoherence in detail
USEFUL FOR

Quantum physicists, students of quantum mechanics, and researchers interested in the foundations of measurement theory in quantum systems.

nomadreid
Gold Member
Messages
1,773
Reaction score
256
Elementary question:
When one talks of a wave function of a measured object collapsing or decohering or splitting (pick your interpretation), what we base everything on is the measuring pointer. So, which of the following is the case?
(a) one calculates with help of coupling constants etc. what wave function of the measured object must correspond to the definite state of the measuring object, or
(b) wave function of the measured object is just shorthand for "the wave form of the measuring device" ?
Thanks.
 
Physics news on Phys.org
In the case of a von Neumann (or Pauli?) measurement of the first kind i think a) is right.

For a measurement of the second kind, it looks like the answer is similar to a) but the state of the measured object after the measurement doesn't actually end up being the state you've measured, due to a "back action" of the detector, according to http://www.stanford.edu/~rsasaki/AP226/text4.pdf
 
Last edited by a moderator:
psmt, thanks very much for the answer and the link, which looked very useful on a first cursory reading. I look forward to reading it more carefully.
 

Similar threads

Graduate Can particles appear and disappear "with" a cause?
  • · Replies 1 ·
Replies
1
Views
2K
High School Can someone please explain to me the motion of an electron?
  • · Replies 11 ·
Replies
11
Views
3K
Undergrad How Do We Model Wave Function Collapse After Measuring Particle Location?
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad Measurement problem - will this work?
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad Does the wave function spread more quickly after it is observed?
  • · Replies 32 ·
2
Replies
32
Views
4K
High School Extremely elementary questions about QM
  • · Replies 24 ·
Replies
24
Views
3K
High School Quantum entanglement and simultaneity
  • · Replies 4 ·
Replies
4
Views
3K
High School Does Schrödinger's Cat Know Its Own Fate?
  • · Replies 17 ·
Replies
17
Views
3K
Undergrad Locality and Wave Function Collapse Implications
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad How non-conscious can an Observer be and cause wave function collapse?
  • · Replies 23 ·
Replies
23
Views
9K