Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A mechanical engineer's approach to the measurement problem: Is a
  picture worth a thousand words?   The measurement problem is approached from a mechanical aspect, utilizing
schematics to better assist in visualizing the boundary and the interplay
between the quantum and classical worlds. This approach graphically illustrates
what happens when a photon is absorbed by the retinal molecule, and reveals
that even after collapse of the wave function, the information previously
carried by the photon and passed on to the pi* electron, is still at the
microscopic level waiting to be amplified up to the macroscopic level by the
rod cell. This analysis reveals that the measuring device or detector is of an
unusual 2-stage nature, consisting of a microscopic entity or rhodopsin
molecule which is not affected by the environment, contained within a
macroscopic rod cell which serves as an amplifier. This approach may also allow
one to better visualize the boundary conditions just prior to collapse and
whether it is necessary to make any kind of adjustment to the Schroedinger
equation to achieve a nonlinear collapse.

5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ