Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Do the Laws of Nature and Physics Agree About What is Allowed and
  Forbidden?   There are countless examples in the history of science that not only were the
laws of physics often incomplete and more limited in their domain of validity
than was realized, but at times they missed the mark completely. Despite this,
our collective memory is often short on such matters, focusing on present
triumphs and quickly forgetting past failures. This makes us less tolerant to
that which challenges present orthodoxy. It may be of value to recall such past
deficiences as well as present shortcomings, particularly since science may
always be encumbered with such limitations. We can avoid serious pitfalls if we
let the past serve as a guide to the future. Subjects covered will include
Godel's theorem, superconductivity, zero-point energy, the quantum and
classical Aharonov-Bohm and similar effects, theories of general relativity,
Mach's principle, black hole radiation, ball lightning, and the universe(s).

6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess