Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Can a falling tree make a noise in two forests at the same time?   It is a commonplace to claim that quantum mechanics supports the old idea
that a tree falling in a forest makes no sound unless there is a listener
present. In fact, this conclusion is far from obvious. Furthermore, if a
tunnelling particle is observed in the barrier region, it collapses to a state
in which it is no longer tunnelling. Does this imply that while tunnelling, the
particle can not have any physical effects? I argue that this is not the case,
and moreover, speculate that it may be possible for a particle to have effects
on two spacelike separate apparatuses simultaneously. I discuss the measurable
consequences of such a feat, and speculate about possible statistical tests
which could distinguish this view of quantum mechanics from a ``corpuscular''
one. Brief remarks are made about an experiment underway at Toronto to
investigate these issues.

28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
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The categories of this paper are: eess
2
The categories of this paper are: math
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The categories of this paper are: stat
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
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The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
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The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
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The categories of this paper are: bayes-an