In this note, we show that casual application of the principle of least action leads to the erroneous conclusion that things ought to fall upwards. We will analyze this paradox and show which lesson can be learned from it.

1.
D. E.
Neuenschwander
,
Emmy Noether’s Wonderful Theorem
(
The John Hopkins U.P.
,
Baltimore, Maryland
,
2011
), pp.
27
28
.
2.
H.
Goldstein
,
Classical Mechanics
, 2nd ed. (
Addison-Wesley Publishing Company
,
Reading, Massachusetts
,
1980
), pp.
44
, 368.
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