  Recently, Abreu et al. (2012, A&A, 548, A88) proposed a long-term modulation
of solar activity through tidal effects exerted by the planets. This claim is
based upon a comparison of (pseudo-)periodicities derived from records of
cosmogenic isotopes with those arising from planetary torques on an
ellipsoidally deformed Sun. We examined the statistical significance of the
reported similarity of the periods. The tests carried out by Abreu et al. were
repeated with artificial records of solar activity in the form of white or red
noise. The tests were corrected for errors in the noise definition as well as
in the apodisation and filtering of the random series. The corrected tests
provide probabilities for chance coincidence that are higher than those claimed
by Abreu et al. by about 3 and 8 orders of magnitude for white and red noise,
respectively. For an unbiased choice of the width of the frequency bins used
for the test (a constant multiple of the frequency resolution) the
probabilities increase by another two orders of magnitude to 7.5% for red noise
and 22% for white noise. The apparent agreement between the periodicities in
records of cosmogenic isotopes as proxies for solar activity and planetary
torques is statistically insignificant. There is no evidence for a planetary
influence on solar activity.
