 I agree with William Connolley that Shaviv's work is highly controversial. This is not necessarily a problem in itself. However, since Wikipedia should not promote a certain point-of-view, this whole paragraph is biased in the way that it only presents a minority of the knowledge of the astrophysics/climatology community. Another point is that, reading Shaviv's work, it is still quite immature in the sense that it is a small group of scientists trying to establish a whole set of causalities - work which would take the larger 'concensus' community shorter time. For example, in comparing several of Shaviv's papers it becomes clear that the spiral arm passage frequency estimates noted therein seem inconsistent. In conclusion, I think this paragraph needs more references and/or removal of the statements related to Shaviv & Veizer. I am a scientist in complex systems and have no interest in taking side in the discussion, but it is clear that Shaviv & Veizer is receiving too much attention to results which are, most likely, inaccurate.  