In science, the saying goes, if it can happen in nature it will. 

This Totalitarian Principle expressed by Nobel laureate Murray Gell-Mann actually originated with Plato. Nothing new there, what is interesting in a recent article by by Tom Siegfried in Science News is that Gell-Mann doesn't seem to have been inspired by T.H. White of "The Sword In The Stone" fame.

White did have that statement in the 1958 edition of "The Once and Future King" compilation but not in the prior books leading back to 1938. Gell-Mann had placed it in a strong nuclear force paper in 1956.

Siegfried knows that this “principle of plenitude” can be a bit of a problem in science and it is obvious to see why. If you can't show time travel is forbidden, then a whole bunch of arXiv players will do some math and claim it is "genuinely" possible and worth experimenting on. If there are 7,000,000,000 people and a whole lot of cancer, it is possible some of those patients ate bacon or sprayed a weedkiller so in an infinite universe epidemiologists at NIEHS, IARC, or Ramazinni can create a statistical correlation and demand governments ban products.