>So does that make a new estimate of the mass of the Earth copyrightable?
Likely not on its own (due to fair use). But in a "collection" of estimates for the mass of all known celestial bodies then yes, it absolutely would be copyrightable. The same way a collection of stock price targets produced by a research company are copyrightable.
I agree with the rest of your comment in general but it's relevance to the discussion is questionable. In court, the speed of light would certainly be "a fact" unless it was expressed to a precision beyond the margin of error, and that margin of error was relevant to the copyright claim. That's getting way off track from the original point since we'd be talking about a singular number instead of a collection of numbers.
Back to the original discussion: A collection of facts is not copyright-able. The poster said the collection of wealth estimates was factual and therefore not copyright-able. That's provably false since another, equally skilled researcher would come up with different numbers and they can't both be factual. Right?
>the CNW guy presumably got competent legal advice and concluded the copyright angle wasn't worth pursuing
You're trying to imply that this means he had no legal basis for his claim. I find that very disingenuous. Besides, there's no need to speculate on why he didn't pursue legal action, the reasons are clearly outlined in the write up.
Edit: I see now why the "speed of light" example is not a good one since the meter is derived from the speed of light. Perhaps pi is the best example of a simple, agreed upon, physical constant or "fact" for the purpose of this debate.