Why is this question about measurement off-topic?

The question Reliable length scales in nature has been received very poorly, for reasons I don't really understand. In the help center, it is stated that questions concerning "Experimental designs and results" and "Experimental technology used in physics or astronomy" are on topic. I can reasonably interpret a question about how to make a ruler from objects in nature as falling under both of these headings.

The spirit of the question I asked was about how to make a measurement. I suspect that if I had instead asked how to determine a length scale from, say, observations of astronomical objects, it would have been much better received. (The question of length scales in astronomy is in fact very important for physics--see the cosmic distance ladder.) The differences I can identify between a question about astronomical objects and about terrestrial objects are the following:

1. We have sophisticated ways of measuring distances on earth that render length scales of nature unnecessary.
2. Plants and animals which provide reliable length scales are also within the purview of biology, and thus are not exclusively of interest to physicists.
3. Why would you need to use natural objects for measuring things anyway?

My question to the stackexchange community is: For which of these reasons (or for what other reasons) was the question dismissed?

My responses to the above points are the following:

1. Not everyone has access to laser range finders all the time. It is still of interest to be able to measure things in a primitive way. (This is also why "back of the envelope physics" is still an important skill.)
2. Science is not mutually exclusive.
3. See response 1.

And by the way, there are good answers (in my opinion) to the question in question. E.g. atmospheric pressure and a lake can furnish a length scale: You could fill up an airtight bag and sink it into water until its volume was half what it was at the surface. The depth of the bag is then 33 feet.

• Also, I note that in the comments for the question under consideration Kyle Kanos remarked that he thought a similar question had been asked in the past. He was not able to find such a question, but the fact that he thought it had already been asked suggests that it is in fact a natural question to think about. – Yly Apr 10 '16 at 22:55
• As a practical matter the way the Boy Scouts taught me to deal with "If I am hiking in the woods (not carrying any sort of ruler with me) and I decide I want to measure something [...]" was to know the actual size of various human measures on my body (my cubit is almost exactly 18", for instance) and to practice stepping off a reliable pace (I can still get $\pm 5\%$ over tens of yards that way). You've ruled that out, but I don't understand why: it is what people do. My suspicion is that what you request is either non-existent or very rare. – dmckee --- ex-moderator kitten Apr 10 '16 at 23:15
• I'd also note that the cosmic distance ladder isn't built on a scale that is reliable in your meaning: it's build starting from a singular exemplar. Imagine explaining our astronomical distance scales to another race by long distance signal: US Well, a parsec is the distance at which you see an angular paralax of 1/(360*3600) of a circle from a 1 AU baseline. THEM What's a "AU"? US Oh, that's the mean radius of Earth's orbit? THEM ...? You'd have to go back to something like an identifiable transition line and counting wavelengths. – dmckee --- ex-moderator kitten Apr 11 '16 at 0:09
• @dmckee The analogy is not 1 to 1, but the point is that there is interesting physics in identifying standard rulers in nature. (See also the wiki article on standard rulers in cosmology: en.wikipedia.org/wiki/Standard_ruler) – Yly Apr 11 '16 at 4:07
• If I remember correctly, the question began its life differently and involved some weird scenarios with a precision metrologist with peculiarly selective memory on a lonely island. That version had little to do with the final version and it was suggestive that physics was somehow dependent on a particular choice of units, which, as I did explain in my comment quite clearly, is a 100% false lesson that we do not want to send. I suggested to edit it, which took it into a completely different direction (into the woods). How we get to cosmic scales from there... the heavens only know. – CuriousOne Apr 16 '16 at 0:23