If you think that's bad, check out the (also terribly sourced) citation they linked for Apollo's exposure of 20 mSv through the Van Allen belts[0]:
"The actual amount of radiation received by the Apollo astronauts during their passage through the van Allen belts is difficult to determine but it is estimated to be about 2 rems (or 20 milli-Sieverts)."
A hyphen between prefix and unit? Capitalizing a unit that's named after a person? It's an absolute mess.
It seems almost nobody is aware of the (official/authoritative) SI brochure[1] anymore, or even its poor cousin, Wikipedia's Manual of Style for Units of Measurement[2].
Yes, "Watt" and "Newton" are surely the most common culprits.
When speaking of them as people, they are of course capitalized.
When speaking of them as units, they are not capitalized (1 watt). However the abbreviation is capitalized (1 W), and I think this is mainly what confuses people.
I don't want to get into a descriptivist vs prescriptivist debate, but it's worth noting that if "everybody" is doing something wrong, then maybe it is the specification that is wrong.
You have it reversed. The truism you're looking for is: "Just because something is popular, doesn't mean it's correct." Don't let Likes and Followers culture fool you.
If you want to make your own SI, feel free to use it however you want. If you use the SI, you MUST (RFC 2119) follow the official SI brochure, otherwise you're objectively wrong. That's what standards mean, and they exist for many good reasons.
It's not your fault. This flavor of philosophical deterioration happens when you tell an entire generation to follow their heart, everybody's a winner, and there's no wrong just "different." This mental trap is hard to escape, and worse it impedes self-improvement.
The spelling and capitalization rules of the SI system are not technical rules, they are a matter of language and do in fact vary. In German, for example, units are always capitalized in long form.
In the field of linguistics it very much IS the case that what is popular is correct. Beginning a sentence with a conjunction, or ending a sentence with a preposition is perfectly fine in English for example, despite what many outdated grammar texts would tell you.
I don’t know if units like watt or newton are more frequently capitalized or not. It is common though. In which case it would not be wrong to do so in a blog post. (For a submitted article you’d use whatever the editorial standard is though.)
It's made for another typographic environment, with restrictions that do not apply the same way today. And adds semantic noise to the text.
The Unicode people could make a different kind of space for use there, but I don't think anybody would adopt it. It looks like something that should be handled by a mechanism similar to ligatures.
