Gold, silver, mercury

Today I heard the phrase "gold standard" used again in a lecture for about the squillionth time in the last eighteen months. But this time I started to wonder about why that phrase is used, and to be honest, it doesn't make any sense. I think someone screwed up.

Let me explain. In medicine, the gold standard diagnostic test is the best possible test that will definitively tell you whether or not a person has a particular condition. It's also used to mean the best available test, even if it's not 100% definitive, and will presumably be replaced at some time in the future by the new gold standard. Okay - that's all fine.

But what really bugs me is that the phrase "gold standard" comes from economics (or is it commerce? anyway...) where it refers to the concept that a country's currency is freely exchangable for gold by the central bank. No-one uses a gold standard anymore - we ran out of gold. Instead, everyone now uses fiat currency, where a country's currency is freely exchangable for Italian sports cars. It seems to work just fine.

See what the problem is? The original gold standard has nothing to do with being the best. It's a literal name for a standard involving gold. But somehow along the way it seems to have become muddled up with the metaphorical meaning of gold as the number one and has entrenched itself in the heart of medicine. Is anyone else with me on this? Or am I just showing signs of frontal lobe damage?

Anyway, while I was writing this up I went off on a little wikitour and learned some good stuff. Interested? Sit down, my young apprentice, I have a tale to tell...

It seems that England used to use a silver standard so the word "sterling", which was used to designate a particular purity of silver alloy ("sterling silver", gottit?), got appended to the name of the pound ("pound sterling").

Then Sir Isaac Newton (who invented the crappy notation for calculus and got all the recognition at the same time as Leibniz was inventing a superior notation and getting none of the recognition (well, nothing but a wikipedia citation anyway)) became Master of the Mint and in 1717 effectively moved England from a silver standard to a gold standard. But the name of currency didn't change. And all the best diagnostic medical tests remained the same!

Newton was obsessed with alchemy, but his experiments got him into dire straits with mercury poisoning which probably made him, literally, as mad as a hatter. And here we are, back at Lewis Carroll again.