An American Pedant in Düsseldorf

I just read a fascinating article about the most distant object ever detected, in which the NY Times tells us that, when the light we are now seeing from the object was emitted, the universe was nine times smaller than it is today.

This formulation drives me nuts. What does it mean for a thing to be nine times smaller than it is now? Measure me. What is my smallness? How big would I be if I had nine times as much of it?

I see this nonsense all over the place, where people don't seem to understand how units of measurement work or how they can be compared. My height is about 178cm: if I say that Joe is half my height, you can easily conclude he must be around 89cm. Would you be able to reach that conclusion if I told you he was twice as short as I am? Similarly, I would be greatly pleased if sports writers would stop informing me of events that happened "twice as slowly" as other events. Slowness is not a measurable quantity.

Temperature is the one iffy area where I'm forced to be a bit less crotchety, because it's more complicated. Technically, you can't say something is "twice as cold" as something else for the same reason you can't say you had fifty potatoes yesterday but three times fewer today. On the other hand, if you are having unseasonably warm weather (say 60 F) for December, and say it was twice as cold (meaning 30 F) last year, you will drive me a little nuts, but go ahead; you'll really be no wronger than if you say it was half as warm. I'm pedantic, but not enough to try to get people to give their ratios in Kelvins.