odd dinner conversation

[cellio]

The question (not mine): if you were building a thermometer (the kind that lives in your medicine cabinet at home), what range of temperatures would you support? I said the problem was insufficiently specified, but that my baseline would be 96-106 and if there's no appreciable expense in widening it, I'd go in the range of 90-110 or -120, because why not. But the problem was still insufficiently specified; I was assuming digital readout, not a column of mercury in a usually-illegibly-marked tube. In the latter case, you want the minimum useful range, because you've got limited real estate for the markings. If you could have those 10 degrees occupy 80% of the tube and have the rest be compressed that'd be different, I said.

So Dani challenged that -- why assume that the tube is uniform? I said because otherwise you're out of the price range of medicine-cabinet thermometers. This, in turn, led to speculation about how that type of thermometer is manufactured; I argued for a large uniform (hollow) rod that's cut to length with ends then treated (seal at one end, mercury + bulb at other), while he argued for individually molded. (Insert tangent about plastic vs. glass here.) Of course, neither of us actually knows anything about this; we're trying to make intelligent guesses and apply design principles from other fields.

I don't think we're the only people who have weird speculative conversations like this, but I never seem to notice stuff like this coming from other tables in restaurants. On the other hand, we haven't been kicked out of any restaurants for annoying the neighbors either. (On the third hand, it seems to take a lot to produce that result.)

Comments

signs of the times

[eub.livejournal.com]

Last time I bought a thermometer, the drugstore had a dozen digital models with features and batteries and no doubt the bad behavior of all computers, plus one cheap analog one in dusty boxes shoved to the back of the shelf. It used a gallium alloy (http://www.1thermometer.com/FAQ_s/faq_s.html); mercury seems to be deprecated.

Re: signs of the times

[goljerp]

Cool. Thanks for the pointer about the gallium alloy... I can't see why anyone would want a digital thermometer with a non-mercury analogue one available. Computers are cool, but not everywhere.

Re: signs of the times

[cellio]

I much prefer the idea of a conventional thermometer to a digital one, because the laws of physics are a little more reliable than computers. I have a mercury (gallium?) thermometer. But if I needed to use it more than once every several years, I'd have to switch to a digital one because finding someone else to read the results for me all the time would be too much of a pain. The bigger digital readouts at least allow me to use the tool without assistance.

(I have trouble with sixteenths of inches -- let alone milimeters! -- on rulers, too.)

Re: signs of the times

[cellio]

Thanks for the link to the gallium thermometer. I am intrigued by their mention of a version with an easy-to-read display.

I, too, had no idea that mercury had been deprecated.