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Comment by ezoe | Hacker News Reader

> some missing technique that the author very likely did not think important enough to mention

That reminds me a funny story I've read: A scientist failed to reproduce a paper which says "room temperature". They later successfully reproduced it in the freezer. The paper was from Russia.

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AFAIR in physics and chemistry, room temperature is a short hand for 27°C in 1 atm.

https://en.wikipedia.org/wiki/Standard_conditions_for_temper...

After checking the reference, I feel like this was probably an assumption in all the textbooks that I had to follow in school. I suppose if each standards body had their own definition, it can get frustrating.

That is a convention mostly used in school problems, because manual computations with a temperature of 300 kelvin are easier.

In most technical contexts, room temperature means either 25 Celsius degrees or 20 Celsius degrees or more seldom various other temperatures between 15 Celsius degrees and 25 Celsius degrees.

Have you heard of room temperature? Welcome to the room. The room temperature room.

Now I’m imagining a “standard room” in France held at the reference temperature (and which the meter long rod and the kilogram weight would be stored, of course).

I'm pretty sure that was a pop culture reference that nobody should be expected to get.

Protip for GP: not all nerds watch shows about nerds. Standalone humor comments don't play well here to begin with.

Of course, they haven't measured it since the 1960s because the body heat of a scientist going in to measure it changes it a little bit.

However or whenever they measure the prototype kilogram, it weighs[0] exactly 1kg by definition.

[0] Well, not any more as the kilogram was redefined in 2019

This was a joke on the TV show Community, but it was exactly what you picture.

Does the length of the metre long rod not vary with temperature?

It does. If you are using that rod to measure something else, or calibrate another rod, you are supposed to keep it at a given fixed temperature.

Also, the standard of length was changed quite a while ago to one based on the definition of the second, and the speed of light.

Edit: here are the latest standards https://en.wikipedia.org/wiki/2019_redefinition_of_the_SI_ba...

That’s why they put the meter in the room.

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