You're viewing a single thread.
Easy. Take a wire that is exactly 1 meter long. Form a circle from the wire. The circumference of that circle is 1 meter.
A nanodegree of difference in temperature will change the length of the metal.
And this why you don't touch the thermostat.
"exactly"
uh huh. and how are you measuring that?
Now the engineers and/or scientists are crying
Scientists maybe, engineering is all about calling things close enough.
You don't need to, it's defined. (Lol). If you take a circle with a circumference of 1, then its circumference will be 1... I think I might have lost some braincells reading this.
He obviously meant to say how do you measure that it’s exactly 1m, even when still in a straight line. Exactly being the key word here.
But is the circumference of the outer circle or inner circle 1m? The wire has a nonzero width.
I don't have to measure it. I stick under glass and define it as the standard which all other measurements are derived from.
I will be measuring it in meters. One. There you go.
Ok, you got another source of water - physicists.
Plancks
Exactly. Use a laser measure to cut a plank, then use that for reference!
Laser Measure.
Laser measure