The celcius was designed without regard to the temperature of absolute zero. Why does the exact value of absolute zero only have 2 decimal points in the celcius scale?

Question

Isn’t it quite a big coincidence that this value would only have 2 decimal points on a scale that puts the temperature value of water boiling and freezing at whole numbers?

In: Mathematics

Answer 1

The Celsius scale was already in use when we began to realize that applications of the gas laws and other aspects of physics imply an absolute zero point in temperature. So we figured out, theoretically, that it is very close to -273.15 *C.

Then, later, we ***re***defined the Celsius scale in terms of absolute zero and the triple point of water, and dropped the boiling point as an anchor. Now, absolute zero is -273.15 by definition, the freezing point of water is still generally at 0 *C (depending on pressure, impurities, etc.), but the boiling point is no longer keyed to 100, and is actually closer to 99.98 *C.