Celsius wasn't "invented" in the sense of being a new discovery. It was developed and popularized by Swedish astronomer Anders Celsius in 1742.

Here's a breakdown:

* 1742: Celsius created a temperature scale where 0 degrees was the boiling point of water and 100 degrees was the freezing point.

* Later reversed: The scale was later reversed, with 0 degrees representing freezing and 100 degrees representing boiling, making it the Celsius scale we know today.

So, while the scale itself was refined and adopted later, the year 1742 marks the creation of the original Celsius scale by Anders Celsius.