We see it all the time, our thermometers always read Fahrenheit as well as Celsius. But most of us in the US don’t even need the celsius side. In fact, it’s something we largely ignore our entire lives.

The Fahrenheit scale is associated with the non-metric system, also known as the imperial system. Celsius is associated with the metric system, which is what most of the world uses. You’re probably much more familiar with the non-metric scale.

The Fahrenheit scale was invented in 1724 by Daniel Gabriel Fahrenheit. Zero is the temperature of equal parts ice, water, and salt… which makes 32 degrees the point where pure water would freeze. For boiling water? 212 degrees.

In 1742, a Swedish astronomer named Anders Celsius came up with a different scale. It was meant to simplify everything. In the Celsius scale, zero is the freezing point of water and 100 is the boiling point.

But why does the US not follow along with the rest of the world in using Celsius? It dates back to the British Empire. Fahrenheit was used, which was then brought with the British Colonies to America.

Once the Celsius scale was invented, the rest of the world decided it was easier but the United States stayed with the non-metric system and continued to use Fahrenheit.

It’s still not clear why Americans haven’t converted. Some researchers suggest it’s because we just got used to it and don’t want to change. They may be on to something. A 2015 Rasmussen poll asked Americans if we should switch to the metric system and adopt Celsius as our main temperature scale. In the poll, 64% said no while 21% said yes. The remaining 15% were undecided. So it looks like we’re perfectly fine with being different.

Since scientists in the United States us the non-metric system, they always have to convert when working with scientists from other countries. That doesn’t come without its problems.

In 1999, A NASA scientist failed to use the right measurements and it resulted in the loss of a 125 million dollar satellite. A simple math error resulted in the end of a 10-month journey to Mars and millions of dollars in research down the drain.