Alexa, what’s the weather today?

Right now in NewYork, it's 65°F

with clear skies and sun.

Today’s forecast has partly sunny weather with a high of 77°F and a low of 61°F.

UHHHH…

I still don’t understand the use of Fahrenheit.

Virtually every country on earth uses Celsius to measure temperature.

But the US still uses Fahrenheit.

And for that reason, we —at Vox— often get comments like these.

*Okay, we get it.*

Besides the fact that the majority of the world uses it—

the metric system makes conversions a lot easier.

The Celsius scale even looks simpler.

It has freezing and boiling points at nice, round numbers— zero and 100.

Where in Fahrenheit, it’s a bit of a mess.

And of course, this isn’t just an issue of aesthetics or weather updates.

America’s unwillingness to switch over to the metric system has had serious consequences.

In 1999, a 125 million dollar satellite sent to Mars, disappeared in the Martian atmosphere.

It’s a setback to years of work already done in the vastness of space — all it takes is one navigation error.

And this colossal mistake was largely due to a

conversion error between US and metric measurements.

Fahrenheit was really useful in the early 18th century.

At the time, no one really had a consistent way to measure temperature.

But then a German scientist came up with the Fahrenheit scale when he invented the

mercury thermometer in 1714.

To make the scale, the most popular theory is that he picked the temperature of an ice/water/salt

mixture at the zero mark.

He then put the freezing point of water, which is higher than a salt mixture, at 32.

And placed the average temperature of the human body at 96.

From there, he placed the boiling point of water at 212 degrees.

In 1724, Fahrenheit formalized that scale and was inducted into the British Royal Society, where his system was a big hit.

As Britain conquered huge parts of the globe in the 18th and 19th centuries, it brought

the Fahrenheit system and other Imperial measurements,

such as feet and ounces along with them.

And Fahrenheit became a standard system for the British Empire across the globe.

In the meantime, the metric system was gaining popularity during the French Revolution.

It was put in place to unify the country at the national level.

So by the second half of the 20th century, Celsius became popular in many parts of the

world, when many English-speaking countries began using the metric system.

Even America attempted to switch over.

The change would have been good for trade and scientific communications with the rest of the world.

So, Congress passed a law, the 1975 Metric Conversion Act—

which led to the United States Metric Board that would educate people about the system.

This created the only metric highway sign in the US— the Interstate 19 connecting Arizona to Mexico.

But it didn’t go much further than that.

The problem was that unlike the UK, Canada or Australia, the law made the switch voluntary

instead of mandatory.

And of course people resisted the change, and the Metric Board couldn't enforce the conversion.

So, President Reagan ended up disbanding the board in 1982.

The next nudge to metricate came when the metric system became the preferred measure

for American trade and commerce in 1988.

But nothing really stuck with the general public...

Even though bizarre measurements like Feet and Fahrenheit are not doing them any favors.

Students have to train for two sets of measurements, making science education even more difficult.

And companies spend extra dollars producing two sets of products,

one for the US and the other for metric.

There’s also an argument for public health.

According to the CDC, about 3 to 4000 kids are brought to the ER due to unintentional

medication overdose, every year.

And conversion errors for dosage are to blame.

So it seems like a no brainer— America needs to switch to the metric system to match the rest of the world.

But it is still struggling to make that change.

That’s because it’ll take a lot of time and money but there’s no financial proof

that this will all be worth it.

So unless that change is proven to be economically better…

We’re not going to be using celsius anytime soon.

What’s 77°F in Celsius?

77°F is 25°C.

Ah!

Okay.