Comment by Leftium | Hacker News Reader

Comment by Leftium | Hacker News Reader

After making a weather app that helps me switch between C/F temperatures, I came to the same conclusion as MKBHD: "Fahrenheit is better for weather..."[1] Fahrenheit roughly covers the scale of air temperatures experienced by humans where 0 is cold and 100 is hot with maximum precision for a given number of digits.

Unfortunately, MKBHD failed to eloquently articulate this. And I couldn't find the Twitter image that helped me realize why F was better for weather.

It's most apparent with air temperature, but both Metric/Imperial systems have their merits. Generalized like this:

- Metric: science-based, regular (powers of 10)

- Imperial: human-scaled, divisible (many divisors, including 3)

For example, in the discussion a surfer says "if you measure wave height in metres or cm it is not as accurate compared to the human body (a 6ft wave is under 2 m and we would not call a wave 182.88 cm high)"

Here is another article that tries to explain this "hot take:" http://thevane.gawker.com/fahrenheit-is-a-better-temperature...

[1]: https://youtu.be/BMGrsOawKac?t=60

>a 6ft wave is under 2 m and we would not call a wave 182.88 cm

This is subjective but we call it 1.8m and I don't really see a problem "seeing" it visually. 1.8 is just a bit above my eye level.

>Fahrenheit is also more precise

You could use a C2 scale where C2 = Celsius*2.

>it’s best to use a temperature gauge that’s suited to the air

I believe neither Celsius nor Fahrenheit alone can tell you how "hot" the weather is. So the advantage argued is not very valid: Air temperature does not give a full picture of "hotness", we have to also include humidity ( that's why weather reports usually have a "feels-like temperature" next to air temp ). This is where we use the Wet Bulb temperature [1] to describe the sense of hotness in our surrounding. Wet Bulb Temperature can tell you the rate at which your body can cool itself.

[1] https://en.wikipedia.org/wiki/Wet-bulb_temperature

The Wet Bulb temperature still needs a unit of measurement.

> Even heat-adapted people cannot carry out normal outdoor activities past a wet-bulb temperature of 32 °C (90 °F), equivalent to a heat index of 55 °C (130 °F)

So the F wet bulb temperature seems to make even better use of 2 digit readings than "plain" F. With 2 digits, C only uses 32% of the possible 2-digit readings.

I couldn't find anything for the low end...

The Wet Bulb temp can use any scale they see fit, it's a derived unit. It's even better if they don't use F and C to avoid confusion.

> The wet-bulb temperature (WBT) is the temperature read by a thermometer covered in water-soaked cloth (wet-bulb thermometer) over which air is passed

It seems to be a direct measurement, not derived from anything. You might be able to derive WBT given the dew point and dry bulb temperature, but it would still need units like C or F.

Perhaps you were thinking of a different measurement?

I believe that's a shortcut to measure WBT directly. By it's nature, WBT are affected by other variables such as humidity and atm pressure, etc... , so it's a derived unit: Twb = F(T, H, P...). As a derived function, you tweak its scale as much as you like, you can take T = C*2 and that solved your problem.

But surely deriving the WBT couldn't change the unit of measurement?

A measurement that has no unit is relative humidity. It is just a percentage. There is no way to measure relative humidity directly and get any other type of unit besides a percentage. Instruments that measure relative humidity directly measure in percentages.

edit: ah, you can use C2 = Celsius*2 whether you're talking about regular temperature or WBT. C2 is the 'derived' unit. Not WBT.

Yes you can use C2, but why not just use F which still has better precision than C2[1]? For low values of C2, you may confuse it with plain C...

[1]: https://uxdesign.cc/celsius-needs-a-redesign-41709e048c4a

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