Fahrenheit and Celsius

The two primary temperature scales of Celsius and Fahrenheit side-by-side calling out water freezing, body temperature and water boiling

Prints

Still need a gift? 🎄

Get the book. 135 sketches explaining the world

The two most commonly used temperature scales are Celsius and Fahrenheit. The Celsius scale, named after Swedish astronomer Anders Celsius, sets 0C at the freezing point of water and 100C as the boiling point of water at 1 atmosphere of pressure — normal air pressure at sea level. The Fahrenheit scale has 32F as the freezing point of water and 212F as the boiling point. With 180F between freezing and boiling that means each degree Celsius is 1.8 degrees Fahrenheit.

Several accounts of the creation of the Fahrenheit scale exist but the general gist is that Daniel Fahrenheit set 0F at the freezing point of a brine mixture, 32F at the freezing point of water, and another point at body temperature around 96F (now 98.6F). He divided up the scale between these points giving a scale with helpful resolution.

It's interesting to think that for most of history, there was no comparable way to say how hot or cold something was.

Having spent time on both sides of the Atlantic I've tried to get at least somewhat familiar with both of them. To convert between them in my head, at least around most air temperatures, I use a quick approximation. As 32F is 0C, and for each one Celsius you move almost two Fahrenheit, you can roughly go from Fahrenheit to Celsius by subtracting 32 and dividing by 2 (or a little less to be closer). So 50F is approximately 9C (actually 10C), or 86F is approximately 27C (actually 29.4C). It's not perfect, but it's often good enough if you're trying to work out if it'll be hot out. To go from Celsius to Fahrenheit, it's the reverse, times by 2 and add 32.

There are also at least two simple anchor points that can help just by swapping the digits around:

82F is near enough 28C
61F is near enough 16C

Both scales are now defined relative to the Kelvin scale, which sets the lowest point of 0K at absolute zero, where basically all movement stops. Zero on the Kelvin scale is around -273C. As such, the Kelvin scale, though helpful for scientists, is not very practical for discussing the weather.

Published 5 Feb 2023

A weekly sketch by email

Learn something new in a sketch each Sunday

Get the book!
Big Ideas Little Pictures

Prefer to listen?
Try the podcast

Sketchplanations is ad-free
thanks to supporters like you.See more on Patreon

Keep exploring

Eat the frog

What is the trust battery example explained with a manager considering 2 employees based on their past interactions

The trust battery: A handy metaphor to think about trust

Eponym

What is the SUCCESS framework for making ideas sticky from the book Made to Stick, highlighting six principles: Simple, Unexpected, Concrete, Credible, Emotional, and Stories

Make your idea sticky

Fight or Flight

What is Naismith's Rule for calculating walking time in the mountains example explained with a mountain ridge with hikers and lines for the horizontal distance and time and ascent and time

Naismith's Rule for mountain hiking time

Eat the Frog is a memorable, if rather gross, metaphor that means choosing the most important thing you must do today and doing that first. It derives from a variant of a quote that Mark Twain never said, "If it's your job to eat a frog, it's best to do it first thing in the morning. And if it's your job to eat two frogs, it's best to eat the biggest one first." — Not Mark Twain Another way to think about it is that if you first Eat the Frog, everything else will be easier for the rest of the day. And won't that feel nice? The Eat the Frog time management technique was popularised in Brian Tracy's productivity book Eat That Frog! Get More of the Important Things Done - Today! Many tools in Tracy's book are based on the general premise that there will always be more to do than you can do. So, find the things that will have the most impact and do those first. The others will drift on by. Why is Eat the Frog helpful? I once saw someone ask for advice on getting motivated to clean the house. One person answered: "Write a book." Sometimes, our most significant and impactful goals are those on which we so readily procrastinate. Often, these will be in the important, not urgent, bucket. The Eat the Frog approach helps if: You are prone to procrastination 🙋 You have a lot of things that need to be done or that you want to do You work well in the morning One of the nice things about eating the frog first thing is that getting it done feels really good. It helps build momentum for the rest of the day with a nice endorphin rush of ticking off something significant. Decide on your Most Important Task (MIT) to tackle, ideally the night before. If it's too big and you can't finish it in one sitting, divide it into manageable chunks. Then start on the first chunk and leave everything else. And sometimes, the hardest thing to do is to start. So consider doing just 5 minutes. Once you've started, very often, keeping going becomes easy. Challenges when Eating the Frog Questions that come up regularly in Tracy's book "Eat That Frog", including for the Eating the Frog principle, are variations of: What is the most important thing you could be doing? What is the highest-value activity? What activity will have the most impact? If you weren't already doing this, would you start doing this? What skills will take you furthest in your career? What are you able to do best that others can't? It all looks pretty straightforward when I read questions like these. But I have found that answering them is usually much harder. Our goals are often interrelated. For example, earning more may require you to increase your skills first. And getting clear on what your most important goals are first is a prerequisite and also not always straightforward. Then, what activities are the most important or will have the most impact can be unclear. And, sometimes, small actions such as an unexpected event or connection may have out-sized benefits. Or neglecting a seemingly minor task could lead to losing a significant client. But does it still make sense to try to work on the most important task first thing in the morning? Yes. Don't Drag it Out Like a child leaving a brussel sprout at the side of the plate to get cold while they eat the roast, it's easy to leave our most impactful and daunting tasks until after the easier stuff is done. But it doesn't usually help to wait. As the saying goes, if you have to eat a live frog, it doesn't pay to look at it for long. Related Ideas Face it, you'll never get caught up, so perhaps think about Oliver Burkeman's Rivers not Buckets Eisenhower Matrix: important/urgent Pomodoro Technique The Power of Streaks Don't make important decisions on an empty stomach The doorstep mile Eat the Frog is a fantastic example of putting the principles of making your idea Sticky into action Use checkboxes Present bias Finishing lines Poor frogs: the Frog boil metaphor Another quote "from" Mark Twain appears in Big Ideas Little Pictures: "Good judgment comes from experience, and experience comes from bad judgment." Notes The always excellent Quote Investigator describes the source of the Eat the Frog family of quotes from the French writer Nicolas Chamfort, who said, more or less, that eating a toad first thing would help steel you against the rest of the day as nothing worse will happen to you.…Eat the Frog is a memorable, if rather gross, metaphor that means choosing the most important thing you must do today and doing that first. It derives from a variant of a quote that Mark Twain never said, "If it's your job to eat a frog, it's best to do it first thing in the morning. And if it's your job to eat two frogs, it's best to eat the biggest one first." — Not Mark Twain Another way to think about it is that if you first Eat the Frog, everything else will be easier for the rest of the day. And won't that feel nice? The Eat the Frog time management technique was popularised in Brian Tracy's productivity book Eat That Frog! Get More of the Important Things Done - Today! Many tools in Tracy's book are based on the general premise that there will always be more to do than you can do. So, find the things that will have the most impact and do those first. The others will drift on by. Why is Eat the Frog helpful? I once saw someone ask for advice on getting motivated to clean the house. One person answered: "Write a book." Sometimes, our most significant and impactful goals are those on which we so readily procrastinate. Often, these will be in the important, not urgent, bucket. The Eat the Frog approach helps if: You are prone to procrastination 🙋 You have a lot of things that need to be done or that you want to do You work well in the morning One of the nice things about eating the frog first thing is that getting it done feels really good. It helps build momentum for the rest of the day with a nice endorphin rush of ticking off something significant. Decide on your Most Important Task (MIT) to tackle, ideally the night before. If it's too big and you can't finish it in one sitting, divide it into manageable chunks. Then start on the first chunk and leave everything else. And sometimes, the hardest thing to do is to start. So consider doing just 5 minutes. Once you've started, very often, keeping going becomes easy. Challenges when Eating the Frog Questions that come up regularly in Tracy's book "Eat That Frog", including for the Eating the Frog principle, are variations of: What is the most important thing you could be doing? What is the highest-value activity? What activity will have the most impact? If you weren't already doing this, would you start doing this? What skills will take you furthest in your career? What are you able to do best that others can't? It all looks pretty straightforward when I read questions like these. But I have found that answering them is usually much harder. Our goals are often interrelated. For example, earning more may require you to increase your skills first. And getting clear on what your most important goals are first is a prerequisite and also not always straightforward. Then, what activities are the most important or will have the most impact can be unclear. And, sometimes, small actions such as an unexpected event or connection may have out-sized benefits. Or neglecting a seemingly minor task could lead to losing a significant client. But does it still make sense to try to work on the most important task first thing in the morning? Yes. Don't Drag it Out Like a child leaving a brussel sprout at the side of the plate to get cold while they eat the roast, it's easy to leave our most impactful and daunting tasks until after the easier stuff is done. But it doesn't usually help to wait. As the saying goes, if you have to eat a live frog, it doesn't pay to look at it for long. Related Ideas Face it, you'll never get caught up, so perhaps think about Oliver Burkeman's Rivers not Buckets Eisenhower Matrix: important/urgent Pomodoro Technique The Power of Streaks Don't make important decisions on an empty stomach The doorstep mile Eat the Frog is a fantastic example of putting the principles of making your idea Sticky into action Use checkboxes Present bias Finishing lines Poor frogs: the Frog boil metaphor Another quote "from" Mark Twain appears in Big Ideas Little Pictures: "Good judgment comes from experience, and experience comes from bad judgment." Notes The always excellent Quote Investigator describes the source of the Eat the Frog family of quotes from the French writer Nicolas Chamfort, who said, more or less, that eating a toad first thing would help steel you against the rest of the day as nothing worse will happen to you.

Newer

RRandom

Older