August 06, 2007

#01-005: How Hot Is It?

A thermometer with Celsius and Fahrenheit scales

Note: This is the last of the five lessons I submitted to the Shenzhen Daily when I applied for the job in August of 2007. As you probably know by now, it was HOT in August, so all of these lessons were about temperature. (Glad that's over with!)

Get Ready: What is the difference between the Fahrenheit and Celsius (or Centigrade) temperature scales? Can you convert one to the other without using your phone?

In Lesson #01-004, I declared that it was impossible to cook an egg on the sidewalk. I wrote there, "It seems that the temperatures required to fry an egg are higher than the hottest temperatures on record."

What are those temperatures, exactly?

Well, eggs cook somewhere between 144 and 158 degrees Fahrenheit. And the highest recorded surface temperature on earth was 136.4 degrees Fahrenheit at Al 'Aziziyah, Libya on September 13, 1922.

144? 158? 136.4? How hot is that? (Can you convert these three temperatures to Celsius, without using your phone? See the formula and answers below.)

I grew up in the United States where Fahrenheit is the common standard. Even today (confirmed in June, 2021), the U.S. is one of only three countries (along with Liberia and Myanmar) to resist converting to metric measurements. American scientists use "the metric system," but common people don't.

Why are we so fond of feet and miles, pounds and tons, quarts and gallons? How did this system become first "the English system," and now the "American" one?

Daniel Gabriel Fahrenheit (1686 - 1736), a German scientist, made thermometers, and he created his scale to mark them. Incidentally, no one is sure why his system says that water freezes at 32 degrees, and boils at 212. The scale invented by Anders Celsius of Sweden (originally called "Centigrade" in English, and still called that by some) makes much more sense: 0 degrees for freezing, 100 for boiling.

The Fahrenheit scale came to England in the days when England's kings spoke German as a first language (a story for another day). And from England, the system came to America. So it was built into the fabric of our culture.

The scale used in my home country and the one used in most of the world do not have a linear relationship. So when someone tells me, "It's 37 degrees out there!" I have to do some complex mathematics: 37 divided by 5 is 7.4; times 9 is 66.6; plus 32 equals 98.6. Then, "Dang!" I can say. "That's hot!"

Or, I just use the converter in my phone to see how hot it really is!

The Formulas:
  • F=9/5C + 32 EXAMPLE: 212=9/5(100) + 32 or 212=(1.8)(100) [which is 180] +32
  • C= 5/9(F-32) EXAMPLE: 100=5/9(212-32) or 100=(0.555...)(180)
(Answers to the above problems: 144F = 62.22C; 158F = 70C; 136F = 57.77C)

Read more:

Practice: Match the term to its definition below:

  1. Celsius
  2. tons
  3. formula
  4. freezing
  5. quarts
  6. boiling
  7. convert
  8. metric
  9. thermometers
  10. Fahrenheit

  1. the point at which water turns to ice
  2. change from one to another
  3. the point at which water turns to steam
  4. the system for describing temperature in which water freezes at 0 and boils at 100
  5. units of volume in the "English" system equal to 1/4 of a gallon
  6. the system for describing temperature in which water freezes at 32 and boils at 212
  7. tools for measuring temperature
  8. units of weight in the "English" system equal to 2,000 pounds
  9. the system of measurements used by most of the world, based on the number 10
  10. "sentence" in mathematics stating a rule for a certain use, like P = 4s to find the perimeter of a square

Answers are in the first comment below.

Submitted to the Shenzhen Daily for August 6, 2007

1 comment:

  1. Answers to the Practice: 1. d; 2. h; 3. j; 4. a; 5. e; 6. c; 7. b; 8. i; 9. g; 10. f