Answer to "temperature" question

TEMPERATURE -- Marge Manor and her husband (Bay City, MI) raised the following question. They noted that they have researched it and still have not found an answer to "If it is zero today and it is twice as cold tomorrow what would the temperature be?" This is not a joke, Marge noted. We are looking forward to an answer. -- 3/3/02

Marge...look no further! Here is your answer.

This is an issue that sometimes even TV meteorologists get caught on. They will say something like "wow...it was 20 degrees yesterday, and 40 degrees today, so it looks like the temperature has doubled..."

It is the same type of situation as you have raised.

To get started, ponder what happens if it is 10 degrees today and it is supposed to be minus 10 degrees tomorrow. How much colder will it be tomorrow? You can see that the problem can take many forms.

What is missing from the discussion so far is a temperature scale. It is implicit that we are talking Fahrenheit because that is the scale we use in the United States. The rest of the world works in metric, so their scale is Centigrade or Celsius. Scientists, however, need an absolute frame of reference. So we use the Kelvin or Absolute Scale. I am now going to show you how to get to a Kelvin temperature value and why this is so important.

If one uses the online temperature conversion program provided by the National Weather Service (Boston, MA) at http://205.156.54.206/er/box/calculate2.html, you can enter a value for Fahrenheit and obtain a Celsius value. NOTE: There is a small error with the program and it produces too many decimal place for the answer. To get the answer to the nearest tenth, simply place the cursor in the answer box and backspace or tab to the left. I have alerted them about this problem and I hope they will have it corrected shortly.

So, for example, the 0 degrees Fahrenheit you talked about would be minus 17.7 degrees Celsius.

To get to degrees Kelvin (Absolute), you now have to add 273 degrees.

Since Absolute Zero (the coldest temperature something can theoretically get to) is zero degrees Absolute (or Kelvin), you can see that this keeps everything as a number above zero. From this, computations such as, "it was 10 degrees warmer than yesterday" can be made easily. It also ensures that scientists, who use many formulas that have a temperature value, don't have to worry about a particular temperature messing up the computations because the value goes from minus 0.3 degrees to plus 0.3 degrees.

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To convert from Celsius to Fahrenheit: °F =(9/5)°C+32

To convert from Fahrenheit to Celsius: °C=(5/9) x (°F-32)

To convert from Celsius to Kelvin (Absolute): °C + 273 = °K

°C = temperature in degrees Celsius
°F = temperature in degrees Fahrenheit
°K = temperature in degrees Kelvin (Absolute)

Take a look back at the Question