(This is the third chapter of the first volume of The Scientific Experience, by Herbert Goldstein, Jonathan L. Gross, Robert E. Pollack and Roger B. Blumberg. The Scientific Experience is a textbook originally written for the Columbia course "Theory and Practice of Science". The primary author of "Measurement" is Jonathan L. Gross, and it has been edited and prepared for the Web by Blumberg. It appears at MendelWeb, for non-commercial educational use only. Although you are welcome to download this text, please do not reproduce it without the permission of the authors.)
The sensible answer to Question 1 is no, of course. It is a mistake in physics to identify the concept of "warmth" with measurements on the Celsius scale. Suppose the temperature drops to 1° C on Tuesday. Was it really twenty times as warm on Sunday? What if it drops to 0.1° C on Wednesday. Was it ten times as warm on Tuesday, and 200 times as warm on Monday? Perhaps by Thursday the temperature drops to -5°. Was it -4 times as warm on Monday as on Thursday?
The Fahrenheit scale is another interval scale for temperature that is not a ratio scale. The comparable Fahrenheit readings for Sunday, Monday, Wednesday, and Thursday would be 50° F, 68° F, 32° F, and 22° F. Their ratios make no more sense than ratios on the Celsius scale.
The point is that, if a scale is not a ratio scale, then inferences based on the calculation of ratios of its data points may be utterly misleading.
Question 2: Using the Celsius temperature measurements given in Question 1 and its answer, is it correct to say that the temperature difference between Monday (20° C) and Sunday (10° C) was about twice as great as the temperature difference between Monday and Wednesday (0.1° C)?